WO2010119726A1 - Method for manufacturing wafer lens - Google Patents

Abstract

A method for manufacturing a wafer lens is provided for the purpose of suppressing generation of sink marks on a lens section. The method wherein the lens section composed of a photocurable resin is formed on a glass substrate achieves the purpose by means of: a step of applying a resin between a metal die and the glass substrate; a step of radiating first light to a resin portion that corresponds to the lens section; and a step of radiating second light to the resin portion that corresponds to the lens section and the resin portion that corresponds to the non-lens section at the periphery of the lens section.

Description

Wafer lens manufacturing method

The present invention relates to a method for manufacturing a wafer lens.

Conventionally, in the field of manufacturing optical lenses, a technique for obtaining a highly heat-resistant optical lens by providing a resin lens portion on a glass substrate has been studied (for example, see Patent Document 1). As an example of a manufacturing method of an optical lens to which this technology is applied, a so-called “wafer lens” in which a plurality of optical members made of a photocurable resin is provided on the surface of a glass substrate is formed, and then the glass substrate is cut for each lens portion. A method has been proposed.

An example of a method for forming a resin lens portion on a glass substrate is disclosed in Patent Document 2. In the technique of Patent Document 2, a composition comprising a photocurable resin, a thermosetting resin, a photopolymerization agent and a thermal polymerization agent is applied to a substrate, the resin is photocured (light irradiation), and then shaped ( (Pressing of mold to resin) and thermosetting (see paragraphs 0069 to 0080).

As another example, there is a method in which a photocurable resin is filled between a glass substrate and a mold and light is irradiated in that state. In this case, at the time of light irradiation, the optical surface of the lens unit is required to be transferred from the mold with high accuracy of the order of submicron or less.

Japanese Patent No. 3926380 JP 2003-286301 A

However, the photo-curable resin generally has a property of shrinking by curing, and is cured while slightly shrinking inside the mold when irradiated with light.

In this case, in particular, when shrinkage occurs in the non-lens part around the lens part (the part where the incident light is converged or diffused by refraction or diffraction action), the shrinkage reaches the lens part and the resin in the lens part is non-lensed. Pulled to the side of the lens, sinks occur in the lens. This particularly affects the optical characteristics of the constructed lens when it occurs in the lens portion within the effective diameter range.

Therefore, a main object of the present invention is to provide a method of manufacturing an optical element capable of suppressing the occurrence of sink marks within the effective diameter range of the lens part, at least the lens part.

According to one aspect of the invention,
In a method for manufacturing a wafer lens, in which a plurality of lenses having a lens portion and a non-lens portion around the lens portion are formed on a substrate with a photocurable resin,
Filling the photocurable resin between the mold and the substrate;
A curing step of advancing curing of the photocurable resin by performing light irradiation on the photocurable resin,
The curing step includes a first light irradiation step of irradiating the first region of the photocurable resin with light, and a second light irradiating the second region of the irradiation region wider than the first region. There is provided a method for manufacturing a wafer lens, comprising an irradiation step.

According to another aspect of the invention,
In a method for manufacturing a wafer lens, in which a plurality of lenses having a lens portion and a non-lens portion around the lens portion are formed on a substrate with a photocurable resin,
Filling the photocurable resin between the mold and the substrate;
A curing step of proceeding curing of the photocurable resin by irradiating the photocurable resin with light, and the curing step irradiates only a portion corresponding to the lens portion of the photocurable resin. And a second light irradiation step of irradiating a portion corresponding to a non-lens portion around the lens portion of the photocurable resin. Is done.

According to the present invention, it is possible to suppress the occurrence of sink marks within the effective diameter within the lens portion, at least the lens portion.

It is sectional drawing which shows schematic structure of the wafer lens concerning preferable embodiment (1st Embodiment) of this invention. It is drawing which shows schematic structure of the wafer lens manufacturing apparatus concerning 1st Embodiment. It is a block diagram which shows the schematic control structure of the wafer lens manufacturing apparatus concerning 1st Embodiment. It is the schematic for demonstrating with time the manufacturing method of the wafer lens concerning 1st Embodiment. It is the schematic which shows an example of the irradiation pattern of the light in the manufacturing method of FIG. It is the schematic which shows an example of the pressure control pattern at the time of forming the resin part (convex lens part) in the manufacturing method of FIG. It is the schematic which shows the modification of FIG. It is the schematic which shows an example of the pressure control pattern at the time of forming the resin part (concave lens part) in the manufacturing method of FIG. It is the schematic which shows the modification of FIG. It is the schematic which shows the modification of FIG. It is the schematic which shows the modification of FIG. It is the schematic for demonstrating the combination of the shaping | molding die used by 1st Embodiment. It is the schematic which shows the modification of FIG. It is the schematic for demonstrating the modification of the wafer lens of FIG. It is drawing for demonstrating schematically the wafer lens manufacturing apparatus concerning preferable embodiment (2nd Embodiment) of this invention, and a manufacturing method using the same. It is the schematic which shows the modification of FIG. It is the schematic which shows the modification of FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
As shown in FIG. 1, the wafer lens 1 has a glass substrate 2. The glass substrate 2 is an example of a substrate and has a wafer shape (circular shape) when viewed from above.

The resin part 4 is provided on the upper part of the glass substrate 2.

The resin part 4 includes a convex lens part 4a that is a part for converging or diverging incident light by refraction or diffraction action with respect to the incident light, and a non-lens part 4b that transmits the incident light as it is. In FIG. 1, the convex lens portion 4a serving as a part that causes a refractive action constitutes a convex lens-shaped optical surface. The non-lens part 4b is a part other than the convex lens part 4a and a part around the convex lens part 4a, and is configured in a flat plate shape to transmit substantially incident light as it is.

The non-lens portion 4b does not necessarily have a flat plate shape, and may be a portion that does not contribute to the optical function as the lens when the present invention is used as a lens of an imaging optical system. The region has a function suitable as a spacer portion for defining the shape suitable for holding and the distance from other lens members and imaging element members for positioning and holding with other members. May be.

The thickness 4ath of the convex lens portion 4a is thicker than the thickness 4bth of the non-lens portion 4b because the convex lens portion 4a has a convex shape.

The resin part 6 is provided in the lower part of the glass substrate 2.

The resin portion 6 includes a concave lens portion 6a that is a portion for converging or diverging incident light by refraction or diffraction action with respect to incident light, and a non-lens portion 6b that transmits incident light as it is. In FIG. 1, the concave lens portion 6a serving as a portion that causes a refractive action constitutes a concave lens-shaped optical surface. The non-lens portion 6b is a portion other than the concave lens portion 6a and a portion around the concave lens portion 6a, and is configured in a flat plate shape to transmit substantially incident light as it is.

The non-lens portion 6b does not necessarily have a flat plate shape, and may be a portion in a range that does not contribute to the optical function as the lens when the present invention is used as a lens of an imaging optical system. The region has a function suitable as a spacer portion for defining the shape suitable for holding and the distance from other lens members and imaging element members for positioning and holding with other members. May be.

The thickness 6ath of the concave lens portion 6a is thinner than the thickness 6bth of the non-lens portion 6b because the concave lens portion 6a has a concave shape.

In FIG. 1, the resin parts 4 and 6 are formed in a form in which the non-lens parts 4 b and 6 b between the adjacent lens parts 4 a and 6 a are connected, but the resin parts 4 and 6 are not necessarily limited thereto. That is, by individually dropping and molding a photo-curable resin on the part corresponding to the cavity of the mold during molding, each lens part 4a, 6a is formed with non-lens parts 4b, 6b around, It may be formed independently.

The wafer lens 1 is a so-called meniscus lens in which the convex lens portion 4a and the concave lens portion 6a are in a one-to-one correspondence. .

The resin part 4 and the resin part 6 are composed of resins 4A and 6A, respectively.

Resins 4A and 6A are photocurable resins, but the present invention is most effective for resins that can be cured by radical polymerization, such as acrylic resins that are highly contracted by curing.

Specific examples of the acrylic resin are as follows.
[acrylic resin]
The (meth) acrylate used for the polymerization reaction is not particularly limited, and the following (meth) acrylate produced by a general production method can be used. That is, ester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, ether (meth) acrylate, alkyl (meth) acrylate, alkylene (meth) acrylate, (meth) acrylate having an aromatic ring, alicyclic Examples include (meth) acrylate having a structure. One or more of these can be used.

(Meth) acrylate having an alicyclic structure is particularly preferable, and may be an alicyclic structure containing an oxygen atom or a nitrogen atom. For example, cyclohexyl (meth) acrylate, cyclopentyl (meth) acrylate, cycloheptyl (meth) acrylate, bicycloheptyl (meth) acrylate, tricyclodecyl (meth) acrylate, tricyclodecane dimethanol (meth) acrylate, isoboronyl (meth) ) Acrylate, di (meth) acrylate of hydrogenated bisphenols, and the like. In particular, it preferably has an adamantane skeleton. For example, 2-alkyl-2-adamantyl (meth) acrylate (see Japanese Patent Application Laid-Open No. 2002-193883), adamantyl di (meth) acrylate (see Japanese Patent Application Laid-Open No. 57-5000785), diallyl adamantyl dicarboxylate (Japanese Patent Application Laid-Open No. 60-10000537), perfluoroadamantyl acrylate (see JP 2004-123687), Shin-Nakamura Chemical Co., Ltd. 2-methyl-2-adamantyl methacrylate, 1,3-adamantanediol diacrylate, 1,3 , 5-adamantanetriol triacrylate, unsaturated carboxylic acid adamantyl ester (see JP 2000-119220 A), 3,3′-dialkoxycarbonyl-1,1 ′ biadamantane (see JP 2001-253835 A) , 1,1 -Biadamantane compound (see US Pat. No. 3,342,880), tetraadamantane (see JP 2006-169177), 2-alkyl-2-hydroxyadamantane, 2-alkyleneadamantane, 1,3-adamantane dicarboxylic acid diacid Curable resins having an adamantane skeleton having no aromatic ring such as tert-butyl (see JP-A-2001-322950), bis (hydroxyphenyl) adamantanes and bis (glycidyloxyphenyl) adamantane (JP-A-11-35522) And Japanese Patent Laid-Open No. 10-130371).

It is also possible to contain other reactive monomers. In the case of (meth) acrylate, for example, methyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, isobutyl acrylate, isobutyl methacrylate, tert-butyl acrylate Tert-butyl methacrylate, phenyl acrylate, phenyl methacrylate, benzyl acrylate, benzyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, and the like.

Examples of the polyfunctional (meth) acrylate include trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) ) Acrylate, dipentaerythritol tetra (meth) acrylate, dipentaerythritol tri (meth) acrylate, tripentaerythritol octa (meth) acrylate, tripentaerythritol septa (meth) acrylate, tripentaerythritol hexa (meth) acrylate, tripenta Erythritol penta (meth) acrylate, tripentaerythritol tetra (meth) acrylate, tripentaerythritol And tri (meth) acrylate.

In addition, an allyl resin or the like can be used as the resins 4A and 6A, and the resin can be cured by radical polymerization.

In addition, photocurable resins that can be used as the resins 4A and 6A include, for example, epoxy resins, and the resins can be cured by cationic polymerization.

Here, the photocurable resin used in the present invention includes not only the photocurable resin as described above but also a thermal polymerization initiator in addition to the photopolymerization initiator, and is combined with curing by thermal polymerization by heating. Also included.

Further, the light to be cured includes not only visible light and ultraviolet light but also electron beams. Furthermore, you may provide what is called a post-cure process which completes hardening by applying heat after the 2nd light irradiation process mentioned later. Even in the case of a photocurable resin containing only a photopolymerization initiator as a polymerization initiator, photocuring is accelerated by heating, but if a thermal polymerization initiator is further blended here, the acceleration is promoted. The effect is further increased.

Subsequently, an example of a wafer lens manufacturing apparatus (30) used when manufacturing the wafer lens 1 will be described.

As shown in FIG. 2, the wafer lens manufacturing apparatus 30 has a base 32.

A protruding portion 34 that protrudes inward is formed on the upper portion of the base 30. A guide 36 is erected between the bottom of the base 32 and the protrusion 34. A stage 40 is provided between the guides 36. A through hole 42 is formed in the stage 40, and the guide 36 passes through the through hole 42.

A geared motor 50 is provided on the base 32 and below the stage 40. The geared motor 50 has a built-in potentiometer 51 indicated by a dotted line. A shaft 52 is connected to the geared motor 50.

A load cell 44 for pressure detection is provided between the lower portion of the stage 40 and the shaft 52, and the tip of the shaft 52 is in contact with the load cell 44 by the weight of the stage 40.

In this wafer lens manufacturing apparatus 30, the shaft 52 extends and contracts in the vertical direction by the operation of the geared motor 50, and accordingly, the stage 40 is movable in the vertical direction while being guided by the guide 36.

The recess 40 having a substantially hemispherical shape is formed on the stage 40. A paralleling member 60 is embedded in the recess 46. The paralleling member 60 can swing with respect to the recess 46 like a bowl floating on the water surface.

An XY stage 62 and a θ stage 64 are provided on the parallel projecting member 60. The XY stage 62 is movable on an XY plane (two-dimensional plane) on the stage 40, and the θ stage 64 is rotatable about its central portion as a rotation axis.

A vacuum chuck device 70 is installed on the XY stage 62 and the θ stage 64. A concentric communication groove 72 is formed in the vacuum chuck device 70. A suction mechanism (not shown) is connected to the communication groove 72, and air can be sucked from the communication groove 72 by the operation of the suction mechanism, and members on the vacuum chuck device 70 can be sucked and fixed. ing.

In this embodiment, the mold 20 is disposed on the vacuum chuck device 70, and the mold 20 is sucked and fixed by the vacuum chuck device 70. The mold 20 is a metal mold and is an example of a mold used for resin molding. A resin (resin 4A or the like) to be molded is placed on the mold 20.

The substrate holder 80 is fixed to the upper part of the base 32. A concentric communication groove 82 is formed at the end of the substrate holder 80, and a suction mechanism (not shown) is connected to the communication groove 82. Similarly to the operation of the vacuum chuck device 70, when the suction mechanism operates, the glass substrate 2 is sucked and fixed to the substrate holder 80 by sucking air from the communication groove 82.

A light source 90 is provided above the substrate holder 80. When the light source 90 is turned on, light passes through the glass substrate 2 and is irradiated onto a resin (resin 4A, etc.) on the mold 20.

As the light source 90, a high-pressure mercury lamp, metal halide lamp, xenon lamp, halogen lamp, fluorescent lamp, black light, G lamp, F lamp, LED, or the like is used.

The high-pressure mercury lamp is a lamp having a narrow spectrum at 365 nm and 436 nm. A metal halide lamp is a kind of mercury lamp, and its output in the ultraviolet region is several times higher than that of a high-pressure mercury lamp. A xenon lamp is a lamp having a spectrum closest to sunlight. Halogen lamps contain a lot of long-wavelength light and are mostly near-infrared light. Fluorescent lamps have uniform illumination intensity for the three primary colors of light. Black light has a peak top at 351 nm and emits near-ultraviolet light of 300 to 400 nm. LEDs have different emission colors depending on the materials used, and can produce LEDs that emit light in the infrared region, visible light region, and ultraviolet region.

As shown in FIG. 3, the load cell 44, geared motor 50, potentiometer 51, parallelizing member 60, XY stage 62, θ stage 64, vacuum chuck device 70 (suction mechanism), substrate holder 80 (suction mechanism), and light source 90 are controlled. It is connected to the device 100. The control device 100 controls the operation of these members.

Particularly in the present embodiment, the control device 100 controls the operation (rotation amount) of the geared motor 50 based on the output values of the load cell 44 and the potentiometer 51.

Subsequently, a method for manufacturing the wafer lens 1 using the wafer lens manufacturing apparatus 30 will be described.

As shown in FIG. 2, first, the glass substrate 2 is placed on the substrate holder 80 and sucked and fixed, and the mold 20 is placed on the vacuum chuck device 70 and the mold 20 is sucked and fixed.

Thereafter, a predetermined amount of resin 4A is dropped on the mold 20. And the paralleling member 60, XY stage 62, and (theta) stage 64 are controlled by the control apparatus 100, and the lower surface of the glass substrate 2 and the upper surface of the metal mold | die 20 are made parallel (preparation process).

In addition, although resin 4A is dripped on the metal mold | die 20 here, this invention is not limited to this, You may dripping on the glass substrate 2. FIG. In addition, the dropping method is also a method in which each cavity 22 is filled by dropping and spreading them on a predetermined location, or each cavity 22 of the mold 20 or each lens portion 4a of the glass substrate 2 is formed in advance. Alternatively, a method may be used in which the liquid is dropped individually, and is filled by pressing them with the mold 20 or the glass substrate 2 facing each other.

In this state, the position of the mold 20 is controlled, the mold 20 is moved to a predetermined position with respect to the glass substrate 2, and the mold 20 is held at that position.

Specifically, the geared motor 50 is operated to extend the shaft 52 upward, and the mold 20 is moved upward. In this case, the control device 100 controls the operation of the geared motor 50 based on the output value of the potentiometer 51, and moves the mold 20 to a predetermined height position.

The height position of the mold 20 to be moved is set in the control device 100 in advance, and the control device 100 operates the geared motor 50 to a position where the mold 20 reaches the reference position S. When reaching the reference position S, the operation of the geared motor 50 is stopped (position control step).

As a result, the resin 4A gradually receives the pressure from the mold 20 to the glass substrate 2 and spreads between the glass substrate 2 and the mold 20 (particularly, the cavity 22 of the mold 20).

Thereafter, as shown in FIG. 4A, a light shielding mask 120 is disposed above the glass substrate 2 and between the glass substrate 2 and the light source 90. The light shielding mask 120 has a portion corresponding to the cavity 22 of the mold 20 (preferably the optical effective diameter range of the convex lens portion 4a in the cavity 22; in the case of configuring an imaging device, the lens portion is transmitted through the lens portion later. An opening 122 in which an entrance pupil diameter range necessary for forming an image in an effective pixel region of the image sensor is opened is formed.

Thereafter, the light source 90 is turned on while the mold 20 is held at the position corresponding to the reference position S, and light is irradiated toward the resin 4A (first light irradiation step).

In the first light irradiation process, since the opening 122 is formed in the light shielding mask 120, the light from the light source 90 passes through the opening 122 and reaches the resin 4 </ b> A, and is shielded at a portion other than the opening 122. Is done. As a result, the portion of the resin 4A that receives the transfer of the cavity 22 of the mold 20 and that corresponds to the convex lens portion 4a is irradiated with light prior to other portions, and the convex lens portion 4a ( Preferably, it begins to cure selectively within the optical effective diameter range of the convex lens portion 4a.

In the first light irradiation step, the convex lens portion 4a is divided according to the size of the diameter from the center by changing the light shielding mask 120 (the opening diameter of the opening portion 122), and the outer periphery from the center region is divided. You may make it irradiate light sequentially toward an area | region.

For example, as shown in FIG. 4A, the convex lens portion 4a is divided into a region (1) and a region (2), the region (1) is irradiated with light first, and then the light shielding mask 120 is changed to change the region ( 2) is irradiated with light.

In this case, preferably, in the region after the division of the convex lens portion 4a, the illuminance is increased for light irradiation in a region including the center of the optical axis with a thick lens thickness (for example, the region (1)), and other regions (for example, In the irradiation of the light in the region (2), the illuminance may be decreased (the illuminance is made smaller than that of the previous light irradiation).

Thereafter, as shown in FIG. 4B, the light shielding mask 120 is removed, and the entire resin 4A is irradiated with light (second light irradiation step).

In the second light irradiation step, since the light shielding mask 120 that shields the light from the light source 90 is removed, the light from the light source 90 propagates directly toward the resin 4A without being shielded. As a result, in the resin 4A, the portion corresponding to the convex lens portion 4a and the portion corresponding to the non-lens portion 4b, that is, the entire resin 4A are irradiated with light, and the non-lens portion 4b is cured together with the convex lens portion 4a. Proceed.

In the first and second light irradiation steps, as shown in FIG. 5, the illuminance of light may be kept constant (irradiation pattern A1), or the first light irradiation step and the second light irradiation step. At the time of switching (when removing the light shielding mask 120), the light source 90 may be temporarily turned off to reduce the illuminance of the light (irradiation pattern A2).

In the second light irradiation step, a light source that emits divergent light is used as the light source 90, and the light shielding mask 120 is moved upward without removing the light shielding mask 120 (the distance between the light shielding mask 120 and the resin 4A is increased). You may make it irradiate light to resin 4A whole, expanding rather than the time of a 1st light irradiation process.

Further, the light shielding mask 120 is formed on the glass substrate 2 in advance as an aperture stop, light is irradiated from the mask side, that is, the aperture stop side in the first light irradiation step, and light shielding by the mask is performed in the second light irradiation step. The light may be irradiated from the side of the glass substrate 2 opposite to the aperture stop where the function does not work. However, the mold 20 at this time needs to be formed transparently, and light irradiation is performed through the mold 20. In this case, there is an advantage that the process can be performed efficiently because it can be performed regardless of the type of light source and without removing the light shielding mask 120 each time.

Furthermore, after finishing the first light irradiation step, the mold 20 and the glass substrate 2 may be removed and passed through a UV furnace to be cured entirely. Further, after the second light irradiation step, heat may be applied to promote photocuring. This is a so-called post-cure process, and accelerates curing by photopolymerization. Furthermore, a thermal polymerization initiator can be blended in the resin, and further curing can be promoted by light irradiation and heating.

Next, the geared motor 50 is operated to shrink the shaft 52 downward, and the mold 20 is returned to the original height position. As shown in FIG. Release from the mold 20 (release process).

As a result, the resin part 4 in which a plurality of convex lens parts 4 a are formed can be formed on the glass substrate 2.

Here, the pressing force of the mold 20 against the glass substrate 2 (pressure value detected by the load cell 44) in the process from the installation of the mold 20 at the reference position S to the release of the resin 4A from the mold 20 is as follows. As shown in FIG. 6, after the light irradiation is started in the first light irradiation step, it continues to gradually decrease until the light irradiation is finished in the second light irradiation step, and the resin 4A is separated from the mold 20. It drops rapidly when molding (pressure pattern B1).

The reason why the pressing force of the mold 20 decreases from the start of light irradiation to the end thereof is considered to be due to the resin 4A being irradiated with light and being cured and contracted.

Therefore, in the present embodiment, as shown in FIG. 6, it is preferable that the gold mold is used in the mold release process from the start of the light irradiation in the first light irradiation process until the end of the light irradiation in the second light irradiation process. Until the resin 4A is released from the mold 20, the operation of the geared motor 50 is controlled so that the pressing force of the mold 20 against the glass substrate 2 is kept constant during light irradiation (pressure pattern B2 ) Or in the middle of light irradiation (pressure pattern B3) to improve the transferability of the mold 20 to the resin 4A.

It should be noted that the resin 4A after light irradiation is temporarily cooled (naturally) between the end of light irradiation in the second light irradiation step and the release of the resin 4A from the mold 20 in the release step. (Including neglected). In particular, a resin that is reactively cured by cationic polymerization, such as an epoxy resin, has a slow reaction rate. Therefore, the reaction does not end only by irradiating a predetermined amount of light. Therefore, it is desirable to maintain the molding state until the reaction ends.

In this case, as shown in FIG. 7, the pressing force of the mold 20 against the glass substrate 2 continues to decrease during the light irradiation period and during the cooling period, and during the transition from the light irradiation period to the cooling period. It switches in steps (pressure pattern B4).

Also in this case, since the resin 4A is considered to shrink during the cooling period, preferably, the pressing force of the mold 20 against the glass substrate 2 is controlled according to the pressure pattern B2 or B3.

Thereafter, as shown in FIG. 4C, the glass substrate 2 is turned over, and the glass substrate 2 is formed in the same manner as the resin portion 4 is formed on the glass substrate 2 (by repeating the processes from the preparation step to the release step). The resin part 6 is formed for 2.

However, in this case, as shown in FIG. 4D, a mold 24 for molding the concave lens portion 6a is used instead of the mold 20, and a resin 6A is used instead of the resin 4A.

Further, in the process from installing the mold 24 at a position corresponding to the reference position S to releasing the resin 6A from the mold 24, as shown in FIG. 8, light irradiation is performed in the first light irradiation process. From the start to the end of the irradiation, the operation of the geared motor 50 is controlled to maintain the pressing force of the mold 24 against the glass substrate 2 at a constant value during the light irradiation, and the second time thereafter. From the start of the light irradiation in the light irradiation step to the end of the irradiation, preferably until the resin 6A is released from the mold 24 in the release step, the glass substrate is not operated. 2 is not controlled (pressure pattern B5). That is, the pressing force is kept lowered by the contraction of the resin 6A.

Of course, even when the resin portion 6 is formed, after the light irradiation in the second light irradiation process and after the resin 6A is released from the mold 24 in the mold release process, after the light irradiation. The resin 6A may be temporarily cooled (including natural standing).

Also in this case, as shown in FIG. 9, during the period of cooling the resin 6A, the pressing force of the mold 24 against the glass substrate 2 is not controlled without operating the geared motor 50 (pressure pattern B6). . The reason why the pressure is not controlled by the pressure patterns B5 and B6 will be described later.

In the above embodiment, the following operations and effects are achieved.

First, when the resin part 4 is formed, the light irradiation is divided into two stages of a first light irradiation process and a second light irradiation process, and the light irradiation range is determined by the convex lens part 4a in the first light irradiation process. Only in the range of the optical effective diameter (preferably within the range of the optical effective diameter), in the subsequent second light irradiation step, the entire resin 4A is changed (see FIGS. 4A and 4B).

In this case, since the convex lens portion 4a begins to harden first, and then the non-lens portion 4b hardens, the convex shrinkage of the convex lens portion 4a occurs first, and the non-lens portion 4b shrinks after that.

Therefore, even if the non-lens part 4b is cured and contracted, the curing of the convex lens part 4a has already progressed at that time, and the shrinkage accompanying the curing of the non-lens part 4b can be reduced from affecting the convex lens part 4a. It is possible to suppress the occurrence of sink marks in the convex lens portion 4a as the resin is cured.

Furthermore, in addition to the light irradiation being performed in two stages, the pressing force of the mold 20 is controlled according to the pressure patterns B2 and B3, so that the transferability of the mold 20 to the resin 4A can be reliably improved.

That is, in the resin part 4, since the thickness 4bth of the non-lens part 4b is thinner than the thickness 4ath of the convex lens part 4a, more accurate transfer can be achieved by simultaneously irradiating the non-lens part 4b and the convex lens part 4a with light. Transferability was not always sufficient for lenses that required high performance. This is because the non-lens portion 4b hardens first, and even if it tries to press the mold 20, the non-lens portion 4b inhibits the movement of the mold 20, and the pressing of the mold 20 is sufficiently transmitted to the convex lens portion 4a. It is thought that it is not possible to do.

On the other hand, in the present embodiment, the convex lens portion 4a is selectively irradiated with light and the non-lens portion 4b is not irradiated with light in the first light irradiation step. It can be seen that there is no hindrance to the movement of the mold 20, the pressure of the mold 20 can be sufficiently transmitted to the convex lens portion 4a, and as a result, the transferability of the mold 20 to the resin 4A can be improved reliably. It was.

Summarizing such contents, as shown in Table 1, it is possible to suppress the occurrence of sink marks in the convex lens portion 4a by two-stage irradiation of light, and further, by controlling the pressure of the mold 20, the resin 20 of the mold 20 is applied to the resin 4A. It can be said that transferability can be improved (a shift from a design value on the optical surface of the convex lens portion 4a can be suppressed).

In Table 1, “◯” is an example in which sink marks are suppressed and shows good transferability, and “X” is an example in which sink marks or transferability is not good. Further, “Δ” in the item of “deviation from optical surface design value” is an evaluation content that the lens portion 4a falls within a range where the optical surface can be corrected.

When forming the resin part 4, instead of the light irradiation patterns A1 and A2, light irradiation may be intermittently performed as shown in FIG. 10 (irradiation pattern A3).

In this case, since the curing of the resin 4A proceeds stepwise and the curing speed is relatively delayed, the pressure control of the mold 20 can be facilitated, and the transfer property of the mold 20 to the resin 4A can be further improved. Can be improved.

Therefore, the light irradiation pattern A3 is effective when a resin having a particularly high curing rate is selected as the resin 4A among the photocurable resins.

On the other hand, even when the resin portion 6 is formed, the light irradiation is divided into two stages of a first light irradiation process and a second light irradiation process, and the light irradiation range is a concave lens in the first light irradiation process. Only the portion 6a (preferably within the optical effective diameter range) is changed to the entire resin 6A in the subsequent second light irradiation step (see FIG. 4D).

Therefore, as in the case of forming the resin portion 4, even when the non-lens portion 6b is cured and contracted, the concave lens portion 6a is already cured, and the contraction accompanying the curing of the non-lens portion 6b is the concave lens portion. 6a can be reduced, and the occurrence of sink marks can be suppressed in the concave lens portion 6a as the resin 6A is cured.

Further, when forming the resin portion 6, in addition to the light irradiation in two stages, the pressing force of the mold 24 is not controlled after the second light irradiation process according to the pressure patterns B5 and B6. Transferability of the mold 24 to the resin 6A can be reliably improved.

That is, in the resin part 6, since the thickness 6ath of the concave lens part 6a is thinner than the thickness 6bth of the non-lens part 6b, the mold 24 is pressed while simultaneously irradiating light to the concave lens part 6a and the non-lens part 6b. If it continues, the concave lens part 6a will harden | cure ahead of the non-lens part 6b, but it will continue to receive the press of the metal mold | die 24 also during hardening of the non-lens part 6b which delays and cures to this. In this case, an excessive burden is applied to the cured concave lens portion 6a, and the concave lens portion 6b may be distorted and possibly cracked.

On the other hand, in the present embodiment, after the second light irradiation step, the pressing of the mold 24 is released and the pressure is not controlled, so that the concave lens portion 6a is delayed during the curing of the non-lens portion 6b. Without being pressed, the state formed in the first light irradiation step can be maintained almost as it is, and as a result, the transferability of the mold 24 to the resin 6A can be reliably improved.

The method that does not control the pressing force in the second light irradiation step is not only in the case of a concave lens, but also in the case of an optical element in which a projection for positioning or the like as a non-lens part is formed thicker than the lens part around the lens part. Is also applicable.

When the resin portion 6 is formed, instead of the light irradiation patterns A1 and A2, as shown in FIG. 11, the resin portion 6 may be temporarily reduced during a predetermined period in the first light irradiation process (irradiation pattern A4). ).

In this case, since the curing of the resin 6A is delayed in the first light irradiation step, the pressure control of the mold 24 can be facilitated, and the transferability of the mold 24 to the resin 6A can be improved. .

In the present embodiment, the light irradiation patterns A1 to A4 are disclosed in accordance with the formation mode of the resin parts 4 and 6, but the light irradiation patterns A1 to A4 are the first every time the resin parts 4 and 6 are formed. The light irradiation step and the second light irradiation step may be appropriately combined.

In this embodiment, the resin parts 4 and 6 are separately formed using the molds 20 and 24. However, the resin parts 4 and 6 may be formed simultaneously.

For example, as shown in FIG. 12, a mold 20 is used for forming the resin part 4 and a light-transmitting resin mold 26 is used for forming the resin part 6. The resin mold 26 is a resin mold and is another example of a mold used for resin molding. The resin mold 26 includes a molding part 26a and a support part 26b. The molding part 26a has a convex surface corresponding to the concave lens part 6a, and the support part 26b supports the molding part 26a and increases its strength.

In this case, the resin 4A is filled between the mold 20 and the glass substrate 2, and the resin 6A is filled between the resin mold 26 and the glass substrate 2, and light is applied in the first and second light irradiation steps. Irradiation is sufficient.

Further, as in the modification shown in FIG. 13, the resin portion 28 may be used for forming the resin portion 4, and the resin die 26 may be used for forming the resin portion 6. The resin mold 28 is also a resin mold and is another example of a mold used for resin molding. The resin mold 28 has substantially the same configuration as the resin mold 26. The molding part 28a has a concave surface corresponding to the convex lens part 4a, and the support part 28b supports the molding part 26a and increases its strength.

In this case, the resin 4A is filled between the resin mold 28 and the glass substrate 2, and the resin 6A is filled between the resin mold 26 and the glass substrate 2, respectively, in the first and second light irradiation steps. Light may be irradiated from both above and below.

Further, in the present embodiment, the wafer lens 1 is disclosed in which only one resin portion 4 or 6 is formed on the glass substrate 2, but a plurality of resin portions 4 (resin portions 6) are provided on the large-diameter glass substrate 2. And this may be used as the wafer lens 1.

In this case, as shown in FIG. 14, the resin portion 4 is sequentially formed on one surface of the glass substrate 2 according to a so-called step-and-repeat method, and then the resin portion 6 is formed on the other surface of the glass substrate 2. You should form sequentially.
[Second Embodiment]
The second embodiment is different from the first embodiment in the following points, and other technical matters are the same as those of the first embodiment.

The second embodiment is largely different from the first embodiment in that the light shielding mask 120 is not used in the first and second light irradiation steps.

As an example, in the second embodiment shown in FIG. 15, a lens array 96 is provided below the light source 90.

In this case (for example, when the resin portion 4 is formed), in the first light irradiation step, the light source 90 is turned on and the light is condensed by the lens array 96, and the convex lens portion 4a of the resin 4A is collected. In the second light irradiation step, the lens array 96 is moved downward (the distance between the lens array 96 and the resin 4A is narrower than that in the first light irradiation step). ) The entire resin 4A is irradiated with light.

In another example shown in FIG. 16, a plurality of point light sources 92 are provided instead of the light source 90. The point light source 92 is disposed in a region where the resin 4A (resin 6A) can be irradiated with light.

In this case (for example, when the resin portion 4 is formed), in the first light irradiation process, the point light source 92 facing the cavity 22 of the mold 20 is turned on among the plurality of point light sources 92. In the resin 4A, light is selectively irradiated only to a portion corresponding to the convex lens portion 4a. In the second light irradiation step, the remaining point light sources 92 are also turned on, and the entire resin 4A is irradiated with light.

In still another example shown in FIG. 17, instead of the light source 90, a plurality of point light sources 94 that are movable in the optical axis direction or a plurality of point light sources 94 ′ with variable irradiation light amount are provided. The point light source 94 is a region where light can be irradiated to the resin 4A (resin 6A) and is disposed at a position facing the cavity 22 (transfer portion of the optical surface). The point light source 94 is a light source that emits divergent light.

In this case (for example, when the resin portion 4 is formed), in the first light irradiation step, each point light source 94 is turned on (see the center of FIG. 17) and corresponds to the convex lens portion 4a in the resin 4A. In the second light irradiation step, each point light source 94 is moved upward (the distance between each point light source 94 and the resin 4A is changed from the time of the first light irradiation step). The resin 4A is irradiated with light (see the left side in FIG. 17). Alternatively, as shown on the right side in FIG. 17, the amount of electric power supplied to each point light source 94 'is increased (the illuminance of each point light source 94' is increased from that in the first light irradiation step), and light is applied to the entire resin 4A. Irradiate. The light distribution of the point light source 94 ′ has the largest amount of light in the central optical axis direction and the light amount in the peripheral portion is small. Therefore, the amount of electric power given in the first light irradiation step may be set to an amount of electric power that is not so large as to cure the resin of the non-lens portion, and in the second light irradiation step, the amount of electric power to cure the resin of the non-lens portion. .

Specifically, as the point light sources 92, 94, 94 ′, LEDs or lasers having an emission wavelength at a wavelength corresponding to the photosensitive wavelength of the reaction initiator or reaction sensitizer contained in the photocurable resin are used. it can.

DESCRIPTION OF SYMBOLS 1 Wafer lens 2 Glass substrate 4 Resin part 4a Convex lens part 4b Non lens part 6 Resin part 6a Concave lens part 6b Non lens part 20 Mold 22 Cavity 24 Mold 26 Resin mold 26a Molding part 26b Support part 28 Resin mold 28a Molding part 28b Support section 30 Wafer lens manufacturing apparatus 32 Base 34 Projection section 36 Guide 40 Stage 42 Through hole 44 Load cell 46 Recess 50 Geared motor 51 Potentiometer 52 Shaft 60 Paralleling member 62 XY stage 64 θ stage 70 Vacuum chuck apparatus 72 Communication groove 80 Stamp holder 82 communication groove 90 light source 92, 94, 94 'point light source 96 lens array 100 control device

Claims (16)

In the method of manufacturing a wafer lens, in which a plurality of lenses having a lens portion and a non-lens portion around the lens portion are formed on a substrate with a photocurable resin,
Filling the photocurable resin between the mold and the substrate;
A curing step of advancing curing of the photocurable resin by performing light irradiation on the photocurable resin,
The curing step includes a first light irradiation step of irradiating the first region of the photocurable resin with light, and a second light irradiating the second region of the irradiation region wider than the first region. A method of manufacturing a wafer lens, comprising: an irradiation step. In a method for manufacturing a wafer lens, in which a plurality of lenses having a lens portion and a non-lens portion around the lens portion are formed on a substrate with a photocurable resin,
Filling the photocurable resin between the mold and the substrate;
A curing step of proceeding curing of the photocurable resin by irradiating the photocurable resin with light, and the curing step irradiates only a portion corresponding to the lens portion of the photocurable resin. And a second light irradiating step of irradiating a portion corresponding to the non-lens portion around the lens portion of the photocurable resin. In the manufacturing method of the wafer lens according to claim 1,
The first region is a portion corresponding to an effective diameter range of the lens unit,
The method of manufacturing a wafer lens, wherein the second region is a portion including an effective diameter range of the lens portion and a peripheral portion thereof. In the manufacturing method of the wafer lens according to claim 1,
The first region is a part corresponding to the lens unit,
The method of manufacturing a wafer lens, wherein the second region is a portion corresponding to the lens portion and a portion corresponding to a non-lens portion around the lens portion. In the method for manufacturing a wafer lens according to any one of claims 1 to 4,
In the first light irradiation step, the light irradiation is shielded by using a light shielding mask outside the irradiation region. In the manufacturing method of the wafer lens according to claim 5,
The method of manufacturing a wafer lens, wherein the light shielding mask is an aperture stop of a lens. In the manufacturing method of the wafer lens according to claim 5,
In the second light irradiation step, the wafer lens is manufactured by irradiating light without using the light shielding mask. In the manufacturing method of the wafer lens according to claim 5,
A light source that emits divergent light is used as a light source, and in the second light irradiation step, the distance between the photocurable resin and the light-shielding mask is made wider than the distance in the first light irradiation step. A method for manufacturing a wafer lens. In the method for manufacturing a wafer lens according to any one of claims 1 to 4,
While arranging a light source having a condensing lens array at a position facing the portion corresponding to the lens portion in a region where light can be irradiated to the photocurable resin,
In the second light irradiation step, the distance between the photocurable resin and the condenser lens is narrower than that in the first light irradiation step. In the method for manufacturing a wafer lens according to any one of claims 1 to 4,
Arranging a plurality of point light sources in the light irradiable area to the photocurable resin,
In the first light irradiation step, only the point light source facing the portion corresponding to the lens portion in the photocurable resin is turned on. In the method for manufacturing a wafer lens according to any one of claims 1 to 4,
Using a light source that irradiates divergent light as the point light source, while arranging a point light source at a position facing the portion corresponding to the lens portion in the light irradiable region to the photocurable resin,
In the second light irradiation step, the wafer lens manufacturing method is characterized in that the distance between the photocurable resin and the point light source is wider than that in the first light irradiation step. In the method for manufacturing a wafer lens according to any one of claims 1 to 4,
Using a light source that irradiates divergent light as the point light source, while arranging a point light source at a position facing the portion corresponding to the lens part in the light irradiable region to the photocurable resin,
In the second light irradiation step, the illuminance of the point light source is made higher than the illuminance at the time of the first light irradiation step. The method of manufacturing a wafer lens according to any one of claims 1 to 12,
In at least one of the first and second light irradiation steps, light is intermittently irradiated. The method for producing a wafer lens according to any one of claims 1 to 13,
The thickness of the lens part is thicker than the thickness of the non-lens part,
A method of manufacturing a wafer lens, wherein the first light irradiation step and the second light irradiation step are controlled so that a pressure on the photocurable resin is maintained at a predetermined pressure. The method for producing a wafer lens according to any one of claims 1 to 13,
The thickness of the lens part is thinner than the thickness of the non-lens part,
In the first light irradiation step, the pressure to the photocurable resin is controlled to be maintained at a predetermined pressure,
In the second light irradiation step, the control of the pressure with respect to the photocurable resin is released. In the method for manufacturing a wafer lens according to any one of claims 1 to 15,
A method for producing a wafer lens, wherein the substrate is a glass substrate.

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