JP5657337B2 - Titanium black dispersion for wafer level lens, photosensitive resin composition containing the same, and wafer level lens - Google Patents

Description

  The present invention relates to a dispersion for a wafer level lens useful for forming a light-shielding film on a wafer level lens, a photosensitive resin composition containing the dispersion, and a wafer level lens.

  In recent years, portable terminals of electronic devices such as mobile phones and PDAs (Personal Digital Assistants) are equipped with small and thin imaging units. Such an imaging unit generally includes a solid-state imaging device such as a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor, and a lens that forms a subject image on the solid-state imaging device. I have.

  With the downsizing / thinning of mobile terminals and the widespread use of mobile terminals, further downsizing / thinning is required for the imaging units mounted on the mobile terminals, and high productivity is required. In response to such a request, a lens substrate on which a plurality of lenses are formed and a sensor substrate on which a plurality of solid-state image sensors are formed are combined together, and then each of the cut pieces includes a lens and a solid-state image sensor. In addition, a method of mass-producing an imaging unit by cutting a lens substrate and a sensor substrate is known. As another example of the manufacturing method, a sensor substrate in which only a lens is produced on a glass wafer, cut into an appropriate size for use in combination with an individual sensor, and cut into an appropriate size in advance. A method of manufacturing an imaging unit in combination with the above imaging device, a method of forming a plurality of lenses with a mold using only a resin, combining the formed lenses on a sensor substrate, cutting the substrate, and a lens substrate individually For example, a method of manufacturing an imaging unit by cutting the sensor into a size to be combined with the sensor and combining with an imaging element on a sensor substrate that has been previously cut to an appropriate size.

As a conventional wafer level lens array, a curable resin material is dropped on the surface of a parallel plate substrate made of a light transmissive material such as glass, and the resin material is shaped into a predetermined shape with a mold. And a plurality of lenses are known (see, for example, Patent Documents 1 and 2). In order to adjust the amount of light, an area other than the lens portion of the wafer level lens or a part of the lens may be formed with a light-shielding area made of a black film or a metal film. A light-shielding region is formed by applying a curable light-shielding composition or depositing a metal.
As an example of a known wafer level lens array, a curable resin material is dropped on the surface of a parallel plate substrate made of a light transmissive material such as glass, and the resin material is shaped into a predetermined shape by a mold. In this state, the resin is cured and formed with a plurality of lenses (for example, see Patent Documents 1 and 2). A light-shielding region made of a black film or a metal film may be formed in a region other than the lens portion of the wafer level lens or a part of the lens in order to adjust the amount of light. The light-shielding region is generally formed by coating a curable light-shielding composition or depositing a metal.

  As another example of a known wafer level lens array, a plurality of through holes are formed in a silicon substrate, a separately formed spherical lens material is disposed in each through hole, and the lens material is bonded to the substrate by soldering. Further, a lens material is further polished to form a plurality of lenses (for example, see Patent Document 3). Also in the lens obtained by this manufacturing method, in order to adjust the amount of light, there may be provided a light-shielding region formed of the same black film or metal film as described above.

When forming a light-shielding region by vapor deposition of metal, the process is complicated, and there are problems such as warping of the lens after vapor deposition and light scattering due to reflection of the metal light-shielding film, productivity, performance Improvement is required from both viewpoints.
On the other hand, in order to develop light-shielding properties, a photosensitive resin composition (light-shielding composition) using carbon black used for a black matrix of LCD may be applied.

Japanese Patent No. 3926380 International Publication No. 2008/102648 Pamphlet US Pat. No. 6,426,829

  When a conventional light-shielding composition is used for forming a light-shielding region (light-shielding film) in a wafer level lens, there is a tendency that a residue generated when the light-shielding film is formed remains on or near the lens. there were. Although the residue has been a problem due to a decrease in the light transmittance of the lens, it has not been improved yet.

This invention is made | formed in view of the said conventional condition, and makes it a subject to achieve the following objectives.
That is, an object of the present invention is to form a light-shielding film provided in a wafer-level lens, which has excellent curability and can reduce residues derived from the photosensitive composition outside the light-shielding film formation region. Another object of the present invention is to provide a photosensitive resin composition and a titanium black dispersion for a wafer level lens used in the photosensitive resin composition.
A further object of the present invention is to provide a wafer level lens capable of suppressing light scattering or a decrease in transmittance in the vicinity of the light shielding film, and a solid-state imaging device including the wafer level lens.

Means for solving the above-mentioned problems are as follows.
<1> (A) Titanium black particles, (B) Dispersant, and (C) Organic solvent, 90% or more of the dispersion made of (A) titanium black particles has a particle size of 30 nm or less. Titanium black dispersion for wafer level lens.
<2> The titanium black for wafer level lenses according to <1>, wherein the (B) dispersant is a graft copolymer including a structural unit represented by any of the following formulas (1) to (5). Dispersion.

^(.Y 1 in formula (1) to ^{(5), X 1, X} 2, X 3, X 4, X 5, and ^{X 6,} which independently represents a hydrogen atom or a monovalent organic group, Y ² , Y ³ , Y ⁴ , and Y ⁵ each independently represent a divalent linking group, and Z ¹ , Z ² , Z ³ , Z ⁴ , and Z ⁵ are each independently a monovalent organic group. N, m, p, q and r are each an integer of 1 to 500. j and k each independently represent an integer of 2 to 8. R is a hydrogen atom or a monovalent group. Represents an organic group.)
<3> In addition to the graft site, a functional group capable of forming an interaction with the (A) titanium black particle is introduced into the graft copolymer, and the functional group includes an acid group, a basic group, and a coordination group. The titanium black dispersion for wafer level lenses according to <2>, wherein the titanium black dispersion is at least one of a functional group and a reactive functional group.
< 4 > Photosensitivity for wafer level lens containing the titanium black dispersion according to any one of <1> to <3> , (D) a photopolymerizable compound, and (E) a photopolymerization initiator. Resin composition.
< 5 > A wafer level lens having a light shielding film obtained by curing the photosensitive resin composition according to the above <4> at a peripheral portion of the lens present on the substrate.
< 6 > A solid-state imaging device including the wafer level lens according to < 5 >.

According to the present invention, a photosensitive resin for a wafer level lens that is used for forming a light shielding film provided in a wafer level lens, has excellent curability, and can reduce residues derived from the photosensitive composition outside the light shielding film formation region. A composition and a titanium black dispersion for a wafer level lens used for the photosensitive resin composition can be provided.
In addition, according to the present invention, it is possible to provide a wafer level lens capable of suppressing light scattering or a decrease in transmittance in the vicinity of the light shielding film, and a solid-state imaging device including the wafer level lens.

It is a top view which shows an example of a wafer level lens array. It is the sectional view on the AA line shown in FIG. It is a figure which shows the state which is supplying the molding material used as a lens to a board | substrate. 4A to 4C are diagrams showing a procedure for forming a lens on a substrate with a mold. 5A to 5C are schematic views illustrating a process of forming a patterned light-shielding film on a substrate on which a lens is molded. It is sectional drawing which shows an example of a wafer level lens array. 7A to 7C are schematic views showing other modes of the light shielding film forming step. FIG. 8A to FIG. 8C are schematic views showing a process of forming a lens on a substrate having a patterned light shielding film.

  Hereinafter, the titanium black dispersion for wafer level lens of the present invention, the photosensitive resin composition containing it, and the wafer level lens will be described in detail.

  In this specification, the “wafer level lens” is a lens provided in a solid-state imaging device, and means a lens composed of individual lenses existing on a substrate and a light-shielding film provided on a peripheral portion of the lens. . A group consisting of the wafer level lenses is referred to as a “wafer level lens array”.

<Titanium black dispersion for wafer level lens and photosensitive resin composition containing the same>
The titanium black dispersion for wafer level lenses of the present invention (hereinafter also simply referred to as “titanium black dispersion”) is a dispersion containing (A) titanium black particles, (B) a dispersant, and (C) an organic solvent. 90% or more of the dispersion of (A) titanium black particles has a particle size of 30 nm or less.

  The photosensitive resin composition for wafer level lenses of the present invention (hereinafter also simply referred to as “photosensitive resin composition”) includes the titanium black dispersion of the present invention, (D) a photopolymerizable compound, and (E ) A photosensitive resin composition containing a photopolymerization initiator.

  The titanium black dispersion and the photosensitive resin composition of the present invention are used for forming a light shielding film in a wafer level lens.

  Hereinafter, each component contained in the titanium black dispersion or the photosensitive resin composition of the present invention will be sequentially described.

(A) Titanium black particles The titanium black dispersion of the present invention contains titanium black particles. The titanium black particles are contained as a dispersion in the dispersion. In the present invention, 90% or more of the dispersion made of titanium black particles needs to have a particle size of 30 nm or less.
In the present invention, the particle size of the dispersed material means the particle diameter of the dispersed material, and the particle diameter is the diameter of a circle having an area equal to the projected area of the outer surface of the particle. The projected area of the particles can be obtained by measuring the area obtained by photographing with an electron micrograph and correcting the photographing magnification.

  Here, the “dispersed body composed of titanium black particles” in the present invention includes both those in which the titanium black particles are in the state of primary particles and those in the state of the aggregates (secondary particles).

  The photosensitive resin composition of this invention contains the to-be-dispersed body which consists of a titanium black particle originating in the titanium black dispersion of this invention. 90% or more of the photosensitive resin composition and a dispersion made of titanium black particles contained in a cured film (light-shielding film) obtained by curing the photosensitive resin composition have a particle size of 30 nm or less. It is.

In the present invention, 90% or more of the dispersion of titanium black particles has a particle size of 30 nm or less, so that when the light shielding film is formed using the photosensitive resin composition of the present invention, Residues derived from the photosensitive composition outside the formation region are reduced. The residue includes components derived from the photosensitive composition such as titanium black particles and a resin component.
The reason why the residue is reduced is not yet clear, but the dispersed material having a small particle size contributes to the improvement of the removability of the uncured photosensitive resin composition (particularly titanium black particles) in the formation of the light shielding film. I guess because.

  In addition, since the titanium black particles are excellent in light-shielding property for light in a wide wavelength range from ultraviolet to infrared, the light-shielding film formed using the titanium black dispersion or the photosensitive resin composition of the present invention is Exhibits excellent light shielding properties.

  In order to determine whether 90% of the dispersion to be contained in the titanium black dispersion or photosensitive resin composition of the present invention has a particle size of 30 nm or less, the following method (1) is used. Use.

  In addition, about 90% of the dispersion to be contained in the cured film (light-shielding film) obtained by curing the photosensitive resin composition of the present invention, it is judged whether or not it has a particle size of 30 nm or less. Uses the method (2) shown below.

<Method (1)>
A titanium black dispersion or a photosensitive resin composition is diluted 500 times with propylene glycol monomethyl ether acetate (hereinafter also abbreviated as PGMEA), dropped onto a carbon thin film and dried to form using a dropping electron microscope. Take an observation picture. From the obtained photograph, the projected area of the outer surface is obtained for 400 particles, the diameter of the circle corresponding to this area is calculated, and the frequency distribution is evaluated.

<Method (2)>
Using a scanning electron microscope (S-3400N (trade name) manufactured by Hitachi High-Technologies Corporation) and an energy dispersive X-ray analyzer (Genesis (trade name) manufactured by EDAX) A morphological observation photograph and an element map of Ti and Si are taken. From the obtained photograph, the projected area of the outer surface is obtained for 400 particles in which Ti element is detected, the diameter of a circle corresponding to this area is calculated, and the frequency distribution is evaluated.

Hereinafter, the titanium black particles will be described in more detail.
In the present invention, the titanium black particles are black particles having titanium atoms, and preferably black particles such as low-order titanium oxide and titanium oxynitride.

  The titanium black particles can be modified on the particle surface as necessary for the purpose of improving dispersibility and suppressing aggregation. As the modification of the particle surface, for example, coating treatment with silicon oxide, titanium oxide, germanium oxide, aluminum oxide, magnesium oxide, zirconium oxide or the like is possible. Treatment with an aqueous material is also possible.

  Examples of commercially available titanium black particles include titanium black 10S, 12S, 13R, 13M, 13M-C, 13R, 13R-N, and 13M-T (trade names: manufactured by Mitsubishi Materials Corporation), Tilac. (Tilac) D (trade name: manufactured by Ako Kasei Co., Ltd.).

As a method for producing titanium black particles, a mixture of titanium dioxide and metal titanium is heated in a reducing atmosphere for reduction (a method described in JP-A-49-5432), or obtained by high-temperature hydrolysis of titanium tetrachloride. A method of reducing the obtained ultrafine titanium dioxide in a reducing atmosphere containing hydrogen (a method described in JP-A-57-205322), a method of reducing titanium dioxide or titanium hydroxide at a high temperature in the presence of ammonia (JP-A No. 57-305322) (Methods described in JP-A-60-65069 and JP-A-61-201610), a method in which a vanadium compound is attached to titanium dioxide or titanium hydroxide and reduced at high temperature in the presence of ammonia (JP-A 61-201610). However, the method is not limited to these.
The titanium black particles applied to the present invention preferably have a small primary particle size.

  The titanium black dispersion and the photosensitive resin composition of the present invention may contain only one type of (A) titanium black particles, or may contain two or more types.

  Further, as long as the effects of the present invention are not impaired, the composite oxide such as Cu, Fe, Mn, V, Ni, cobalt oxide, iron oxide, You may use together as a to-be-dispersed body, combining the black pigment which consists of carbon black, aniline black, etc. 1 type, or 2 or more types. In this case, it is preferable that 50% by mass or more of the dispersion is occupied by the dispersion made of titanium black particles.

  Further, as will be described later, other colorants (such as organic pigments and dyes) may be used in combination with the titanium black particles, if desired, for the purpose of adjusting the light shielding property and the like, as long as the effects of the present invention are not impaired. .

The content of (A) titanium black particles in the titanium black dispersion is preferably 5% by mass to 60% by mass and more preferably 10% by mass to 50% by mass with respect to the total mass of the dispersion. preferable.
Moreover, it is preferable that content of (A) titanium black particle in the photosensitive resin composition is 2.5 mass%-30 mass% with respect to the total mass of a dispersion, and 5 mass%-20 mass%. More preferably

(B) Dispersant The titanium black dispersion and the photosensitive resin composition of the present invention contain a dispersant.
The dispersant in the present invention includes a polymer dispersant [for example, polyamidoamine and its salt, polycarboxylic acid and its salt, high molecular weight unsaturated acid ester, modified polyurethane, modified polyester, modified poly (meth) acrylate, (meta ) Acrylic copolymer, naphthalene sulfonic acid formalin condensate], and polyoxyethylene alkyl phosphate ester, polyoxyethylene alkyl amine, alkanol amine, and pigment derivatives.
The dispersant in the present invention can be further classified into a linear polymer, a terminal-modified polymer, a graft polymer, and a block polymer according to its structure.

The dispersant in the present invention acts to adsorb on the surface of a dispersion such as titanium black particles and a pigment used in combination, if desired, and prevent reaggregation. Therefore, a terminal-modified polymer, a graft polymer and a block polymer having an anchor site to the pigment surface can be mentioned as preferred structures.
On the other hand, the dispersant in the present invention has an effect of promoting the adsorption of the dispersed resin by modifying the surface of the dispersion.

Specific examples of the dispersant that can be used in the present invention include “Disperbyk-101 (trade name, polyamidoamine phosphate), 107 (trade name, carboxylic acid ester), 110 (trade name, containing acid group) manufactured by BYK Chemie. Copolymer)), 130 (trade name, polyamide), 161, 162, 163, 164, 165, 166, 170, 180 (trade name, polymer copolymer) "," BYK-P104, P105 (trade name, High molecular weight unsaturated polycarboxylic acid), “EFKA 4047, 4050, 4010, 4165 (trade name, polyurethane), EFKA 4330, 4340 (trade name, block copolymer), 4400, 4402 (trade name, modified poly) manufactured by EFKA Acrylate), 5010 (polyesteramide), 5765 (trade name, high molecular weight polycarboxylate) , 6220 (trade name, fatty acid polyester), 6745 (trade name, phthalocyanine derivative), 6750 (trade name, azo pigment derivative) ”,“ Ajisper PB821, PB822 ”manufactured by Ajinomoto Fine Techno Co., Ltd., manufactured by Kyoeisha Chemical Co., Ltd. “Floren TG-710 (urethane oligomer)”, “Polyflow No. 50E, No. 300 (trade name, acrylic copolymer)”, “Disparon KS-860, 873SN, 874, # 2150” manufactured by Enomoto Kasei Co., Ltd. (Trade name, aliphatic polyvalent carboxylic acid), # 7004 (polyether ester), DA-703-50, DA-705, DA-725 "," Demol RN, N (trade name, naphthalene) manufactured by Kao Corporation Sulfonic acid formalin polycondensate), demole MS, C, SN-B (trade name, aromatic sulfonic acid formalin) Condensate) ”,“ homogenol L-18 (trade name, high molecular weight polycarboxylic acid) ”,“ emulgen 920, 930, 935, 985 (trade name, polyoxyethylene nonylphenyl ether) ”,“ acetamine 86 (stearylamine) Acetate), “Solsperse 5000 (phthalocyanine derivative), 22000 (trade name, azo pigment derivative), 13240 (polyesteramine), 3000, 17000, 27000 (trade name, polymer having a functional part at the terminal part) manufactured by Lubrizol ), 24000, 28000, 32000, 38500 (graft type polymer) "," Nikkor T106 (polyoxyethylene sorbitan monooleate), MYS-IEX (trade name, polyoxyethylene monostearate) "manufactured by Nikko Chemical Co., Ltd. Can be mentioned. Also included are amphoteric dispersants such as Hinoact T-8000E (trade name) manufactured by Kawaken Fine Chemicals.
These dispersants may be used alone or in combination of two or more.

The acid value of the dispersant is preferably in the range of 5.0 mgKOH / g to 200 mgKOH / g, more preferably in the range of 10 mgKOH / g to 150 mgKOH / g, still more preferably in the range of 60 mgKOH / g to 150 mgKOH / g. Range.
When the acid value of the dispersant is 200 mgKOH / g or less, pattern peeling during development when forming the light-shielding film is more effectively suppressed. Moreover, if the acid value of a dispersing agent is 5.0 mgKOH / g or more, alkali developability will become more favorable. Further, if the acid value of the dispersant is 60 mgKOH / g or more, the precipitation of titanium black particles can be further suppressed, the number of coarse particles can be reduced, and the time stability of the titanium black dispersion or the photosensitive resin composition can be reduced. Can be improved.

  In the present invention, the acid value of the dispersant can be calculated from, for example, the average content of acid groups in the dispersant. Moreover, the resin which has a desired acid value can be obtained by changing content of the monomer unit containing the acid group which is a structural component of a dispersing agent.

  The weight average molecular weight of the dispersant in the present invention is preferably 10,000 or more and 300,000 or less, and preferably 15,000 or more, from the viewpoint of pattern peeling inhibition during development and developability when forming a light shielding film. It is more preferably 200,000 or less, further preferably 20,000 or more and 100,000 or less, and particularly preferably 25,000 or more and 50,000 or less. In addition, the weight average molecular weight of a dispersing agent can be measured by GPC, for example.

(Graft copolymer)
In the present invention, it is also preferable to use a graft copolymer (hereinafter also referred to as “specific resin”) as a dispersant. Dispersibility and storage stability can be further improved by using a graft copolymer as a dispersant.

As the graft copolymer, those having a graft chain in which the number of atoms excluding hydrogen atoms is in the range of 40 to 10,000 are preferable. The graft chain in this case refers to a portion from the base of the main chain of the copolymer to the end of the group branched from the main chain.
This specific resin is a dispersion resin capable of imparting dispersibility to the titanium black particles, and has excellent dispersibility and affinity with the solvent due to the graft chain. Excellent dispersion stability. Moreover, when it is set as the photosensitive resin composition, since it has affinity with a polymerizable compound or other resins that can be used in combination due to the presence of the graft chain, a residue is hardly generated by alkali development.

Further, by introducing an alkali-soluble partial structure such as a carboxylic acid group into this specific resin, a function as a resin imparting developability can be imparted for pattern formation by alkali development.
Therefore, by introducing an alkali-soluble partial structure into the graft copolymer, the dispersion resin itself essential for the dispersion of titanium black particles in the titanium black dispersion of the present invention has alkali solubility. The photosensitive resin composition containing such a titanium black dispersion has excellent light-shielding properties in the exposed area, and the alkali developability in the unexposed area is improved.

  When the graft chain becomes longer, the steric repulsion effect becomes higher and the dispersibility is improved. On the other hand, when the graft chain is too long, the adsorptive power to titanium black is lowered and the dispersibility is lowered. For this reason, as the graft copolymer used in the present invention, the number of atoms excluding hydrogen atoms per graft chain is preferably 40 to 10,000, and the hydrogen atoms per graft chain are excluded. The number of atoms is more preferably 50 to 2,000, and the number of atoms excluding hydrogen atoms per graft chain is more preferably 60 to 500.

  Examples of the polymer structure of the graft chain include poly (meth) acryl, polyester, polyurethane, polyurea, polyamide, polyether and the like. The graft chain is preferably a graft chain having poly (meth) acryl, polyester, or polyether in order to improve the interaction between the graft site and the solvent and thereby increase dispersibility. A graft chain having a polyether is more preferable.

  The structure of the macromonomer having such a polymer structure as a graft chain is not particularly limited as long as it has a substituent capable of reacting with the polymer main chain portion and satisfies the requirements of the present invention. A macromonomer having a reactive double bond group can be preferably used.

  Commercially available macromonomers suitably used for the synthesis of specific resins include AA-6 (trade name, (trade name, Toa Gosei Co., Ltd.), AA-10 (trade name, manufactured by Toa Gosei Co., Ltd.), AB -6 (trade name, manufactured by Toa Gosei Co., Ltd.), AS-6 (Toa Gosei Co., Ltd.), AN-6 (trade name, manufactured by Toa Gosei Co., Ltd.), AW-6 (trade name, manufactured by Toa Gosei Co., Ltd.) Co., Ltd.), AA-714 (trade name, manufactured by Toa Gosei Co., Ltd.), AY-707 (trade name, manufactured by Toa Gosei Co., Ltd.), AY-714 (trade name, manufactured by Toa Gosei Co., Ltd.), AK-5 (trade name, manufactured by Toa Gosei Co., Ltd.), AK-30 (trade name, manufactured by Toa Gosei Co., Ltd.), AK-32 (trade name, manufactured by Toa Gosei Co., Ltd.), BLEMMER PP-100 ( Trade name, manufactured by NOF Corporation), Blemmer PP-500 (trade name, manufactured by NOF Corporation), Blemmer PP-800 (trade name, manufactured by NOF Corporation), Blemmer PP-10 0 (trade name, manufactured by NOF Corporation), BREMMER 55-PET-800 (manufactured by NOF Corporation), BREMMER PME-4000 (trade name, manufactured by NOF Corporation), Blemmer PSE-400 (product) Name, manufactured by NOF Corporation), BLEMMER PSE-1300 (trade name, manufactured by NOF Corporation), BLEMMER 43PAPE-600B (trade name, manufactured by NOF Corporation), and the like. AA-6 (manufactured by Toa Gosei Co., Ltd.), AA-10 (trade name, Toa Gosei Co., Ltd.), AB-6 (trade name, produced by Toa Gosei Co., Ltd.), AS-6 trade name Toa Gosei Co., Ltd.), AN-6 (trade name, manufactured by Toa Gosei Co., Ltd.), Bremer PME-4000 (trade name, manufactured by NOF Corporation) and the like are used.

  The graft site in the specific resin preferably includes at least a structural unit represented by any of the following formulas (1) to (5), and at least includes the following formula (1A), the following formula (2A), and the following formula It is more preferable to include a structural unit represented by any one of (3), the following formula (4), and the following (5).

In Formula (1) to Formula (5), X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ each independently represent a hydrogen atom or a monovalent organic group. X ¹ , X ² , X ³ , X ⁴ , X ⁵ , and X ⁶ are preferably each independently a hydrogen atom or an alkyl group having 1 to 12 carbon atoms, from the viewpoint of synthesis constraints. Independently, a hydrogen atom or a methyl group is more preferable, and a methyl group is particularly preferable.

In Formula (1) to Formula (5), Y ¹ , Y ² , Y ³ , Y ⁴ , and Y ⁵ each independently represent a divalent linking group, and the linking group is not particularly limited in structure. Specific examples of the divalent linking group represented by Y ¹ , Y ² , Y ³ , Y ⁴ , or Y ⁵ include the following (Y-1) to (Y-20) linking groups. As mentioned. In the structures shown below, A and B each represent a binding site with the left terminal group and the right terminal group in Formulas (1) to (5). Of the structures shown below, (Y-2) or (Y-13) is more preferable from the viewpoint of ease of synthesis.

In the formulas (1) to (5), Z ¹ , Z ² , Z ³ , Z ⁴ , and Z ⁵ each independently represent a monovalent organic group. Although the structure of the organic group is not particularly limited, specifically, an alkyl group, a hydroxyl group, an alkoxy group, an aryloxy group, a heteroaryloxy group, an alkylthioether group, an arylthioether group, a heteroarylthioether group, and an amino group Etc. Among these, as the organic group represented by Z ¹ , Z ² , Z ³ , Z ⁴ , and Z ⁵ , those having a steric repulsion effect are particularly preferable from the viewpoint of improving dispersibility, and each independently has a carbon number. An alkyl group having 5 to 24 is preferable, and among them, a branched alkyl group having 5 to 24 carbon atoms or a cyclic alkyl group having 5 to 24 carbon atoms is particularly preferable.

In Formula (1)-Formula (5), n, m, p, q, and r are integers of 1 to 500, respectively.
Moreover, in Formula (1) and Formula (2), j and k represent the integer of 2-8 each independently. J and k in Formula (1) and Formula (2) are preferably integers of 4 to 6, and most preferably 5, from the viewpoints of dispersion stability and developability.

  In the specific resin, the structural units represented by the formulas (1) to (5) are preferably contained in a range of 10% to 90%, in terms of mass, with respect to the total mass of the specific resin, and 30% to 70%. It is more preferable that it is contained in the range of%. When the structural units represented by the formulas (1) to (5) are included within this range, the dispersibility of the titanium black particles is high and the developability when forming the light-shielding film is good.

  Further, the specific resin can contain two or more types of graft copolymers having different structures.

  In formula (5), R represents a hydrogen atom or a monovalent organic group and is not particularly limited in terms of structure, but preferably includes a hydrogen atom, an alkyl group, an aryl group, and a heteroaryl group, and more preferably , A hydrogen atom, or an alkyl group. When R is an alkyl group, the alkyl group is preferably a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, or a cyclic alkyl group having 5 to 20 carbon atoms. A linear alkyl group having 1 to 20 carbon atoms is more preferable, and a linear alkyl group having 1 to 6 carbon atoms is particularly preferable. Moreover, as R, you may use 2 or more types of R from which structure differs in specific resin.

The structural unit represented by the formula (1) is more preferably a structural unit represented by the following formula (1A) from the viewpoint of dispersion stability and developability.
The structural unit represented by the formula (2) is more preferably a structural unit represented by the following formula (2A) from the viewpoint of dispersion stability and developability.

Wherein ^(1A), X ^1, Y 1, ^{Z 1} and n, the equation (1) is ^{X 1,} Y 1, synonymous with ^{Z 1} and n in, and preferred ranges are also the same.
Wherein ^(2A), X ^2, Y 2, ^{Z 2} and m is the formula (2) have the same meanings as ^{X 2,} Y 2, ^{Z 2} and m in the preferred range is also the same.

A functional group capable of forming an interaction with the titanium black particles can be introduced into the specific resin in addition to the graft site.
Examples of functional groups capable of interacting with titanium black particles include acid groups, basic groups, coordinating groups, reactive functional groups, and the like. It can be introduced using a structural unit having a group, a structural unit having a basic group, a structural unit having a coordinating group, or a structural unit having reactivity.

Examples of the acid group in the structural unit having an acid group include a carboxylic acid group, a sulfonic acid group, a phosphoric acid group, and a phenolic hydroxyl group, and particularly preferable ones have good adsorption power to titanium black and are dispersed. It is a highly carboxylic acid group. The specific resin may have one or more of these acid groups.
By introducing such an acid group, there is also an advantage that the alkali developability of the specific resin is improved.

  When introduced into the specific resin as a copolymerization component, the preferred content of the structural unit having an acid group is 0.1 mol% or more and 50 mol% or less, particularly preferably based on all structural units in the specific resin. From the viewpoint of suppressing damage to the image strength due to alkali development, it is 1 mol% or more and 30 mol% or less.

Examples of the basic group in the structural unit having a basic group include a primary amino group, a secondary amino group, a tertiary amino group, a heterocyclic ring containing an N atom, an amide group, and the like. Is a tertiary amino group having good adsorption power to the pigment and high dispersibility. One or more of these basic groups can be introduced into the specific resin.
When introduced into the specific resin as a copolymerization component, the preferred content of the structural unit having a basic group is 0.01 mol% or more and 50 mol% or less, particularly preferably based on all structural units in the specific resin. Is from 0.01 mol% to 30 mol% from the viewpoint of inhibiting developability inhibition.

Examples of the coordinating group, which is a functional group capable of forming an interaction with the titanium black particles, and the group having reactivity in the structural unit having reactivity include, for example, an acetylacetoxy group, trialkoxysilyl group, isocyanate group, acid An anhydride, an acid chloride, etc. are mentioned. Particularly preferred is an acetylacetoxy group which has a good adsorptive power to the pigment and a high dispersibility. The specific resin may have one or more of these groups.
A suitable content of the structural unit having a basic group or a reactive structural unit that can be introduced as the specific resin copolymerization component is 0.5 mol% or more and 50 mol% or less with respect to all the structural units of the specific resin. Yes, and particularly preferably from 1 mol% to 30 mol% from the standpoint of inhibiting developability inhibition.

  The functional group structure capable of forming an interaction with titanium black particles other than the graft site is not particularly limited as long as it contains a functional group capable of interacting with titanium black other than the graft site. Preferably has at least one repeating unit obtained from a monomer represented by any one of the following general formulas (i) to (iii).

In formulas (i) to (iii), R ¹ , R ² , and R ³ each independently represent a hydrogen atom, a halogen atom (eg, fluorine, chlorine, bromine, etc.), or a carbon atom number of 1 to 6 An alkyl group (for example, a methyl group, an ethyl group, a propyl group, etc.) is represented.
R ¹ , R ² , and R ³ are more preferably each independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and most preferably each independently a hydrogen atom or a methyl group. . R ² and R ³ are each particularly preferably a hydrogen atom.
X represents an oxygen atom (—O—) or an imino group (—NH—), and is preferably an oxygen atom.

L in the formulas (i) to (ii) represents a single bond or a divalent linking group. Examples of the divalent linking group include a divalent aliphatic group (for example, an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group, and a substituted alkynylene group), a divalent aromatic group ( For example, an arylene group and a substituted arylene group), a divalent heterocyclic group and an oxygen atom (—O—), a sulfur atom (—S—), an imino group (—NH—), a substituted imino group (—NR) ^31- , wherein R ³¹ is a combination with one or more of an aliphatic group, an aromatic group or a heterocyclic group) or a carbonyl group (—CO—).

  The divalent aliphatic group may have a cyclic structure or a branched structure. 1-20 are preferable, as for the carbon atom number of the said aliphatic group, 1-15 are more preferable, and 1-10 are still more preferable. The aliphatic group is preferably a saturated aliphatic group rather than an unsaturated aliphatic group. Further, the aliphatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aromatic group, and a heterocyclic group.

  6-20 are preferable, as for the carbon atom number of the said bivalent aromatic group, 6-15 are more preferable, and 6-10 are the most preferable. The aromatic group may have a substituent. Examples of the substituent include a halogen atom, a hydroxyl group, an aliphatic group, an aromatic group, and a heterocyclic group.

The divalent heterocyclic group preferably has a 5-membered or 6-membered ring as a heterocycle. One or more heterocycles, aliphatic rings or aromatic rings may be condensed with the heterocycle. Moreover, the heterocyclic group may have a substituent. Examples of substituents include halogen atoms, hydroxy groups, oxo groups (═O), thioxo groups (═S), imino groups (═NH), substituted imino groups (═N—R ³² , where R ³² is a fatty acid. Aromatic group, aromatic group or heterocyclic group), aliphatic group, aromatic group and heterocyclic group.

L is preferably a single bond, an alkylene group or a divalent linking group containing an oxyalkylene structure. The oxyalkylene structure is more preferably an oxyethylene structure or an oxypropylene structure. L may contain a polyoxyalkylene structure containing two or more oxyalkylene structures. The polyoxyalkylene structure is preferably a polyoxyethylene structure or a polyoxypropylene structure. The polyoxyethylene structure is represented by — (OCH ₂ CH ₂ ) _n —, and n is preferably an integer of 2 or more, and more preferably an integer of 2 to 10.

  In the formulas (i) to (iii), Z represents a functional group capable of forming an interaction with titanium black separately from the graft site, preferably a carboxylic acid or a tertiary amino group, and preferably a carboxylic acid. Is more preferable. Y represents a methine group or a nitrogen atom.

In formula (iii), R ⁴ , R ⁵ , and R ⁶ are each independently a hydrogen atom, a halogen atom (for example, fluorine, chlorine, bromine, etc.), or an alkyl group having 1 to 6 carbon atoms (for example, , Methyl group, ethyl group, propyl group, etc.), Z, or -LZ. Here, L and Z are as defined above. R ⁴ , R ⁵ , and R ⁶ are each independently preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and more preferably a hydrogen atom.

In the present invention, as the monomer represented by the general formula (i), R ¹ , R ² , and R ³ are hydrogen atoms or methyl groups, and L is an alkylene group or an oxyalkylene structure. A compound in which X is an oxygen atom or imino group and Z is a carboxylic acid is preferable.

Further, as the monomer represented by the general formula (ii), R ¹ is a hydrogen atom or a methyl group, L is an alkylene group, Z is a carboxylic acid, and Y is a methine group. Compounds are preferred. As the monomer represented by the general formula (iii), R ⁴ , R ⁵ , and R ⁶ are a hydrogen atom or a methyl group, L is a single bond or an alkylene group, and Z is a carboxylic acid. Is preferred.

Below, the typical example of the monomer (compound) represented by Formula (i)-(iii) is shown.
Examples of the monomer include a reaction product of methacrylic acid, crotonic acid, isocrotonic acid, a compound having an addition polymerizable double bond and a hydroxyl group in the molecule (for example, 2-hydroxyethyl methacrylate) and succinic anhydride. , A reaction product of a compound having an addition polymerizable double bond and a hydroxyl group in the molecule and a phthalic anhydride, a reaction product of a compound having an addition polymerizable double bond and a hydroxyl group in the molecule and a tetrahydroxyphthalic anhydride, a molecule A reaction product of a compound having an addition polymerizable double bond and hydroxyl group and trimellitic anhydride, a reaction product of a compound having an addition polymerizable double bond and hydroxyl group in the molecule and pyromellitic anhydride, acrylic acid, acrylic Acid dimer, acrylic acid oligomer, maleic acid, itaconic acid, fumaric acid, 4-vinylbenzoic acid, vinylphenol, 4-hydroxyphenyl methacrylate And the like.

  The content of a functional group capable of forming an interaction with titanium black such as a monomer having an acidic group in a specific resin is from the viewpoint of interaction with titanium black, dispersion stability, and permeability to a developer. The specific resin is preferably 0.05 to 90% by mass, more preferably 1.0 to 80% by mass, and still more preferably 10 to 70% by mass.

  Furthermore, the specific resin contained in the dispersion composition of titanium black according to the present invention is not limited to the structural unit having the graft site and titanium as long as the effects of the present invention are not impaired for the purpose of improving various performances such as image strength. In addition to the functional group capable of forming an interaction with black, another structural unit having various functions, for example, a functional unit having an affinity for the dispersion medium used in the dispersion is shared. It can be included as a polymerization component.

  Examples of the copolymerizable component that can be copolymerized with the specific resin include radically polymerizable compounds selected from acrylic esters, methacrylic esters, styrenes, acrylonitriles, methacrylonitriles, and the like.

  These can be used singly or in combination of two or more. The content of these copolymerization components in the specific resin is preferably 0 mol% or more and 90 mol% or less, particularly preferably 0 mol% or more. 60 mol% or less. When the content is in the above range, sufficient pattern formation can be obtained.

  Examples of the solvent used when synthesizing the specific resin include ethylene dichloride, cyclohexanone, methyl ethyl ketone, acetone, methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 2-methoxyethyl acetate, 1 Examples include -methoxy-2-propanol, 1-methoxy-2-propyl acetate, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, toluene, ethyl acetate, methyl lactate, and ethyl lactate. These solvents may be used alone or in combination of two or more.

  Specific examples of such a specific resin include the following exemplary compounds 1 to 53. In addition, the suffix of each structural unit (main chain part) is mass%.

The content of the dispersant in the titanium black dispersion of the present invention is 1% by mass to 90% with respect to the total solid content mass of the dispersion (including the dispersion made of titanium black particles and other colorants). % By mass is preferable, and 3% by mass to 70% by mass is more preferable.
Moreover, as content of the dispersing agent in the photosensitive resin composition of this invention, it is 1 mass with respect to the total solid content mass of a to-be-dispersed body (a to-be-dispersed body consisting of a titanium black particle and another coloring agent). % To 90% by mass is preferable, and 3% to 70% by mass is more preferable.

(C) Organic solvent The titanium black dispersion and photosensitive resin composition of the present invention contain an organic solvent.
Examples of organic solvents include acetone, methyl ethyl ketone, cyclohexane, ethyl acetate, ethylene dichloride, tetrahydrofuran, toluene, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol dimethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, acetylacetone , Cyclohexanone, diacetone alcohol, ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether acetate, 3-methoxypropanol, methoxymethoxyethanol, diethylene glycol monomethyl ether, diethyl Glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 3-methoxypropyl acetate, N, N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, ethyl acetate, acetic acid Examples include but are not limited to butyl, methyl lactate, and ethyl lactate.

An organic solvent may be used individually by 1 type, and may be used in combination of 2 or more type.
When two or more organic solvents are used in combination, the above-mentioned methyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, ethyl cellosolve acetate, ethyl lactate, diethylene glycol dimethyl ether, butyl acetate, 3-methoxypropionic acid It is a mixed solution composed of two or more selected from methyl, 2-heptanone, cyclohexanone, ethyl carbitol acetate, butyl carbitol acetate, propylene glycol methyl ether, and propylene glycol methyl ether acetate.
The amount of the organic solvent contained in the titanium black dispersion is preferably 10% by mass to 80% by mass, more preferably 20% by mass to 70% by mass with respect to the total amount of the dispersion, 30 It is still more preferable that it is mass%-65 mass%.
The amount of the organic solvent contained in the photosensitive resin composition is preferably 10% by mass to 90% by mass and more preferably 20% by mass to 80% by mass with respect to the total amount of the composition. Preferably, it is 25 mass%-75 mass%.

(D) Photopolymerizable compound The photosensitive resin composition of the present invention contains a photopolymerizable compound.
The photopolymerizable compound is preferably a compound having at least one addition-polymerizable ethylenically unsaturated group and having a boiling point of 100 ° C. or higher at normal pressure.

Examples of the compound having at least one addition-polymerizable ethylenically unsaturated group and having a boiling point of 100 ° C. or higher at normal pressure include, for example, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate Monofunctional acrylates and methacrylates such as phenoxyethyl (meth) acrylate; polyethylene glycol di (meth) acrylate, trimethylolethane tri (meth) acrylate, neopentylglycol di (meth) acrylate, pentaerythritol tri (meth) acrylate , Pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, hexanediol (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) Ether, tri (acryloyloxyethyl) isocyanurate, polyfunctional alcohols such as glycerin and trimethylolethane, and the addition of ethylene oxide and propylene oxide followed by (meth) acrylate conversion, poly (pentaerythritol or dipentaerythritol poly ( (Meth) acrylate, urethane acrylates described in JP-B-48-41708, JP-B-50-6034, JP-A-51-37193, JP-A-48-64183, JP-B-49- Examples include polyfunctional acrylates and methacrylates such as polyester acrylates and epoxy acrylates, which are reaction products of epoxy resin and (meth) acrylic acid, as described in JP-B 43191 and JP-B 52-30490. it can.
Furthermore, the Japan Adhesion Association Vol. 20, No. 7, pages 300 to 308, those introduced as photocurable monomers and oligomers can also be used.

  In addition, a compound which has been (meth) acrylated after adding ethylene oxide or propylene oxide to the polyfunctional alcohol described in JP-A-10-62986 as general formulas (1) and (2) together with specific examples thereof. Can be used.

  Of these, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and structures in which these acryloyl groups are linked to dipentaerythritol via ethylene glycol and propylene glycol residues are preferred. These oligomer types can also be used.

  Also, urethane acrylates as described in JP-B-48-41708, JP-A-51-37193, JP-B-2-32293, and JP-B-2-16765, and JP-B-58- Urethane compounds having an ethylene oxide skeleton described in JP-A-49860, JP-B-56-17654, JP-B-62-39417, and JP-B-62-39418 are also suitable. Furthermore, addition polymerizable compounds having an amino structure or a sulfide structure in the molecule described in JP-A-63-277653, JP-A-63-260909, and JP-A-1-105238 are used. Depending on the situation, a photopolymerizable composition having an extremely excellent photosensitive speed can be obtained. Commercially available products include urethane oligomers UAS-10, UAB-140 (trade name, manufactured by Nippon Paper Chemicals Co., Ltd.), UA-7200 (manufactured by Shin-Nakamura Chemical Co., Ltd., DPHA-40H (trade name, Nippon Kasei). Medicinal Co., Ltd.), UA-306H, UA-306T, UA-306I, AH-600, T-600, AI-600 (trade name, manufactured by Kyoeisha Chemical Co., Ltd.) and the like.

In addition, ethylenically unsaturated compounds having an acid group are also suitable. Examples of commercially available products include TO-756, which is a carboxyl group-containing trifunctional acrylate manufactured by Toagosei Co., Ltd., and a carboxyl group-containing pentafunctional acrylate. Some TO-1382 and the like can be mentioned.
The polymerizable compound used in the present invention is more preferably a tetrafunctional or higher acrylate compound.

A photopolymerizable compound may be used individually by 1 type, and may be used in combination of 2 or more type. When using in combination of 2 or more types of photopolymerizable compounds, the combination aspect can be suitably set according to the physical property etc. which are requested | required of the photosensitive composition. As one suitable combination aspect of a photopolymerizable compound, the aspect which combines 2 or more types of polymeric compounds selected from the polyfunctional acrylate compound mentioned above is mentioned, for example, As an example, dipentaerythritol hexa A combination of acrylate and pentaerythritol triacrylate may be mentioned.
As content in the photosensitive resin composition of a photopolymerizable compound, 3 parts-55 parts are preferable with respect to 100 parts of total solid content, More preferably, they are 10 parts-50 parts.

(E) Photopolymerization initiator The photosensitive resin composition of the present invention contains a photopolymerization initiator.
The photopolymerization initiator is a compound that is decomposed by light or heat and starts and accelerates the polymerization of the above-described photopolymerizable compound, and preferably has absorption with respect to light having a wavelength of 300 to 500 nm. .

Specific examples of the photopolymerization initiator include organic halogenated compounds, oxydiazole compounds, carbonyl compounds, ketal compounds, benzoin compounds, organic peroxide compounds, azo compounds, coumarin compounds, azide compounds, metallocene compounds, organic boron. Examples thereof include acid compounds, disulfonic acid compounds, oxime ester compounds, onium salt compounds, and acylphosphine (oxide) compounds.
More specific examples include polymerization initiators described in paragraph numbers [0081] to [0100] and [0101] to [0139] of JP-A-2006-78749.
Among the above photopolymerization initiators, oxime ester compounds are more preferable.

  The content of the polymerization initiator in the photosensitive resin composition of the present invention is preferably 0.1% by mass to 30% by mass in the total solid content of the photosensitive resin composition, and 1% by mass to 25% by mass. It is more preferable that it is 2 mass%-20 mass%.

(F) Other additives The photosensitive resin composition of the present invention contains various additives depending on the purpose in addition to the titanium black dispersion, the photopolymerizable compound, and the photopolymerization initiator of the present invention. Can do.

(F-1) Binder polymer In the photosensitive resin composition, a binder polymer can be further included as needed for the purpose of improving film properties.
As the binder polymer, a linear organic polymer is preferably used. As such a “linear organic polymer”, a known one can be arbitrarily used. Preferably, a linear organic polymer that is soluble or swellable in water or weak alkaline water is selected in order to enable water development or weak alkaline water development. The linear organic polymer is selected and used not only as a film forming agent but also according to the use as water, weak alkaline water or an organic solvent developer.

For example, when a water-soluble organic polymer is used, water development becomes possible. Examples of such linear organic polymers include radical polymers having a carboxylic acid group in the side chain, such as JP-A-59-44615, JP-B-54-34327, JP-B-58-12777, and JP-B-54. No. 25957, JP-A-54-92723, JP-A-59-53836, JP-A-59-71048, that is, a resin obtained by homopolymerizing or copolymerizing a monomer having a carboxyl group, Resins in which acid anhydride units are hydrolyzed, half-esterified or half-amidated, or epoxy acrylate modified with unsaturated monocarboxylic acid and acid anhydride, etc. Is mentioned. Examples of monomers having a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, 4-carboxylstyrene, and examples of monomers having an acid anhydride include maleic anhydride. An acid etc. are mentioned.
Similarly, an acidic cellulose derivative having a carboxylic acid group in the side chain is also exemplified. In addition, those obtained by adding a cyclic acid anhydride to a polymer having a hydroxyl group are useful.

  In addition, Japanese Patent Publication No. 7-2004, Japanese Patent Publication No. 7-120041, Japanese Patent Publication No. 7-120042, Japanese Patent Publication No. 8-12424, Japanese Patent Laid-Open No. 63-287944, Japanese Patent Laid-Open No. 63-287947, Japanese Patent Laid-Open No. Urethane-based binder polymers containing acid groups described in Japanese Patent No. 271741 and Japanese Patent Application No. 10-116232 are very excellent in strength and are advantageous in terms of suitability for low exposure.

  In addition, the acetal-modified polyvinyl alcohol-based binder polymer having an acid group described in each of publications such as European Patent No. 993966, European Patent No. 1204000, and Japanese Patent Application Laid-Open No. 2001-318463 has an excellent balance of film strength and developability. It is preferable. In addition, polyvinyl pyrrolidone, polyethylene oxide, and the like are useful as the water-soluble linear organic polymer. In order to increase the strength of the cured film, alcohol-soluble nylon, polyether of 2,2-bis- (4-hydroxyphenyl) -propane and epichlorohydrin, and the like are also useful.

  In particular, among these, [benzyl (meth) acrylate / (meth) acrylic acid / other addition-polymerizable vinyl monomer as required] copolymer, and [allyl (meth) acrylate / (meth) acrylic acid / necessary The other addition-polymerizable vinyl monomer] copolymer is suitable because it is excellent in the balance of film strength, sensitivity, and developability.

  The weight average molecular weight of the binder polymer used in the photosensitive resin composition of the present invention is preferably 1,000 to 300,000 from the viewpoint of pattern peeling inhibition during development and developability, and preferably 1,500 to 250,000 is more preferable, 2,000 to 200,000 is still more preferable, and 2,500 to 100,000 is particularly preferable. About the number average molecular weight of a binder polymer, Preferably it is 1000 or more, More preferably, it is the range of 1500-250,000. The polydispersity (weight average molecular weight / number average molecular weight) of the binder polymer is preferably 1 or more, more preferably in the range of 1.1-10.

  These binder polymers may be any of random polymers, block polymers, graft polymers and the like.

The binder polymer that can be used in the present invention can be synthesized by a conventionally known method. Examples of the solvent used in the synthesis include tetrahydrofuran, ethylene dichloride, cyclohexanone and the like. These solvents are used alone or in combination of two or more.
Examples of the radical polymerization initiator used for synthesizing the binder polymer include known compounds such as an azo initiator and a peroxide initiator.

Among various binder polymers, by including an alkali-soluble resin having a double bond in the side chain, both the curability of the exposed area and the alkali developability of the unexposed area can be improved.
The alkali-soluble binder polymer having a double bond in the side chain has a non-image area removability by having an acid group for making the resin alkali-soluble in the structure and at least one unsaturated double bond. Improve various performances. The binder resin having such a partial structure is described in detail in JP-A No. 2003-262958, and the compounds described herein can be used in the present invention.

  In addition, the weight average molecular weight of a binder polymer can be measured by GPC, for example.

  The content of the binder polymer in the photosensitive resin composition of the present invention is preferably 0.1% by mass to 7.0% by mass with respect to the total solid content of the composition, and can prevent peeling of the light shielding film. From the viewpoint of coexistence of development residue suppression, it is more preferably 0.3% by mass to 6.0% by mass, and further preferably 1.0% to 5.0% by mass.

(F-2) Colorant In the photosensitive resin composition of the present invention, a colorant other than an inorganic pigment such as a known organic pigment or dye can be used in combination in order to develop a desired light-shielding property.

  Examples of the colorant that can be used in combination include organic pigments such as pigments described in paragraph numbers [0030] to [0044] of JP-A-2008-224982, and C.I. I. Pigment Green 58, C.I. I. Pigment Blue 79 in which the Cl substituent is changed to OH, and the like. Among these, pigments that can be preferably used include the following. However, the colorant applicable to the present invention is not limited to these.

C. I. Pigment Yellow 11, 24, 108, 109, 110, 138, 139, 150, 151, 154, 167, 180, 185
C. I. Pigment Orange 36, 38, 62, 64,
C. I. Pigment Red 122,150,171,175,177,209,224,242,254,255
C. I. Pigment Violet 19, 23, 29, 32,
C. I. Pigment Blue 15: 1, 15: 3, 15: 6, 16, 22, 60, 66,
C. I. Pigment Green 7, 36, 37, 58
C. I. Pigment Black 1

  There is no restriction | limiting in particular as an example of the dye which can be used as a coloring agent, A well-known dye can be selected suitably and can be used. For example, Japanese Patent Application Laid-Open No. 64-90403, Japanese Patent Application Laid-Open No. 64-91102, Japanese Patent Application Laid-Open No. 1-94301, Japanese Patent Application Laid-Open No. 6-11614, No. 2592207, US Pat. No. 4,808,501. Specification, US Pat. No. 5,667,920, US Pat. No. 5,059,500, JP-A-5-333207, JP-A-6-35183, JP-A-6-51115 JP-A-6-194828, JP-A-8-21599, JP-A-4-249549, JP-A-10-123316, JP-A-11-302283, JP-A-7-286107, JP 2001-4823, JP-A-8-15522, JP-A-8-29771, JP-A-8-146215, JP-A-11-3434. 7, JP-A-8-62416, JP-A-2002-14220, JP-A-2002-14221, JP-A-2002-14222, JP-A-2002-14223, JP-A-8-302224 Examples thereof include dyes described in JP-A-8-73758, JP-A-8-179120, JP-A-8-151531, and the like.

  The chemical structure of the dye includes pyrazole azo, anilino azo, triphenyl methane, anthraquinone, anthrapyridone, benzylidene, oxonol, pyrazolotriazole azo, pyridone azo, cyanine, phenothiazine, pyrrolopyrazole Examples include chemical structures such as azomethine, xanthene, phthalocyanine, benzopyran, indigo, and pyromethene.

  As a colorant in the photosensitive resin composition of the present invention, an orange pigment, a red pigment, from the viewpoint of achieving both curability and shading when combined with titanium black particles that the composition essentially contains, One or more organic pigments selected from the group consisting of violet pigments are preferred, and most preferred are combinations with red pigments.

  Examples of the orange pigment, red pigment, and violet pigment used in combination with the titanium black particles in the present invention include “CI Pigment Orange”, “CI Pigment Red”, and “C.I. What is necessary is just to select suitably from the various pigments which belong to "I. Pigment Violet" according to the target light-shielding property. From the viewpoint of improving the light shielding property, C.I. I. Pigment Violet 29, C.I. I. Pigment Orange 36, 38, 62, 64, C.I. I. Pigment Red 177, 254, 255 and the like are preferable.

(F-3) Sensitizer The photosensitive resin composition of the present invention may contain a sensitizer for the purpose of improving the radical generation efficiency of the polymerization initiator and increasing the photosensitive wavelength.
As a sensitizer, what sensitizes the polymerization initiator used by an electron transfer mechanism or an energy transfer mechanism is preferable.
Preferable examples of the sensitizer include compounds described in paragraph numbers [0085] to [0098] of JP-A-2008-214395.
The content of the sensitizer is preferably in the range of 0.1 to 30% by mass and 1 to 20% by mass with respect to the total solid content of the photosensitive resin composition from the viewpoint of sensitivity and storage stability. Is more preferable, and it is still more preferable that it exists in the range of 2-15 mass%.

(F-4) Polymerization inhibitor The photosensitive resin composition of the present invention contains a small amount of a polymerization inhibitor in order to prevent unnecessary thermal polymerization of the polymerizable compound during the production or storage of the composition. It is desirable to do. As the polymerization inhibitor, known thermal polymerization inhibitors can be used. Specifically, hydroquinone, p-methoxyphenol, di-t-butyl-p-cresol, pyrogallol, t-butylcatechol, benzoquinone, 4 , 4′-thiobis (3-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-methyl-6-tert-butylphenol), N-nitrosophenylhydroxyamine primary cerium salt and the like.
The content of the thermal polymerization inhibitor is preferably about 0.01 to about 5% by mass with respect to the total solid content of the photosensitive resin composition.

  If necessary, higher fatty acid derivatives such as behenic acid and behenic acid amide may be added to prevent polymerization inhibition due to oxygen, and may be unevenly distributed on the surface of the coating film during the drying process after coating. . The amount of the higher fatty acid derivative added is preferably from about 0.5 to about 10% by weight of the total composition.

(F-5) Adhesion improver The photosensitive resin composition of the present invention may contain an adhesion improver in order to improve adhesion to a hard surface such as a support. Examples of the adhesion improver include a silane coupling agent and a titanium coupling agent.

  Examples of silane coupling agents include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, and γ-mercaptopropyl. Trimethoxysilane, γ-aminopropyltriethoxysilane, and phenyltrimethoxysilane are preferable, and γ-methacryloxypropyltrimethoxysilane is preferable.

  The content of the adhesion improver is preferably 0.5% by mass to 30% by mass and more preferably 0.7% by mass to 20% by mass in the total solid content of the photosensitive resin composition.

  In addition, when a glass substrate is applied to a wafer level lens having a light-shielding film by applying the photosensitive resin composition of the present invention, it is preferable to add an adhesion improver from the viewpoint of improving sensitivity.

(F-6) Surfactant Various surfactants may be added to the photosensitive resin composition of the present invention from the viewpoint of further improving coatability. As the surfactant, various surfactants such as a fluorine-based surfactant, a nonionic surfactant, a cationic surfactant, an anionic surfactant, and a silicone-based surfactant can be used.

In particular, since the photosensitive resin composition of the present invention contains a fluorosurfactant, the liquid properties (particularly fluidity) when prepared as a coating liquid are further improved, so that the coating thickness is uniform. And the liquid-saving property can be further improved.
That is, in the case of forming a film using a coating liquid to which a photosensitive resin composition containing a fluorosurfactant is applied, by reducing the interfacial tension between the coating surface and the coating liquid, The wettability is improved, and the coating property to the coated surface is improved. For this reason, even when a thin film of about several μm is formed with a small amount of liquid, it is effective in that it is possible to more suitably form a film having a uniform thickness with small thickness unevenness.

  The fluorine content in the fluorosurfactant is preferably 3% by mass to 40% by mass, more preferably 5% by mass to 30% by mass, and particularly preferably 7% by mass to 25% by mass. A fluorine-based surfactant having a fluorine content within this range is effective in terms of uniformity of coating film thickness and liquid-saving properties, and has good solubility in the photosensitive resin composition.

  Examples of the fluorosurfactant include Megafac F171, F172, F173, F176, F176, F177, F141, F142, F143, F144, R30, F437, F475, F479, F482, F554, F780, F780, F781 (above DIC Corporation), Florard FC430, FC431, FC171 (above, Sumitomo 3M Limited), Surflon S-382, SC-101, Same SC-103, Same SC-104, Same SC-105, Same SC1068, Same SC-381, Same SC-383, Same S393, Same KH-40 (above, manufactured by Asahi Glass Co., Ltd.), Solsperse 20000 (Japan Rouble) Zole Co., Ltd.).

  Specific examples of nonionic surfactants include glycerol, trimethylolpropane, trimethylolethane, and ethoxylates and propoxylates thereof (for example, glycerol propoxylate, glycerin ethoxylate, etc.), polyoxyethylene lauryl ether, polyoxyethylene Stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, sorbitan fatty acid ester (Pluronic L10, L31, L61, L62 manufactured by BASF, 10R5, 17R2, 25R2, Tetronic 304, 701, 704, 901, 904, 150R1, etc. It is.

  Specific examples of the cationic surfactant include phthalocyanine derivatives (trade name: EFKA-745, manufactured by Morishita Sangyo Co., Ltd.), organosiloxane polymer KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), (meth) acrylic acid ( Co) polymer polyflow no. 75, no. 90, no. 95 (Kyoeisha Chemical Co., Ltd.), W001 (manufactured by Yusho Co., Ltd.) and the like.

  Specific examples of the anionic surfactant include W004, W005, W017 (manufactured by Yusho Co., Ltd.) and the like.

  Examples of silicone surfactants include Toray Dow Corning (Toray Silicone DC3PA, Toray Silicone SH7PA, Toray Silicone DC11PA, Toray Silicone SH21PA, Toray Silicone SH28PA, Tore Silicone SH29PA. ”,“ Tore Silicone SH30PA ”,“ Tore Silicone SH8400 ”,“ TSF-4440 ”,“ TSF-4300 ”,“ TSF-4445 ”,“ TSF-4460 ”,“ TSF-4442 ”manufactured by Momentive Performance Materials, Inc. ”,“ KP341 ”,“ KF6001 ”,“ KF6002 ”manufactured by Shin-Etsu Silicone Co., Ltd.,“ BYK307 ”,“ BYK323 ”,“ BYK330 ”manufactured by BYK Chemie.

Only one type of surfactant may be used, or two or more types may be combined.
The content of the surfactant is preferably 0.001% by mass to 2.0% by mass, more preferably 0.005% by mass to 1.0% by mass with respect to the total mass of the photosensitive resin composition of the present invention. %.

(F-7) Other Additives Further, the photosensitive resin composition further improves the sensitivity of the sensitizing dye and initiator to active radiation, or suppresses polymerization inhibition of the photopolymerizable compound by oxygen. And may contain a co-sensitizer. Moreover, in order to improve the physical property of a cured film, you may add well-known additives, such as a diluent, a plasticizer, a fat-sensitizing agent, as needed.

-Preparation of titanium black dispersion-
The preparation mode of the titanium black dispersion of the present invention is not particularly limited. For example, the titanium black particles, the dispersant, and the organic solvent are mixed using a stirrer, a homogenizer, a high-pressure emulsifier, a wet pulverizer, a wet disperser, and the like. Although it can prepare by performing a dispersion process, the method is not limited to these.
The dispersion process may be performed by two or more dispersion processes (multistage dispersion).

-Preparation of photosensitive resin composition-
The preparation mode of the photosensitive resin composition of the present invention is not particularly limited. For example, the titanium black dispersion of the present invention, a polymerization initiator, a polymerizable compound, and various additives used in combination as desired are mixed. Can be prepared.

<Wafer level lens>
The wafer level lens of the present invention has a light-shielding film obtained by curing the photosensitive resin composition of the present invention at the peripheral edge of the lens present on the substrate.

  Hereinafter, the wafer level lens of the present invention will be described.

  FIG. 1 is a plan view showing an example of the configuration of a wafer level lens array having a plurality of wafer level lenses. In FIG. 1, reference numeral 10 denotes a substrate, and a lens 12 is provided on the substrate 10. The plurality of lenses 12 are arranged one-dimensionally or two-dimensionally with respect to the substrate 10.

FIG. 2 is a cross-sectional view taken along the line AA shown in FIG.
As shown in FIG. 2, the wafer level lens array includes a substrate 10 and a plurality of lenses 12 arranged on the substrate 10. A light shielding film 14 is provided between the plurality of lenses 12 to prevent light from being transmitted from locations other than the lenses. The wafer level lens of the present invention is composed of one lens 12 existing on the substrate 10 and a light shielding film 14 provided on the peripheral edge thereof. The photosensitive resin composition of the present invention is used for forming the light shielding film 14.

  Hereinafter, a configuration of a wafer level lens array in which a plurality of lenses 12 are two-dimensionally arranged with respect to the substrate 10 as shown in FIG. 1 will be described as an example.

  The lens 12 is generally made of the same material as the substrate 10 and is molded integrally on the substrate 10 or formed as a separate structure and fixed on the substrate. is there. Although an example is given here, the wafer level lens of the present invention is not limited to this mode, and can take various modes such as a multi-layer structure and a lens module separated by dicing.

  Another example of the material forming the lens 12 is glass. There are many types of glass, and a glass having a high refractive index can be selected. Therefore, the glass is suitable for a lens material that requires a large power. Further, glass has excellent heat resistance, and has an advantage of withstanding reflow mounting on an imaging unit or the like.

  Resin is mentioned as another material which forms the lens 12. FIG. Resin is excellent in processability, and is suitable for forming a lens surface easily and inexpensively using a mold or the like.

In forming the wafer level lens, it is preferable to use an energy curable resin. The energy curable resin may be either a resin curable by heat or a resin curable by irradiation with active energy rays (for example, heat, ultraviolet rays, electron beam irradiation).
In consideration of reflow mounting of the imaging unit, a resin having a relatively high softening point such as 200 ° C. or higher is preferable, and a resin having a softening point of 250 ° C. or higher is more preferable.
Hereinafter, a resin suitable as a lens material will be described.

Examples of the ultraviolet curable resin include an ultraviolet curable silicone resin, an ultraviolet curable epoxy resin, and an acrylic resin. The epoxy resin may be an epoxy resin having a linear expansion coefficient of 40 to 80 [10 ⁻⁶ / K] and a refractive index of 1.50 to 1.70, preferably 1.50 to 1.65.

Examples of the thermosetting resin include a thermosetting silicon resin, a thermosetting epoxy resin, a thermosetting phenol resin, and a thermosetting acrylic resin. For example, the silicon resin may be a silicon resin having a linear expansion coefficient of 30 to 160 [10 ⁻⁶ / K] and a refractive index of 1.40 to 1.55. The epoxy resin may be an epoxy resin having a linear expansion coefficient of 40 to 80 [10 ⁻⁶ / K] and a refractive index of 1.50 to 1.70, preferably 1.50 to 1.65.
The phenol resin may be a phenol resin having a linear expansion coefficient of 30 to 70 [10 ⁻⁶ / K] and a refractive index of 1.50 to 1.70. The acrylic resin may be an acrylic resin having a linear expansion coefficient of 20 to 60 [10 ⁻⁶ / K] and a refractive index of 1.40 to 1.60, preferably 1.50 to 1.60.

  Commercially available products can be used as these thermosetting resins. Specifically, for example, SMX-7852 / SMX-7877 (trade name) manufactured by Fuji Polymer Industries Co., Ltd., IVSM-4500 manufactured by Toshiba Corporation. (Trade name), SR-7010 (trade name) manufactured by Toray Dow Corning Co., Ltd., and the like can be exemplified.

Examples of the thermoplastic resin include polycarbonate resin, polysulfone resin, polyether sulfone resin, and the like. Polycarbonate having a linear expansion coefficient of 60 to 70 [10 ⁻⁶ / K] and a refractive index of 1.40 to 1.70, preferably 1.50 to 1.65 can be used. A polysulfone resin having a linear expansion coefficient of 15 to 60 [10 ⁻⁶ / K] and a refractive index of 1.63 can be used. As the polyethersulfone resin, one having a linear expansion coefficient of 20 to 60 [10 ⁻⁶ / K] and a refractive index of 1.65 can be used.

In general, the linear expansion coefficient of optical glass is 4.9 to 14.3 [10 ⁻⁶ / K] at 20 ° C., and the refractive index is 1.4 to 2.1 at a wavelength of 589.3 nm. Further, the linear expansion coefficient of quartz glass is 0.1 to 0.5 [10 ⁻⁶ / K], and the refractive index is about 1.45.

  It is preferable that the curable resin composition applied to the lens formation has an appropriate fluidity before curing from the viewpoint of moldability such as mold shape transfer suitability. Specifically, a curable resin composition that is liquid at room temperature and has a viscosity of about 1000 to 50000 mPa · s is preferable.

  On the other hand, it is preferable that the curable resin composition applied to the formation of the lens has a heat resistance that does not cause thermal deformation even after the reflow process after curing. From this viewpoint, the glass transition temperature of the cured product is preferably 200 ° C. or higher, more preferably 250 ° C. or higher, and particularly preferably 300 ° C. or higher. In order to give such a high heat resistance to the resin composition, it is necessary to constrain the mobility at the molecular level. Examples of effective means include (1) increasing the crosslinking density per unit volume. Means (2) means utilizing a resin having a rigid ring structure (for example, cycloaliphatic, norbornane, alicyclic structures such as tetracyclododecane, aromatic ring structures such as benzene and naphthalene, cardos such as 9,9′-biphenylfluorene, etc. Resin having a spiro structure such as spirobiindane, specifically, for example, JP-A-9-137043, JP-A-10-67970, JP-A-2003-55316, JP-A-2007-334018, JP-A-2007- (Resins described in Japanese Patent No. 238883), (3) means for uniformly dispersing a substance having a high Tg such as inorganic fine particles (for example, Japanese Patent Laid-Open No. Hei 5- 09027, JP-described), and the like in the 10-298265 Patent Publication. A plurality of these means may be used in combination, and it is preferable to adjust the heat resistance as long as other characteristics such as fluidity, shrinkage rate, and refractive index characteristics are not impaired.

  From the viewpoint of shape transfer accuracy, a resin composition having a small volume shrinkage due to the curing reaction is preferable. The curing shrinkage rate of the resin composition is preferably 10% or less, more preferably 5% or less, and particularly preferably 3% or less.

  Examples of the resin composition having a low curing shrinkage rate include, for example, (1) a resin composition containing a high molecular weight curing agent (such as a prepolymer) (for example, JP-A Nos. 2001-19740, 2004-302293, The number average molecular weight of the high molecular weight curing agent is preferably in the range of 200 to 100,000, more preferably in the range of 500 to 50,000, particularly preferably 1, The value calculated by the number average molecular weight of the curing agent / the number of curing reactive groups is preferably in the range of 50 to 10,000, preferably 100 to 5,000. And (2) non-reactive substances (organic / inorganic fine particles, non-reactive resins, etc.) are more preferable. (3) Resin composition containing a low shrinkage cross-linking reactive group (for example, an open resin composition described in JP-A-6-298883, JP-A-2001-247793, JP-A-2006-225434, etc.) A ring-polymerizable group (for example, an epoxy group (for example, described in JP-A No. 2004-210932), an oxetanyl group (for example, described in JP-A No. 8-134405), an episulfide group (for example, JP-A-2002-105110). Etc.), cyclic carbonate groups (for example, described in JP-A-7-62065), etc., ene / thiol curing groups (for example, described in JP-A 2003-20334), hydrosilylation curing Groups (for example, described in JP-A-2005-15666) and the like, and (4) rigid skeleton resins (fluorene, adamantane, isophoro) Etc.) (for example, described in JP-A-9-137043), (5) a resin comprising two types of monomers having different polymerizable groups to form an interpenetrating network structure (so-called IPN structure) Composition (for example, described in JP-A-2006-131868), (6) Resin composition containing an expandable substance (for example, described in JP-A-2004-2719, JP-A-2008-238417, etc.) And can be suitably used in the present invention. In addition, it is preferable from the viewpoint of optimizing physical properties to use a plurality of curing shrinkage reducing means in combination (for example, a resin composition containing a prepolymer containing a ring-opening polymerizable group and fine particles).

For forming the wafer level lens of the present invention, it is desirable to use two or more types of resin compositions having different Abbe numbers.
The resin on the high Abbe number side preferably has an Abbe number (νd) of 50 or more, more preferably 55 or more, and particularly preferably 60 or more. The refractive index (nd) is preferably 1.52 or more, more preferably 1.55 or more, and particularly preferably 1.57 or more.
As the resin contained in such a resin composition, an aliphatic resin is preferable, and a resin having an alicyclic structure (for example, a cyclic structure such as cyclohexane, norbornane, adamantane, tricyclodecane, or tetracyclododecane). Resin, specifically, for example, JP-A-10-152551, JP-A-2002-212500, JP-A-2003-20334, JP-A-2004-210932, JP-A-2006-199790, JP-A-2007-2144 And the resins described in JP-A-2007-284650, 2008-105999, and the like.

The resin on the low Abbe number side preferably has an Abbe number (νd) of 30 or less, more preferably 25 or less, and particularly preferably 20 or less. The refractive index (nd) is preferably 1.60 or more, more preferably 1.63 or more, and particularly preferably 1.65 or more.
As such a resin, a resin having an aromatic structure is preferable. For example, a resin having a structure such as 9,9′-diarylfluorene, naphthalene, benzothiazole, benzotriazole (specifically, for example, JP-A-60-38411). Publication No. 10-67977, No. 2002-47335, No. 2003-238842, No. 2004-83855, No. 2005-325331, No. 2007-238883, International Publication 2006. / 095610 publication, Japanese Patent No. 2537540 publication, etc.) are preferable.

In addition, as a resin used for forming a wafer level lens, it is also preferable to contain an organic-inorganic composite material in which inorganic fine particles are dispersed in a matrix for the purpose of increasing the refractive index and adjusting the Abbe number. It is an aspect. Examples of the inorganic fine particles include oxide fine particles, sulfide fine particles, selenide fine particles, and telluride fine particles. More specific examples include fine particles of zirconium oxide, titanium oxide, zinc oxide, tin oxide, zinc sulfide and the like.
More specifically, for example, fine particles of zirconium oxide, titanium oxide, zinc oxide, tin oxide, niobium oxide, cerium oxide, aluminum oxide, lanthanum oxide, yttrium oxide, zinc sulfide, and the like can be given.

In particular, it is preferable to disperse fine particles such as lanthanum oxide, aluminum oxide, and zirconium oxide in the high Abbe number resin as described above, and titanium oxide, tin oxide, zirconium oxide, etc. in the low Abbe number resin. The fine particles are preferably dispersed.
The inorganic fine particles may be used alone or in combination of two or more. Moreover, the composite by several components may be sufficient. In addition, for various purposes such as reducing photocatalytic activity and water absorption, the inorganic fine particles are doped with different metals, the surface layer is coated with different metal oxides such as silica and alumina, silane coupling agents and titanate cups. The surface of the inorganic fine particles may be modified with a ring agent, an organic acid (carboxylic acid, sulfonic acid, phosphoric acid, phosphonic acid, etc.) or a dispersant having an organic acid group.
If the number average particle size of the inorganic fine particles is too small, the properties of the substance may change. In addition, when the refractive index difference between the resin matrix and the inorganic fine particles is large, if the number average particle size of the inorganic fine particles is too large, the influence of Rayleigh scattering becomes significant. For this reason, the number average particle size of the inorganic fine particles is usually about 1 nm to 1000 nm, but if it is too small, the properties of the substance may change. If it is too large, the effect of Rayleigh scattering becomes significant. 15 nm is preferable, 2 nm-10 nm are still more preferable, and 3 nm-7 nm are especially preferable. Further, it is desirable that the particle size distribution of the inorganic fine particles is narrow. There are various ways of defining such monodisperse particles. For example, a numerical value range as described in JP-A No. 2006-160992 applies to a preferable particle size distribution range.
Here, the above-mentioned number average primary particle size is, for example, XRD (X-ray diffraction), X-ray small angle scattering (SAXS), X-ray diffuse scattering (XDS), oblique Incident X-ray scattering It can be measured with a small angle X-ray scattering (GI-SAXS), a scanning electron microscope (SEM), or a transmission electron microscope (TEM).

  The refractive index of the inorganic fine particles is preferably 1.90 to 3.00, more preferably 1.90 to 2.70 at 22 ° C. and a wavelength of 589.3 nm, and more preferably 2.00 to 2 .70 is particularly preferred.

  The content of the inorganic fine particles with respect to the resin is preferably 5% by mass or more, more preferably 10% by mass to 70% by mass, and particularly preferably 30% by mass to 60% by mass from the viewpoint of transparency and high refractive index. preferable.

As the resin used as the matrix used in the organic-inorganic composite material, any of the ultraviolet curable resin, thermosetting resin, and thermoplastic resin described above can be used as the material for the wafer level lens. Further, a resin having a refractive index higher than 1.60 described in JP-A-2007-93893, a block copolymer composed of a hydrophobic segment and a hydrophilic segment described in JP-A-2007-211114, and JP-A-2007 238929, Japanese Patent Application Nos. 2008-12645, 2008-208427, 2008-229629, and 2008-219952 can form arbitrary chemical bonds with inorganic fine particles at the polymer terminals or side chains. Examples thereof include resins having functional groups and thermoplastic resins described in Japanese Patent Application Nos. 2008-197054 and 2008-198878.
If necessary, additives such as a plasticizer and a dispersant can be added to the organic-inorganic composite material.

Here, preferred combinations of the matrix resin and the inorganic fine particles include the following.
That is, when a high Abbe number resin as described above is used as a matrix, it is preferable to disperse fine particles such as lanthanum oxide, aluminum oxide, and zirconium oxide as inorganic fine particles, and when a low Abbe number resin is used as a matrix. It is preferable to disperse fine particles such as titanium oxide, tin oxide, and zirconium oxide as inorganic fine particles.

  In order to uniformly disperse the fine particles in the resin composition, for example, a dispersant containing a functional group having reactivity with a resin monomer that forms a matrix (for example, described in Examples of JP 2007-238884 A), hydrophobic Block copolymer composed of a hydrophilic segment and a hydrophilic segment (for example, described in JP-A-2007-2111164), or having a functional group capable of forming an arbitrary chemical bond with inorganic fine particles at the polymer terminal or side chain It is desirable to disperse the fine particles by appropriately using a resin (for example, described in JP 2007-238929 A, JP 2007-238930 A, etc.).

  In addition, the resin composition used for forming the wafer level lens is appropriately added with known release agents such as silicon-based, fluorine-based, and long-chain alkyl group-containing compounds and additives such as antioxidants such as hindered phenols. You may contain.

  The resin composition used for forming the wafer level lens may contain a curing catalyst or an initiator as necessary. Specific examples thereof include compounds that promote the curing reaction (radical polymerization or ionic polymerization) by the action of heat or active energy rays described in paragraph numbers [0065] to [0066] of JP-A-2005-92099. Can do. The amount of these curing reaction accelerators to be added varies depending on the type of catalyst and initiator, or the difference in the curing reactive site, and cannot be specified unconditionally, but in general, the total solid content of the resin composition It is preferably about 0.1 to 15% by mass, and more preferably about 0.5 to 5% by mass.

The resin composition used for producing the wafer level lens of the present invention can be produced by appropriately blending the above components. At this time, if other components can be dissolved in the liquid low molecular weight monomer (reactive diluent), etc., it is not necessary to add a separate solvent, but if this is not the case, use a solvent. A resin composition can be produced by dissolving each component. The solvent that can be used in the resin composition is not particularly limited as long as the composition can be uniformly dissolved or dispersed without precipitation, and specific examples thereof include ketones ( For example, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), esters (eg, ethyl acetate, butyl acetate etc.), ethers (eg, tetrahydrofuran, 1,4-dioxane etc.) alcohols (eg, methanol, ethanol, isopropyl alcohol) , Butanol, ethylene glycol, etc.), aromatic hydrocarbons (eg, toluene, xylene, etc.), water and the like. When the resin composition contains a solvent, it is preferable to perform a mold shape transfer operation after casting the composition on a substrate and / or a mold and drying the solvent.
The same material as the molding material of the lens 12 can be used for the substrate 10. Moreover, as long as the board | substrate 10 consists of materials, such as glass transparent with respect to visible light, you may form with the material different from the molding material of the lens 12. FIG. In this case, the material forming the substrate 10 is preferably a material having the same linear expansion coefficient as the material forming the lens 12 but very close. When the linear expansion coefficients of the material forming the lens 12 and the material forming the substrate 10 are the same or close to each other, heating caused by different linear expansion coefficients in the reflow mounting of the wafer level lens on the imaging unit. The distortion and cracking of the lens 12 at the time can be suppressed.

  Although not shown in FIGS. 1 and 2, an infrared filter (IR filter) may be formed on the surface of the substrate 10 on the light incident side.

[Formation of wafer level lens]
Hereinafter, the formation of the wafer level lens will be specifically described with reference to an example of forming a wafer level lens array.

-Lens formation-
FIG. 3 is a diagram showing a state in which a resin (denoted as M in FIG. 3) as a molding material is supplied to the substrate 10. As shown in FIG. 3, the molding material M is dropped onto the portion of the substrate 10 where the lens is to be molded using the dispenser 50. Here, an amount of the molding material M corresponding to one lens 12 is supplied to one part to be supplied.

  After the molding material M is supplied to the substrate 10, as shown in FIG. 4A, a mold 60 for molding a lens is disposed. The mold 60 is provided with recesses 62 for transferring the shape of the lens 12 according to the desired number of lenses 12.

  As shown in FIG. 4B, the mold 60 is pressed against the molding material M on the substrate 1, and the molding material M is deformed following the shape of the recess. When the mold 60 is pressed against the molding material M and the molding material M is a thermosetting resin or an ultraviolet curable resin, the molding material M is cured by irradiating heat or ultraviolet rays from the outside of the mold. .

  After the molding material M is cured, the substrate 1 and the lens 12 are released from the mold 60 as shown in FIG. 4C.

  5A to 5C are schematic cross-sectional views showing a process of providing a light shielding film on a substrate on which a lens is molded.

-Method of forming light shielding film-
Next, a method for forming the light shielding film 14 on the periphery of the lens 12 will be described.

  The light-shielding film 14 is formed by a light-shielding coating layer forming step in which the photosensitive resin composition of the present invention is applied to the substrate 10 to form the light-shielding coating layer 14A, and the light-shielding coating layer 14A is masked. 16 and an exposure process for pattern exposure through a developing process for developing the light-shielding coating layer 14A after exposure to remove uncured portions and forming a patterned light-shielding film 14.

The formation of the light shielding film can be arbitrarily performed before or after the lens 12 is manufactured.
Hereinafter, each process in the formation method of a light shielding film is demonstrated.

<Light-shielding coating layer forming step>
In the light-shielding coating layer forming step, as shown in FIG. 5A, a photosensitive resin composition is applied on the substrate 10 to form a light-shielding coating layer 14A made of the photosensitive resin composition and having a low light reflectance. . At this time, the light-shielding coating layer 14 </ b> A is formed so as to cover the surface of the substrate 10 and the surfaces of the lens surface 12 a and the lens edge portion 12 b of the lens 12.

There is no restriction | limiting in particular as the board | substrate 10 which can be used for this process. Examples include soda glass, Pyrex (registered trademark) glass, quartz glass, and transparent resin.
In addition, the board | substrate 10 said here says the form containing both the lens 12 and the board | substrate 10 in the aspect which forms the lens 12 and the board | substrate 10 integrally.
In addition, an undercoat layer may be provided on these substrates 1 as necessary to improve adhesion to the upper layer, prevent diffusion of substances, or flatten the surface of the substrate 10.

As a method of applying the photosensitive resin composition to the substrate 10 and the lens 12, various coating methods such as slit coating, spray coating, ink jet method, spin coating, cast coating, roll coating, and screen printing are applied. be able to.
The film thickness immediately after the application of the photosensitive resin composition is preferably 0.1 μm to 10 μm, and preferably 0.2 μm to 5 μm, from the viewpoint of film thickness uniformity of the coating film and ease of drying of the coating solvent. It is more preferable that it is 0.2 μm to 3 μm.

  The light-shielding coating layer 14A applied on the substrate 10 can be dried (pre-baked) at a temperature of 50 ° C. to 140 ° C. for 10 seconds to 300 seconds using a hot plate, oven, or the like.

  The coating film thickness after drying of the photosensitive resin composition (hereinafter referred to as “dry film thickness” as appropriate) can be arbitrarily selected from performance such as desired light-shielding properties, and is generally about 0.1 μm or more and less than 50 μm. Range.

<Exposure process>
In the exposure step, the light-shielding coating layer 14A formed in the light-shielding coating layer forming step is exposed in a pattern. The pattern exposure may be scanning exposure, but as shown in FIG. 5B, a mode in which exposure is performed through a mask 70 having a predetermined mask pattern is preferable.

  In the exposure in this step, pattern exposure of the light-shielding coating layer 14A is performed through a predetermined mask pattern, and only the portion irradiated with light in the light-shielding coating layer 14A is cured by this exposure. Here, a mask pattern for irradiating light onto the surface of the lens edge 12b and the surface of the substrate 10 between the lenses 12 is used. By doing so, only the light-shielding coating layer 14A in the region excluding the lens surface 12a is cured by light irradiation, and this cured region forms the light-shielding film 14. As radiation that can be used for exposure, ultraviolet rays such as g-line, h-line, and i-line are particularly preferably used. This radiation may be a light source having a single wavelength, or a light source including all wavelengths such as a high-pressure mercury lamp may be used.

<Development process>
Next, by performing an alkali development process (development process), the light non-irradiated part in exposure, that is, the uncured region of the light-shielding coating layer 14A is eluted in the alkaline aqueous solution, and only the region cured by light irradiation is left. In this example, only the light-shielding coating layer 14A formed on the lens surface 12a is removed, and the cured light-shielding film 14 is formed in other regions (see FIG. 5C).

As the alkali agent contained in the developer used in the development step, any of organic or inorganic alkali agents and combinations thereof can be used. In the formation of the light shielding film in the present invention, an organic alkali developer is desirable from the viewpoint of hardly damaging surrounding circuits.
Examples of the alkaline agent used in the developer include, for example, aqueous ammonia, ethylamine, diethylamine, dimethylethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, choline, pyrrole, piperidine, 1,8-diazabicyclo- [5, Organic alkaline compounds such as 4,0] -7-undecene, and inorganic compounds such as sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, and the like. An alkaline aqueous solution obtained by diluting these alkaline agents with pure water so as to have a concentration of 0.001% by mass to 10% by mass, preferably 0.01% by mass to 1% by mass is preferably used as the developer.

  The development temperature is usually 20 ° C. to 30 ° C., and the development time is in the range of 20 seconds to 90 seconds.

  When a developer composed of such an alkaline aqueous solution is used, the unexposed portion of the coating film is generally removed with a developer and then washed (rinsed) with pure water. That is, after the development process, the excess developer is removed by washing thoroughly with pure water, and a drying process is performed.

  In addition, after performing the light-shielding coating layer forming step, the exposure step, and the development step described above, the formed light-shielding film (light-shielding pattern) is cured by heating (post-baking) and / or exposure as necessary. A curing step may be performed.

The post-baking is a heat treatment after development for complete curing, and is usually a heat curing treatment at 100 ° C. to 250 ° C. Conditions such as post-baking temperature and time can be appropriately set depending on the material of the substrate or lens. For example, when the substrate is made of glass, 180 ° C. to 240 ° C. is preferably used in the above temperature range.
In this post-baking process, the light-shielding film 14 formed after the development is continuously or batchwise heated using a heating means such as a hot plate, a convection oven (hot air circulation dryer) or a high-frequency heater so as to satisfy the above conditions. It can carry out by making it thermoset by a type | formula.

  In the above procedure, the case where the shape of the lens 12 is concave has been described as an example, but the shape of the lens is not particularly limited, and may be a convex shape or an aspherical shape. In the above procedure, a wafer level lens in which a plurality of lenses 12 are molded on one surface of the substrate 1 has been described as an example. However, a configuration in which a plurality of lenses 12 are molded on both surfaces may be used. On both surfaces, a patterned light shielding film 14 is formed in a region excluding the lens surface.

  FIG. 6 is a diagram showing another configuration example of the wafer level lens array. The wafer level lens shown in FIG. 6 has a configuration (monolithic type) in which the substrate 10 and the lens 12 are simultaneously molded using the same molding material. As the molding material, the same materials as described above can be used. In this example, a plurality of concave lenses 12 are formed on one surface (upper surface in the drawing) of the substrate 10, and a convex lens 20 is formed on the other surface (lower surface in the drawing). A plurality of are formed. A patterned light-shielding film 14 is formed in a region excluding the lens surface 12a of the substrate 1, that is, the surface of the substrate 10 and the surface of the lens edge portion 12b. As a patterning method for forming the light shielding film 14, the above-described procedure can be applied.

  Next, another procedure of patterning for forming the light shielding film will be described. In the above example, the patterned light shielding film 14 is formed on the substrate 10 provided with the lens. However, in the procedure described below, first, after the patterned light shielding film 14 is formed on the substrate 10. This is a procedure for forming a lens on a substrate.

7A to 7C are schematic views showing another process for forming the patterned light-shielding film 14.
FIG. 8A to FIG. 8C are schematic views showing a process of forming the lens 12 after forming the patterned light-shielding film 14 first.

  First, as shown in FIG. 7A, a light-shielding coating layer forming step of forming a light-shielding coating layer 14A by coating a photosensitive resin composition on the substrate 10 is performed.

  Thereafter, the light-shielding coating layer 14A applied on the substrate 10 is dried at a temperature of 50 ° C. to 140 ° C. for 10 seconds to 300 seconds using a hot plate, oven, or the like. The dry film thickness of the photosensitive resin composition can be arbitrarily selected from performances such as desired light shielding properties, and is generally in the range of 0.1 μm or more and less than 50 μm.

  Next, as illustrated in FIG. 7B, an exposure process is performed in which the light-shielding coating layer 14 </ b> A formed in the light-shielding coating layer forming process is exposed in a pattern through a mask 70. The mask 70 has a predetermined mask pattern. In the exposure in this step, the light-shielding coating layer 14 is subjected to pattern exposure to cure only the light-irradiated portion of the light-shielding coating layer 14A. Here, a mask pattern that irradiates light only to the light-shielding coating layer 14 </ b> A in a region excluding a portion that becomes the lens opening 14 a of the lens 12 when the lens 12 is molded in a subsequent process is used. By this method, only the light-shielding coating layer 14A in the region excluding the portion that becomes the lens opening 14a of the lens 12 is cured by light irradiation. As radiation that can be used for exposure, ultraviolet rays such as g-line, h-line, and i-line are preferably used as in the procedure described above.

  Next, by performing an alkali development process (development process), only the light-shielding coating layer 14A in the region corresponding to the lens opening 14a of the lens 12 which is an uncured region of the light-shielding coating layer 14A in the pattern exposure is converted into an alkaline aqueous solution. Is eluted. Further, the light-cured light-shielding coating layer 14A in the region other than the region of the lens opening 14a of the lens 12 remains on the substrate 10 to form the light-shielding film 14 (see FIG. 7C). As the alkali agent, the same procedure as described above can be used. Thereafter, the excess developer is washed away and dried.

  Also in this embodiment, after performing the light-shielding coating layer forming step, the exposure step, and the development step, the curing step of curing the formed light-shielding film by the above-described post-baking and / or exposure as necessary. You may give it.

  Next, the manufacturing process of the wafer level lens which forms the light shielding film 14 and then forms the lens 12 will be described.

  As shown in FIG. 8A, the molding material M constituting the lens 12 is dropped by the dispenser 50 on the substrate 10 on which the patterned light shielding film 14 is formed. The molding material M is supplied so as to partially include an end portion of the light shielding film 14 adjacent to the opening so as to cover a region corresponding to the lens opening 14 a of the lens 12.

  After supplying the molding material M to the substrate 10, as shown in FIG. 8B, a mold 80 for molding a lens is disposed. The mold 80 is provided with concave portions 82 for transferring the shape of the lens 12 in accordance with the desired number of lenses 12.

  The mold 80 is pressed against the molding material M on the substrate 10, and the molding material M is deformed following the shape of the recess. When the mold 80 is pressed against the molding material M and the molding material M is a thermosetting resin or an ultraviolet curable resin, the molding material M is cured by irradiating heat or ultraviolet rays from the outside of the mold. .

  After the molding material M is cured, the substrate 10 and the lens 12 are released from the mold 80 to obtain a wafer level lens having a patterned light shielding film 14 on the substrate 10 as shown in FIG. 8C.

  As described above, the patterned light shielding film 14 provided in the wafer level lens is not only provided in the region excluding the lens surface 12a of the lens 12 as shown in FIG. 5C, but also as shown in FIG. 8C. The film 14 may be provided in a region excluding the lens opening 14 a of the lens 12.

  The wafer level lens has a light shielding film 14 formed on a pattern on at least one surface of the substrate 10 and having a low light reflectance, while sufficiently shielding light in a region other than the lens surface 12a or the lens opening 14a of the lens 12. Generation of reflected light can be suppressed. For this reason, when applied to an imaging module including an imaging element, it is possible to prevent the occurrence of problems such as ghosts and flares associated with reflected light during imaging.

  Further, since the light shielding film 14 is provided on the surface of the substrate, it is not necessary to attach another light shielding member or the like to the wafer level lens, and an increase in manufacturing cost can be suppressed.

  Note that, in the case where a structure having an uneven surface is provided around the lens as in the structure shown in Patent Document 2 described above, the light incident on the structure is reflected or diverged, thereby causing a ghost or the like. There is a concern that these problems are likely to occur. Therefore, as shown in FIG. 5C, if the patterned light shielding film 14 is provided in a region other than the lens surface 12a of the lens 12, light can be shielded except the lens surface 12a, and the optical performance can be improved. .

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof. Unless otherwise specified, “part” is based on mass. Room temperature refers to 25 ° C.

(Synthesis of Dispersant 1)
Into a 500 mL three-necked flask, 600.0 g of ε-caprolactone and 22.8 g of 2-ethyl-1-hexanol were introduced and dissolved with stirring while blowing nitrogen. 0.1 g of monobutyltin oxide was added to the flask, and the contents of the flask were heated to 100 ° C. After 8 hours, the disappearance of the raw materials was confirmed by gas chromatography, and then the contents of the flask were cooled to 80 ° C. After adding 0.1 g of 2,6-di-t-butyl-4-methylphenol, 27.2 g of 2-methacryloyloxyethyl isocyanate was added. After 5 hours, the disappearance of the raw material was confirmed by ¹ H-NMR, and then cooled to room temperature to obtain 200 g of a solid precursor M1 [the following structure]. It was confirmed by ¹ H-NMR, IR, and mass spectrometry that the obtained substance was M1.

30.0 g of the precursor M1, 70.0 g of NK ester CB-1, 2.3 g of dodecyl mercaptan, and 233.3 g of propylene glycol monomethyl ether acetate were introduced into a nitrogen-substituted three-necked flask, and a stirrer ( The mixture was stirred with Shinto Kagaku Co., Ltd. (Three-One Motor) and heated to 75 ° C. while flowing nitrogen into the flask. To this, 0.2 g of 2,2-azobis (2-methylpropionic acid) dimethyl (“V-601” manufactured by Wako Pure Chemical Industries, Ltd.) was added, and the mixture was heated and stirred at 75 ° C. for 2 hours. Two hours later, 0.2 g of V-601 was further added, and the mixture was heated and stirred for 3 hours to obtain a 30% solution of Dispersant 1 below.

The composition ratio, acid value, and weight average molecular weight (Mw) of the dispersant 1 are as follows.
The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and calculated in terms of polystyrene. The measurement by GPC was performed using HLC-8020GPC (manufactured by Tosoh Corporation) and using TSKgel SuperHZM-H, TSKgel SuperHZ4000, TSKgel SuperHZ200 (manufactured by Tosoh Corporation) as columns.
Composition ratio: x = 35 (mass%), y = 65 (mass%)
・ Acid value: 80 mgKOH / g
・ Mw: 30,000

[Example 1, Comparative Example 1]
<Production of titanium black>
100 g of titanium oxide MT-150A (trade name: manufactured by Teika Co., Ltd.) having an average particle diameter of 15 nm, 25 g of silica particles AROPERL (registered trademark) 300/30 (manufactured by Evonik) having a BET surface area of 300 m ² / g, and Disperbyk190 Uniform by weighing 100 g (product name: manufactured by Big Chemie), adding 71 g of ion-exchange water, and using KURABO MAZERSTAR KK-400W for 20 minutes at a revolution speed of 1360 rpm and a rotation speed of 1047 rpm. An aqueous mixture was obtained. This aqueous solution is filled in a quartz container, heated to 920 ° C. in an oxygen atmosphere using a small rotary kiln (manufactured by Motoyama Co., Ltd.), then the atmosphere is replaced with nitrogen, and ammonia gas is kept at 100 mL / min for 5 hours at the same temperature. The nitriding reduction treatment was carried out by flowing. After completion, the recovered powder was pulverized in a mortar to obtain a powdery titanium black having an average particle size of 30 nm or less.

<Preparation of titanium black dispersions A and B>
The ingredients shown in the following composition 1 were mixed with a stirrer (IKA's Eurostar).
) To give dispersion a.

(Composition 1)
-Titanium black produced above (titanium black with an average particle size of 30 nm or less) ... 25 parts-30% solution of dispersant 1 ... 25 parts-Propylene glycol monomethyl ether acetate (PGMEA) (solvent)・ 50 copies

The obtained dispersion a was subjected to dispersion treatment under the following conditions using Ultra Apex Mill UAM015 (trade name) manufactured by Kotobuki Industries Co., Ltd.
<Distribution conditions>
・ Bead diameter: 0.05mm in diameter
・ Bead filling rate: 75% by volume
・ Mill peripheral speed: 8m / sec
・ Amount of liquid mixture to be dispersed: 500 g
・ Circulation flow rate (pump supply amount): 13 kg / hour
・ Processing liquid temperature: 25-30 ° C
・ Cooling water: Tap water ・ Bead mill annular passage volume: 0.15L
・ Number of passes: 90 passes

  Thus, Dispersion A of Example 1 was obtained.

  Also, a dispersion b having the same composition as the dispersion a in Example 1 was prepared except that the titanium black used in Example 1 was changed to “13M-T” (trade name) manufactured by Mitsubishi Materials Corporation. A dispersion B of Comparative Example 1 was obtained by performing the same dispersion treatment as in Example 1.

<Evaluation of titanium black dispersions A and B>
Each of the obtained titanium black dispersions A and B was diluted 500 times with propylene glycol monomethyl ether acetate, dropped onto a carbon thin film and dried, and each was subjected to TEM (manufactured by Hitachi High-Technologies Corporation). A morphological observation photograph of titanium black particles (dispersed material) contained in the dispersion was taken. From the obtained photograph, the projected area of the outer surface was obtained for 400 particles, the diameter of the circle corresponding to this area was calculated, and the frequency distribution was evaluated.
Moreover, about the average particle diameter of the titanium black particle (to-be-dispersed body) contained in each dispersion liquid, 400 particle images are sampled from a TEM photograph, the projected area of an outer surface is calculated | required, and the circle | round | yen equivalent to this area The diameter was calculated, and the average value was obtained.

As a result, in the titanium black dispersion A of Example 1, the average particle size of the titanium black particles contained was 22 nm, and the proportion of particles having a particle size of 30 nm or less in all titanium black particles was 93%. there were.
In addition, in the dispersion B of Comparative Example 1, the average particle size of the titanium black particles contained was 50 nm, and the proportion of particles having a particle size of 30 nm or less in all titanium black particles was 4.2%. It was.

[Example 2, Comparative Example 2]
1A. Preparation of black curable composition (photosensitive resin composition) The components of the following composition 2 were mixed with a stirrer to prepare black curable composition A of Example 2.

(Composition 2)
-Benzyl methacrylate / methyl methacrylate / hydroxyethyl methacrylate / acrylic acid copolymer (50/15/5/30 [molar ratio]) [binder polymer] ... 1.6 parts dipentaerythritol hexaacrylate [polymerizable compound ] 2.0 parts pentaerythritol triacrylate [polymerizable compound] 1.0 parts polymerization initiator with the following structure [photopolymerization initiator] 0.3 parts


-Titanium black dispersion A-24 parts-Propylene glycol monomethyl ether acetate (PGMEA)-10 parts-Ethyl-3-ethoxypropionate ("EEP")-8 parts

  Moreover, except having changed the titanium black dispersion A into the titanium black dispersion B among the components of the composition 2, the black curable composition B of Comparative Example 2 was changed in the same manner as the black curable composition A. Prepared.

2A. Formation of Light-shielding Film for Wafer Level Lens The black curable composition A or B obtained above is applied to a glass wafer (Corning 1737, Corning) as a substrate by a spin coating method, and then 120 on a hot plate. A black curable composition coating layer was obtained by heating at ° C for 2 minutes.
Then, the resultant coating layer, an i-line stepper, and changed from the exposure amount 100 mJ / cm ² through a photomask by 100 mJ / cm ² exposure having a hole pattern of 50 [mu] m.
The exposed coating layer was subjected to paddle development at 23 ° C. for 60 seconds using a 0.3% aqueous solution of tetramethylammonium hydroxide. Thereafter, the coated layer after development is rinsed with a spin shower and further washed with pure water to obtain a patterned light-shielding film formed of the black curable compositions of Example 2 and Comparative Example 2. It was.

[Example 3, Comparative Example 3]
In Example 2 and Comparative Example 2, instead of the glass wafer used as the substrate, heat treatment was performed at 210 ° C. for 1 hour on “SR-7010 (trade name)” manufactured by Toray Dow Corning, which is a thermosetting resin. A patterned light-shielding film was formed in the same manner as in Example 2 and Comparative Example 2 except that a 1 mm-thick flat plate obtained by performing and curing was used as the substrate.
The thermosetting resin used in this example can also be used as a lens forming material.

<Evaluation>
In the formation of each of the patterned light-shielding films obtained in Examples 2 and 3 and Comparative Examples 2 and 3, the exposure amount at which peeling did not occur was determined using an optical microscope. The smaller the exposure amount, the more effective the adhesion between the light shielding film and the substrate.

The particle size (nm) of the dispersion in each of the patterned light shielding films (cured films) obtained in Examples 2 and 3 and Comparative Examples 2 and 3 was measured as follows.
Observe the cross-section of the film-formed substrate with a scanning electron microscope (S-3400N (trade name) manufactured by Hitachi High-Technologies Corporation) and an energy dispersive X-ray analyzer (Genesis (trade name) manufactured by EDAX). Thus, a morphology observation photograph and an element map of Ti and Si were obtained. From the obtained photograph, the projected area of the outer surface was obtained for 400 particles in which Ti element was detected, the diameter of a circle corresponding to this area was calculated, and the frequency distribution was evaluated.
As a result, in each of the light shielding films formed in Examples 2 and 3, the ratio of those having a particle diameter of 30 nm or less among the dispersions included in the light shielding film was 90%.
Further, in each of the light shielding films formed in Comparative Examples 2 and 3, the proportion of the dispersions contained in the light shielding film having a particle size of 30 nm or less was 6%.

Moreover, about the image development part of each pattern-shaped light shielding film (exposure amount is described in Table 1 and 2) obtained in Example 2, 3 and Comparative Examples 2 and 3, a scanning electron microscope (Corporation | KK) Observation was made with Hitachi High-Technologies S-4800), and the presence or absence of development residue on the substrate was evaluated.
The fact that a residue of 10 nm or more is not observed on the glass substrate indicates that the wafer-level lens light-shielding film is good.
The above results are shown in Tables 1 and 2.

  As shown in Table 1 and Table 2, the black curable composition A of the example is excellent in curability at any exposure amount in comparison with the black curable composition B of the comparative example, and In the formation of the light-shielding film using this, no development residue was observed when either the glass substrate or the resin substrate was used.

[Example 4]
In the same manner as in Example 3, a curable resin layer was formed using a curable resin composition having the following composition 3 on a substrate on which a patterned light-shielding film was formed, and the shape was cured with a quartz mold having a lens shape. A wafer level lens array having a plurality of wafer level lenses was prepared by transferring the curable resin layer and curing the curable resin layer with an exposure amount of 400 mJ / cm ² using a high pressure mercury lamp.

(Composition 3)
・ N-vinylpyrrolidone ・ ・ ・ 35 parts ・ Epoxy acrylate (epoxy ester 80MF, manufactured by Kyoeisha Chemical Co., Ltd.) ・ ・ ・ 40 parts ・ Pentaerythritol tetraacrylate ・ ・ ・ 20 parts ・ Irgacure 907 (made by BASF Japan) ・ ・・ 5 copies

  The produced wafer level lens array was cut and a lens module was produced thereon, and then an imaging device and a sensor substrate were attached to produce an imaging unit.

The wafer level lens obtained in Example 4 was free from residue at the lens opening, had good transparency, had high uniformity of the coated surface of the light shielding layer, and had high light shielding properties. .
Also, when an image was obtained using an imaging unit equipped with this wafer level lens, the image quality was good.

[Example 5]
A wafer provided with a light shielding layer by forming a patterned light shielding layer in the same manner as in Example 4 except that the black curable composition A prepared in Example 2 was applied to a silicon wafer provided with a lens. A level lens array was prepared.
The produced wafer level lens array was cut and a lens module was produced thereon, and then an imaging device and a sensor substrate were attached to produce an imaging unit.

The wafer level lens obtained in Example 5 was free from residue at the lens opening, had good transparency, had high uniformity of the coating surface of the light shielding layer, and had high light shielding properties. .
Also, when an image was obtained using an imaging unit equipped with this wafer level lens, the image quality was good.

10 substrate 12 lens 14 light shielding film

Claims (6)

  A wafer level lens comprising (A) titanium black particles, (B) a dispersant, and (C) an organic solvent, wherein 90% or more of the dispersions made of (A) titanium black particles have a particle size of 30 nm or less. Titanium black dispersion. 2. The titanium black dispersion for a wafer level lens according to claim 1, wherein the (B) dispersant is a graft copolymer containing a structural unit represented by any one of the following formulas (1) to (5).

(In Formula (1)-Formula (5), X ¹ , X ² , X ³ , X ⁴ , X ⁵ And X ⁶ Each independently represents a hydrogen atom or a monovalent organic group. Y ¹ , Y ² , Y ³ , Y ⁴ And Y ⁵ Each independently represents a divalent linking group. Z ¹ , Z ² , Z ³ , Z ⁴ And Z ⁵ Each independently represents a monovalent organic group. n, m, p, q, and r are each an integer of 1 to 500. j and k each independently represents an integer of 2 to 8. R represents a hydrogen atom or a monovalent organic group. ) In the graft copolymer, a functional group capable of interacting with the (A) titanium black particles is introduced in addition to the graft site, and the functional group includes an acid group, a basic group, a coordinating group, and the like. The titanium black dispersion for a wafer level lens according to claim 2, which is at least one of reactive functional groups. The photosensitive resin composition for wafer level lenses containing the titanium black dispersion of any one of Claims 1-3 , (D) a photopolymerizable compound, and (E) a photoinitiator. The wafer level lens which has the light shielding film obtained by hardening | curing the photosensitive resin composition of Claim 4 in the peripheral part of the lens which exists on a board | substrate. A solid-state imaging device comprising the wafer level lens according to claim 5 .