JP2010276967A - Method of manufacturing wafer lens - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To uniformly cure a photocurable resin constituting a lens part having positive power. <P>SOLUTION: A method of manufacturing a wafer lens 1, wherein photocurable resin lens parts 4a and 6a are formed on both front and back surfaces of a glass substrate 2 includes: a process for radiating light to the photocurable resin for forming a concave lens part 6a on one surface of the substrate; and a process for having an irradiated light to the photocurable resin, for forming a convex lens part 4a on the other surface. The convex lens part 4a has positive power for making an incident light condense, and in the process for forming the convex lens part 4a having positive power, parallel beams are made incident on the photocurable resin constituting the convex lens part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

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

  Conventionally, in the field of manufacturing optical lenses, a technique for obtaining an optical lens having high heat resistance 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.

  Patent Document 2 discloses an example in which lens portions (optical components) are formed on both the front and back surfaces of a glass substrate. In the technique of Patent Document 2, a refractive component is formed on one surface of a glass substrate, and a diffractive component is formed on the other surface (see paragraphs 0022 and 0037, FIG. 4A). In addition, Patent Document 3 discloses an example of a method for forming a lens portion made of a photocurable resin on a glass substrate. In the technique of Patent Document 3, a photocurable resin is applied to a substrate, the resin is photocured (light irradiation), and thereafter, shaping (pressing a molding die against the resin) and thermosetting are performed. (See paragraphs 0069-0080).

Japanese Patent No. 3926380 JP-T-2001-519601 JP 2003-286301 A

By the way, in the wafer lens manufacturing method in which the lens portions made of the photocurable resin are formed on both the front and back surfaces of the glass substrate, the lens material filled between the molds on both surfaces of the substrate is simultaneously irradiated with light. It is difficult to employ curing, and after one surface is irradiated with light to cure the resin, the other surface is then subjected to a photocuring step.
This is because the mold for molding the resin lens is generally made of metal, and therefore, even when trying to irradiate the curing light through the mold, the light transmittance is low and cannot be cured sufficiently. It is.
However, when at least one lens part formed on both front and back surfaces in the manufacturing method of forming lens parts on both surfaces of such a substrate has a positive power for converging incident light (when it has a convex shape, etc.), The following inconvenience has occurred.

  Briefly described with reference to FIG. 6, for example, in the wafer lens 100 in which the lens unit 104 and the lens unit 106 are formed on both surfaces of the glass substrate 102, the lens unit 104 has a concave shape, and the lens unit 106. Is convex. In this case, when the lens unit 104 is formed first (irradiating the resin with light) and then the lens unit 106 is to be formed, a mold (not shown) is disposed below the glass substrate 102. At the same time, a light curable resin is filled between the glass substrate 102 and the mold 110, and light is irradiated from above the lens part 104 where the mold is released, but the lens part 104 has a concave shape. For this reason, light diffuses on the optical surface of the lens unit 104, and a region A in which the amount of incident light is dense and a region B in which the amount of incident light is sparse are formed in the resin constituting the lens unit 106.

For this reason, incident light is condensed in the dense area A and curing of the resin is promoted, whereas in the sparse area B, incident light is not collected and curing of the resin is delayed. . That is, when the lens part has a positive power as a whole, such as when it has a convex shape, it cannot be uniformly cured over the entire area of the resin when it is intended to cure the resin that constitutes the lens part. There is an inconvenience.
Therefore, the main object of the present invention is to uniformly distribute a photocurable resin even in a wafer lens manufacturing method for forming a lens portion having a positive power using a metal mold having low light transmittance such as metal. An object of the present invention is to provide a method of manufacturing a wafer lens that can be cured and a high-quality wafer lens can be obtained.

In order to solve the above problems, according to the present invention,
In the method of manufacturing a wafer lens in which a lens portion made of a photocurable resin is formed on each of the front and back surfaces of the glass substrate,
Irradiating the photocurable resin with light to form a first lens portion on one surface;
Irradiating the photocurable resin with light to form a second lens portion on the other surface;
With
At least one of the first and second lens portions has a positive power for focusing incident light, and in the step of forming the lens portion having the positive power, the photocurable resin constituting the lens portion On the other hand, a method for manufacturing a wafer lens is provided, in which parallel light is incident.

  According to the present invention, parallel light is incident on the constituent resin even in a wafer lens having a lens portion having a positive power with a mold having low light transmittance with respect to curing light for curing the lens resin material. Therefore, it is possible to suppress the formation of a sparse region of incident light of the lens unit configured thereby, and it is possible to uniformly cure the resin constituting the lens unit having a positive power. .

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 drawing for demonstrating schematically the one part process of the manufacturing method of the wafer lens concerning 1st Embodiment. It is drawing for demonstrating schematically the one part process of the manufacturing method of the wafer lens concerning preferable embodiment (2nd Embodiment) of this invention. 6 is a diagram for schematically explaining the problems of the prior art.

  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) in plan view.

A resin portion 4 is provided on the glass substrate 2.
The resin portion 4 is made of a photocurable resin 4A, and includes a convex lens portion 4a having a convex shape and a non-lens portion 4b that transmits incident light as it is. The convex lens portion 4a forms an optical surface and has a positive power for focusing incident light. 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 so as to transmit incident light as it is. 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 convex lens portion 4a has “positive power” means that the convex lens portion 4a has positive power as a whole. For example, as shown in FIG. 1, the central portion of the convex lens portion 4a. In this case, even if there is a concave portion 4c having a negative power, if the convex lens portion 4a has a positive power exceeding the power of the portion as a whole, the convex lens portion 4a has a positive power. Will be.

  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 shape suitable for holding for positioning and holding with other members, and a function as a spacer portion for defining a distance from other lens members and imaging element members. May be.

A resin portion 6 is provided at the lower portion of the glass substrate 2.
The resin portion 6 is made of a photo-curable resin 6A, and has a concave lens portion 6a having a concave shape and a non-lens portion 6b that transmits incident light as it is. The concave lens portion 6a constitutes an optical surface and has a negative power for diverging incident light. 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 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.

  The concave lens portion 6a has “negative power” means that the concave lens portion 6a has negative power as a whole. For example, as shown in FIG. 1, the central portion of the concave lens portion 6a. Even if there is a portion having a positive power in the convex portion 6c, if the concave lens portion 6a as a whole has a negative power exceeding the power of the portion, the concave lens portion 6a has a negative power. Will have.

  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 shape suitable for holding for positioning and holding with other members, and a function as a spacer portion for defining a distance from other lens members and imaging element members. May be.

  In FIG. 1, the resin parts 4 and 6 are formed in a form in which the non-lens parts 4b and 6b between the adjacent lens parts 4a and 6a are connected, but the present invention is 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 have a one-to-one correspondence.

  Next, 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 protruding inward is formed on the upper portion of the base 32. 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 (see FIG. 3). A shaft 52 is connected to the geared motor 50.
A load cell 44 for pressure detection is provided below the stage 40. The tip of the shaft 52 is in contact with the load cell 44 by the weight of the stage 40.
In the 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 can move in the vertical direction while being guided by the guide 36.

The stage 40 is formed with a concave portion 46 having a substantially hemispherical shape. 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 paralleling 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 the present 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 resin 6A) to be molded is disposed on the mold 20.

  Although not shown in detail in FIG. 2, the mold 20 has a surface shape that matches the object (resin part 4, resin part 6) to be molded, and a convex lens when forming the resin part 4. When the mold 20 having a surface shape (concave) corresponding to the portion 4a forms the resin portion 6, the mold 20 having a surface shape (convex) corresponding to the concave lens portion 6a is used.

  A 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 the resin (resin 4A or resin 6A) on the mold 20. Yes. That is, the light source 90 is configured to irradiate the resin 4A and the resin 6A with light that promotes curing.
The light from the light source 90 is parallel light and is incident on the glass substrate 2 so as to be orthogonal.

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, 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 is light that has a peak top at 351 nm and emits near-ultraviolet light of 300 to 400 nm.

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.

  Then, the manufacturing method of the wafer lens 1 using the wafer lens manufacturing apparatus 30 is demonstrated.

  In the manufacturing method according to the present embodiment, the resin part 6 is formed first out of the resin part 4 and the resin part 6, and then the resin part 4 is formed.

Specifically, first, as shown in FIG. 2, the glass substrate 2 is placed on the substrate holder 80 to be sucked and fixed, and the mold 20 is placed on the vacuum chuck device 70 to suck and mold the mold 20. Fix it.
Thereafter, a predetermined amount of resin 6 </ b> A 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 6A is dripped on the metal mold | die 20 here, this invention is not limited to this, You may dripped on the glass substrate 2. FIG. In addition, a dropping method is also applied to a method in which the mold 20 is filled by dropping and spreading them on a predetermined place, or in each cavity of the mold 20 or each concave lens portion 6a of the glass substrate 2 is formed in advance. A method may be used in which the liquid is dropped individually and filled by pressing them with the mold 20 or the glass substrate 2 arranged to face 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.
In the wafer lens manufacturing apparatus 30, the height position of the mold 20 to be moved is preset in the control apparatus 100, and the control apparatus 100 moves the geared motor 50 to a position where the mold 20 reaches the reference position S. When the mold 20 reaches the reference position S, the operation of the geared motor 50 is stopped (position control process).

  As a result, the resin 6 </ b> A gradually spreads upon receiving a pressure from the mold 20 to the glass substrate 2 and is filled between the glass substrate 2 and the mold 20.

  Thereafter, the light source 90 is turned on while the mold 20 is held at the position corresponding to the reference position S, light is irradiated toward the resin 6A, and the resin 6A is cured (light irradiation step).

  Here, when the resin 6A is cured (during or after the resin 6A is cured), if the stage 40 is held at a predetermined height position, the glass substrate 2 is not damaged even if the resin 6A is cured and contracted. There is a possibility that the resin 6A does not follow the shrinkage and distortion is generated inside the resin 6A, or the transfer of the surface shape of the mold 20 to the resin 6A becomes insufficient.

Therefore, in this embodiment, when the light source 90 is turned on for a certain period of time and a certain amount of light is irradiated to the resin 6A, the pressure of the mold 20 is controlled to a predetermined pressure by controlling the pressure of the mold 20. Hold.
Specifically, the geared motor 50 is actuated again, the shaft 52 is extended upward, and the stage 40 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 load cell 44, and moves the stage 40 upward while maintaining the pressing force of the stage 40 against the glass substrate 2 at a predetermined pressure.
In the wafer lens manufacturing apparatus 30, the pressing force of the stage 40 against the glass substrate 2 is preset in the control apparatus 100, and the control apparatus 100 controls the operation of the geared motor 50 based on the output value received from the load cell 44. The pressing force against the glass substrate 2 is maintained at a predetermined pressure (pressure control step).

  In this case, the control device 100 also controls the paralleling member 60, the XY stage 62, and the θ stage 64 based on the output values of the potentiometer 51 and the load cell 44, and the parallelism between the glass substrate 3 and the sub master 20 and the resin 6A. The uniform load is kept constant.

Thereafter, the light source 90 is turned off and light irradiation to the resin 6A is stopped. The light irradiation on the resin 6A may be stopped before the pressure control step.
Thereafter, the geared motor 50 is operated to shrink the shaft 52 downward, the mold 20 is returned to the original height position, and the cured resin 6A is released from the mold 20 together with the glass substrate 2 (release). Process).
As a result, the resin part 6 in which the plurality of concave lens parts 6 a are formed can be formed on the glass substrate 2.

Thereafter, as shown in FIG. 4A, the resin part 6 is arranged on the upper side, and the resin part 6 is formed on the glass substrate 2 (repeating the process from the preparation process to the mold release process). 4B, the resin part 4 is formed on the glass substrate 2. As shown in FIG.
In this case, the mold 20 for forming the resin part 4 is used instead of the mold 20 for forming the resin part 6, and the resin 4A is used instead of the resin 6A.

Here, when forming the resin part 4, as shown in FIG.4 (c), before irradiating light with respect to resin 4A, the concave lens part 6a of the resin part 6 is filled with the light-transmitting agent 10, and a concave lens is used. The surface of the part 6a is made flat. The light transmitting agent 10 is obtained by removing the photoinitiator from the material constituting the resin 6A, and is a light transmitting resin material that prevents light incident from the resin portion 6 toward the resin portion 4 from diffusing. is there.
The resin 4A and the resin 6A are basically the same (same type) material.

  The light transmitting agent 10 is preferably one that satisfies the condition of the formula (1) in relation to the resin 6A constituting the concave lens portion 6a.

  In formula (1), “n1” is the refractive index of the resin 6A (resin that forms the concave optical surface) constituting the resin part 6, and “n2” is the resin material of the light transmitting agent 10 (fills the concave lens part 6a). The refractive index of the resin material), and “θ” represents the largest angle among the angles formed with respect to the glass substrate 2 on the optical surface of the concave lens portion 6a (see FIG. 1).

  In this state, the light source 90 is turned on, and the light from the light source 90 is applied to the resin 4 </ b> A constituting the resin portion 4 through the resin portion 6 and the glass substrate 2.

  According to the above embodiment, when forming the convex lens part 4a having positive power, the concave lens part 6a is filled with the light transmitting agent 10 to flatten the surface of the concave lens part 6a. In this case, the light can be incident on the resin 4A constituting the convex lens portion 4a as parallel light. Therefore, when the convex lens portion 4a is formed, it is possible to suppress the formation of a sparse region of incident light, and thus the resin 4A constituting the lens portion 4a having positive power can be uniformly cured. it can.

  In the present embodiment, an example in which the concave lens portion 6 a having negative power is filled with the light transmitting agent 10 is shown. However, the concave lens portion 6 a has a surface shape that is flattened by the filling of the light transmitting agent 10. For example, a case in which a concave portion is formed at least in part is included, and a case in which an irregular shape such that the concave and convex shape is continuous is included.

[Second Embodiment]
The second embodiment is different from the first embodiment in the following points, and other technical matters (configuration, operation, etc.) are the same as those of the first embodiment.

  In 2nd Embodiment, regarding the order of forming the resin part 4 and the resin part 6, the resin part 4 is formed first and the resin part 6 is formed after that. That is, as shown in FIG. 5A, the resin portion 4 is formed by first irradiating the light of the light source 90 with the curing light directly on the resin 4A constituting the resin portion 4 only through the glass substrate 2. Then, the resin portion 6 is formed by irradiating the resin 6 </ b> A constituting the resin portion 6 with the light of the light source 90 through the resin portion 4 and the glass substrate 2.

Also in the above embodiment, when the convex lens portion 4a having positive power is formed, the light from the light source 90 can be incident on the resin 4A constituting the convex lens portion 4a as parallel light, and thus the convex lens portion 4a. The formation of a sparse region of incident light can be suppressed at the time of forming, and as a result, the resin 4A constituting the lens portion 4a having a positive power can be uniformly cured.
In this case, the concave lens portion 6a is affected by the previously formed convex lens portion 4a, but is less affected than the convex lens portion 4a.

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 10 Light transmitting agent 20 Mold 30 Wafer lens manufacturing apparatus 32 Base 34 Protrusion part 36 Guide 40 Stage 42 Through-hole 44 Load cell 46 Concave part 50 Geared motor 51 Potentiometer 52 Shaft 60 Parallel member 62 XY stage 64 θ stage 70 Vacuum chuck device 72 Communication groove 80 Stamp holder 82 Communication groove 90 Light source 100 Wafer lens 102 Glass substrate 104, 106 Lens part 110 Mold A dense area B sparse area

Claims (8)

In the method of manufacturing a wafer lens in which a lens portion made of a photocurable resin is formed on each of the front and back surfaces of the glass substrate,
Irradiating the photocurable resin with light that promotes curing to form a first lens portion on one surface;
Irradiating the photocurable resin with light that promotes curing to form a second lens portion on the other surface;
With
At least one of the first and second lens portions has a positive power for focusing incident light, and in the step of forming the lens portion having the positive power, the photocurable resin constituting the lens portion A method of manufacturing a wafer lens, wherein parallel light is incident on the wafer lens. In the manufacturing method of the wafer lens according to claim 1,
The second lens unit has a positive power for focusing incident light;
After the step of forming the first lens portion, the step of forming the second lens portion is performed,
In the step of forming the second lens portion, the second lens is configured through the first lens portion and the glass substrate in a state where the surface of the first lens portion is flattened. A method for producing a wafer lens, comprising irradiating a photocurable resin with light. In the manufacturing method of the wafer lens according to claim 2,
The first lens unit has a negative power to diverge incident light;
In the step of forming the second lens portion, a method of manufacturing a wafer lens, comprising filling the first lens portion with a light transmitting agent to flatten the surface of the first lens portion. In the manufacturing method of the wafer lens according to claim 2,
The first lens portion has a recess at least in part;
In the step of forming the second lens portion, the concave portion of the first lens portion is filled with a light transmitting agent to flatten the surface of the first lens portion. . In the manufacturing method of the wafer lens according to claim 2,
The first lens portion has an irregular shape;
In the step of forming the second lens portion, the concave portion of the first lens portion is filled with a light transmitting agent to flatten the surface of the first lens portion. . In the manufacturing method of the wafer lens according to any one of claims 3 to 5,
The method for producing a wafer lens, wherein the light transmitting agent is a resin material obtained by removing a photoinitiator from the photocurable resin. In the manufacturing method of the wafer lens according to any one of claims 3 to 6,
The method for producing a wafer lens, wherein the light transmissive agent satisfies the condition of the formula (1) in relation to the photocurable resin.

In formula (1), “n1” is the refractive index of the photocurable resin, “n2” is the refractive index of the light transmitting agent, and “θ” is the optical surface of the first lens unit. The largest angle among the angles formed with respect to the glass substrate is shown. Manufacture of a wafer lens in which a first lens portion having a positive power made of a photocurable resin is formed on one surface of a glass substrate and a second lens portion having a negative power of a photocurable resin property is formed on the other surface. In the method
A first lens part filling step of filling a photocurable resin between one surface of the glass substrate and a mold having a molding surface corresponding to the shape of the first lens part;
A second lens portion filling step of filling a photocurable resin between the other surface of the glass substrate and a molding die having a molding surface corresponding to the shape of the second lens portion;
After performing the first lens portion filling step, before the second lens portion filling step, the photocurable resin of the first lens portion filled through the glass substrate from the other surface side of the glass substrate. A method for producing a wafer lens, comprising performing a photocuring step for curing.

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