JP7578565B2 - Light-emitting device - Google Patents

Description

The present invention relates to a light-emitting device.

Patent Document 1 discloses a light-emitting device having a base having a wiring layer and a light-emitting element flip-chip mounted on the wiring layer. In a light-emitting device in which a light-emitting element is flip-chip mounted on the wiring layer, the p-side electrode and n-side electrode of the light-emitting element are formed on the same side of the light-emitting element, and light emitted from the light-emitting element is extracted on the side opposite to the side on which the p-side electrode and n-side electrode of the light-emitting element are formed.

JP 2016-127056 A

However, the light-emitting device described in Patent Document 1 has room for improvement in terms of making it easier to extract the light emitted from the light-emitting element to the outside of the light-emitting device and improving the light output.

The present invention was made in consideration of the above circumstances, and aims to provide a light-emitting device that can improve light output.

In order to achieve the above-mentioned object, the present invention provides a light-emitting device comprising: a mounting board having a substrate and a mounting electrode provided on one surface of the substrate, a light-emitting element mounted on the mounting electrode, and a light-collecting member located on the side of the mounting board on which the light-emitting element is arranged, wherein the mounting electrode has a flat electrode main body and an electrode protrusion formed to protrude from the electrode main body to the side opposite the substrate, the light-emitting element is mounted on the electrode protrusion, the light-collecting member collects light emitted by the light-emitting element toward the side opposite the mounting board of the light-emitting element, the light-collecting member is a conductive reflector, and the reflector has a reflective surface that collects light emitted by the light-emitting element toward the side opposite the mounting board of the light-emitting element, and the surface of the electrode protrusion facing the light-emitting element is located closer to the substrate than the end of the reflective surface facing the mounting board .

The present invention makes it possible to provide a light-emitting device that can improve light output.

1 is a cross-sectional view of a light emitting device according to a first embodiment. 1 is a plan view of a light emitting device according to a first embodiment. FIG. 2 is an enlarged view of a portion of FIG. 1 . 2 is a cross-sectional view of a mounting substrate and a light-emitting element according to the first embodiment. FIG. FIG. 2 is a plan view of a mounting substrate and a light-emitting element according to the first embodiment. FIG. 2 is a plan view of a mounting board according to the first embodiment. FIG. 2 is a perspective view of a mounting board according to the first embodiment. 4 is a cross-sectional view of the light emitting device, illustrating a schematic view of how a reflector reflects light emitted from a light emitting element in the first embodiment. FIG. 11 is a cross-sectional view of a light emitting device in a comparative embodiment, illustrating a state in which a reflector reflects light emitted from a light emitting element. FIG. FIG. 11 is a plan view of a mounting board according to a second embodiment. FIG. 13 is a cross-sectional view of a mounting substrate and a light-emitting element according to a third embodiment. FIG. 13 is a cross-sectional view of a mounting substrate and a light-emitting element according to a fourth embodiment. FIG. 13 is a cross-sectional view of a light emitting device according to a fifth embodiment. FIG. 13 is a cross-sectional view of a light emitting device according to a sixth embodiment.

[First embodiment]
A first embodiment of the present invention will be described with reference to Figures 1 to 8. Note that the embodiment described below is shown as a preferred specific example for carrying out the present invention, and while there are some parts that specifically exemplify various technical matters that are technically preferable, the technical scope of the present invention is not limited to this specific embodiment.

(Light-emitting device 1)
Fig. 1 is a cross-sectional view of a light emitting device 1 according to the present embodiment. Fig. 2 is a plan view of the light emitting device 1 according to the present embodiment. Fig. 3 is an enlarged view of a part of Fig. 1.

The light emitting device 1 of this embodiment can be, for example, a light emitting diode (LED) or a semiconductor laser (LD). In this embodiment, the light emitting device 1 is a deep ultraviolet LED that emits deep ultraviolet light, and can be used in fields such as sterilization (e.g., air purification, water purification, etc.), medicine (e.g., phototherapy, measurement and analysis, etc.), and UV curing.

The light emitting device 1 of this embodiment includes a mounting substrate 2, a mounting substrate 3 arranged on the mounting substrate 2, a light emitting element 4 flip-chip mounted on the mounting substrate 3, a reflector 5 as a light collecting member that collects light emitted from the light emitting element 4, and a reflector mount 6 to which the reflector 5 is attached. Hereinafter, the overlapping direction of the mounting substrate 3 and the light emitting element 4 is referred to as the vertical direction. Also, one side in the vertical direction on which the light emitting element 4 is arranged with respect to the mounting substrate 3 is referred to as the upper side, and the opposite side is referred to as the lower side. Note that the expressions "upper" and "lower" are for convenience, and do not limit the position of the light emitting device 1 in the vertical direction, for example, when the light emitting device 1 is in use.

(Mounting Substrate 2)
The mounting substrate 3 and the reflector mount 6 are mounted on the mounting substrate 2. Although not shown, a heat sink for dissipating heat from the mounting substrate 3 and the light emitting element 4 may be connected to the mounting substrate 2.

(Mounting Board 3)
Fig. 4 is a cross-sectional view of the mounting substrate 3 and the light emitting element 4. Fig. 5 is a plan view of the mounting substrate 3 and the light emitting element 4. Fig. 6 is a plan view of the mounting substrate 3. Fig. 7 is a perspective view of the mounting substrate 3.

The mounting substrate 3 is also called a submount, and includes a base material 31 and a conductive portion 32. The base material 31 is formed in a flat plate shape and has electrical insulation properties. The base material 31 can be a ceramic substrate made of, for example, aluminum nitride (AlN), alumina (Al ₂ O ₃ ), or the like.

3 and 4, the conductive portion 32 has a p-side lower electrode 321 and an n-side lower electrode 322 spaced apart from each other on the lower surface of the substrate 31, and a p-side mounting electrode 323 and an n-side mounting electrode 324 spaced apart from each other on the upper surface of the substrate 31. The p-side lower electrode 321 is electrically connected to the p-side mounting electrode 323, and the n-side lower electrode 322 is electrically connected to the n-side mounting electrode 324. The electrical connection between the p-side lower electrode 321 and the p-side mounting electrode 323, and the electrical connection between the n-side lower electrode 322 and the n-side mounting electrode 324 can be made, for example, through a via hole (not shown) formed in the substrate 31. Hereinafter, when the p-side mounting electrode 323 and the n-side mounting electrode 324 are not particularly distinguished from each other, they are referred to as "mounting electrodes 323, 324". The direction in which the p-side mounting electrode 323 and the n-side mounting electrode 324 are arranged (for example, the left-right direction in FIGS. 5 and 6) is referred to as the electrode arrangement direction. The direction perpendicular to the up-down direction and the electrode arrangement direction (for example, the up-down direction in FIGS. 5 and 6) is referred to as the vertical direction.

The mounting electrodes 323 and 324 have a flat electrode body 325 and an electrode protrusion 326 formed to protrude upward from the electrode body 325. As shown in Figures 5 to 7, the electrode body 325 of the p-side mounting electrode 323 and the electrode body 325 of the n-side mounting electrode 324 each have an E-shape and are arranged symmetrically with respect to the electrode arrangement direction. The electrode body 325 has a vertical portion 325a that is long in the vertical direction, a pair of end extension portions 325b that extend from both ends of the vertical portion 325a to one side in the electrode arrangement direction, and a central extension portion 325c that extends from the center of the vertical portion 325a to the same side as the side to which the end extension portion 325b is extended. The direction in which the end extensions 325b and the central extensions 325c extend from the vertical portion 325a in the electrode body 325 of the p-side mounting electrode 323 and the direction in which the end extensions 325b and the central extensions 325c extend from the vertical portion 325a in the electrode body 325 of the n-side mounting electrode 324 face each other. The end extensions 325b of the electrode body 325 of the p-side mounting electrode 323 and the electrode body 325 of the n-side mounting electrode 324 are aligned in the electrode arrangement direction, and the central extensions 325c of each other are aligned in the electrode arrangement direction.

The central extension 325c has a narrow portion 325d formed adjacent to the vertical portion 325a, and a wide portion 325e formed on the opposite side of the narrow portion 325d from the vertical portion 325a and protruding further on both sides in the vertical direction than the narrow portion 325d. An electrode protrusion 326 is formed so as to extend straight upward from the entire wide portion 325e.

The electrode protrusion 326 is formed in a rectangular parallelepiped shape that is long in the vertical direction. As shown in FIG. 4, the thickness T1 of the electrode protrusion 326 is greater than the thickness T2 of the electrode body 325. In this embodiment, the thickness T1 of the electrode protrusion 326 is more than twice the thickness T2 of the electrode body 325. As shown in FIG. 6, the electrode protrusion 326 of the p-side mounting electrode 323 and the electrode protrusion 326 of the n-side mounting electrode 324 are aligned in the vertical direction at one end surface, and are aligned in the vertical direction at the other end surface.

The mounting electrodes 323, 324 can be formed, for example, by plating the surface of the substrate 31. In this case, for example, the electrode body 325 is first formed by plating, and then the electrode protrusion 326 is formed by plating only the upper side of the wide portion 325e of the electrode body 325. As a result, the electrode body 325 and the electrode protrusion 326 are formed integrally without any separation. Although not shown in the figure, the mounting electrodes 323, 324 may be composed of multiple layers. In this case, for example, a configuration can be adopted in which the base material of the mounting electrodes 323, 324 is formed of highly conductive copper or the like, and the surface of the base material is coated with at least one metal layer to suppress corrosion, etc.

As shown in FIG. 4, the p-side pad electrode 43 of the light-emitting element 4 is electrically connected to the upper surface of the electrode protrusion 326 of the p-side mounting electrode 323, and the n-side pad electrode 44 of the light-emitting element 4 is electrically connected to the upper surface of the electrode protrusion 326 of the n-side mounting electrode 324. As shown in FIG. 5, when the mounting substrate 3 and the light-emitting element 4 are viewed from above, the light-emitting element 4 is arranged so that the outer shape of the light-emitting element 4 follows the outer shape of the wide portion 325e and the electrode protrusion 326. In this way, when mounting the light-emitting element 4 on the electrode protrusion 326, the outer shape of the light-emitting element 4 is matched to the outer shape of the wide portion 325e and the electrode protrusion 326, making it easier to position the light-emitting element 4 and the pair of electrode protrusions 326.

(Light-emitting element 4)
The light-emitting element 4 can emit ultraviolet light, visible light, or infrared light. In this embodiment, the light-emitting element 4 can emit deep ultraviolet light having a central wavelength of 200 nm or more and 365 nm or less, and the light-emitting device 1 is a deep ultraviolet LED.

The light-emitting element 4 includes a transparent substrate 41, a semiconductor laminate structure 42 formed on the transparent substrate 41, and a p-side pad electrode 43 and an n-side pad electrode 44 connected to mounting electrodes 323, 324. For convenience, FIG. 1 shows the outer shapes of the transparent substrate (see reference numeral 41 in FIGS. 3 and 4) and the semiconductor laminate structure (see reference numeral 42 in FIGS. 3 and 4), but does not show the boundaries between them.

The transparent substrate 41 is made of, for example, sapphire (Al ₂ O ₃ ) or aluminum nitride (AlN), and has the property of transmitting light (deep ultraviolet light in this embodiment) emitted from the light emitting layer of the semiconductor laminate structure 42 .

The semiconductor laminated structure 42 is epitaxially grown on the transparent substrate 41, and includes an n-type semiconductor layer, a light-emitting layer, and a p-type semiconductor layer in this order from the transparent substrate 41 side. In addition, in Figures 3 and 4, the outer shape of the semiconductor laminated structure 42 is shown typically, and the boundaries of each layer of the semiconductor laminated structure 42 are omitted. For the epitaxial growth, epitaxial growth methods such as metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), and hydride vapor phase epitaxy (HVPE) can be used. In the light-emitting layer, electrons supplied from the n-type semiconductor layer and holes supplied from the p-type semiconductor layer recombine to emit light. The total thickness of the transparent substrate 41 and the semiconductor laminate structure 42 formed thereon is mostly the thickness of the transparent substrate 41.

The p-side pad electrode 43 is connected to the p-side semiconductor layer on the side opposite the transparent substrate 41. The n-side pad electrode 44 is connected to the n-side semiconductor layer on the side opposite the transparent substrate 41. Although not shown in the figure, a portion of the light-emitting layer and the p-type semiconductor layer is removed to expose the n-type semiconductor layer on the side opposite the transparent substrate 41, and the n-side pad electrode 44 is connected to the exposed surface of the n-type semiconductor layer thus created.

The light emitting element 4 is flip-chip mounted on the mounting substrate 3 with the transparent substrate 41 positioned on the opposite side to the mounting substrate 3. The p-side pad electrode 43 is connected to the electrode protrusion 326 of the p-side mounting electrode 323, and the n-side pad electrode 44 is connected to the electrode protrusion 326 of the n-side mounting electrode 324. The light emitting element 4 mounted on the submount (mounting substrate 3) is also called chip on submount (CoS). The light generated in the light emitting layer is mainly extracted upward from the transparent substrate 41 of the light emitting element 4. As shown in Figures 1 to 3, the light emitting device 1 is provided with a reflector 5 that focuses the light extracted from the light emitting element 4 upward.

(Reflector 5)
FIG. 8 is a cross-sectional view of the light-emitting device 1, which shows a schematic view of the reflector 5 reflecting the light emitted from the light-emitting element 4. In FIG. 8, an example of the path of light is shown by a dashed line. The reflector 5 is a light-collecting member located on the upper side of the mounting substrate 3 and condensing the light emitted from the light-emitting element 4 toward the upper side. The reflector 5 has a reflection surface 51 that reflects the light emitted from the light-emitting element 4 toward the upper side (including the diagonally upward side). The reflector 5 is made of a material that can reflect deep ultraviolet light and has electrical conductivity, such as aluminum. As shown in FIG. 3, the reflector 5 of this embodiment is disposed at a position away from the electrode body 325 on the upper side in order to suppress short-circuiting with the electrode body 325.

The reflecting surface 51 has a shape in which the inner diameter increases toward the upper side. In FIG. 1 and FIG. 8, the reflecting surface 51 is shown as a curved surface, but the present invention is not limited thereto and may be tapered. As shown in FIG. 2, when the light-emitting device 1 is viewed from above, the light-emitting element 4 and the pair of electrode protrusions 326 are contained in the inner region of the reflecting surface 51. As shown in FIG. 3, the position of the lower end 511 of the reflecting surface 51 is located below the position of the upper end of the light-emitting element 4 (i.e., the upper surface position of the transparent substrate 41). That is, at least a part of the light-emitting element 4 is arranged in the inner region of the reflecting surface 51. In this embodiment, the light-emitting element 4 is arranged in the inner region of the reflecting surface 51 over half or more of the transparent substrate 41 in the vertical direction. In addition, the lower end 511 of the reflecting surface 51 is located above the upper surface of the electrode protrusion 326. As shown in FIG. 1, the reflector 5 is attached to the mounting substrate 2 via the reflector mount 6.

(Reflector mount 6)
The reflector mount 6 is formed with a countersunk hole 61 penetrating in the vertical direction. The countersunk hole 61 is formed in a stepped shape with the inner diameter of the upper part being larger than the inner diameter of the lower part, and the reflector 5 is fitted into it from above. The mounting substrate 3 and the light emitting element 4 are arranged inside the countersunk hole 61.

(Functions and Effects of the First Embodiment)
In this embodiment, the mounting electrodes 323, 324 have a flat electrode body 325 and an electrode protrusion 326 formed to protrude from the electrode body 325 toward the light emitting element 4. The light emitting element 4 is mounted on the electrode protrusion 326. Therefore, the position of the light emitting element 4 can be set to a position above the electrode body 325. This makes it possible to improve the output of light extracted from the side opposite to the side on which the mounting substrate 3 is disposed (i.e., the upper side) of the light emitting element 4 in the light emitting device 1. In other words, the light emitting element 4 can be brought closer to the side from which light is extracted, improving the light emission output of the light emitting device 1.

In addition, the thickness T1 of the electrode protrusion 326 is greater than the thickness T2 of the electrode body 325. Therefore, the position of the light-emitting element 4 mounted on the electrode protrusion 326 can be positioned higher. As a result, the output of light extracted from the upper side of the light-emitting device 1 can be further improved.

The light emitting device 1 of this embodiment also includes a light collecting member (reflector 5 in this embodiment) located on the side of the mounting substrate 3 where the light emitting element 4 is arranged (i.e., the upper side). The light collecting member collects the light emitted by the light emitting element 4 toward the side of the light emitting element 4 opposite the mounting substrate 3 (i.e., the upper side). In a light emitting device 1 including such a light collecting member, it is possible to increase the amount of light extracted from the upper side. By mounting the light emitting element 4 on the electrode protrusion 326 as described above, it is possible to further increase the amount of light extracted from the upper side, and the light output of the light emitting device 1 can be further improved.

The light collecting member is a reflector 5 having conductivity. Therefore, the reflector 5 is arranged at a position away from the upper side of the mounting substrate 3 in order to avoid short circuit with the mounting electrodes 323, 324 of the mounting substrate 3. Therefore, as shown in FIG. 9, if the mounting electrodes 323, 324 do not have the electrode protrusions of this embodiment, the position of the light emitting element 4 is likely to be located lower than the reflector 5. Therefore, in this case, as shown by the arrow with the symbol L, more light is likely to escape to the lower side of the reflector 5 and not be extracted from the light emitting device 1. On the other hand, in this embodiment, as shown in FIG. 8, the mounting electrodes 323, 324 are provided with electrode protrusions 326, and the light emitting element 4 is mounted on the electrode protrusions 326, so that the position of the light emitting element 4 can be moved higher, and the output of the light extracted to the upper side from the reflector 5 can be improved.

In addition, at least a portion of the light-emitting element 4 is disposed in the inner region of the reflecting surface 51. In other words, the upper surface of the light-emitting element 4 is located above the lower end of the reflecting surface 51. This makes it possible to further improve the output of light extracted upward from the reflector 5.

More than half of the area of the transparent substrate 41 of the light-emitting element 4 in the thickness direction (i.e., the vertical direction) is disposed in the area on the inner periphery side of the reflective surface 51. Most of the light emitted from the light-emitting element 4 is emitted from the surface of the transparent substrate 41, and according to this embodiment, the output of the light extracted upward from the reflector 5 can be further increased.

In addition, the upper surface of the electrode protrusion 326 is located below the lower end 511 of the reflecting surface 51. Therefore, for example, when assembling the light emitting device 1, it is possible to prevent the electrode protrusion 326 and the reflector 5 from interfering with each other.

As described above, this embodiment provides a light-emitting device that can improve light output.

[Second embodiment]
FIG. 10 is a plan view of the mounting substrate 3 in this embodiment.
This embodiment has the same basic structure as the first embodiment, but changes the configuration of the electrode protrusion 326. In this embodiment, when the mounting substrate 3 is viewed from above, the outer shape of the electrode protrusion 326 is configured to be contained inside the outer shape of the electrode main body 325. When the mounting substrate 3 is viewed from above, the electrode protrusion 326 is formed to be one size smaller than the outer shape of the wide portion 325e. When viewed from above, the light-emitting element 4 is arranged so that the outer shape of the light-emitting element 4 follows the outer shape of the wide portion 325e.

The rest is similar to the first embodiment.
In addition, among the symbols used in the second and subsequent embodiments, the same symbols as those used in the previously described embodiments represent the same components, etc. as those in the previously described embodiments, unless otherwise specified.

(Functions and Effects of the Second Embodiment)
In this embodiment, when viewed from above, the outer shape of the electrode protrusion 326 is contained inside the outer shape of the electrode main body 325. This makes it easy to ensure electrical insulation between the pair of electrode protrusions 326. In other words, it is possible to suppress a decrease in electrical insulation between the pair of electrode protrusions 326 caused by the pair of electrode protrusions 326 being formed excessively close to each other due to manufacturing errors, for example.
In addition, the second embodiment has the same effects as the first embodiment.

[Third embodiment]
FIG. 11 is a cross-sectional view of the mounting substrate 3 and the light emitting element 4 in this embodiment.
In this embodiment, the basic configuration is the same as that of the first embodiment, but the electrode body 325 and the electrode protrusion 326 are configured as separate bodies. The electrode body 325 and the electrode protrusion 326 are joined to each other.
The rest is similar to the first embodiment.

(Functions and Effects of the Third Embodiment)
This embodiment also has the same effects as the first embodiment.

[Fourth embodiment]
FIG. 12 is a cross-sectional view of the mounting substrate 3 and the light emitting element 4 in this embodiment.
In this embodiment, the electrode protrusion 326 is separate from the electrode body 325 as in the third embodiment, but the configuration of the electrode protrusion 326 is changed. The electrode protrusion 326 in this embodiment is formed in a substrate shape like the mounting substrate 3, and includes a flat insulating portion 326a, a pair of first electrodes 326b spaced apart from each other on the lower surface of the insulating portion 326a, and a pair of second electrodes 326c spaced apart from each other on the upper surface of the insulating portion 326a. Each of the pair of first electrodes 326b is connected to a different electrode body 325. Each of the pair of first electrodes 326b is connected to a different second electrode 326c through a via hole (not shown) formed in the insulating portion 326a. The pair of second electrodes 326c is connected to a p-side pad electrode 43 or an n-side pad electrode 44.
The rest is the same as in the third embodiment.

(Functions and Effects of the Fourth Embodiment)
In this embodiment, the pair of electrode main bodies 325 can be easily connected to the p-side pad electrode 43 and the n-side pad electrode 44 of the light-emitting element 4 via the electrode protrusion 326 of a member formed in a substrate shape.
In addition, the second embodiment has the same effects as the third embodiment.

[Fifth embodiment]
FIG. 13 is a cross-sectional view of the light emitting device 1 of this embodiment.
The light emitting device 1 of this embodiment has the same mounting substrate 3 and light emitting element 4 as those of the first embodiment, and further includes a sealing member 7 that seals the light emitting element 4. The sealing member 7 protects the light emitting element 4 by sealing the light emitting element 4. The sealing member 7 is made of a material that transmits light emitted from the light emitting element 4. It is preferable that the sealing member 7 has a refractive index between the refractive index of the transparent substrate 41 and the refractive index of air from the viewpoint of making it easier to extract light to the outside. In addition, when the light emitting element 4 emits deep ultraviolet light, it is preferable that the sealing member 7 is made of a material (e.g., silicone resin) that is not easily deteriorated by deep ultraviolet light. In the light emitting device 1 of this embodiment, the reflector (reference numeral 5 in FIG. 1) and the reflector mount (reference numeral 6 in FIG. 1) in the first embodiment are not provided. The sealing member 7 has a hemispherical shape that bulges upward, and is a light collecting member that collects light emitted from the light emitting element 4 toward the upper side, similar to the reflector in the first embodiment. The sealing member 7 is not limited to a hemispherical shape, and other shapes may be adopted as long as the light emitted from the light emitting element 4 can be condensed upward.

(Functions and Effects of the Fifth Embodiment)
Even in a configuration in which a sealing member 7 having a light-collecting function is provided without providing a reflector as in the present embodiment, by mounting the light-emitting element 4 on the electrode protrusion 326, it is possible to prevent the light emitted from the light-emitting element 4 from being blocked by the mounting substrate 3, thereby improving the light extraction efficiency of the light-emitting device 1.
In addition, the second embodiment has the same effects as the first embodiment.

Sixth embodiment
FIG. 14 is a cross-sectional view of the light emitting device 1 of this embodiment.
This embodiment is a hermetically sealed light emitting device 1 in which a light emitting element 4 is arranged in a hermetically sealed space. The base material 31 of the mounting substrate 3 of this embodiment has a box shape with an opening on the upper side. That is, the base material 31 has a rectangular bottom 311 on which mounting electrodes 323 and 324 are formed, and a rectangular cylindrical side 312 standing upright from the periphery of the bottom 311, and the upper side of the side 312 is open. The opening of the side 312 is closed by the lid 8. The lid 8 and the upper surface of the side 312 are bonded via an adhesive layer 11, thereby ensuring the airtightness of the space surrounded by the base material 31 and the lid 8. The lid 8 is made of a material that transmits deep ultraviolet light, for example, quartz (SiO ₂ ) glass. The configurations of the mounting substrate 3 and the light emitting element 4 are the same as those of the first embodiment.

(Functions and Effects of the Sixth Embodiment)
Even in the case of an airtightly sealed light-emitting device 1 as in this embodiment, by mounting the light-emitting element 4 on the electrode protrusion 326, the light-emitting element 4 can be brought closer to the lid body 8, which serves as the light extraction port, and the amount of light extracted from the lid body 8 can be increased.
In addition, the second embodiment has the same effects as the first embodiment.

It is also possible to adopt a configuration in which the lid 8 and adhesive layer 11 of the light-emitting device 1 of this embodiment are omitted.

(Summary of the embodiment)
Next, the technical ideas grasped from the above-described embodiment will be described by using the reference numerals and the like in the embodiment. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiment.

[1] A first embodiment of the present invention is a light-emitting device (1) comprising a mounting board (3) having a base material (31) and mounting electrodes (323, 324) provided on one side of the base material (31), and a light-emitting element (4) mounted on the mounting electrodes (323, 324), wherein the mounting electrodes (323, 324) have a flat electrode main body portion (325) and an electrode protrusion portion (326) formed to protrude from the electrode main body portion (325) to the side opposite the base material (31), and the light-emitting element (4) is mounted on the electrode protrusion portion (326).
This makes it possible to improve the output of light extracted from the side opposite to the side on which the mounting substrate is disposed with respect to the light emitting element in the light emitting device.

[2] A second embodiment of the present invention is the first embodiment, wherein the thickness (T1) of the electrode protrusion (326) is greater than the thickness (T2) of the electrode body (325).
This makes it possible to further improve the output of light extracted from the side opposite to the side on which the mounting substrate is disposed with respect to the light emitting element.

[3] A third embodiment of the present invention is the first or second embodiment, further comprising a light collecting member (5, 7) located on the side of the mounting substrate (3) on which the light emitting element (4) is arranged, and the light collecting member (5, 7) collects light emitted by the light emitting element (4) toward the side of the light emitting element (4) opposite the mounting substrate (3).
This makes it possible to further improve the light emission output of the light emitting device.

[4] A fourth embodiment of the present invention is the third embodiment, in which the light-collecting member (5, 7) is a conductive reflector (5), and the reflector (5) has a reflective surface (51) that collects light emitted by the light-emitting element (4) toward the opposite side of the light-emitting element (4) from the mounting substrate (3).
This makes it possible to improve the output of light extracted from the reflector.

[5] A fifth embodiment of the present invention is the fourth embodiment, in which at least a part of the light-emitting element (4) is disposed in an area on the inner periphery of the reflecting surface (51).
This makes it possible to further improve the output of light extracted from the reflector.

[6] A sixth embodiment of the present invention is the fifth embodiment, in which the light-emitting element (4) has a transparent substrate (41) that transmits light emitted by the light-emitting element (4), and more than half of the area of the transparent substrate (41) in the thickness direction is arranged in the area on the inner periphery of the reflecting surface (51).
This makes it possible to further improve the output of light extracted from the reflector.

[7] A seventh embodiment of the present invention is any one of the fourth to sixth embodiments, in which the surface of the electrode protrusion (326) facing the light-emitting element (4) is located closer to the base material (31) than the end (511) of the reflective surface (51) facing the mounting substrate (3).
This can prevent the electrode protrusion and the reflector from interfering with each other.

[8] An eighth embodiment of the present invention is any one of the first to seventh embodiments, in which a pair of mounting electrodes (323, 324) are arranged on one side of the base material (31), the electrode protrusions (326) of the pair of mounting electrodes (323, 324) are arranged side by side, and when viewed from the light-emitting element (4) side relative to the mounting board (3), the outer shape of the electrode protrusions (326) is contained inside the outer shape of the electrode main body (325).
This makes it easier to ensure electrical insulation between the pair of electrode projections.

(Additional Note)
Although the embodiment of the present invention has been described above, the invention according to the claims is not limited to the above embodiment. It should be noted that not all of the combinations of features described in the embodiment are essential to the means for solving the problems of the invention. The present invention can be modified appropriately without departing from the spirit of the invention.

1... Light emitting device 3... Mounting substrate 31... Base material 323... P-side mounting electrode 324... N-side mounting electrode 325... Electrode body 326... Electrode protrusion 4... Light emitting element 41... Transparent substrate 5... Reflector (light collecting member)
51: Reflection surface 511: Lower end of reflection surface 7: Sealing member (light collecting member)

Claims (5)

a mounting board having a base material and a mounting electrode provided on one surface of the base material;
a light emitting element mounted on the mounting electrode ;
a light collecting member located on a side of the mounting substrate on which the light emitting element is disposed ,
The mounting electrode has a flat electrode body and an electrode protrusion formed to protrude from the electrode body to a side opposite to the base material,
the light emitting element is mounted on the electrode protrusion ,
the light collecting member collects light emitted by the light emitting element toward a side of the light emitting element opposite to the mounting substrate,
the light collecting member is a reflector having electrical conductivity,
the reflector has a reflection surface that collects light emitted by the light-emitting element toward a side of the light-emitting element opposite to the mounting substrate,
a surface of the electrode protrusion on the light emitting element side is located closer to the base material than an end of the reflection surface on the mounting substrate side;
Light emitting device. The thickness of the electrode protrusion is greater than the thickness of the electrode body.
The light emitting device according to claim 1 . At least a portion of the light emitting element is disposed in an area on the inner periphery of the reflecting surface.
3. A light emitting device according to claim 1 or 2 . The light emitting element has a transparent substrate that transmits light emitted by the light emitting element,
a transparent substrate having a thickness that is at least half the area of the transparent substrate, the transparent substrate being disposed on the inner peripheral side of the reflecting surface;
The light emitting device according to claim 3 . A pair of the mounting electrodes is disposed on one surface of the base material,
The electrode protrusions of the pair of mounting electrodes are arranged side by side,
When viewed from the light emitting element side of the mounting substrate, an outer shape of the electrode protrusion is contained inside an outer shape of the electrode main body.
A light emitting device according to claim 1 .

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