JP2012123239A - Photographic lens, wafer lens provided with spacer and wafer lens laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent peeling between layers of a wafer lens and between the wafer lens and a spacer and crack of them in manufacturing a photographic lens by cutting, into individual lens portions, a wafer lens connected to a spacer or a wafer lens laminate.SOLUTION: A wafer lens provided with a spacer comprises: a wafer lens including a plurality of lens portions made of a resin and two-dimensionally arranged on at least one face of a substrate; and a spacer having a plurality of openings and connected to at least one face of the wafer lens. The spacer is disposed so that optical axes of the respective lens portions penetrate the respective openings of the spacer, and the spacer has a bending elastic modulus of 1.5 GPa or more and 30 GPa or less.

Description

  The present invention relates to an imaging lens made of a resin optical element, a wafer lens with a spacer and a wafer lens laminate for manufacturing the imaging lens by separating the lens.

  Conventionally, in the field of manufacturing optical lenses, a technique for obtaining an imaging lens having high heat resistance by providing a lens portion (optical element) made of a curable resin such as a thermosetting resin on a glass flat plate has been studied. .

  As a method for industrially manufacturing such an imaging lens, a curable resin is applied to a glass plate, and a mold having a two-dimensional shape for molding the lens is pressed and cured. As a result, a wafer lens in which a large number of lens portions are two-dimensionally arranged is formed, and the wafer lens is cut along a plane parallel to the optical axis of the lens portion, thereby obtaining an individual imaging lens. A method has been proposed. In such a manufacturing method, when the wafer lens is set on the work table and cut, an opening is previously formed at a position corresponding to the lens unit so that the lens unit does not touch the work table and damage the lens unit. A step of adhering the provided spacer to the lens portion forming surface of the glass flat plate so as to surround the lens portion with the opening edge can be adopted.

  In addition, when a wafer lens laminate is manufactured by laminating the lens parts of a plurality of wafer lenses to face each other, a spacer is sandwiched between both wafer lenses so as not to contact each other. Thus, a wafer lens laminate is manufactured, and the wafer lens laminate thus obtained is cut into individual pieces, and a plurality of lens portions stacked in the vertical direction are used as one set for imaging. It has also been proposed to manufacture a lens (see Patent Document 1).

  In addition, as a technique for improving the adhesiveness of the layer formed in the optical member, as disclosed in Patent Document 2, an antireflection film for suppressing reflection on the surface of the optical member and a base material on which the antireflection film is formed A technique for improving the adhesion of the antireflection film to the base material by providing a layer containing a silane coupling agent between them is known.

JP 2009-301061 A JP 2000-241604 A

  When cutting the wafer lens or wafer lens laminate as described above for each lens unit, according to the study of the present inventor, the lens unit may be peeled off from the substrate, and a diaphragm is formed integrally with the substrate. In some cases, in addition to this, it has been found that there may be a further problem of delamination due to the substrate formed with the lens portion and the diaphragm, the substrate and the diaphragm, and cutting at each interface.

  In order to prevent peeling at the time of cutting, the adhesion between the substrate and the lens unit should be improved. If a diaphragm is provided, the adhesion between each lens unit and the diaphragm and between the diaphragm and the substrate It is possible to improve power.

  According to the study of the present inventor, in order to improve the adhesion between the substrate and the resin layer and to improve the adhesion between the spacer and the resin layer, as shown in Patent Document 2, the silane cup is attached to the substrate. Even if the ring agent treatment is performed and the spacer is subjected to the silane coupling agent treatment, the improvement in peeling during dicing is insufficient.

  The present invention has been made in view of the above circumstances. When an imaging lens is manufactured by cutting a wafer lens and a wafer lens laminated body into individual lens parts and manufacturing the imaging lens, the wafer lens is interposed between the wafer lens and the wafer lens. An object is to affix a spacer having a predetermined elastic modulus, relieve stress generated during dicing, and prevent peeling and cracking between each layer of the wafer lens and between the wafer lens and the spacer.

  It is another object of the present invention to prevent the diaphragm from peeling from the substrate when the wafer lens and wafer lens laminate have a diaphragm, and to prevent the lens portion from peeling from the diaphragm and the substrate. It is another object of the present invention to provide a wafer lens with a spacer, a wafer lens laminate, and an imaging lens that are free from failure due to the peeling.

  The above problem is solved by the following means.

  1. In the wafer lens with a spacer, wherein a spacer having a plurality of openings is joined to at least one surface of a wafer lens in which a plurality of lens portions made of resin are two-dimensionally arranged on at least one surface of the substrate. A wafer lens with a spacer, wherein the spacer is disposed so that the optical axis of the lens portion passes through the opening of the spacer, and the flexural modulus of the spacer is 1.5 GPa or more and 30 GPa or less.

  2. 2. The wafer lens with a spacer according to 1 above, wherein the spacer has an elastic modulus of 2 GPa or more and 7 GPa or less.

  3. 3. The wafer lens with a spacer according to 1 or 2, wherein the spacer has a thickness of 0.1 mm or more and 0.8 mm or less.

  4). 4. The wafer lens with a spacer according to any one of 1 to 3, wherein the light transmittance of the spacer is 30% or more at a wavelength of 350 nm.

  5). The wafer with a spacer according to any one of 1 to 4, wherein the plurality of lens portions are respectively disposed on both surfaces of the substrate, and the lens portions on both surfaces have a substantially common optical axis. lens.

  6). 6. The wafer lens with a spacer according to any one of 1 to 5, further comprising a stop having an opening through which an optical axis of the lens unit passes.

  7). The wafer lens with a spacer according to any one of 1 to 6, wherein the wafer lens has an IR cut layer.

  8). 8. An imaging lens cut out from the wafer lens with a spacer according to any one of 1 to 7 by a plane parallel to the optical axis of the lens unit, wherein the lens unit and at least one surface of the substrate An imaging lens, wherein the spacer is disposed.

  9. The wafer lens with a spacer according to any one of 1 to 7 is a second wafer lens, and a first wafer lens in which a plurality of lens portions containing a curable resin is two-dimensionally arranged on a first substrate; A wafer lens laminate in which the second wafer lens is laminated, wherein the first wafer lens is laminated on a surface opposite to the spacer of the second wafer lens.

  10. 10. The wafer lens laminate according to 9 above, wherein a spacer is provided between the first wafer lens and the second wafer lens.

  11. 11. The wafer lens laminate according to 9 or 10, wherein each of the first wafer lens and the second wafer lens has the diaphragm.

  12 The wafer lens laminate according to any one of 9 to 11, wherein the first wafer lens has an IR cut layer.

  13. 13. An imaging lens cut out from the wafer lens stack according to any one of 9 to 12 in a plane parallel to an optical axis, the first substrate having at least one lens unit, and the same as the lens unit An imaging lens comprising a second substrate having a lens portion having an optical axis and a spacer.

  When wafer lenses and wafer lens stacks to which spacers are bonded are cut and separated into individual lens parts to produce imaging lenses, peeling and cracking between wafer lens layers and between wafer lenses and spacers are performed. Can be prevented.

It is sectional drawing of one Embodiment of a wafer lens. (A) It is a typical perspective exploded view of one Embodiment of the wafer lens with a spacer. (B) It is an external view of one Embodiment of the wafer lens with a spacer. It is a figure which shows the preparation methods of a wafer lens. (A) It is a figure which shows the process of adhere | attaching a spacer on a wafer lens. (B) It is a figure which shows the state before performing dicing. FIG. 10 is a cross-sectional view showing a configuration after a diaphragm is formed, which is a substrate used in another embodiment. (A) It is a figure which shows the process of joining a spacer to a wafer lens. (B) It is a figure which shows the state before performing dicing. It is sectional drawing of one Embodiment of the wafer lens laminated body by which the 1st wafer lens and the 2nd wafer lens were laminated | stacked through the spacer. It is sectional drawing of one Embodiment of a wafer lens laminated body before performing dicing. FIG. 6 is a cross-sectional view of another embodiment of a wafer lens, wherein (a) is a cross-sectional view of the first wafer lens, (b) is a cross-sectional view of the second wafer lens, and (c) is a spacer of the first wafer lens. It is sectional drawing of the wafer lens laminated body which bonded and laminated | stacked the part and the spacer part of the 2nd wafer lens. (A) It is sectional drawing of one Embodiment of the lens for imaging cut out from the wafer lens with a spacer. (B) It is sectional drawing of one Embodiment of the lens for imaging cut out from the wafer lens laminated body.

  Hereinafter, preferred embodiments of the present invention will be described.

(Wafer lens)
As shown in FIG. 1, the wafer lens 1 of the present embodiment has a structure in which a plurality of lens portions 42 and 52 are formed on a substrate. As will be described later, an imaging lens can be manufactured by cutting the wafer lens 1 along a plane parallel to the optical axis (perpendicular to the substrate surface) and dividing it into individual lens portions. In this embodiment, a wafer lens having lens portions on both sides of the substrate will be described as an example. However, a wear lens having lens portions only on one side of the substrate may be used.

  As shown in FIG. 1, the wafer lens 1 mainly includes a glass substrate 10, an IR cut layer 12, diaphragms 20 and 30, and resin portions 40 and 50. FIG. 1 is a cross-sectional view taken along the line II in FIG. 2B (the line II passes through two lens portions), and the spacer is omitted.

  The substrate 10 is disposed at the center of the wafer lens 1, the IR cut layer 12 and the light shielding layer 20 are formed on the substrate 10, and the light shielding layer 30 is formed below the substrate 10. . Each of the light shielding layers 20 and 30 is partially formed with an opening as will be described later, and functions as a stop. A resin portion 40 is formed on the top of the substrate 10, and the resin portion 40 covers the upper surface and the opening of the diaphragm 20. A resin part 50 is formed in the lower part of the substrate 10, and the resin part 50 covers the lower surface and the opening of the diaphragm 30.

  FIG. 2A is a schematic perspective exploded view showing a layer structure of a wafer lens with a spacer manufactured by bonding a spacer to the wafer lens 1. In FIG. 2A, the IR cut layer 12 is not shown. The diaphragms 20 and 30 are elements for adjusting the amount of light with respect to the wafer lens 1. The diaphragms 20 and 30 are made of a light-shielding material, and are formed on the upper surface and the lower surface of the substrate 10, respectively.

  The diaphragm 20 is formed with a plurality of circular openings 22, and the diaphragm 30 is formed with a plurality of circular openings 32.

  The resin portion 40 is formed with a plurality of lens portions 42 arranged in an array. The lens portion 42 is a convex portion on the upper side, and its surface is an optical surface. The resin portion 50 is also formed with a plurality of lens portions 52 arranged in an array. The lens portion 52 is a portion having a convex shape on the lower side, and the surface thereof is an optical surface.

  In the wafer lens 1 described above, in FIG. 2A, the lens part 42, the opening part 22, the opening 32, and the lens part 52 are arranged in the corresponding positions in the vertical direction from the top. 32 has a common optical axis. When these are viewed in plan, their positions all coincide.

  FIG.2 (b) is an external view which shows the state which laminated | stacked the part of Fig.2 (a).

  Next, a method for manufacturing the wafer lens 1 will be described.

  First, the IR cut layer 12 is provided on one surface of the substrate 10 using vacuum deposition, sputtering, or the like. Then, as shown in FIG. 3A, a diaphragm 20 is formed on the IR cut layer 12 of the substrate 10 using a known photoetching technique. Specifically, there is a method of forming an opaque metal film on the substrate 10 by a method such as vapor deposition or sputtering, and then forming an opening (light transmitting portion) 22 in the metal film by a photoresist process. A diaphragm may be formed by the photoresist itself by forming a film with a dark color photoresist and forming an opening in the photoresist process.

  Thereafter, as shown in FIG. 3B, an uncured curable resin is placed on the glass substrate 10 and the mold 60 is pressed from above, and the uncured curability is placed in the cavity 62 of the mold 60. Fill with resin.

  Then, as shown in FIG.3 (b), light irradiation is performed from the upper direction of the shaping | molding die 60. FIG. The mold 60 has translucency that transmits light having a wavelength for curing the curable resin. The light passes through the mold 60 and enters the uncured curable resin, and the curable resin is cured. To do. As a result, the resin part 40 (including the lens part 42) is formed.

  Thereafter, the glass substrate 10 on which the resin part 40 is formed is released from the mold 60 and turned over, and a known lift-off technique or printing method is used on the other surface of the glass substrate 10 as shown in FIG. Thus, the diaphragm 30 is formed.

  Thereafter, as shown in FIG. 3D, an uncured curable resin is placed on the glass substrate 10, and the mold 80 is pressed from above, and the uncured curability in the cavity 82 of the mold 80. Fill with resin.

  Thereafter, light is irradiated from above with the uncured curable resin filled in the cavity 82 of the mold 80. Since the mold 80 is also translucent like the mold 60, the light passes through the mold 80 and enters the uncured curable resin, and the curable resin is cured. As a result, the resin part 50 (including the lens part 52) is formed.

  Thereafter, the glass substrate 10 on which the resin portion 50 is formed is released from the forming mold 80, and the wafer lens 1 is manufactured.

  After the steps of FIGS. 3A to 3D, an adhesive 142 is applied to the upper surface of the resin portion 50 of the wafer lens 1 or the lower surface of the spacer 140 as shown in FIG. The spacer 140 is placed. Thereafter, the adhesive 142 is cured by irradiating light from the spacer 140 side, the spacer 140 is fixed to the wafer lens 1, and the wafer lens 6 with a spacer is manufactured.

  The spacer-attached wafer lens 6 to which the spacer is fixed is turned over and placed on the work table with the spacer 140 facing downward, and is cut along the cutting line 170 located between the individual lens portions by a dicer from above. It is cut together with the diaphragm and divided into individual imaging lenses.

  Instead of the diaphragm 20 of FIG. 1, as shown in FIG. 5, it is also possible to use a substrate provided with diaphragms 120 and 130 in which a region without a diaphragm member is provided at the adhesion position of the spacer. In this case, as shown in FIG. 6A, the spacer 140 is bonded to the wafer lens 3 manufactured using the substrate provided with the diaphragms 120 and 130, and the adhesive 142 is cured by irradiating with light. A wafer lens 6 is produced.

  The light irradiation may be performed from the spacer 140 side, from the wafer lens 3 side, or from both sides. In FIG. 5, the IR cut layers 12 and 13 are provided on both surfaces of the substrate 10, but may be provided only on one surface of the substrate. Further, in the case of a wafer lens laminated body in which a plurality of wafer lenses are laminated as will be described later, when an IR cut layer is provided on another wafer lens, the IR cut layer can be omitted.

  Thereafter, as shown in FIG. 6 (b), the spacer 140 is placed on the work table, and the dicer is cut along the cutting line 171 located between the individual lens portions from above, thereby reducing the aperture. The wafer lens with the spacer is cut without being cut, and divided into individual imaging lenses. Here, by dicing the portions 73 and 83 of the wafer lens 3 that do not have a diaphragm, when the adhesion between the diaphragm and the substrate is low, it is possible to reduce peeling and cracking at those portions.

(Wafer lens laminate)
A cross-sectional view of the wafer lens laminate 100 of the present embodiment is shown in FIG. Wafer lens laminate 100 has a structure in which wafer lens 6 with spacer (second wafer lens) and wafer lens 2 (first wafer lens) are bonded via adhesive 152, spacer 150 and adhesive 154.

  The wafer lens 6 with a spacer, which is the second wafer lens, is obtained by bonding a spacer 140 to the wafer lens 3 shown in FIG. However, the IR cut layer is not provided on the substrate 10.

  The wafer lens, which is the first wafer lens, has a configuration similar to that of the wafer lens 3 shown in FIG. 6 and has diaphragms 120 and 130 provided on both surfaces of the substrate 10. This is a form in which no diaphragm member is provided in the adhesion region of the spacer. Resin portions 40 and 50 having lens portions 42 and 52 are formed on both surfaces of the substrate 10 with a curable resin. The IR cut layer 12 is provided only on one side of the substrate 10.

  A method for manufacturing wafer lens laminate 100 will be described below.

  First, the wafer lens 3 is manufactured by the same procedure as described with reference to FIG. 5, and the spacer 140 is bonded by the same procedure described with reference to FIG. 6A to manufacture the wafer lens 6 with spacer.

  As the second wafer lens, the wafer lens 1 shown in FIG. 1 (a configuration having a diaphragm member in the spacer adhesion region) can be used, but a wafer lens having a configuration having no diaphragm member in the spacer adhesion region is used. This method is advantageous in reducing peeling and cracking because dicing is performed on a portion without a diaphragm when dividing into individual imaging lenses.

  In FIG. 7, a spacer 150 is bonded to the wafer lens 2 (first wafer lens) with an adhesive 152 in the same manner as the second wafer lens.

  The spacer 150 of the first wafer lens and the non-lens portion of the resin portion 50 in the region 83 without the diaphragm of the second wafer lens are bonded via an adhesive 154, and light is irradiated from the first wafer lens side. Thus, the adhesive is cured to produce the wafer lens laminate 100 shown in FIG.

  Although a photo-curing type adhesive was used for bonding, the first wafer lens diaphragm is transparent because the adhesion portion of the spacer is transparent and the irradiation light is not shielded by the first wafer lens diaphragm. Is cured.

  Since the light irradiation is performed from the first wafer lens side, the second wafer lens has no problem in curing the adhesive even if there is a diaphragm at the bonding portion of the spacer. For this reason, the wafer lens 1 of FIG. 1 may be used as the second wafer lens. However, as described above, from the viewpoint of reduction by peeling and cracking due to dicing, the wafer lens 3 having no diaphragm member in the adhesion region of the spacer is used. It is preferable.

(Imaging lens)
The imaging lens is a lens that has a lens portion having a curable resin on at least one surface of a substrate and can image a subject, and has a spacer that has an opening on at least one surface of the substrate. The spacer is arranged so that the optical axis of the lens portion passes through the opening.

  The imaging lens preferably has a plurality of lens portions sharing one optical axis, and may have a structure having lens portions on both sides of a single substrate, or a structure in which a plurality of substrates having lens portions are laminated. There may be.

  For example, when an imaging lens having a structure having lens portions on both surfaces of a single substrate is prepared, the wafer lens spacer 140 in FIG. 6B is placed in contact with the work table, and the resin portion 40 side in FIG. Dicing is performed at the cutting line 171 shown in FIG.

  Further, for example, when an imaging lens having a structure in which two substrates are laminated from the wafer lens laminate shown in FIG. 7, the spacer 140 on the second wafer lens side is used as a work table as shown in FIG. A piece of imaging lens can be obtained by placing the electrodes in contact with each other and dicing the resin part 40 from the cutting line 180 shown in FIG.

  Therefore, the imaging lens has a spacer on at least one surface, and an imaging device can be easily manufactured by joining an imaging element to the spacer.

(Dicing)
The dicing of the wafer lens can be performed using a conventionally known cutting tool. For example, a dicer using a rotary blade is used, and the blade rotation speed is 3000 rpm to 50000 rpm, and the cutting speed is 1 to 10 mm / sec. Is preferred.

  Note that during dicing, dust moves at the dicing portion. Therefore, it is preferable to cut the dicing portion while flowing (spouting) a dust-proof fluid (for example, pure water).

  Since the spacer is also diced simultaneously by dicing the wafer lens, if the elastic modulus of the spacer is too high, failure due to peeling or cracking of each member is likely to occur, and if the elastic modulus is too low, it is likely to be deformed by the force at the time of cutting. As a result, the accuracy of the cutting position decreases. In the present embodiment, as will be described later, the problem of dicing is avoided by defining the bending elastic modulus of the spacer within a predetermined range.

  As described above, a plurality of imaging lenses having a single optical axis having a plurality of common lens portions as shown in FIGS. 10A and 10B are produced from one wafer lens or wafer lens laminate. Can do.

(substrate)
Both the first substrate and the second substrate are transparent, and a thermosetting resin, a photocurable resin, a thermoplastic resin, ceramic, or glass can be used, and glass is particularly preferable.

(Resin part)
The resin part is formed with a lens part and a non-lens part located around the lens part. The resin part is made of a transparent curable resin. Examples of the curable resin include a thermosetting resin and a photocurable resin, and a photocurable resin is preferable.

  When the resin portion is formed from a photocurable resin, the resin portion is formed by the following method.

  A curable resin is filled in a mold (transparent) of the resin part, pressed against a glass substrate, and irradiated with ultraviolet rays through the mold. The resin is cured to form a lens portion and a non-lens portion.

  As shown in FIG. 1, the thickness of the non-lens portion may be smaller than the thickness of the apex of the lens portion, or the spacer portion (non-lens portion) 92 in FIG. 9A and the spacer portion in FIG. An area thicker than the apex of the lens portion, such as a non-lens portion 93, may be included. When the non-lens portion includes a thick region, the distance between the first substrate and the second substrate can be appropriately maintained as shown in FIG. 9C, and the spacer can be omitted.

  As the photocurable resin, for example, acrylic resins, allyl ester resins, epoxy resins and the like as shown below can be used.

  When an acrylic resin or an allyl ester resin is used, it can be cured by radical polymerization. When an epoxy resin is used, it can be cured by cationic polymerization.

  Details of the resin are as follows (1) to (3).

(1) 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. 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 structure The (meth) acrylate which has is mentioned. One or more of these can be used.

  In particular, (meth) acrylate having an alicyclic structure is 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 JP 2002-193883 A), adamantyl di (meth) acrylate (JP 57-5000785), diallyl adamantyl dicarboxylate (JP 60-60). No. 100537), perfluoroadamantyl acrylate (see JP-A No. 2004-123687), Shin-Nakamura Chemical 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'- Adamantane compound (see US Pat. No. 3,342,880), tetraadamantane (see JP 2006-169177), 2-alkyl-2-hydroxyadamantane, 2-alkyleneadamantane, 1,3-adamantane dicarboxylic acid di-tert Curable resins having an adamantane skeleton having no aromatic ring such as butyl (see JP-A-2001-322950), bis (hydroxyphenyl) adamantanes, and bis (glycidyloxyphenyl) adamantane (JP-A-11-35522) And JP-A-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.

  As polyfunctional (meth) acrylate, for example, 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 Such as Li (meth) acrylate.

(2) Allyl ester resin A resin having an allyl group and cured by radical polymerization. Examples thereof include the following, but are not particularly limited to the following.

  Bromine-containing (meth) allyl ester not containing an aromatic ring (see JP 2003-66201 A), allyl (meth) acrylate (see JP 5-286896 A), allyl ester resin (JP 5-286896 A) , JP 2003-66201 A), a copolymer compound of an acrylate ester and an epoxy group-containing unsaturated compound (see JP 2003-128725 A), an acrylate compound (see JP 2003-147072 A), acrylic Examples include ester compounds (see JP 2005-2064 A).

(3) Epoxy resin The epoxy resin is not particularly limited as long as it has an epoxy group and is polymerized and cured by light or heat, and an acid anhydride, a cation generator, or the like can be used as a curing initiator. Epoxy resin is preferable in that it has a low cure shrinkage and can be a lens with excellent molding accuracy.

  Examples of the epoxy include novolak phenol type epoxy resin, biphenyl type epoxy resin, and dicyclopentadiene type epoxy resin. Examples include bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, 2,2'-bis (4-glycidyloxycyclohexyl) propane, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, vinyl Cyclohexene dioxide, 2- (3,4-epoxycyclohexyl) -5,5-spiro- (3,4-epoxycyclohexane) -1,3-dioxane, bis (3,4-epoxycyclohexyl) adipate, 1,2 -Cyclopropanedicarboxylic acid bisglycidyl ester etc. can be mentioned.

  A hardening | curing agent is used when comprising curable resin material, and there is no limitation in particular.

  As the curing agent, an acid anhydride curing agent, a phenol curing agent, or the like can be preferably used. Specific examples of the acid anhydride curing agent include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, 3-methyl-hexahydrophthalic anhydride, 4-methyl-hexahydrophthalic anhydride. Examples thereof include an acid, a mixture of 3-methyl-hexahydrophthalic anhydride and 4-methyl-hexahydrophthalic anhydride, tetrahydrophthalic anhydride, nadic anhydride, methyl nadic anhydride and the like.

  Moreover, a hardening accelerator is contained as needed. The curing accelerator is not particularly limited as long as it has good curability, is not colored, and does not impair the transparency of the curable resin. For example, 2-ethyl-4-methylimidazole ( 2E4MZ) and other imidazoles, tertiary amines, quaternary ammonium salts, bicyclic amidines such as diazabicycloundecene and derivatives thereof, phosphines, phosphonium salts, and the like can be used. You may mix and use a seed | species or more.

(spacer)
When dicing a wafer lens or wafer lens laminate, the spacer is used to prevent the lens portion from being damaged by contact with the work table, and when the wafer lens laminate is formed by stacking the wafer lenses. In addition, the lens portion of one wafer lens is provided so as not to come into contact with the other wafer lens and be damaged. The spacer is cut together with the substrate and the resin part during dicing.

  Also, a spacer provided on a wafer lens with a spacer or a wafer lens laminate and an array in which image sensors are arranged two-dimensionally are bonded so that each lens unit and image sensor correspond to each other, A large number of imaging devices having a lens unit and an image sensor are manufactured in a two-dimensional array, and then the multilayer body is diced and separated into individual imaging devices. Can be produced.

  The material of the spacer is not particularly limited, such as soft glass, resin, and organic / inorganic hybrid material. However, a heat resistant resin or a heat resistant organic / inorganic hybrid material is preferable. The organic-inorganic hybrid material is preferably a heat-resistant glass fiber reinforced resin, a filler reinforced resin, an organic-silica hybrid, or the like. In particular, organic silica hybrids are good, and among them, epoxy resin-silica hybrids and acrylic-silica hybrids are preferable because they have good adhesion to the lens resin part.

  As glass fiber reinforced resin, Sumitomo Bakelite Co., Ltd. Sumilite EL-3762, Ryoden Kasei Co., Ltd. PGE-6711, etc. are mentioned, for example. Examples of the epoxy resin-silica hybrid and the acrylic-silica hybrid include Comporacene E and Compolacene AC manufactured by Arakawa Chemical Industries.

  As the heat resistant resin, polyimide is preferable, and Neoprim 3430 manufactured by Mitsubishi Gas Chemical Co., Ltd. is preferable because of its high transmittance.

  The thickness of the spacer is set to a value that appropriately maintains the distance between the lens unit and the imaging element or the interval between a plurality of laminated lens units. The thickness of the spacer depends on the optical characteristics of the lens portion, the performance of the imaging device, the function and application required for the imaging lens, but is preferably about 0.1 mm to 0.8 mm, preferably 0.2 mm to 0 mm. More preferably, it is 6 mm or less. When the thickness is 0.1 mm or more, handling is easy, stress relaxation is high, and peeling and cracking failures are unlikely to occur. Moreover, it is preferable that it is 0.8 mm or less because the transmittance is high.

  It is important that the spacer has a high light transmittance, because when the wafer lens and spacer are bonded using a photocurable adhesive, the adhesive is irradiated with light through the spacer and cured. It is. If the transmittance of light having a wavelength of 350 nm is 30% or more, it is preferable that the UV curing proceeds rapidly at the time of bonding with a lens or a wafer lens. More preferably, it is 50% or more.

  The flexural modulus of the spacer is 1.5 GPa or more and 30 GPa or less, more preferably 2 GPa or more and 7 GPa or less. Within this range, cutting stress is absorbed during dicing, and the diaphragm, lens, and IR cut member are not peeled off, cracked, and brittle fracture of the glass substrate is unlikely to occur. When the flexural modulus is 1.5 GPa or more, the spacer is hardly distorted and high cutting accuracy can be maintained. Moreover, if it is 30 GPa or less, the effect which absorbs cutting stress in the case of dicing will be large. The flexural modulus is measured according to JIS K 7203.

  Although the detailed reason for preventing the occurrence of problems during dicing by using a spacer having a flexural modulus in the above range is unknown, the wafer lens manufacturing process, spacer bonding process, wafer lens In the lamination process, etc., internal stress is accumulated in the wafer lens, and this is released at once by dicing. By absorbing it by the bending elasticity of the spacer, one factor is to reduce the impact caused by the release of internal stress. It is estimated that.

(Aperture)
Examples of the diaphragm include a negative resist curable by UV or heat, a positive resist containing a black filler, and a resist mainly composed of chromium oxide.

  There are various positions for forming the diaphragm member, such as a position in contact with the substrate, a portion formed on the lens resin layer after the lens resin layer is formed, a portion of the substrate itself is blackened, and a portion formed on the IR cut member. Takes form. An example of a method of forming on a substrate or an IR cut member is to form a diaphragm on the substrate by a vapor deposition method or a coating method, and then processing it in an annular shape in plan view so as to cover the periphery of the lens portion. Can be mentioned.

  Even when the diaphragm is not in the dicing position when the lens is separated, failure such as peeling or cracking is likely to occur, but in the configuration of the present invention, the diaphragm is in the dicing position when the lens is separated. However, failures such as peeling and cracking are unlikely to occur.

  A first wafer lens and a second wafer lens are manufactured, a spacer is bonded to the non-lens portion of the resin portion of the first wafer lens, and the spacer and the second wafer lens are bonded using a photocurable adhesive. In some cases, it is preferable that the first wafer lens has regions 73 and 83 in which the diaphragm member does not exist in the adhesion region of the spacer so that the light irradiated from the first wafer lens side reaches the adhesive without being blocked by the diaphragm member. (See FIG. 7).

  FIG. 5 is a cross-sectional view when the diaphragms 120 and 130 are provided on both surfaces of the substrate 10 provided with the IR cut layer 12 by using a known photo-etching or lift-off technique. In addition to the openings 74 and 84 through which the optical axis of the lens unit passes, there are regions 73 and 83 where no diaphragm member is present.

(IR cut layer)
The IR cut layer is formed on the lens resin layer using a known vacuum deposition method, sputtering, CVD (Chemical Vapor Deposition) method, etc., on the position in contact with the substrate or on the diaphragm member, after the lens resin layer is formed, etc. Various configurations are possible.

  The IR cut member is configured by alternately laminating layers such as silicon dioxide and titanium oxide, and the uppermost surface is a layer of silicon dioxide.

  The IR cut member is a member for shielding infrared rays, and has a transmittance of 50% or more for light having a wavelength of 365 nm.

  Examples of the present invention and comparative examples will be described below.

[Example 1]
Seven layers of silicon dioxide and titanium oxide were alternately stacked on both sides (S1 and S2 sides) of a borosilicate glass substrate having a thickness of 0.5 mm and a diameter of 10 cm, and the outermost surface was silicon dioxide. An IR cut layer having a total thickness of 1.2 μm, which was a layer of, was formed with a vapor deposition machine.

  Next, a metal film having a plurality of chromium oxide layers having a total thickness of 800 nm was formed on the IR cut layer by a vapor deposition machine, and a positive photoresist was applied and dried by a known method. Then, using a mask, the resist is exposed and developed, and the chromium compound in the exposed area is removed by etching. After removing the unnecessary resist, it is heated at 130 ° C. for 2 minutes to open the opening corresponding to the lens area. A chromium oxide-based diaphragm having a portion, a portion having no diaphragm member corresponding to the adhesion portion of the spacer, and an alignment mark was formed. By similarly forming a diaphragm on the S2 surface, a substrate on which an IR cut layer and a diaphragm were formed as shown in FIG. 5 was produced.

While dripping an epoxy resin on the S1 surface of the substrate thus prepared and pressing it with a molding die (molding die capable of producing ten imaging lenses), UV light having an irradiation amount of 15200 mJ / cm ² is irradiated. The resin was cured. Similarly, after dropping the resin, pressing the mold, and curing the resin on the S2 surface, the molds on both sides were released to form a resin portion having a lens portion, thereby producing a wafer lens.

Next, the wafer lens is turned over, and as shown in FIG. 6A, the spacer 140 having an opening at the position corresponding to the optical axis of the lens portion has a thickness of PGE-6671 ((glass epoxy (glass fiber reinforced Resin), manufactured by Ryoden Kasei Co., Ltd., flexural modulus: 21.4 GPa, 350 nm light transmittance: 13.3%) is bonded to the S2 surface via an adhesive UVX-B18 (manufactured by Denki Kagaku Kogyo), spacer side Then, UV light of 6700 mJ / cm ² was irradiated and heated at 80 ° C. for 1 hour to cure the adhesive and produce a wafer lens with a spacer.

  Thereafter, the spacer of the wafer lens with the spacer is fixed in contact with the pedestal, and a position corresponding to the cutting line 171 in FIG. 6B is obtained with a known dicer under the conditions of a blade rotation speed of 20000 rpm and a cutting speed of 4 mm / s. Dicing was performed from the S1 surface (the side opposite to the spacer) to obtain 10 imaging lenses.

  The dicing was evaluated as follows, and the results are shown in Table 1.

(Evaluation of peeling and cracking after dicing)
The cross section of the individual lens obtained by dicing was observed with a microscope, and the level of failure such as delamination and cracking between the lens portion, diaphragm, IR cut member, and base material was evaluated. Details of the evaluation level are as follows.

5: The number of lens pieces, diaphragms, IR cut members, separation between layers of the substrate, cracks, etc. is 0. 4 ... Pieces with the same failure as above The number of lenses is 1 3... The number of individual lenses in which the same failure occurs 2 is 2. 2 The number of individual lenses in which the same failure occurs is 3 or more 7 1 or less 1 ... The number of individual lenses with the same failure as above is 8 or more (cutting accuracy evaluation after dicing)
The dimensions of the cut four sides of the obtained individual lens were measured, the amount of deviation from the design value was confirmed, and the level was evaluated in three stages. Details of the evaluation level are as follows.

3. Deviation amount from design value is less than ± 40 μ 2 Deviation amount from design value is ± 40 μ or more and less than 60 μ 1. Deviation amount from design value is ± 60 μ or more [Examples 2 to 16] ]
(Production of imaging lens (piece))
In Examples 1, Examples 2 to 16 were carried out in the same manner except that the curable resin in the resin part, the material and shape of the drawing, the IR cut layer, and the spacer were changed as shown in Table 1. The evaluation results are shown in Table 1. In Examples 2 and 3, no IR cut layer was provided, and in Example 4, no diaphragm was provided. When the material of the resin part is an acrylic resin, the irradiation amount of UV light is 9500 mJ / cm ² .

  The contents of the symbols shown in Table 1 will be described below.

(Material of resin part)
C: Epoxy resin D: Acrylic resin (Drawing material)
E: Chrome oxide system F: Black resist system (diaphragm shape)
Q: Shape with no diaphragm at the spacer adhesion R: Shape with diaphragm at the spacer adhesion (Spacer material)
G: PGE-6771 made by Ryoden Kasei, glass epoxy (glass fiber reinforced resin)
H: Comporacene E: Arakawa Chemical Industries, epoxy resin-silica hybrid I: Comporacene AC: Arakawa Chemical Industries, acrylic-silica hybrid J: Neoprim L-3430 ... Mitsubishi Gas Chemical, Polyimide K: Sumilite EL-3762 ... manufactured by Sumitomo Bakelite Co., Ltd., glass fiber reinforced epoxy L: UR4800 ... manufactured by Toyobo Co., Ltd. polyurethane M: JF-30G ... manufactured by Toyobo Co., Ltd., glass fiber reinforced polyamide No aperture was provided at 4. In Examples 2 and 3, no IR cut layer was provided.

  The black resist-type diaphragm is a negative resist material containing a black filler and an epoxy resin on an IR cut member, applied by a spin coat method and dried to form a film having a thickness of 2 μm. The resist was exposed and developed, and heated at 200 ° C. for 20 minutes to form a diaphragm having a light transmission part and an alignment mark.

[Examples 17, 19, and 20]
(Production of second wafer lens)
A wafer lens with a spacer was prepared in the same manner as in Example 1 except that the IR cut layer was not provided and the spacer was changed to the spacer shown in Table 1, and a second wafer lens was obtained. However, an acrylic photo-curable resin was used for the resin part, and spacers corresponding to Examples 17, 19, and 20 shown in Table 1 were used. Here, the side where the spacer is not joined is called the S3 plane, and the side where the spacer is joined is called the S4 plane.

(Production of first wafer lens)
An IR cut layer is provided on one surface (S1 surface) of a borosilicate glass substrate having a thickness of 0.5 mm and a diameter of 10 cm in the same manner as the wafer lens of Example 1, a diaphragm is formed, a resin portion is formed, and a first wafer lens Was made. However, the said resin part was formed in both surfaces using acrylic type photocurable resin. The surface opposite to the S1 surface of the first wafer lens is referred to as the S2 surface.

(Production of wafer lens laminate)
The spacer described in Table 1 was bonded to the S2 surface of the first wafer lens in the same manner as in the production of the second wafer lens.

  The spacer of the first wafer lens was adhered to the S3 surface of the second wafer lens via an adhesive, and UV light was irradiated from the first wafer lens side to produce a wafer lens laminate in which the adhesive was cured.

  Next, dicing was performed in the same manner as in Example 1 to obtain 10 individual lens stacks for imaging.

  (Evaluation of peeling and cracking after dicing) and (cutting accuracy evaluation after dicing) were performed in the same manner as in Example 1.

[Example 18]
(Production of first wafer lens)
A first wafer lens was produced in the same manner as in the production of the first wafer lens of Example 17. However, when forming the resin part, the resin part 50 having the spacer part 92 shown in FIG. 9A is formed by using a mold that forms the spacer part together with the lens part.

(Production of second wafer lens)
Similar to the production of the second wafer lens in Example 17, a wafer lens having resin portions on both surfaces of another substrate was produced. However, when forming the resin portion, the resin portion 40 having the spacer portion 93 shown in FIG. 9B is formed by using a mold that forms the spacer portion together with the lens portion. The non-lens part of the resin part opposite to the side having the spacer part of the wafer lens and the spacer 190 were bonded via an adhesive 158 to produce a second wafer lens. The spacer of Table 1 was used for the spacer.

(Production of wafer lens laminate)
As shown in FIG. 9C, the spacer portion of the first wafer lens and the spacer portion of the second wafer lens are bonded via an adhesive 156 via an adhesive, and UV light is irradiated from the first wafer lens side. The adhesive was cured to obtain a wafer lens laminate.

  Next, dicing was performed in the same manner as in Example 1 to obtain 10 pieces of imaging lenses.

  (Evaluation of peeling and cracking after dicing) and (cutting accuracy evaluation after dicing) were performed in the same manner as in Example 1.

[Comparative Examples 1, 5, 7]
The wafer lenses of Comparative Examples 1, 5, and 7 were produced in the same manner as in Example 1 except that the spacers were changed as shown in Table 1.

  Next, dicing was performed in the same manner as in Example 1 to obtain 10 pieces of imaging lenses.

  (Evaluation of peeling and cracking after dicing) and (cutting accuracy evaluation after dicing) were performed in the same manner as in Example 1.

[Comparative Examples 2 and 3]
In Comparative Example 1, the wafer lenses of Comparative Examples 2 and 3 were prepared in the same manner as in Comparative Example 1 except that no diaphragm was provided (Comparative Example 2) or no IR cut layer was provided (Comparative Example 3). Dicing was evaluated.

[Comparative Examples 4, 6, 8]
The wafer lens laminates of Comparative Examples 4, 6, and 8 were produced in the same manner as in Example 17 except that the spacers were changed to the spacers shown in Table 1.

  Next, dicing was performed in the same manner as in Example 1 to obtain 10 pieces of imaging lenses.

  (Evaluation of peeling and cracking after dicing) and (cutting accuracy evaluation after dicing) were performed in the same manner as in Example 1.

  In addition, the measuring method of a bending elastic modulus is the data measured based on JISK7203.

  The symbols described in Table 1 will be described.

(Wafer lens structure)
A: Wafer lens B: Wafer lens laminate (resin part)
C: Epoxy system D: Acrylic system (Drawing material)
E: Chromium oxide system F: Black resist system (drawing shape)
Q: Shape with no squeezing member at the spacer bonding part R: Shape with squeezing member at the spacer bonding part (Spacer)
N: Borosilicate glass O: SCR1011 ... Silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd.)
P: MP5... Magnesium alloy The results are shown in Table 1.

  From Table 1, the imaging lens, wafer lens, or laminate thereof having a spacer having a flexural modulus of 1.5 GPa or more and 30 GPa or less has high cutting accuracy during dicing, and the diaphragm, lens, and IR cut member are peeled off. It can be seen that failures such as cracks are unlikely to occur.

DESCRIPTION OF SYMBOLS 1 Wafer lens 2 Wafer lens 3 Wafer lens 4 Wafer lens 5 Wafer lens 6 Wafer lens with a spacer 10 Substrate 12 IR cut layer 13 IR cut layer 20 Aperture (light shielding layer)
22 Aperture 30 Aperture (light shielding layer)
32 opening 40 resin part 42 lens part 50 resin part 52 lens part 60 molding die 62 cavity 74 opening part 80 molding die 82 cavity 84 opening part 92 spacer part 93 spacer part 100 wafer lens laminated body 120 diaphragm (light shielding layer)
130 Aperture (shading layer)
140 Spacer 142 Adhesive 150 Spacer 152 Adhesive 154 Adhesive 156 Adhesive 158 Adhesive 170 Cutting line 171 Cutting line 180 Cutting line 190 Spacer

Claims (13)

  In the wafer lens with a spacer, wherein a spacer having a plurality of openings is joined to at least one surface of a wafer lens in which a plurality of lens portions made of resin are two-dimensionally arranged on at least one surface of the substrate. A wafer lens with a spacer, wherein the spacer is disposed so that the optical axis of the lens portion passes through the opening of the spacer, and the flexural modulus of the spacer is 1.5 GPa or more and 30 GPa or less.   The wafer lens with a spacer according to claim 1, wherein the spacer has an elastic modulus of 2 GPa or more and 7 GPa or less.   The spacer-attached wafer lens according to claim 1 or 2, wherein the spacer has a thickness of 0.1 mm or more and 0.8 mm or less.   The wafer lens with a spacer according to any one of claims 1 to 3, wherein the light transmittance of the spacer is 30% or more at a wavelength of 350 nm.   5. The spacer according to claim 1, wherein the plurality of lens portions are respectively disposed on both surfaces of the substrate, and the lens portions on both surfaces have a substantially common optical axis. Wafer lens.   The wafer lens with a spacer according to any one of claims 1 to 5, further comprising a stop having an opening through which an optical axis of the lens unit passes.   It has IR cut layer, The wafer lens with a spacer of any one of Claims 1-6 characterized by the above-mentioned.   An imaging lens cut out from a wafer lens with a spacer according to any one of claims 1 to 7 along a plane parallel to the optical axis of the lens unit, wherein the lens unit is formed on at least one surface of the substrate. And an imaging lens, wherein the spacer is disposed.   A wafer lens with a spacer according to claim 1 is used as a second wafer lens, and a first wafer lens in which a plurality of lens portions containing a curable resin is two-dimensionally arranged on a first substrate. And a wafer lens laminate in which the second wafer lens is laminated, wherein the first wafer lens is laminated on a surface opposite to the spacer of the second wafer lens. .   The wafer lens laminate according to claim 9, further comprising a spacer between the first wafer lens and the second wafer lens.   11. The wafer lens laminate according to claim 9, wherein each of the first wafer lens and the second wafer lens has the diaphragm.   The wafer lens laminate according to claim 9, wherein the first wafer lens has an IR cut layer.   An imaging lens cut out from the wafer lens laminate according to any one of claims 9 to 12 in a plane parallel to the optical axis, the first substrate having at least one lens portion, the lens portion, An imaging lens comprising a second substrate having a lens portion having a common optical axis and a spacer.

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