JP7572521B2 - Optical semiconductor element encapsulation sheet and display body - Google Patents

Description

The present invention relates to a sheet for encapsulating optical semiconductor elements. More specifically, the present invention relates to a sheet suitable for encapsulating optical semiconductor elements of self-luminous display devices such as mini/micro LEDs.

In recent years, self-emitting display devices, such as mini/micro LED display devices (Mini/Micro Light Emitting Diode Displays), have been devised as next-generation display devices. In the basic configuration of a mini/micro LED display device, a substrate on which numerous tiny optical semiconductor elements (LED chips) are densely arranged is used as the display panel, and the optical semiconductor elements are sealed with a sealant, with a cover member such as a resin film or glass plate laminated on the outermost layer.

In displays equipped with self-luminous display devices such as mini/micro LED display devices, wiring (metal wiring) made of metal or metal oxide such as ITO is arranged on the substrate of the display panel. Such display devices have a problem in that, for example, when the light is turned off, the light is reflected by the metal wiring, making the screen look bad and inferior in design. For this reason, technology is being adopted that uses an anti-reflection layer to prevent reflection by the metal wiring as a sealant for sealing optical semiconductor elements.

Patent document 1 discloses an adhesive sheet that is a laminate of a colored adhesive layer and a colorless adhesive layer, with the colorless adhesive layer positioned so as to come into contact with an optical semiconductor element. It is described that the adhesive sheet described above, when brought into contact with and conforming to the uneven shape formed by a substrate and an optical semiconductor element mounted on the substrate, can improve the design when the display is turned off and can also suppress uneven brightness.

JP 2020-169262 A

However, although adhesive sheets with a colored adhesive layer are expected to prevent reflections caused by metal wiring when sealing optical semiconductor elements and suppress uneven brightness, they have the problem of reducing the transmittance of light emitted by the optical semiconductor elements, resulting in reduced front brightness of the display. When the front brightness decreases, power consumption increases in order to increase the brightness. For this reason, there is a demand for displays with excellent anti-reflection properties and high brightness.

The present invention was conceived under these circumstances, and its purpose is to provide a sheet for encapsulating optical semiconductor elements that can be used to create a display with excellent anti-reflection properties and high brightness by encapsulating optical semiconductor elements.

As a result of intensive research conducted by the inventors to achieve the above object, they discovered that a sheet for sealing optical semiconductor elements, which comprises a sealing resin layer including a colored layer and a non-colored layer, and in which the hardness of the non-colored layer is harder than the hardness of the colored layer, can provide a display with excellent anti-reflection properties and high brightness when sealing an optical semiconductor element placed on a substrate. The present invention was completed based on these findings.

That is, the present invention provides a sheet for sealing one or more optical semiconductor elements arranged on a substrate, the sheet comprising an encapsulating resin layer including a colored layer and a non-colored layer, and the hardness A of the non-colored layer and the hardness B of the colored layer satisfy A>B.

When the optical semiconductor element is sealed with the sheet for sealing the optical semiconductor element, the colored layer and the non-colored layer are laminated in this order from the optical semiconductor element side. At this time, the hardness A of the non-colored layer on the front side of the display body is harder than the hardness B of the colored layer on the optical semiconductor element side. As a result, in the sealed state of the optical semiconductor element, the colored layer located on the front side of the optical semiconductor element is sandwiched and compressed between the optical semiconductor element and the non-colored layer, and the light emitted by the optical semiconductor element can be efficiently transmitted to the front side. On the other hand, the colored layer located on the substrate on which the optical semiconductor element is not arranged is compressed to a smaller extent than the colored layer located on the front side of the optical semiconductor element, so that the reflection of the metal wiring on the substrate can be sufficiently suppressed. Therefore, the display body in which the optical semiconductor element is sealed with the sheet for sealing the optical semiconductor element has excellent anti-reflection properties and high brightness.

The hardness may be one or more selected from the group consisting of residual stress, elastic modulus, Young's modulus, and hardness measured by nanoindentation.

The hardness is a residual stress, and the ratio of the residual stress A1 of the non-colored layer to the residual stress B1 of the colored layer [residual stress A1/residual stress B1] may be 1.2 or more. When the ratio is 1.2 or more, the colored layer located in front of the optical semiconductor element is more compressed when the optical semiconductor element is sealed, resulting in higher brightness.

The sealing resin layer preferably further comprises a non-colored layer having a hardness C on the side of the colored layer opposite the non-colored layer. Furthermore, it is preferable that the hardness C of the non-colored layer and the hardness B of the colored layer satisfy C>B. With such a configuration, the colored layer located in front of the optical semiconductor element and between the two non-colored layers is sandwiched between both non-colored layers and sufficiently compressed when sealing the optical semiconductor element, resulting in higher brightness.

It is preferable that the encapsulating resin layer includes a diffusion functional layer. With this configuration, the light emitted by the optical semiconductor element can be diffused in the diffusion functional layer, thereby increasing the front brightness.

The present invention also provides a display comprising a substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element encapsulation sheet or a cured product thereof that encapsulates the optical semiconductor element. Such an optical display has excellent anti-reflection properties and high brightness.

The display preferably comprises a self-luminous display device.

The display is preferably an image display device.

The sheet for encapsulating optical semiconductor elements of the present invention can encapsulate optical semiconductor elements to provide a display with excellent anti-reflection properties and high brightness. Therefore, the display is bright and looks good without high power consumption, and has excellent design even when the light is off.

1 is a cross-sectional view of a sheet for encapsulating an optical semiconductor element according to one embodiment of the present invention. 2 is a partial cross-sectional view showing one embodiment of a display body using the optical semiconductor element encapsulation sheet shown in FIG. 1. 4 is a partial cross-sectional view showing another embodiment of a display body using the optical semiconductor element encapsulation sheet shown in FIG. 1 . 4 is a partial cross-sectional view showing still another embodiment of a display body using the optical semiconductor element encapsulation sheet shown in FIG. 1 .

[Optical semiconductor element encapsulation sheet]
The optical semiconductor element encapsulation sheet of the present invention includes at least an encapsulating resin layer including a colored layer and a non-colored layer. In this specification, the optical semiconductor element encapsulation sheet refers to a sheet for encapsulating one or more optical semiconductor elements arranged on a substrate with an encapsulating resin layer. In this specification, "encapsulating an optical semiconductor element" refers to embedding at least a part of the optical semiconductor element in the encapsulating resin layer, or covering the optical semiconductor element with the encapsulating resin layer. The encapsulating resin layer has flexibility that allows embedding at least a part of the optical semiconductor element, or covering the optical semiconductor element with the encapsulating resin layer.

<Sealing resin layer>
In the encapsulating resin layer, when the hardness of the non-colored layer is A and the hardness of the colored layer is B, A>B is satisfied. That is, the encapsulating resin layer at least includes a non-colored layer having a hardness A and a colored layer having a hardness B that satisfy A>B. The non-colored layer having a hardness A may be referred to as a "non-colored layer A" and the colored layer having a hardness B may be referred to as a "colored layer B". The encapsulating resin layer may have a layer other than the non-colored layer A and the colored layer B. In addition, the total number of layers constituting the encapsulating resin layer is 2 or more including the non-colored layer A and the non-colored layer B, and may be 3 or more. The total number of layers may be, for example, 10 or less, 5 or less, or 4 or less, from the viewpoint of reducing the thickness of the optical semiconductor element encapsulating sheet and the optical semiconductor device.

Each layer (colored layer and non-colored layer) constituting the encapsulating resin layer may be a single layer in the encapsulating resin layer, or may be a multilayer having the same or different compositions. When multiple colored layers and non-colored layers are included, the multiple layers may be laminated in contact with each other, or may be laminated in isolation (for example, two colored layers are laminated via one non-colored layer). When the encapsulating resin layer includes one or more multiple colored layers and non-colored layers, at least one colored layer is colored layer B, and at least one non-colored layer is non-colored layer A. In addition, each non-colored layer included in the encapsulating resin layer may be independently a diffusion functional layer or a non-diffusion functional layer, as described below.

When the optical semiconductor element is sealed with the sheet for sealing the optical semiconductor element, with the colored layer B side facing the optical semiconductor element rather than the non-colored layer A, the colored layer B and the non-colored layer A are laminated in this order from the optical semiconductor element side. At this time, the hardness A of the non-colored layer A on the front side of the display body is harder than the hardness B of the colored layer B on the optical semiconductor element side. As a result, in the sealed state of the optical semiconductor element, the colored layer B located on the front side of the optical semiconductor element is sandwiched and compressed between the optical semiconductor element and the non-colored layer A, and the light emitted by the optical semiconductor element can be efficiently transmitted to the front side. On the other hand, the colored layer B located on the substrate on which the optical semiconductor element is not arranged is compressed to a smaller extent than the colored layer B located on the front side of the optical semiconductor element, so that the reflection of the metal wiring on the substrate can be sufficiently suppressed. Therefore, the display body in which the optical semiconductor element is sealed with the sheet for sealing the optical semiconductor element has excellent anti-reflection properties and high brightness.

Examples of the hardness of the colored layer and the non-colored layer include residual stress, elastic modulus, and Young's modulus. The hardness may be measured by a nanoindentation method. In the nanoindentation method, for example, the surfaces of the colored layer and the non-colored layer, and the exposed surfaces of the colored layer and the non-colored layer in a cross section can be measured. The hardness measured by the nanoindentation method is obtained by continuously measuring the load and the indentation depth of the indenter when the indenter is pressed into the target surface during loading and unloading, and then obtaining a load-indentation depth curve. As the hardness, the residual stress is preferable from the viewpoint of suppressing the influence of the viscosity of the layer on the hardness of the measurement result. The hardness can be adjusted by a known or conventional method. Specifically, the hardness of the layer can be controlled by adjusting the amount of a curing agent, a crosslinking agent, a compound having crosslinkability such as a polyfunctional monomer, or a polymerization initiator when preparing the resin constituting each layer.

The difference between the residual stress of the non-colored layer A (sometimes referred to as "residual stress A1") and the residual stress of the colored layer B (sometimes referred to as "residual stress B1") [residual stress A1-residual stress B1] is not particularly limited, but is preferably 1.0 N/cm2 or ^more , more preferably 3.0 N/ ^cm2 or more, and even more preferably 5.0 N/cm2 or ^more . When the difference is 1.0 N/ ^cm2 or more, the colored layer B located in front of the optical semiconductor element is further compressed during encapsulation of the optical semiconductor element, resulting in higher brightness. The difference is, for example, 30.0 N/ ^cm2 or less, and may be 20.0 N/cm2 or ^less , from the viewpoint of excellent encapsulation of the optical semiconductor element by the encapsulating resin layer.

The ratio of residual stress A1 to residual stress B1 [residual stress A1/residual stress B1] is not particularly limited, but is preferably 1.2 or more, more preferably 1.5 or more, and even more preferably 2.0 or more. When the above ratio is 1.2 or more, the colored layer B located in front of the optical semiconductor element is more compressed when the optical semiconductor element is encapsulated, and the brightness is higher. From the viewpoint of excellent encapsulation of the optical semiconductor element by the encapsulating resin layer, the above ratio is, for example, 10.0 or less, and may be 5.0 or less.

The residual stress A1 is preferably more than 6.0 N/ ^cm2 , more preferably 7.0 N/ ^cm2 or more, and even more preferably 10.0 N/cm2 or ^more , within the range satisfying A>B. The residual stress A1 is preferably 50.0 N/cm2 or ^less , more preferably 40.0 N/cm2 or ^less , and even more preferably 30.0 N/cm2 ^or less, within the range satisfying A>B.

The residual stress B1 is preferably 0.5 N/cm2 or ^more , more preferably 1.0 N/ ^cm2 or more, and even more preferably 3.0 N/cm2 or ^more , within the range satisfying A>B. The residual stress B1 is preferably 20.0 N/cm2 or ^less , more preferably 15.0 N/cm2 or ^less , and even more preferably 10.0 N/cm2 or ^less , within the range satisfying A>B.

In the sheet for encapsulating optical semiconductor elements of the present invention, the encapsulating resin layer comprises, in this order from the optical semiconductor element side, a colored layer B and a non-colored layer A when the optical semiconductor element is encapsulated. The encapsulating resin layer may further comprise a non-colored layer on the side opposite to the non-colored layer A of the colored layer B (i.e., on the optical semiconductor element side of the colored layer B when the optical semiconductor element is encapsulated). The non-colored layer other than the non-colored layer A that the encapsulating resin layer further comprises on the side opposite to the non-colored layer A of the colored layer B may be referred to as a "non-colored layer C."

In the above-mentioned encapsulating resin layer, when the hardness of the non-colored layer C is C, it is preferable that C>B. With such a configuration, the colored layer B, which is located in front of the optical semiconductor element and between the non-colored layer A and the non-colored layer C, is sandwiched between the non-colored layer A and the non-colored layer C and sufficiently compressed when the optical semiconductor element is encapsulated, resulting in higher brightness. Examples of the hardness of the non-colored layer C include those exemplified as the hardness of the non-colored layer A and the colored layer B.

The difference between the residual stress of the non-colored layer C (sometimes referred to as "residual stress C1") and the residual stress B1 [residual stress C1-residual stress B1] is not particularly limited, but is preferably 0.01 N/ ^cm2 or more, more preferably 0.05 N/ ^cm2 or more, even more preferably 0.1 N/cm2 or ^more , and may be 0.5 N/ ^cm2 or ^more , 1.0 N/cm2 or ^more , or 2.0 N/cm2 or ^more . If the difference is 0.01 N/cm2 or more, the colored layer B located in front of the optical semiconductor element is more compressed when the optical semiconductor element is sealed, and the brightness is higher. The difference is, for example, 20.0 N/ ^cm2 or less, and may be 10.0 N/cm2 or ^less .

The ratio of residual stress C1 to residual stress B1 [residual stress C1/residual stress B1] is not particularly limited, but is preferably 0.05 or more, more preferably 0.1 or more, and even more preferably 0.5 or more, and may be 1.1 or more, 1.2 or more, or 1.3 or more. If the ratio is 0.05 or more, the colored layer B located in front of the optical semiconductor element is more compressed when the optical semiconductor element is sealed, resulting in higher brightness. The ratio is, for example, 10.0 or less, and may be 5.0 or less.

The residual stress C1 is preferably 3.0 N/cm ² or more, more preferably 4.0 N/cm ² or more, and even more preferably 7.0 N/cm ² or more. The residual stress C1 is preferably 50.0 N/cm ² or less, more preferably 40.0 N/cm ² or less, and even more preferably 30.0 N/cm ² or less.

In the above-mentioned encapsulating resin layer, it is preferable that A>C is satisfied. With such a configuration, the colored layer B located between the non-colored layer A and the non-colored layer C on the optical semiconductor element is sufficiently compressed by the non-colored layer A when encapsulating the optical semiconductor element, resulting in higher brightness.

The difference between the residual stress A1 and the residual stress C1 [residual stress A1-residual stress C1] is not particularly limited, but is preferably 0.5 N/cm2 or ^more , more preferably 1.0 N/cm2 or ^more , and even more preferably 2.0 N/ ^cm2 or more. When the difference is 0.5 N/cm2 or ^more , the colored layer B located in front of the optical semiconductor element is further compressed during sealing of the optical semiconductor element, resulting in higher brightness. The difference is, for example, 30.0 N/cm2 or ^less , and may be 20.0 N/cm2 ^or less.

The ratio of residual stress A1 to residual stress C1 [residual stress A1/residual stress C1] is not particularly limited, but is preferably 1.1 or more, more preferably 1.2 or more, and even more preferably 1.3 or more. When the ratio is 1.1 or more, the colored layer B located in front of the optical semiconductor element is more compressed when the optical semiconductor element is sealed, resulting in higher brightness. The ratio is, for example, 10.0 or less, and may be 5.0 or less.

The encapsulating resin layer preferably includes a diffusion functional layer. With such a configuration, the light emitted by the optical semiconductor element can be diffused in the diffusion functional layer, thereby increasing the front brightness. The diffusion functional layer is preferably a layer that corresponds to the non-colored layer in this specification. In particular, it is preferable that the non-colored layer A and/or the non-colored layer C is the diffusion functional layer, and it is preferable that the non-colored layer C is the diffusion functional layer.

When the sealing resin layer includes the diffusion functional layer, the sealing resin layer preferably includes, from the optical semiconductor element side, the diffusion functional layer, the colored layer, and the non-colored layer in this order. The non-colored layer may be either a diffusion functional layer or a non-diffusion functional layer. With this configuration, the front luminance can be increased, while the appearance of the display body can be improved both when the light is off and when the light is on.

In the above-mentioned encapsulating resin layer, it is preferable that the surface of the non-colored layer A opposite to the side encapsulating the optical semiconductor element is flat. In this case, diffuse reflection of external light is less likely to occur on the surface of the encapsulating resin layer when the optical semiconductor element is encapsulated, improving the appearance of the display both when the light is off and when the light is on.

Each layer (the colored layer and the non-colored layer) constituting the encapsulating resin layer may or may not have adhesiveness and/or adhesion independently. Among them, it is preferable that the encapsulating resin layer has adhesiveness and/or adhesion. By having such a configuration, the encapsulating resin layer can easily encapsulate the optical semiconductor element, and also has excellent adhesion and/or adhesion between the layers, and is more excellent in encapsulating the optical semiconductor element. In particular, it is preferable that at least the layer in contact with the optical semiconductor element has adhesiveness and/or adhesion. By having such a configuration, the encapsulating resin layer has excellent followability and embeddability of the optical semiconductor element. As a result, even if the step due to the optical semiconductor element is high, the design is excellent. Note that layers other than the layer in contact with the optical semiconductor element may not have adhesiveness and/or adhesion. In this case, the adhesiveness between adjacent encapsulating resin layers in a tiling state is low, and when adjacent small-sized laminates (laminates in which the encapsulating resin layer encapsulates the optical semiconductor element arranged on the substrate) are pulled apart from each other, loss of the sheet and adhesion of adjacent encapsulating resin layers are unlikely to occur.

Each layer constituting the encapsulating resin layer (the colored layer and the non-colored layer) may be, independently of the other, a resin layer that has the property of being cured by irradiation with radiation (a radiation-curable resin layer), or a resin layer that does not have the property of being cured by irradiation with radiation (a non-radiation-curable resin layer). Examples of the radiation include electron beams, ultraviolet rays, α rays, β rays, γ rays, and X-rays.

(Colored Layer)
The colored layer in the sealing resin layer is a layer intended to prevent light reflection due to metal wiring or the like provided on a substrate in a display body. The colored layer contains at least a colorant. The colored layer is preferably a resin layer composed of a resin. The colorant may be a dye or a pigment as long as it is soluble or dispersible in the colored layer. Dyes are preferred because low haze can be achieved even with a small amount of addition, and they are not prone to settling like pigments and can be easily distributed uniformly. Pigments are also preferred because they have high color expression even with a small amount of addition. When a pigment is used as a colorant, it is preferable that the pigment has low or no electrical conductivity. Only one type of colorant may be used, or two or more types may be used.

As the above-mentioned colorant, a black colorant is preferable. As the above-mentioned black colorant, a colorant (pigment, dye, etc.) for presenting a known or conventional black color can be used, and examples thereof include carbon black (furnace black, channel black, acetylene black, thermal black, lamp black, pine soot, etc.), graphite, copper oxide, manganese dioxide, aniline black, perylene black, titanium black, cyanine black, activated carbon, ferrite (non-magnetic ferrite, magnetic ferrite, etc.), magnetite, chromium oxide, iron oxide, molybdenum disulfide, chromium complex, anthraquinone colorant, zirconium nitride, etc. In addition, a colorant that functions as a black colorant by combining and blending colorants that present a color other than black may be used.

When the colored layer is a radiation-curable resin layer, the colorant preferably absorbs visible light and is transparent to light of a wavelength at which the radiation-curable resin layer can be cured.

From the viewpoint of imparting an appropriate anti-reflection function to the display, the content of the colorant in the colored layer is preferably 0.2% by mass or more, more preferably 0.4% by mass or more, relative to 100% by mass of the total amount of the colored layer. The content of the colorant is, for example, 10% by mass or less, preferably 5% by mass or less, more preferably 3% by mass or less. The content may be appropriately set depending on the type of colorant, the color tone and light transmittance of the display, etc. The colorant may be added to the composition as a solution or dispersion dissolved or dispersed in an appropriate solvent.

The haze value (initial haze value) of the colored layer is not particularly limited, but from the viewpoint of ensuring the front luminance and visibility of the display, it is preferably 50% or less, more preferably 40% or less, even more preferably 30% or less, and particularly preferably 20% or less. In addition, from the viewpoint of efficiently reducing the luminance unevenness of the display, the haze value of the colored layer is preferably 1% or more, more preferably 3% or more, even more preferably 5% or more, and particularly preferably 8% or more, and may be 10% or more.

The total light transmittance of the colored layer is not particularly limited, but from the viewpoint of further improving the anti-reflection function of metal wiring and the like in the display and the contrast, it is preferably 80% or less, more preferably 60% or less, even more preferably 40% or less, and particularly preferably 30% or less. In addition, from the viewpoint of ensuring the brightness of the display, the total light transmittance of the colored layer is preferably 0.5% or more, more preferably 1% or more, even more preferably 1.5% or more, and particularly preferably 2% or more, and may be 2.5% or more, or 3% or more.

The haze value and total light transmittance of the colored layer are the values for a single layer and can be measured by the methods specified in JIS K7136 and JIS K7361-1, and can be controlled by the type and thickness, the type and amount of colorant, etc.

(Non-colored layer)
The non-colored layer is a layer different from the colored layer, and is not intended to prevent light reflection by metal wiring or the like provided on a substrate in a display body. The non-colored layer may be a colorless layer or may be slightly colored. The non-colored layer may be, for example, a diffusion functional layer intended to perform a function of diffusing light, or may be a non-diffusion functional layer not intended to perform a function of diffusing light. The non-colored layer may be transparent or non-transparent. The non-colored layer is preferably a resin layer made of resin.

The content of the colorant in the non-colored layer is preferably less than 0.2% by mass, more preferably less than 0.1% by mass, and even more preferably less than 0.05% by mass, relative to 100% by mass of the total amount of the non-colored layer, and may be less than 0.01% by mass or less than 0.005% by mass.

The total light transmittance of the non-colored layer is not particularly limited, but from the viewpoint of ensuring brightness, it is preferably 40% or more, more preferably 60% or more, even more preferably 70% or more, and particularly preferably 80% or more. In addition, the upper limit of the total light transmittance of the non-colored layer is not particularly limited, but it may be less than 100%, 99.9% or less, or 99% or less.

The total light transmittance of the non-colored layer is a value for a single layer and can be measured by the methods specified in JIS K7136 and JIS K7361-1, and can be controlled by the type and thickness of the non-colored layer.

The diffusion functional layer is a layer intended to diffuse light. When the encapsulating resin layer has the diffusion functional layer, the light emitted from the optical semiconductor element is diffused in the diffusion functional layer, and for example, the light emitted from the side of the optical semiconductor element is emitted in the front direction of the display body, improving the front brightness of the display body. The diffusion functional layer is preferably a resin layer made of resin. The diffusion functional layer is not limited, but preferably contains light-diffusing fine particles. In other words, the diffusion functional layer preferably contains light-diffusing fine particles dispersed in the resin layer. Only one type of light-diffusing fine particles may be used, or two or more types may be used.

The light-diffusing fine particles have an appropriate refractive index difference with the resin constituting the diffusion functional layer, and impart diffusion performance to the diffusion functional layer. Examples of light-diffusing fine particles include inorganic fine particles and polymer fine particles. Examples of materials for inorganic fine particles include silica, calcium carbonate, aluminum hydroxide, magnesium hydroxide, clay, talc, and metal oxides. Examples of materials for polymer fine particles include silicone resin, acrylic resin (including polymethacrylate resin such as polymethyl methacrylate), polystyrene resin, polyurethane resin, melamine resin, polyethylene resin, and epoxy resin.

As the polymeric fine particles, fine particles composed of silicone resin are preferable. As the inorganic fine particles, fine particles composed of metal oxide are preferable. As the metal oxide, titanium oxide and barium titanate are preferable, and titanium oxide is more preferable. By having such a configuration, the light diffusion property of the diffusion functional layer is excellent, and brightness unevenness is further suppressed.

The shape of the light-diffusing microparticles is not particularly limited and may be, for example, spherical, flat, or irregular.

From the viewpoint of imparting appropriate light diffusion performance, the average particle diameter of the light diffusing microparticles is preferably 0.1 μm or more, more preferably 0.15 μm or more, even more preferably 0.2 μm or more, and particularly preferably 0.25 μm or more. In addition, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image, the average particle diameter of the light diffusing microparticles is preferably 12 μm or less, more preferably 10 μm or less, and even more preferably 8 μm or less. The average particle diameter can be measured, for example, using a Coulter counter.

The refractive index of the light diffusing fine particles is preferably 1.2 to 5, more preferably 1.25 to 4.5, even more preferably 1.3 to 4, and particularly preferably 1.35 to 3.

The absolute value of the refractive index difference between the light diffusing microparticles and the resin constituting the diffusion functional layer (the resin layer in the diffusion functional layer excluding the light diffusing microparticles) is preferably 0.001 or more, more preferably 0.01 or more, even more preferably 0.02 or more, and particularly preferably 0.03 or more, and may be 0.04 or more, or 0.05 or more, from the viewpoint of more efficiently reducing the brightness unevenness of the display body. Furthermore, the absolute value of the refractive index difference between the light diffusing microparticles and the resin is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image.

From the viewpoint of imparting appropriate light diffusion performance to the sheet for encapsulating optical semiconductor elements, the content of the light diffusing fine particles in the diffusion functional layer is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and particularly preferably 0.15 parts by mass or more, relative to 100 parts by mass of the resin constituting the diffusion functional layer. Furthermore, from the viewpoint of preventing the haze value from becoming too high and displaying a high-definition image, the content of the light diffusing fine particles is preferably 80 parts by mass or less, more preferably 70 parts by mass or less, relative to 100 parts by mass of the resin constituting the diffusion functional layer.

The haze value (initial haze value) of the diffusion functional layer is not particularly limited, but from the viewpoint of efficiently reducing brightness unevenness, it is preferably 30% or more, more preferably 40% or more, even more preferably 50% or more, and particularly preferably 60% or more, and may be 70% or more, 80% or more, 90% or more, 95% or more, or 97% or more, and is preferably around 99.9% because it has a superior effect of improving brightness unevenness. The upper limit of the haze value of the diffusion functional layer is not particularly limited, that is, it may be 100%.

The total light transmittance of the diffusion functional layer is not particularly limited, but from the viewpoint of ensuring brightness, it is preferably 40% or more, more preferably 60% or more, even more preferably 70% or more, and particularly preferably 80% or more. In addition, the upper limit of the total light transmittance of the diffusion functional layer is not particularly limited, but it may be less than 100%, 99.9% or less, or 99% or less.

The haze value and total light transmittance of the diffusion functional layer are the values for a single layer and can be measured by the methods specified in JIS K7136 and JIS K7361-1, and can be controlled by the type and thickness of the diffusion functional layer, the type and amount of light-diffusing fine particles, etc.

The haze value (initial haze value) of the non-diffusion functional layer is not particularly limited, but from the viewpoint of providing excellent brightness to the display, it is preferably less than 30%, more preferably 10% or less, even more preferably 5% or less, and particularly preferably 1% or less, and may be 0.5% or less. The lower limit of the haze value of the non-diffusion functional layer is not particularly limited.

The total light transmittance of the non-diffusion functional layer is not particularly limited, but from the viewpoint of ensuring the brightness of the display, it is preferably 60% or more, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more. In addition, the upper limit of the total light transmittance of the non-diffusion functional layer is not particularly limited, but it may be less than 100%, 99.9% or less, or 99% or less.

The haze value and total light transmittance of the non-diffusion functional layer are values for a single layer, and can be measured by the methods specified in JIS K7136 and JIS K7361-1. They can be controlled by the type and thickness of the non-diffusion functional layer.

From the viewpoint of improving the brightness of the display, the content of the colorant and/or light-diffusing fine particles in the non-diffusion functional layer is preferably less than 0.01 parts by mass, and more preferably less than 0.005 parts by mass, per 100 parts by mass of the resin constituting the non-diffusion functional layer.

Examples of the laminate structure of the sealing resin layer include [colored layer/diffusion functional layer], [colored layer/non-diffusion functional layer], [colored layer/diffusion functional layer/non-diffusion functional layer], [colored layer/non-diffusion functional layer/diffusion functional layer], [colored layer/diffusion functional layer/diffusion functional layer], [colored layer/non-diffusion functional layer/non-diffusion functional layer], [diffusion functional layer/colored layer/non-diffusion functional layer], [non-diffusion functional layer/colored layer/diffusion functional layer], [diffusion functional layer/colored layer/diffusion functional layer], [non-diffusion functional layer/colored layer/non-diffusion functional layer], [colored layer/diffusion functional layer/colored layer/non-diffusion functional layer] (all in order from the optical semiconductor element side), etc.

1 is a cross-sectional view showing one embodiment of the optical semiconductor element encapsulation sheet of the present invention. As shown in FIG. 1, the optical semiconductor element encapsulation sheet 1 can be used to encapsulate one or more optical semiconductor elements arranged on a substrate, and includes a substrate 4 and an encapsulating resin layer 2 formed on the substrate 4. The substrate 4 is composed of a substrate film 41 and a functional layer 42 which is a surface treatment layer, but may be composed of the substrate film 41 without the functional layer 42. The encapsulating resin layer 2 is formed of a laminate of a diffusion functional layer 21, a colored layer 22, and a non-colored layer 23. The colored layer 22 is directly laminated on the diffusion functional layer 21, and the non-colored layer 23 is directly laminated on the colored layer 22. A release liner 3 is attached to the diffusion functional layer 21, and a substrate 4 is attached to the non-colored layer 23. The diffusion functional layer 21 is a non-colored layer C, the colored layer 22 is a colored layer B, and the non-colored layer 23 is a non-colored layer A. The hardness of the non-colored layer 23 is harder than the hardness of the colored layer 22. The hardness of the non-colored layer 23 is harder than the hardness of the diffusion function layer 21. The hardness of the diffusion function layer 21 is harder than the hardness of the colored layer 22.

Note that, although FIG. 1 shows an example in which the encapsulating resin layer has a three-layer structure consisting of two non-colored layers and one colored layer, the total number of layers constituting the encapsulating resin layer is not particularly limited as long as it is two or more layers including one each of non-colored layer A and colored layer B.

(Resin Layer)
When the colored layer and the non-colored layer are the resin layers, the resin constituting the resin layer may be a known or commonly used resin, such as an acrylic resin, a urethane acrylate resin, a urethane resin, a rubber resin, an epoxy resin, an epoxy acrylate resin, an oxetane resin, a silicone resin, a silicone acrylic resin, a polyester resin, a polyether resin (polyvinyl ether, etc.), a polyamide resin, a fluorine resin, a vinyl acetate/vinyl chloride copolymer, a modified polyolefin, etc. The resin may be used alone or in combination of two or more. The resins constituting each layer of the sealing resin layer may be the same or different from each other.

When the resin layer is a layer having adhesive properties (adhesive layer), a known or commonly used pressure-sensitive adhesive can be used as the resin. Examples of the adhesive include acrylic adhesives, rubber adhesives (natural rubber, synthetic rubber, mixed systems thereof, etc.), silicone adhesives, polyester adhesives, urethane adhesives, polyether adhesives, polyamide adhesives, and fluorine adhesives. Only one type of adhesive may be used, or two or more types may be used.

The acrylic resin is a polymer that contains a structural unit derived from an acrylic monomer (a monomer component having a (meth)acryloyl group in the molecule) as a structural unit of the polymer. Only one type of the acrylic resin may be used, or two or more types may be used.

The acrylic resin is preferably a polymer that contains the largest amount of structural units derived from (meth)acrylic acid esters by mass. In this specification, "(meth)acrylic" refers to "acrylic" and/or "methacrylic" (either one or both of "acrylic" and "methacrylic"), and the same applies to other terms.

The above (meth)acrylic acid esters include, for example, hydrocarbon group-containing (meth)acrylic acid esters. The above hydrocarbon group-containing (meth)acrylic acid esters include (meth)acrylic acid alkyl esters having a linear or branched aliphatic hydrocarbon group, (meth)acrylic acid esters having an alicyclic hydrocarbon group such as (meth)acrylic acid cycloalkyl esters, and (meth)acrylic acid esters having an aromatic hydrocarbon group such as (meth)acrylic acid aryl esters. Only one type of the above hydrocarbon group-containing (meth)acrylic acid esters may be used, or two or more types may be used.

Examples of the (meth)acrylic acid alkyl esters include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and ethyl (meth)acrylate. Examples of such acrylates include isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate.

As the (meth)acrylic acid alkyl ester, a (meth)acrylic acid alkyl ester having a linear or branched aliphatic hydrocarbon group with a carbon number of 1 to 20 (preferably 1 to 14, more preferably 2 to 10) is preferred. When the carbon number is within the above range, it is easy to adjust the glass transition temperature of the acrylic resin, and it is easy to make the adhesion of the resin layer more appropriate.

Examples of (meth)acrylic acid esters having the above-mentioned alicyclic hydrocarbon group include (meth)acrylic acid esters having a monocyclic aliphatic hydrocarbon ring, such as cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, cycloheptyl (meth)acrylate, and cyclooctyl (meth)acrylate; (meth)acrylic acid esters having a bicyclic aliphatic hydrocarbon ring, such as isobornyl (meth)acrylate; and (meth)acrylic acid esters having a tricyclic or higher aliphatic hydrocarbon ring, such as dicyclopentanyl (meth)acrylate, dicyclopentanyloxyethyl (meth)acrylate, tricyclopentanyl (meth)acrylate, 1-adamantyl (meth)acrylate, 2-methyl-2-adamantyl (meth)acrylate, and 2-ethyl-2-adamantyl (meth)acrylate.

Examples of the (meth)acrylic acid ester having an aromatic hydrocarbon group include (meth)acrylic acid phenyl ester and (meth)acrylic acid benzyl ester.

The above-mentioned hydrocarbon group-containing (meth)acrylic acid ester preferably contains a (meth)acrylic acid alkyl ester having a linear or branched aliphatic hydrocarbon group, and more preferably contains a (meth)acrylic acid ester having an alicyclic hydrocarbon group. In this case, the adhesiveness of the resin layer is well balanced, and the sealing property of the optical semiconductor element is excellent.

In order to adequately express the basic properties of the hydrocarbon group-containing (meth)acrylic acid ester, such as adhesion to optical semiconductor elements, in the resin layer, the proportion of the hydrocarbon group-containing (meth)acrylic acid ester in all monomer components constituting the acrylic resin is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more, based on the total amount (100% by mass) of all monomer components. In addition, the proportion is preferably 95% by mass or less, more preferably 80% by mass or less, from the viewpoint of copolymerizing other monomer components and obtaining the effects of the other monomer components.

The proportion of (meth)acrylic acid alkyl esters having linear or branched aliphatic hydrocarbon groups in all monomer components constituting the acrylic resin is preferably 30% by mass or more, more preferably 40% by mass or more, based on the total amount (100% by mass) of all monomer components. The proportion is preferably 90% by mass or less, more preferably 70% by mass or less.

The proportion of the (meth)acrylic acid ester having an alicyclic hydrocarbon group in all monomer components constituting the acrylic resin is preferably 1% by mass or more, more preferably 5% by mass or more, based on the total amount (100% by mass) of all monomer components. The proportion is preferably 30% by mass or less, more preferably 20% by mass or less.

The acrylic resin may contain a structural unit derived from another monomer component copolymerizable with the hydrocarbon group-containing (meth)acrylic acid ester for the purpose of introducing a first functional group described below or for the purpose of modifying the cohesive force, heat resistance, etc. Examples of the other monomer components include polar group-containing monomers such as carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and nitrogen atom-containing monomers. Only one type of the other monomer components may be used, or two or more types may be used.

Examples of the carboxyl group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples of the acid anhydride monomer include maleic anhydride and itaconic anhydride.

Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate.

Examples of the glycidyl group-containing monomer include glycidyl (meth)acrylate and methyl glycidyl (meth)acrylate.

Examples of the sulfonic acid group-containing monomer include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid.

Examples of the phosphate group-containing monomer include 2-hydroxyethyl acryloyl phosphate.

Examples of the nitrogen atom-containing monomer include morpholino group-containing monomers such as (meth)acryloylmorpholine, cyano group-containing monomers such as (meth)acrylonitrile, and amide group-containing monomers such as (meth)acrylamide.

It is preferable that the polar group-containing monomer constituting the acrylic resin contains a hydroxy group-containing monomer. By using a hydroxy group-containing monomer, it is easy to introduce the first functional group described below. In addition, the acrylic resin and the resin layer have excellent water resistance, and the sheet for sealing optical semiconductor elements is less likely to cloud and has excellent whitening resistance even when used in a high humidity environment.

The above hydroxy group-containing monomer is preferably 2-hydroxyethyl (meth)acrylate or 4-hydroxybutyl (meth)acrylate, more preferably 2-hydroxyethyl (meth)acrylate.

In order to adequately express the basic properties of the hydrocarbon group-containing (meth)acrylic ester, such as adhesion to optical semiconductor elements, in the resin layer, the proportion of the polar group-containing monomer in the total monomer components (100% by mass) constituting the acrylic resin is preferably 5 to 50% by mass, and more preferably 10 to 40% by mass. In particular, from the viewpoint of achieving superior water resistance of the resin layer, it is preferable that the proportion of the hydroxyl group-containing monomer is within the above range.

The other monomer components may further include vinyl monomers such as caprolactone adducts of (meth)acrylic acid, vinyl acetate, vinyl propionate, styrene, and α-methylstyrene; glycol-based acrylic ester monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; and acrylic ester monomers such as tetrahydrofurfuryl (meth)acrylate, fluorine (meth)acrylate, silicone (meth)acrylate, and alkoxy-substituted hydrocarbon group-containing (meth)acrylate (2-methoxyethyl (meth)acrylate, 3-phenoxybenzyl (meth)acrylate, etc.).

The proportion of the other monomer components in the total monomer components (100% by mass) constituting the acrylic resin is, for example, about 3 to 50% by mass, and may be 5 to 40% by mass or 10 to 30% by mass.

The acrylic resin may contain a structural unit derived from a polyfunctional (meth)acrylate that is copolymerizable with the monomer components that constitute the acrylic resin in order to form a crosslinked structure in the polymer skeleton. Examples of the polyfunctional (meth)acrylate include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol hexa(meth)acrylate. Only one type of the polyfunctional monomer may be used, or two or more types may be used.

In order to adequately express the basic properties of the hydrocarbon group-containing (meth)acrylic ester, such as adhesion to optical semiconductor elements, in the resin layer, the proportion of the polyfunctional monomer in the total monomer components (100% by mass) constituting the acrylic resin is preferably 40% by mass or less, and more preferably 30% by mass or less.

When the resin layer is a radiation-curable resin layer, examples of the resin layer include a layer containing a base polymer and a radiation-polymerizable monomer component or oligomer component having a functional group such as a radiation-polymerizable carbon-carbon double bond, and a layer containing a polymer having a radiation-polymerizable functional group (especially an acrylic resin) as a base polymer.

The above-mentioned radiation-polymerizable functional group includes a radiation-radical polymerizable group such as a group containing a carbon-carbon unsaturated bond, such as an ethylenically unsaturated group, and a radiation-cationically polymerizable group. Examples of the above-mentioned group containing a carbon-carbon unsaturated bond include a vinyl group, a propenyl group, an isopropenyl group, an acryloyl group, and a methacryloyl group. Examples of the above-mentioned radiation-cationically polymerizable group include an epoxy group, an oxetanyl group, and an oxolanyl group. Among these, a group containing a carbon-carbon unsaturated bond is preferred, and an acryloyl group and a methacryloyl group are more preferred. The above-mentioned radiation-polymerizable functional group may be one type only or two or more types. The position of the above-mentioned radiation-polymerizable functional group may be any of the polymer side chains, the polymer main chain, and the polymer main chain terminals.

The polymer having the radiation-polymerizable functional group can be prepared, for example, by a method in which a polymer having a reactive functional group (first functional group) is reacted with a compound having a functional group (second functional group) capable of reacting with the first functional group to form a bond and the radiation-polymerizable functional group while maintaining the radiation polymerizability of the radiation-polymerizable functional group to bond them together. For this reason, it is preferable that the polymer having the radiation-polymerizable functional group contains a structural part derived from the polymer having the first functional group and a structural part derived from the compound having the second functional group and the radiation-polymerizable functional group.

Examples of combinations of the first functional group and the second functional group include a carboxy group and an epoxy group, an epoxy group and a carboxy group, a carboxy group and an aziridyl group, an aziridyl group and a carboxy group, a hydroxy group and an isocyanate group, and an isocyanate group and a hydroxy group. Among these, from the viewpoint of ease of reaction tracking, a combination of a hydroxy group and an isocyanate group, and a combination of an isocyanate group and a hydroxy group are preferred. The above combinations may be one type only, or two or more types.

Examples of compounds having the above-mentioned radiation-polymerizable functional group and isocyanate group include methacryloyl isocyanate, 2-acryloyloxyethyl isocyanate, 2-methacryloyloxyethyl isocyanate (MOI), m-isopropenyl-α,α-dimethylbenzyl isocyanate, etc. One or more of the above compounds may be used.

The content of the structural part derived from the compound having the second functional group and the radiation-polymerizable functional group in the acrylic resin having the radiation-polymerizable functional group is preferably 0.5 moles or more, more preferably 1 mole or more, even more preferably 3 moles or more, and even more preferably 10 moles or more, per 100 moles of the total amount of the structural part derived from the acrylic resin having the first functional group, from the viewpoint of being able to further proceed with the curing of the radiation-curable resin layer. The content is, for example, 100 moles or less.

The molar ratio of the second functional group to the first functional group in the acrylic resin having the radiation-polymerizable functional group [second functional group/first functional group] is preferably 0.01 or more, more preferably 0.05 or more, even more preferably 0.2 or more, and particularly preferably 0.4 or more, from the viewpoint of further promoting the curing of the radiation-curable resin layer. In addition, the molar ratio is preferably less than 1.0, more preferably 0.9 or less, from the viewpoint of further reducing low molecular weight substances in the radiation-curable resin layer.

The acrylic resin is obtained by polymerizing the various monomer components described above. The polymerization method is not particularly limited, but examples include a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, and a polymerization method using active energy radiation (active energy radiation polymerization method). The obtained acrylic resin may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

The acrylic resin having the radiation-polymerizable functional group can be prepared, for example, by polymerizing (copolymerizing) a raw material monomer containing a monomer component having a first functional group to obtain an acrylic resin having a first functional group, and then subjecting a compound having the second functional group and a radiation-polymerizable functional group to a condensation reaction or addition reaction with the acrylic resin while maintaining the radiation polymerizability of the radiation-polymerizable functional group.

When polymerizing the monomer components, various common solvents may be used. Examples of the solvent include organic solvents such as esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as toluene and benzene; aliphatic hydrocarbons such as n-hexane and n-heptane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and ketones such as methyl ethyl ketone and methyl isobutyl ketone. Only one of the above solvents may be used, or two or more of them may be used.

The polymerization initiator, chain transfer agent, emulsifier, etc. used in the radical polymerization of the monomer components are not particularly limited and can be selected as appropriate. The weight average molecular weight of the acrylic resin can be controlled by the amount of polymerization initiator and chain transfer agent used and the reaction conditions, and the amount used is adjusted appropriately depending on the type of these.

As the polymerization initiator used for the polymerization of the monomer components, a thermal polymerization initiator or a photopolymerization initiator (photoinitiator) can be used depending on the type of polymerization reaction. Only one type of the above polymerization initiator may be used, or two or more types may be used.

The thermal polymerization initiator is not particularly limited, but examples thereof include azo-based polymerization initiators, peroxide-based polymerization initiators, and redox-based polymerization initiators. The amount of the thermal polymerization initiator used is preferably 1 part by mass or less, more preferably 0.005 to 1 part by mass, and even more preferably 0.02 to 0.5 parts by mass, per 100 parts by mass of the total amount of all monomer components constituting the acrylic resin having the first functional group.

Examples of the photopolymerization initiator include benzoin ether-based photopolymerization initiators, acetophenone-based photopolymerization initiators, α-ketol-based photopolymerization initiators, aromatic sulfonyl chloride-based photopolymerization initiators, photoactive oxime-based photopolymerization initiators, benzoin-based photopolymerization initiators, benzyl-based photopolymerization initiators, benzophenone-based photopolymerization initiators, ketal-based photopolymerization initiators, thioxanthone-based photopolymerization initiators, acylphosphine oxide-based photopolymerization initiators, and titanocene-based photopolymerization initiators. Among these, acetophenone-based photopolymerization initiators are preferred.

Examples of the acetophenone-based photopolymerization initiator include 2,2-diethoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 4-phenoxydichloroacetophenone, 4-(t-butyl)dichloroacetophenone, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, and methoxyacetophenone.

The amount of the photopolymerization initiator used is preferably 0.005 to 1 part by mass, more preferably 0.01 to 0.7 parts by mass, and even more preferably 0.18 to 0.5 parts by mass, relative to 100 parts by mass of the total amount of all monomer components constituting the acrylic resin. When the amount used is 0.005 parts by mass or more (particularly, 0.18 parts by mass or more), it is easier to control the molecular weight of the acrylic resin to a small value, and the residual stress of the resin layer tends to increase, resulting in better step absorbency.

The reaction between the acrylic resin having the first functional group and the compound having the second functional group and the radiation-polymerizable functional group can be carried out, for example, in a solvent by stirring in the presence of a catalyst. Examples of the solvent include those mentioned above. The catalyst is appropriately selected depending on the combination of the first functional group and the second functional group. The reaction temperature in the reaction is, for example, 5 to 100°C, and the reaction time is, for example, 1 to 36 hours.

The acrylic resin may have a structural portion derived from a crosslinking agent. For example, the acrylic resin may be crosslinked to further reduce low molecular weight substances in the resin layer. The weight average molecular weight of the acrylic resin may be increased. When the acrylic resin has a radiation polymerizable functional group, the crosslinking agent crosslinks functional groups other than the radiation polymerizable functional group (for example, between first functional groups, between second functional groups, or between a first functional group and a second functional group). Only one type of crosslinking agent may be used, or two or more types may be used.

Examples of the crosslinking agent include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, melamine-based crosslinking agents, peroxide-based crosslinking agents, urea-based crosslinking agents, metal alkoxide-based crosslinking agents, metal chelate-based crosslinking agents, metal salt-based crosslinking agents, carbodiimide-based crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, amine-based crosslinking agents, silicone-based crosslinking agents, and silane-based crosslinking agents. Among these crosslinking agents, isocyanate-based crosslinking agents and epoxy-based crosslinking agents are preferred, and isocyanate-based crosslinking agents are more preferred, from the viewpoints of excellent adhesion to optical semiconductor elements and low impurity ions.

Examples of the isocyanate-based crosslinking agent (polyfunctional isocyanate compound) include lower aliphatic polyisocyanates such as 1,2-ethylene diisocyanate, 1,4-butylene diisocyanate, and 1,6-hexamethylene diisocyanate; alicyclic polyisocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated xylene diisocyanate; and aromatic polyisocyanates such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate. Examples of the isocyanate crosslinking agent include a trimethylolpropane/tolylene diisocyanate adduct, a trimethylolpropane/hexamethylene diisocyanate adduct, and a trimethylolpropane/xylylene diisocyanate adduct.

The content of the structural part derived from the crosslinking agent is not particularly limited, but is preferably 5 parts by mass or less, more preferably 0.001 to 5 parts by mass, and even more preferably 0.01 to 3 parts by mass, per 100 parts by mass of the total amount of the acrylic resin excluding the structural part derived from the crosslinking agent.

The resin layer may contain other components in addition to the above-mentioned components in each layer, as long as the effects of the present invention are not impaired. Examples of the other components include curing agents, crosslinking accelerators, tackifier resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), oligomers, antioxidants, fillers (metal powders, organic fillers, inorganic fillers, etc.), antioxidants, plasticizers, softeners, surfactants, antistatic agents, surface lubricants, leveling agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, granular materials, foil-like materials, etc. Only one type of the other components may be used, or two or more types may be used.

<Base material>
In the optical semiconductor element encapsulation sheet of the present invention, the encapsulating resin layer may be provided on at least one surface of the substrate. When the optical semiconductor element encapsulation sheet of the present invention includes the substrate, the encapsulating resin layer is in contact with the substrate on the side opposite to the non-colored layer A and the colored layer B. When the substrate is provided on the optical semiconductor element encapsulation sheet on the side opposite to the optical semiconductor element side of the encapsulating resin layer, the surface of the encapsulating resin layer can be made flat, which makes it difficult for diffuse reflection of light to occur, and improves the appearance of the display both when the light is off and when the light is on. In addition, the display can be given anti-glare properties and anti-reflection properties by forming an anti-glare layer or an anti-reflection layer described later on the substrate. In addition, the substrate serves as a support for the encapsulating resin layer in the optical semiconductor element encapsulation sheet, and the substrate provides excellent handling of the optical semiconductor element encapsulation sheet. The substrate does not necessarily have to be provided.

The substrate may be a single layer, or may be multiple layers having the same or different compositions, thicknesses, etc. When the substrate is multiple layers, each layer may be bonded to another layer such as an adhesive layer. The substrate layer used in the substrate is the part that is attached to the substrate having the optical semiconductor element together with the encapsulating resin layer, and does not include the release liner that is peeled off when the optical semiconductor element encapsulating sheet is used (attached) or the surface protection film that merely protects the substrate surface.

Examples of the substrate layer constituting the substrate part include glass and plastic substrates (particularly plastic films). Examples of the resin constituting the plastic substrate include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, very low-density polyethylene, random copolymer polypropylene, block copolymer polypropylene, homopolypropylene, polybutene, polymethylpentene, ionomers, ethylene-(meth)acrylic acid copolymers, ethylene-(meth)acrylic acid ester (random, alternating) copolymers, ethylene-vinyl acetate copolymers (EVA), ethylene-propylene copolymers, cyclic olefin polymers, ethylene-butene copolymers, ethylene-hexene copolymers, etc. Examples of the resin include polyolefin resin, polyurethane, polyester such as polyethylene terephthalate (PET), polyethylene naphthalate, polybutylene terephthalate (PBT), etc., polycarbonate, polyimide resin, polyether ether ketone, polyetherimide, polyamide such as aramid, wholly aromatic polyamide, polyphenyl sulfide, fluororesin, polyvinyl chloride, polyvinylidene chloride, cellulose resin such as triacetyl cellulose (TAC), silicone resin, acrylic resin such as polymethyl methacrylate (PMMA), polysulfone, polyarylate, polyvinyl acetate, etc. Only one of the above resins may be used, or two or more of them may be used. The above substrate layer may be various optical films such as anti-reflection (AR) films, polarizing plates, retardation plates, etc.

The thickness of the plastic film is preferably 20 to 300 μm, and more preferably 40 to 250 μm. If the thickness is 20 μm or more, the supportability and handleability of the sheet for encapsulating optical semiconductor elements are further improved. If the thickness is 300 μm or less, the display body can be made thinner.

The surface of the substrate on the side having the sealing resin layer may be subjected to a surface treatment such as a physical treatment such as corona discharge treatment, plasma treatment, sand mat processing treatment, ozone exposure treatment, flame exposure treatment, high-voltage shock exposure treatment, or ionizing radiation treatment; a chemical treatment such as chromate treatment; or an easy-adhesion treatment using a coating agent (primer) in order to improve adhesion and retention with the sealing resin layer. It is preferable that the surface treatment for improving adhesion is applied to the entire surface of the substrate on the side of the sealing resin layer.

The thickness of the substrate is preferably 5 μm or more, more preferably 10 μm or more, from the viewpoint of excellent support function and surface scratch resistance. The thickness of the substrate is preferably 300 μm or less, more preferably 250 μm or less, from the viewpoint of excellent transparency.

<Optical semiconductor element encapsulation sheet>
The optical semiconductor element encapsulation sheet may have a layer having anti-glare and/or anti-reflection properties. By having such a configuration, gloss and light reflection can be suppressed when encapsulating an optical semiconductor element, and the appearance can be improved. An example of the layer having anti-glare properties is an anti-glare treatment layer. An example of the layer having anti-reflection properties is an anti-reflection treatment layer. The anti-glare treatment and the anti-reflection treatment can be performed by known or conventional methods. The layer having anti-glare properties and the layer having anti-reflection properties may be the same layer or different layers. The layer having anti-glare properties and/or anti-reflection properties may have only one layer, or two or more layers.

The haze value (initial haze value) of the optical semiconductor element encapsulation sheet is not particularly limited, but from the viewpoint of suppressing luminance unevenness and achieving a superior design, it is preferably 80% or more, more preferably 85% or more, even more preferably 90% or more, and particularly preferably 95% or more. There is no particular upper limit to the haze value.

The total light transmittance of the sheet for encapsulating optical semiconductor elements is not particularly limited, but from the viewpoint of further improving the anti-reflection function of metal wiring and the like and the contrast, it is preferably 40% or less, more preferably 30% or less, and even more preferably 20% or less. In addition, from the viewpoint of ensuring brightness, the total light transmittance is preferably 0.5% or more.

The haze value and total light transmittance can be measured by the methods specified in JIS K7136 and JIS K7361-1, respectively, and can be controlled by the lamination order, type, thickness, etc. of the layers constituting the encapsulating resin layer and the base material.

The thickness of the optical semiconductor element encapsulation sheet is preferably 10 to 600 μm, more preferably 20 to 550 μm, even more preferably 30 to 500 μm, even more preferably 40 to 450 μm, and particularly preferably 50 to 400 μm, from the viewpoint of more efficiently reducing color shift while improving the anti-reflection function and contrast of metal wiring, etc. Note that the release liner is not included in the above thickness.

The thickness of the non-colored layer A is preferably 30 to 480 μm, more preferably 40 to 380 μm, and even more preferably 50 to 280 μm. If the thickness of the non-colored layer A is 30 μm or more, the surface opposite to the colored layer B tends to be flat, making it difficult for diffuse reflection of external light to occur on the surface of the encapsulating resin layer when the optical semiconductor element is encapsulated, improving the appearance of the display both when the light is off and when the light is on. If the thickness of the non-colored layer A is 480 μm or less, the thickness of the sheet for encapsulating optical semiconductor elements can be made thin.

The thickness of the colored layer B is preferably 5 to 100 μm, more preferably 10 to 80 μm, and even more preferably 20 to 70 μm. If the thickness of the colored layer B is 5 μm or more, the anti-reflection properties are superior when the optical semiconductor element is encapsulated. If the thickness of the colored layer B is 100 μm or less, the thickness becomes sufficiently thin when compressed by the non-colored layer A when the optical semiconductor element is encapsulated, making it easier to ensure the brightness of the optical semiconductor element when it emits light. In addition, the thickness of the colored layer B is preferably thinner than the height of the optical semiconductor element (the height from the substrate surface to the end of the optical semiconductor element on the front side).

The thickness of the non-colored layer C is, for example, 5 to 480 μm, preferably 5 to 100 μm, more preferably 10 to 80 μm, and even more preferably 20 to 70 μm. If the thickness of the non-colored layer C is 5 μm or more, the sealing property of the optical semiconductor element is improved. If the thickness of the non-colored layer C is 480 μm or less, it is easier to ensure the brightness when the optical semiconductor element emits light.

The thickness of the sealing resin layer is, for example, 100 to 500 μm, preferably 120 to 400 μm, and more preferably 150 to 300 μm. If the thickness is 100 μm or more, the sealing property of the optical semiconductor element is better. If the thickness is 500 μm or less, the thickness of the display body becomes thinner.

The optical semiconductor element encapsulation sheet, in a state where a functional layer is laminated on one side thereof, is laminated to a wafer in which the encapsulation resin layer on the side having the colored layer B with respect to the non-colored layer A is convexly processed to a height of 120 μm, and the L ^* (SCI) in L ^* a ^* b ^* (SCI) measured under conditions of a 10° field of view from the functional layer side and a light source D65 is preferably less than 54, more preferably 40 or less, and even more preferably 30 or less. The light reflected by an object includes regular reflected light and diffuse reflected light, and regular reflected light is light that is difficult to recognize with the naked eye. L ^* (SCE) is a measurement of reflected light that does not include regular reflected light, whereas L ^* (SCI) is a measurement of reflected light that includes regular reflected light, and although it has little relevance to the visibility with the naked eye, it is possible to measure a color tone close to the true color tone of the object. Therefore, when L ^* (SCI) is less than 54, the design is excellent even when the visibility of the display body is affected by the environment.

In the above L ^* a ^* b ^* (SCI), a ^* (SCI) is preferably -5.0 to 5.0, more preferably -3.0 to 3.0, and even more preferably -2.0 to 2.0. In the above L ^* a ^* b ^* (SCI), b ^* (SCI) is preferably -5.0 to 5.0, more preferably -3.0 to 3.0, and even more preferably -2.5 to 2.5. When ^a* (SCI) and/or b ^* (SCI) are each within the above range, the color of the light emitted by the optical semiconductor element is good and the visibility is excellent.

The L ^* (SCI), a ^* (SCI), and b ^* (SCI) in the above L ^* a ^* b ^* (SCI) can be measured using a known or conventional spectrophotometer, specifically, by the method described in the examples.

The functional layer is a layer that is not included in the encapsulating resin layer, and can impart various functions to the optical semiconductor element encapsulating sheet of the present invention. Examples of the functional layer include a layer including a surface treatment layer. By having such a configuration, the optical semiconductor element encapsulating sheet having the functional layer including the surface treatment layer laminated thereon has excellent light diffusion properties and excellent light extraction efficiency. Examples of the surface treatment layer include an anti-glare treatment layer (anti-glare treatment layer), an anti-reflection treatment layer, a hard coat treatment layer, and the like. The functional layer may be laminated on the encapsulating resin layer in the optical semiconductor element encapsulating sheet of the present invention, or may be laminated on the substrate portion if the substrate portion is provided, but is preferably laminated on the substrate portion, and is preferably laminated on the side opposite to the side of the substrate portion that has the encapsulating resin layer.

The optical semiconductor element encapsulation sheet of the present invention may have the functional layer. When the functional layer is provided, the L ^* a ^* b ^* (SCI) can be measured without laminating a separate functional layer. When the optical semiconductor element encapsulation sheet of the present invention does not have the functional layer, a separate functional layer is laminated and the L ^* a ^* b ^* (SCI) is measured. The functional layer is preferably laminated on the non-colored layer A side relative to the colored layer B side.

When the above-mentioned sheet for encapsulating optical semiconductor elements is attached to a wafer in which the encapsulating resin layer on the side having the colored layer B relative to the non-colored layer A is processed to have a convex shape with a height of 120 μm and observed under a microscope from the encapsulating resin layer side, it is preferable that the average brightness of the concave portions is 10 to 30 and/or the maximum brightness of the convex portions is greater than 143. The above-mentioned maximum brightness of the convex portions is more preferably 150 or more, and even more preferably 160 or more. When the average brightness of the concave portions and/or the maximum brightness of the convex portions are within the above ranges, the anti-reflection properties and high brightness when the optical semiconductor element is encapsulated are superior.

[Release liner]
The encapsulating resin layer may be formed on a release-treated surface on a release liner. When the encapsulating resin layer is formed on the release liner, the release liner contacts the side of the encapsulating resin layer opposite to the non-colored layer A of the colored layer B. When the substrate portion is not present, both sides of the encapsulating resin layer may contact the release liner. The release liner is used as a protective material for the optical semiconductor element encapsulation sheet, and is peeled off when encapsulating the optical semiconductor element. The release liner is not necessarily provided.

The release liner is an element for covering and protecting the surface of the optical semiconductor element encapsulation sheet, and is peeled off from the sheet when the optical semiconductor element encapsulation sheet is attached to a substrate on which an optical semiconductor element is disposed.

Examples of the release liner include polyethylene terephthalate (PET) film, polyethylene film, polypropylene film, plastic films and papers whose surfaces are coated with a release agent such as a fluorine-based release agent or a long-chain alkyl acrylate-based release agent.

The thickness of the release liner is, for example, 10 to 200 μm, preferably 15 to 150 μm, and more preferably 20 to 100 μm. If the thickness is 10 μm or more, the release liner is less likely to break due to cuts during processing. If the thickness is 200 μm or less, the release liner is more easily peeled off from the optical semiconductor element encapsulation sheet during use.

[Method of manufacturing the sheet for encapsulating optical semiconductor elements]
An embodiment of the method for producing a sheet for encapsulating an optical semiconductor element of the present invention will be described. For example, the sheet for encapsulating an optical semiconductor element 1 shown in Fig. 1 is prepared by separately preparing a diffusion functional layer 21, a colored layer 22, and a non-colored layer 23, each of which is sandwiched between the release-treated surfaces of two release liners. One of the release liners bonded to the diffusion functional layer 21 is a release liner 3.

Next, one of the release liners attached to the non-colored layer 23 is peeled off to expose the surface of the non-colored layer 23, and the exposed surface is bonded to the substrate 4. After that, one of the release liners attached to the colored layer 22 is peeled off, and the release liner on the surface of the non-colored layer 23 is peeled off to expose the surface of the non-colored layer 23, and the exposed surface of the colored layer 22 is bonded to the surface of the non-colored layer 23.

Next, one of the release liners attached to the diffusion functional layer 21 (a release liner other than release liner 3) is peeled off, and the release liner on the surface of the colored layer 22 is peeled off to expose the colored layer 22, and the exposed surface of the diffusion functional layer 21 is attached to the surface of the colored layer 22. The lamination of the various layers can be performed using a known roller or laminator. In this way, the sheet 1 for encapsulating optical semiconductor elements shown in FIG. 1 can be produced, in which the non-colored layer 23, the colored layer 22, the diffusion functional layer 21, and the release liner 3 are laminated in this order on the substrate portion 4.

[Optical semiconductor device]
An optical semiconductor device such as a display can be produced using the sheet for encapsulating an optical semiconductor element of the present invention. The display produced using the sheet for encapsulating an optical semiconductor element of the present invention comprises a substrate, an optical semiconductor element arranged on the substrate, and the sheet for encapsulating an optical semiconductor element of the present invention or a cured product obtained by curing the sheet, which encapsulates the optical semiconductor element. The cured product is a cured product obtained by curing the radiation-curable resin layer by irradiation when the sheet for encapsulating an optical semiconductor element of the present invention comprises a radiation-curable resin layer.

Examples of the optical semiconductor elements include light-emitting diodes (LEDs), such as blue light-emitting diodes, green light-emitting diodes, red light-emitting diodes, and ultraviolet light-emitting diodes.

In the above optical semiconductor device, the optical semiconductor element encapsulation sheet of the present invention has excellent conformability to the unevenness when the optical semiconductor elements are convex portions and the gaps between multiple optical semiconductor elements are concave portions, and has excellent conformability and embeddability of the optical semiconductor elements, so it is preferable to encapsulate multiple optical semiconductor elements collectively.

It is preferable that the height of the optical semiconductor element on the substrate (the height from the substrate surface to the end of the optical semiconductor element on the front side) is 500 μm or less. If the height is 500 μm or less, the sealing resin layer will have better conformability to the uneven shape.

Figure 2 shows one embodiment of an optical semiconductor device using the optical semiconductor element encapsulation sheet 1 shown in Figure 1. The optical semiconductor device 10 shown in Figure 2 includes a substrate 5, a plurality of optical semiconductor elements 6 arranged on one side of the substrate 5, an encapsulating resin layer 7 that encapsulates the optical semiconductor elements 6, and a base material portion 4 laminated on the encapsulating resin layer 7. The plurality of optical semiconductor elements 6 are encapsulated in the encapsulating resin layer 7. The encapsulating resin layer 7 is formed by laminating a diffusion function layer 71, a colored layer 72, and a non-colored layer 73. The diffusion function layer 21 is in close contact with the optical semiconductor elements 6 and the substrate 5, following the uneven shape formed by the plurality of optical semiconductor elements 6, and embeds the optical semiconductor elements 6. In addition, the diffusion function layer 71 has an uneven shape at the interface on the optical semiconductor element 6 side, following the uneven shape, and the other interface is flat.

The encapsulating resin layer 7 is formed by the encapsulating resin layer 2. Specifically, when the encapsulating resin layer 2 in the sheet 1 for encapsulating an optical semiconductor element does not have a radiation curable resin layer, the encapsulating resin layer 2 becomes the encapsulating resin layer 7 in the optical semiconductor device 10. On the other hand, when the encapsulating resin layer 2 in the sheet 1 for encapsulating an optical semiconductor element has a radiation curable resin layer, for example, when the colored layer 22 is a radiation curable resin layer, the colored layer 22 is cured to form the colored layer 72, which becomes the encapsulating resin layer 7.

In the optical semiconductor device 10 shown in FIG. 2, the optical semiconductor element 6 is completely embedded and sealed in the diffusion function layer 71, and is indirectly sealed by the colored layer 72 and the non-colored layer 73. That is, the optical semiconductor element 6 is sealed by the sealing resin layer 7 consisting of a laminate of the diffusion function layer 71, the colored layer 72, and the non-colored layer 73. The optical semiconductor device is not limited to this embodiment, and may be, for example, as shown in FIG. 3, in an embodiment in which the optical semiconductor element 6 is completely embedded and sealed in the diffusion function layer 71 and the colored layer 72, and is indirectly sealed by the non-colored layer 73. Also, as shown in FIG. 4, the optical semiconductor element 6 may be completely embedded and sealed in the diffusion function layer 71, the colored layer 72, and the non-colored layer 73.

In the above optical semiconductor device, it is preferable that the non-colored layer in the encapsulating resin layer formed from the non-colored layer A, the colored layer in the encapsulating resin layer formed from the colored layer B, and the non-colored layer in the encapsulating resin layer formed from the non-colored layer C each satisfy the above-mentioned hardness A, hardness B, and hardness C relationships.

The optical semiconductor device may be a tiled arrangement of individual optical semiconductor devices. In other words, the optical semiconductor device may be a tiled arrangement of multiple optical semiconductor devices in a planar direction.

The display body preferably includes a self-luminous display device. The self-luminous display device and a display panel, if necessary, can be combined to form a display body that is an image display device. In this case, the optical semiconductor element is an LED element. Examples of the self-luminous display device include an LED display, a backlight, and an organic electroluminescence (organic EL) display device. The backlight is preferably a backlight that is directly under the entire surface. The backlight includes, for example, a laminate that includes the substrate and a plurality of optical semiconductor elements arranged on the substrate as at least a part of its components. For example, in the self-luminous display device, a metal wiring layer is laminated on the substrate for sending a light emission control signal to each LED element. The LED elements that emit light of each color, red (R), green (G), and blue (B), are alternately arranged on the substrate via a metal wiring layer. The metal wiring layer is formed of a metal such as copper, and the light emission degree of each LED element is adjusted to display each color.

The optical semiconductor element encapsulation sheet of the present invention can be used in optical semiconductor devices that are folded when used, such as optical semiconductor devices having a foldable image display device (flexible display) (particularly, a foldable image display device (foldable display)). Specifically, it can be used in foldable backlights and foldable self-luminous display devices.

The optical semiconductor element encapsulation sheet of the present invention has excellent conformability and embeddability for optical semiconductor elements, and can therefore be preferably used when the optical semiconductor device is a mini LED display device or a micro LED display device.

[Method of manufacturing optical semiconductor device]
The optical semiconductor device can be produced, for example, by laminating the optical semiconductor element encapsulation sheet of the present invention to a substrate on which an optical semiconductor element is disposed, and encapsulating the optical semiconductor element with an encapsulating resin layer.

(Sealing process)
The method for manufacturing an optical semiconductor device using the optical semiconductor element encapsulation sheet includes an encapsulation step of laminating the optical semiconductor element encapsulation sheet to a substrate on which an optical semiconductor element is arranged, and encapsulating the optical semiconductor element with an encapsulating resin layer. Specifically, the encapsulation step includes first peeling off the release liner from the optical semiconductor element encapsulation sheet to expose the encapsulating resin layer. Then, the encapsulating resin layer surface, which is the exposed surface of the optical semiconductor element encapsulation sheet, is laminated to the substrate surface on which the optical semiconductor element is arranged of a laminate (such as an optical member) including a substrate and an optical semiconductor element (preferably a plurality of optical semiconductor elements) arranged on the substrate, and when the laminate includes a plurality of optical semiconductor elements, the encapsulating resin layer is further arranged to fill the gaps between the plurality of optical semiconductor elements, and the plurality of optical semiconductor elements are encapsulated together. Specifically, the release liner 3 is peeled off from the sheet 1 for encapsulating optical semiconductor elements shown in FIG. 1 to expose the diffusion function layer 21, which is positioned opposite the surface of the substrate 5 on which the optical semiconductor element 6 is arranged, and the sheet 1 for encapsulating optical semiconductor elements is bonded to the surface of the substrate 5 on which the optical semiconductor element 6 is arranged, and the optical semiconductor element 6 is embedded in the encapsulating resin layer 2.

The temperature during the lamination is, for example, within the range of room temperature to 110°C. In addition, the pressure may be reduced or pressurized during the lamination. The reduced pressure or pressurization can prevent the formation of voids between the encapsulating resin layer and the substrate or the optical semiconductor element. In the encapsulation step, it is preferable to laminate the optical semiconductor element encapsulation sheet under reduced pressure and then pressurize it. When reduced pressure is applied, the pressure is, for example, 1 to 100 Pa, and the depressurization time is, for example, 5 to 600 seconds. When pressurized, the pressure is, for example, 0.05 to 0.5 MPa, and the pressurization time is, for example, 5 to 600 seconds.

(Radiation Irradiation Step)
When the encapsulating resin layer comprises a radiation curable resin layer, the manufacturing method may further comprise a radiation irradiation step of irradiating radiation to a laminate comprising the substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element encapsulating sheet encapsulating the optical semiconductor element, to cure the radiation curable resin layer and form a cured product layer. As described above, examples of the radiation include electron beams, ultraviolet rays, α rays, β rays, γ rays, and X-rays. Among these, ultraviolet rays are preferred. The temperature during radiation irradiation is, for example, within the range of room temperature to 100° C., and the irradiation time is, for example, 1 minute to 1 hour.

(Dicing process)
The manufacturing method may further include a dicing step of dicing a laminate including the substrate, the optical semiconductor element disposed on the substrate, and the optical semiconductor element encapsulation sheet encapsulating the optical semiconductor element. The laminate may be diced after the radiation irradiation step. When the laminate includes a cured layer in which the radiation curable resin layer is cured by the radiation irradiation, the dicing step involves dicing and removing the cured layer of the optical semiconductor element encapsulation sheet and the side end of the substrate. This allows the surface of the cured layer that has been sufficiently cured and reduced in adhesion to be exposed on the side. The dicing can be performed by a known or conventional method, for example, a method using a dicing blade or laser irradiation.

(Tiling process)
The manufacturing method may further include a tiling step of arranging the plurality of optical semiconductor devices obtained in the dicing step so as to be in contact with each other in a planar direction. In the tiling step, the plurality of laminates obtained in the dicing step are tiled so as to be in contact with each other in a planar direction. In this manner, one large display body can be manufactured.

In this manner, an optical semiconductor device can be manufactured. When the encapsulating resin layer 2 in the sheet 1 for encapsulating an optical semiconductor element does not have a radiation curable resin layer, the encapsulating resin layer 2 becomes the encapsulating resin layer 7 in the optical semiconductor device 10. On the other hand, when the encapsulating resin layer 2 in the sheet 1 for encapsulating an optical semiconductor element has a radiation curable resin layer, for example, when the colored layer 22 is a radiation curable resin layer, the colored layer 22 is cured to form the colored layer 72, which becomes the encapsulating resin layer 7.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

Production Example 1
(Preparation of Acrylic Prepolymer Solution A)
A separable flask equipped with a thermometer, a stirrer, a reflux condenser, and a nitrogen gas inlet tube was charged with 78 parts by mass of 2-ethylhexyl acrylate (2-EHA), 18 parts by mass of N-vinyl-2-pyrrolidone (NVP), 5 parts by mass of 2-hydroxyethyl acrylate (HEA), 0.035 parts by mass of a photopolymerization initiator (trade name "omnirad 184", manufactured by IGM Resins Italia Srl), and 0.035 parts by mass of a photopolymerization initiator (trade name "omnirad 651", manufactured by IGM Resins Italia Srl), as monomer components, and then nitrogen gas was flowed and nitrogen substitution was performed for about 1 hour while stirring. Thereafter, polymerization was performed by irradiating ultraviolet light at 5 mW / cm ² , and the reaction rate was adjusted to 5 to 15%, to obtain an acrylic prepolymer solution A.

Production Example 2
(Preparation of Acrylic Oligomer Solution)
100 parts by mass of toluene, 60 parts by mass of dicyclopentanyl methacrylate (DCPMA) (trade name "FA-513M", manufactured by Hitachi Chemical Co., Ltd.), 40 parts by mass of methyl methacrylate (MMA), and 3.5 parts by mass of α-thioglycerol as a chain transfer agent were charged into a four-neck flask. Then, after stirring for 1 hour under a nitrogen atmosphere at 70°C, 0.2 parts by mass of AIBN was charged as a thermal polymerization initiator, and the mixture was reacted for 2 hours at 70°C, and then reacted for 2 hours at 80°C. Thereafter, the reaction liquid was charged under a temperature atmosphere of 130°C, and the toluene, chain transfer agent, and unreacted monomers were dried and removed to obtain a solid acrylic oligomer. The Tg of this acrylic oligomer was 144°C, and the Mw was 4300. 50 parts by mass of 2-ethylhexyl acrylate (2-EHA) was added to 50 parts by mass of the above acrylic oligomer, and dissolved to obtain an acrylic oligomer solution.

Production Example 3
(Preparation of Pressure-Sensitive Adhesive Composition A)
To the acrylic prepolymer solution A prepared in Production Example 1 (total amount of prepolymers taken as 100 parts by mass), 17.6 parts by mass of 2-hydroxyethyl acrylate (HEA), 11.8 parts by mass of the acrylic oligomer solution prepared in Production Example 2, 0.088 parts by mass of a bifunctional monomer (product name "NK Ester A-HD-N", manufactured by Shin-Nakamura Chemical Co., Ltd.), and 0.353 parts by mass of a silane coupling agent (product name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane) were added to obtain a pressure-sensitive adhesive composition A.

Production Example 4
(Preparation of Pressure-Sensitive Adhesive Composition B)
To the acrylic prepolymer solution A prepared in Production Example 1 (total amount of prepolymers taken as 100 parts by mass), 17.6 parts by mass of 2-hydroxyethyl acrylate (HEA), 11.8 parts by mass of the acrylic oligomer solution prepared in Production Example 2, 0.294 parts by mass of a bifunctional monomer (product name "NK Ester A-HD-N", manufactured by Shin-Nakamura Chemical Co., Ltd.), and 0.353 parts by mass of a silane coupling agent (product name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane) were added to obtain a pressure-sensitive adhesive composition B.

Production Example 5
(Preparation of Acrylic Prepolymer Solution B)
A thermometer, a stirrer, a reflux condenser, and a separable flask equipped with a nitrogen gas inlet tube were charged with 67 parts by mass of butyl acrylate (BA), 14 parts by mass of cyclohexyl acrylate (CHA), 19 parts by mass of 4-hydroxybutyl acrylate (4-HBA), 0.09 parts by mass of a photopolymerization initiator (trade name "omnirad 184", manufactured by IGM Resins Italia Srl), and 0.09 parts by mass of a photopolymerization initiator (trade name "omnirad 651", manufactured by IGM Resins Italia Srl), as monomer components, and then nitrogen gas was flowed and nitrogen substitution was performed for about 1 hour while stirring. Thereafter, polymerization was performed by irradiating ultraviolet light at 5 mW / cm ² , and the reaction rate was adjusted to 5 to 15%, to obtain an acrylic prepolymer solution B.

Production Example 6
(Preparation of Pressure-Sensitive Adhesive Composition C)
To the acrylic prepolymer solution B prepared in Production Example 5 (total amount of prepolymers taken as 100 parts by mass), 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 8 parts by mass of 4-hydroxybutyl acrylate (4-HBA), 0.1 parts by mass of dipentaerythritol hexaacrylate (product name "KAYARAD DPHA", manufactured by Shin-Nakamura Chemical Co., Ltd.) as a polyfunctional monomer, and 0.4 parts by mass of a silane coupling agent (product name "KBM-403", manufactured by Shin-Etsu Chemical Co., Ltd., 3-glycidoxypropyltrimethoxysilane) were added to obtain a pressure-sensitive adhesive composition C.

Production Example 7
(Preparation of Pressure-Sensitive Adhesive Composition D)
To the acrylic prepolymer solution B (total amount of prepolymer is 100 parts by mass) prepared in Production Example 5, 9 parts by mass of 2-hydroxyethyl acrylate (HEA), 8 parts by mass of 4-hydroxybutyl acrylate (4-HBA), 0.02 parts by mass of dipentaerythritol hexaacrylate (trade name "KAYARAD DPHA", manufactured by Shin-Nakamura Chemical Co., Ltd.) as a polyfunctional monomer, 0.35 parts by mass of a silane coupling agent (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM-403"), and 0.3 parts by mass of a photopolymerization initiator (trade name "omnirad 651", manufactured by IGM Resins Italia Srl) were added to obtain a pressure-sensitive adhesive composition D.

Production Example 8
(Preparation of non-light-diffusing adhesive layers 1 to 8)
The adhesive compositions A to D and the additives were mixed in the mass ratios shown in Table 1. This mixture was applied onto the release-treated surface of a release liner (product name "MRE38", manufactured by Mitsubishi Chemical Corporation, a polyethylene terephthalate film with one side subjected to release treatment, thickness 38 μm) to form a resin composition layer, and then the release-treated surface of a release liner (product name "MRF38", manufactured by Mitsubishi Chemical Corporation) was also bonded onto the resin composition layer. Next, ultraviolet rays with an illuminance shown in Table 1 were irradiated using a black light until the accumulated light amount reached 3600 mJ/cm ² to perform polymerization, thereby producing non-diffusion functional layers (non-light-diffusion adhesive layers) 1 to 8 having adhesive properties.

Production Example 9
(Preparation of Antireflection Layers 1 and 2)
The adhesive composition D and the additives were mixed in the mass ratio shown in Table 1. This mixture was applied onto the release-treated surface of a release liner (trade name "MRE38", manufactured by Mitsubishi Chemical Corporation, a polyethylene terephthalate film with one side subjected to release treatment, thickness 38 μm) to form a resin composition layer, and then the release-treated surface of a release liner (trade name "MRF38", manufactured by Mitsubishi Chemical Corporation) was also bonded onto the resin composition layer. Next, ultraviolet rays with the illuminance shown in Table 1 were irradiated by a black light until the accumulated light amount reached 3600 mJ/cm ² to perform polymerization, and colored layers (anti-reflection layers) 1 and 2 were prepared. Note that 9256BLACK is a 20% dispersion of black pigment (trade name "9256BLACK", manufactured by Tokushiki Co., Ltd.).

Production Example 10
(Preparation of light-diffusing pressure-sensitive adhesive layer 1)
The adhesive composition D and the additives were mixed in the mass ratio shown in Table 1. This mixture was applied onto the release-treated surface of a release liner (trade name "MRE38", manufactured by Mitsubishi Chemical Corporation, a polyethylene terephthalate film with one side subjected to release treatment, thickness 38 μm) to form a resin composition layer, and then the release-treated surface of a release liner (trade name "MRF38", manufactured by Mitsubishi Chemical Corporation) was also bonded onto the resin composition layer. Next, ultraviolet light with the illuminance shown in Table 1 was irradiated by a black light until the accumulated light amount reached 3600 mJ/cm ² to perform polymerization, and a diffusion function layer (light diffusion adhesive layer) 1 having adhesive properties was produced. Note that Tospearl 145 is the trade name "Tospearl 145" (manufactured by Momentive Performance Materials Japan, a silicone resin with a refractive index of 1.42 and an average particle size of 4.5 μm). Also, POB-A is the trade name "Light Acrylate POB-A" (manufactured by Kyoeisha Chemical Co., Ltd.).

Production Example 11
(Preparation of substrate film with antiglare treatment layer)
As the resin contained in the antiglare treatment layer forming material, 40 parts by mass of an ultraviolet-curable multifunctional acrylate resin (product name "UA-53H", manufactured by Shin-Nakamura Chemical Co., Ltd.) and 60 parts by mass of a multifunctional acrylate mainly composed of pentaerythritol triacrylate (product name "Viscoat #300", manufactured by Osaka Organic Chemical Industry Ltd.) were prepared. Per 100 parts by mass of the total resin solid content of the above resin, 7.0 parts by mass of copolymer particles of acrylic and styrene (product name "Techpolymer SSX-103DXE", manufactured by Sekisui Chemical Co., Ltd.) as antiglare treatment layer-forming particles, 3 parts by mass of silicone resin (product name "TOSPEARL130", manufactured by Momentive Performance Materials Japan, Ltd.), 2.5 parts by mass of synthetic smectite (product name "Sumecton SAN", manufactured by Kunimine Industries Co., Ltd.) as a thixotropy-imparting agent, 3 parts by mass of a photopolymerization initiator (product name "OMNIRAD907", manufactured by BASF), and 0.15 parts by mass of a leveling agent (product name "GRANDIC PC4100", manufactured by DIC Corporation) were mixed. This mixture was diluted with a toluene/cyclopentanone mixed solvent (mass ratio 80/20) so that the solid content concentration was 40 mass %, to prepare an antiglare treatment layer forming material (coating liquid).

A transparent plastic film substrate (trade name "KC4UY", TAC, manufactured by Konica Minolta, Inc.) was prepared as a light-transmitting substrate. The anti-glare treatment layer forming material (coating liquid) was used to form a coating film on one side of the transparent plastic film substrate using a bar coater. The transparent plastic film substrate on which the coating film was formed was then transported to a drying process. In the drying process, the coating film was dried by heating at 80°C for 1 minute. Thereafter, ultraviolet rays with an integrated light amount of 300 mJ/ ^cm2 were irradiated from a high-pressure mercury lamp to cure the coating film to form an anti-glare treatment layer with a thickness of 8.5 μm, and an anti-glare film (substrate film with anti-glare treatment layer) with a haze of 25% was obtained.

Example 1
(Preparation of Sheet for Encapsulating Optical Semiconductor Elements)
The release liner (product name "MRE38") was peeled off from the non-light-diffusing pressure-sensitive adhesive layer 1 obtained in Production Example 8 to expose the adhesive surface. The exposed surface of the light-diffusing pressure-sensitive adhesive layer 1 was attached to the easy-adhesion treated surface of the base film with the antiglare treatment layer prepared in Production Example 11 to form the non-light-diffusing pressure-sensitive adhesive layer 1 on the base film.
Next, the release liner (product name "MRF38") was peeled off from the surface of the non-light-diffusing pressure-sensitive adhesive layer 1 to expose the adhesive surface. The release liner (product name "MRE38") was peeled off from the anti-reflection layer 1 obtained in Production Example 9, and the exposed adhesive surface was attached to the exposed surface of the non-light-diffusing pressure-sensitive adhesive layer 1 to form the anti-reflection layer 1 on the non-light-diffusing pressure-sensitive adhesive layer 1.
Next, the release liner (product name "MRF38") was peeled off from the surface of the antireflective layer 1 to expose the adhesive surface. The adhesive surface exposed by peeling off the release liner (product name "MRE38") from the light diffusing pressure-sensitive adhesive layer 1 obtained in Production Example 10 was attached to the exposed surface of the antireflective layer 1 to form the light diffusing pressure-sensitive adhesive layer 1 on the antireflective layer 1.
The sheets were then laminated at room temperature (23° C.) using a hand roller to avoid air bubbles, and left for two days in a dark place. In this way, a sheet for encapsulating optical semiconductor elements was obtained, which was composed of [release liner/light-diffusing adhesive layer 1 (50 μm)/antireflection layer 1 (50 μm)/non-light-diffusing adhesive layer 1 (100 μm)/substrate film].

Example 2
A sheet for encapsulating optical semiconductor elements was obtained in the same manner as in Example 1, except that non-light-diffusing adhesive layer 2 was used instead of non-light-diffusing adhesive layer 1, and the sheet consisted of [release liner/light-diffusing adhesive layer 1 (50 μm)/anti-reflection layer 1 (50 μm)/non-light-diffusing adhesive layer 2 (100 μm)/base film].

Example 3
A sheet for encapsulating optical semiconductor elements was obtained in the same manner as in Example 1, except that non-light-diffusing adhesive layer 3 was used instead of non-light-diffusing adhesive layer 1, and the sheet consisted of [release liner/light-diffusing adhesive layer 1 (50 μm)/anti-reflection layer 1 (50 μm)/non-light-diffusing adhesive layer 3 (100 μm)/base film].

Example 4
A sheet for encapsulating optical semiconductor elements was obtained in the same manner as in Example 1, except that non-light-diffusing adhesive layer 4 was used instead of non-light-diffusing adhesive layer 1, and the sheet consisted of [release liner/light-diffusing adhesive layer 1 (50 μm)/anti-reflection layer 1 (50 μm)/non-light-diffusing adhesive layer 4 (100 μm)/base film].

Example 5
A sheet for encapsulating optical semiconductor elements was obtained in the same manner as in Example 1, except that non-light-diffusing adhesive layer 5 was used instead of non-light-diffusing adhesive layer 1, and the sheet consisted of [release liner/light-diffusing adhesive layer 1 (50 μm)/anti-reflection layer 1 (50 μm)/non-light-diffusing adhesive layer 5 (100 μm)/base film].

Example 6
A sheet for encapsulating optical semiconductor elements was obtained in the same manner as in Example 1, except that non-light-diffusing adhesive layer 6 was used instead of non-light-diffusing adhesive layer 1, and the sheet consisted of [release liner/light-diffusing adhesive layer 1 (50 μm)/anti-reflection layer 1 (50 μm)/non-light-diffusing adhesive layer 6 (100 μm)/base film].

Example 7
The release liner (product name "MRE38") was peeled off from the non-light-diffusing pressure-sensitive adhesive layer 7 obtained in Production Example 8 to expose the adhesive surface. The exposed surface of the light-diffusing pressure-sensitive adhesive layer 7 was attached to the easy-adhesion treated surface of the base film with the antiglare treatment layer prepared in Production Example 11 to form the non-light-diffusing pressure-sensitive adhesive layer 7 on the base film.
Next, the release liner (product name "MRF38") was peeled off from the surface of the non-light-diffusing pressure-sensitive adhesive layer 7 to expose the adhesive surface. The adhesive surface exposed by peeling off the release liner (product name "MRE38") from the antireflection layer 2 obtained in Production Example 9 was attached to the exposed surface of the non-light-diffusing pressure-sensitive adhesive layer 7 to form the antireflection layer 2 on the non-light-diffusing pressure-sensitive adhesive layer 7.
The sheets were then laminated at room temperature (23° C.) using a hand roller to avoid air bubbles, and left for two days in a dark place. In this way, a sheet for encapsulating optical semiconductor elements comprising [release liner/antireflection layer 2 (50 μm)/non-light-diffusing pressure-sensitive adhesive layer 7 (100 μm)/substrate film] was obtained.

Comparative Example 1
A sheet for encapsulating optical semiconductor elements was obtained in the same manner as in Example 1, except that non-light-diffusing adhesive layer 8 was used instead of non-light-diffusing adhesive layer 1, and the sheet consisted of [release liner/light-diffusing adhesive layer 1 (50 μm)/anti-reflection layer 1 (50 μm)/non-light-diffusing adhesive layer 8 (100 μm)/base film].

Comparative Example 2
The release liner (product name "MRE38") was peeled off from the antireflection layer 1 obtained in Production Example 9 to expose the adhesive surface. The exposed surface of the antireflection layer 1 was attached to the easy-adhesion treated surface of the substrate film with the antiglare treatment layer prepared in Production Example 11 to form the antireflection layer 1 on the substrate film.
Next, the release liner (product name "MRF38") was peeled off from the surface of the antireflective layer 1 to expose the adhesive surface. The adhesive surface exposed by peeling off the release liner (product name "MRE38") from the non-light-diffusing adhesive layer 8 obtained in Production Example 8 was attached to the exposed surface of the antireflective layer 1 to form the non-light-diffusing adhesive layer 8 on the antireflective layer 1.
The sheets were then laminated at room temperature (23° C.) using a hand roller to avoid air bubbles, and left for two days in a dark place. In this way, a sheet for encapsulating optical semiconductor elements consisting of [release liner/non-light-diffusing adhesive layer 8 (150 μm)/antireflection layer 1 (50 μm)/substrate film] was obtained.

Comparative Example 3
The release liner (product name "MRE38") was peeled off from the non-light-diffusing pressure-sensitive adhesive layer 8 obtained in Production Example 8 to expose the adhesive surface. The exposed surface of the non-light-diffusing pressure-sensitive adhesive layer 8 was attached to the easy-adhesion treated surface of the base film with the antiglare treatment layer prepared in Production Example 11 to form the non-light-diffusing pressure-sensitive adhesive layer 8 on the base film.
The sheets were then laminated at room temperature (23° C.) using a hand roller while being careful not to trap air bubbles, and left for two days in a dark place. In this way, a sheet for encapsulating optical semiconductor elements comprising [release liner/non-light-diffusing pressure-sensitive adhesive layer 8 (200 μm)/substrate film] was obtained.

<Evaluation>
The layers produced in each Production Example and the sheets for encapsulating optical semiconductor elements obtained in the Examples and Comparative Examples were evaluated as follows. The results are shown in Table 2.

(1) Residual stress The light diffusion adhesive layer, anti-reflection layer (anti-reflection adhesive layer), and non-light diffusion adhesive layer prepared in each manufacturing example were cut into 40 mm x 40 mm, and the adhesive layer was rolled from one side to prepare a string-like wound test piece with a length of 40 mm. The above test pieces were pulled with a universal testing machine (product name "Autograph AG-IS", manufactured by Shimadzu Corporation) at an initial chuck distance of 20 mm, a tensile ratio of 300% (chuck distance after pulling 80 mm), and a pulling speed of 300 mm/sec, and the residual stress after holding the pulled state for 300 seconds was measured.

(2) Brightness (Preparation of evaluation samples)
The release liner was peeled off from the optical semiconductor element encapsulation sheet, and the exposed adhesive surface was attached to an 8-inch wafer with a convex shape of 120 μm in height. The attachment was performed by differential pressure attachment using a device "MSV300" manufactured by Nitto Seiki Co., Ltd. The conditions for differential pressure attachment were vacuum degree: 20 Pa, attachment pressure: 0.1 MPa, and wafer surface temperature: 60° C.

(Brightness measurement)
Using a microscope (product name "VHX-7000", manufactured by Keyence Corporation) and a high-performance low-magnification zoom lens (product name "VH-Z00R", manufactured by Keyence Corporation), a magnification of 50 and ring illumination (maximum brightness) were used to focus on the convex portions of the uneven wafer from the side of the base film with the anti-glare treatment layer, and an image of a range including multiple convex portions and concave portions was obtained. "ImageJ" was used for image analysis. In the obtained image, three convex portions were selected to produce a histogram, the maximum brightness of the convex portions was recorded, and the average value of n3 was taken as the maximum brightness of the convex portions. In addition, in the obtained image, three concave portions were selected to produce a histogram, and the average value of n3 was taken as the average brightness of the concave portions.

The higher the maximum brightness of the convex portion, the more the reflection of light emitted by the microscope in the convex portion is observed, and the better the transparency of the convex portion is. Excellent transparency indicates that the light emitted by the optical semiconductor element is extracted efficiently, resulting in high brightness. In Table 2, a maximum brightness of the convex portion of 150 or more is evaluated as a brightness of "○", and a maximum brightness of the convex portion of less than 150 is evaluated as a brightness of "×". In addition, a lower average brightness of the concave portion indicates that the reflection of light emitted by the microscope in the concave portion is suppressed, and a value of 10 to 30 is evaluated as having a sufficient anti-reflection effect (anti-reflection "○"). On the other hand, in Comparative Example 3, it was not possible to reduce the brightness below 140, and the anti-reflection was evaluated as "×".

(Anti-reflection and brightness)
The case where both the anti-reflection and the brightness were "good" was rated as "good", and the case where at least one of the anti-reflection and the brightness was "bad" was rated as "bad".

(3) L ^* a ^* b ^* (SCI)
The evaluation sample prepared in the above (2) Brightness Evaluation was placed on a flat surface with the substrate film surface of the optical semiconductor element encapsulation sheet facing outward. The entire surface of the measurement part of a measuring instrument ("CM-26dG" manufactured by Konica Minolta, Inc.) was placed on the substrate film surface of the optical semiconductor element encapsulation sheet, and L ^* (SCI), a ^* (SCI), and b ^* The colorimeter was set so that the measurement area was at the center of the measurement sample, and the measurement was performed under the following conditions. Zero point calibration, white calibration, and GROSS calibration were performed according to the manufacturer's manual. When measuring only the uneven wafer, L ^* (SCI) was 66.8, a ^* (SCI) was 0.6, and b ^* (SCI ) was −6.1.
<Measurement conditions>
Measurement method: Color & gloss Geometry: di: 8°, de: 8°
Regular reflection processing: SCI + SCE
Observation light source: D65
Observation conditions: 10° field of view Measurement diameter: MAV (8 mm)
UV conditions: 100%Full
Automatic average measurement: 3 times Zero calibration skip: Enabled

Variations of the invention according to the present disclosure are described below.
[Appendix 1] A sheet for encapsulating one or more optical semiconductor elements arranged on a substrate,
the sheet includes a sealing resin layer including a colored layer and a non-colored layer,
The sheet for encapsulating an optical semiconductor element, wherein a hardness A of the non-colored layer and a hardness B of the colored layer satisfy A>B.
[Appendix 2] The sheet for encapsulating an optical semiconductor element according to Appendix 1, wherein the hardness is one or more selected from the group consisting of residual stress, elastic modulus, Young's modulus, and hardness measured by a nanoindentation method.
[Appendix 3] The sheet for encapsulating optical semiconductor elements described in Appendix 1, wherein the hardness is a residual stress, and the ratio of the residual stress A1 of the non-colored layer to the residual stress B1 of the colored layer [residual stress A1/residual stress B1] is 1.2 or more.
[Appendix 4] The sheet for encapsulating optical semiconductor elements according to any one of Appendices 1 to 3, wherein the encapsulating resin layer further comprises a non-colored layer having a hardness C on the opposite side of the colored layer to the non-colored layer.
[Appendix 5] The sheet for encapsulating an optical semiconductor element according to Appendix 4, wherein the hardness C of the non-colored layer and the hardness B of the colored layer satisfy C>B.
[Appendix 6] The sheet for encapsulating an optical semiconductor element according to any one of Appendices 1 to 5, wherein the encapsulating resin layer includes a diffusion functional layer.
[Appendix 7] A display comprising a substrate, an optical semiconductor element disposed on the substrate, and the sheet for encapsulating an optical semiconductor element or a cured product thereof according to any one of Appendices 1 to 6, which encapsulates the optical semiconductor element.
[Appendix 8] The display according to appendix 7, comprising a self-luminous display device.
[Appendix 9] The display according to appendix 7 or 8, which is an image display device.

1 Optical semiconductor element encapsulation sheet 2 Encapsulating resin layer 21 Diffusion functional layer (non-colored layer C)
22 Colored layer (colored layer B)
23 Non-colored layer (non-colored layer A)
Reference Signs List 3 Release liner 4 Base material portion 41 Base material film 42 Functional layer 5 Substrate 6 Optical semiconductor element 7 Sealing resin layer 71 Diffusion functional layer 72 Colored layer 73 Non-colored layer 10 Optical semiconductor device

Claims (8)

A sheet for encapsulating one or more optical semiconductor elements disposed on a substrate, comprising:
the sheet includes a sealing resin layer including a colored layer and a non-colored layer,
the non-colored layer has tackiness and/or adhesive properties;
the colored layer and the non-colored layer are laminated in this order from the side in contact with the optical semiconductor element,
a hardness A of the non-colored layer and a hardness B of the colored layer satisfy A>B,
The sheet for encapsulating an optical semiconductor element, wherein the hardness is an elastic modulus. A sheet for encapsulating one or more optical semiconductor elements disposed on a substrate, comprising:
the sheet includes a sealing resin layer including a colored layer and a non-colored layer,
the non-colored layer has tackiness and/or adhesive properties;
the colored layer and the non-colored layer are laminated in this order from the side in contact with the optical semiconductor element,
a hardness A of the non-colored layer and a hardness B of the colored layer satisfy A>B,
The sheet for encapsulating optical semiconductor elements, wherein the hardness is Young's modulus. A sheet for encapsulating one or more optical semiconductor elements disposed on a substrate, comprising:
the sheet includes a sealing resin layer including a colored layer and a non-colored layer,
the non-colored layer has tackiness and/or adhesive properties;
the colored layer and the non-colored layer are laminated in this order from the side in contact with the optical semiconductor element,
a hardness A of the non-colored layer and a hardness B of the colored layer satisfy A>B,
The sheet for encapsulating an optical semiconductor element, wherein the hardness is measured by a nanoindentation method. the sealing resin layer further includes a non-colored layer having a hardness C on the opposite side of the colored layer to the non-colored layer,
4. The sheet for encapsulating an optical semiconductor element according to claim 1, wherein a hardness B of the colored layer and a hardness C of the non-colored layer satisfy C>B. The sheet for encapsulating optical semiconductor elements according to any one of claims 1 to 3, wherein the encapsulating resin layer includes a diffusion functional layer. A display comprising a substrate, an optical semiconductor element disposed on the substrate, and the optical semiconductor element encapsulation sheet according to any one of claims 1 to 3 or a cured product thereof, which encapsulates the optical semiconductor element. The display according to claim 6, which is equipped with a self-luminous display device. The display according to claim 6, which is an image display device.

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