JP2012185468A - Light selective transmission filter, resin sheet and solid state image sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light selective transmission filter which sufficiently suppresses the incident angle dependency of light shielding performance, is excellent in light selective transmissivity and can be sufficiently made thin; a resin sheet used for the light selective transmission filter; and a solid state image sensor having the light selective transmission filter.SOLUTION: A light selective transmission filter includes a resin sheet and an optical multilayer film formed on at least one surface of the resin sheet, in which the resin sheet includes a resin layer containing a dye having an absorption maximum in the wavelength region of 600 to 800 nm.

Description

The present invention relates to a light selective transmission filter, a resin sheet, and a solid-state imaging device. More specifically, it is useful for optical applications such as lens units and optical device applications, and in addition, a light selective transmission filter that can be used as display device applications, mechanical components, electrical / electronic components, etc., a resin sheet used therefor, and The present invention relates to a solid-state imaging device having a light selective transmission filter.

The light selective transmission filter is a filter that selectively reduces the transmittance of light of a specific wavelength. For example, the light selective transmission filter is suitably used as an optical filter member, an optical member, etc. used in mechanical parts, electrical / electronic parts, automobile parts, etc. It is what For example, in a solid-state imaging device (also referred to as a camera module), which is one of typical optical members, an infrared cut filter (IR cut filter) that blocks infrared light (particularly wavelength> 780 nm) that becomes optical noise is used. Yes. As such a light selective transmission filter, a filter in which a metal or the like is vapor-deposited on a base material to form an inorganic multilayer film and the refractive index of each wavelength is controlled is mainly used.

By the way, in recent years, in the optical member and the like, for example, a digital camera module is mounted on a mobile phone and the miniaturization has progressed. Accordingly, it is desired to reduce the thickness of a light selective transmission filter (infrared cut filter) used in a digital camera module or the like. Conventionally, a glass plate has been used as the base material for the light selective transmission filter. However, in response to the increasing demand for such a thin film, a light selective transmission filter using a resin as a base material has been studied.

As the light selective transmission filter using a resin as a base material, for example, a light selective transmission filter having a thickness of less than 200 μm and the base material including a reflow-resistant functional film is disclosed (for example, (See Patent Document 1). Patent Document 1 describes that this filter is excellent in heat resistance even if it is sufficiently thin.
The light selective transmission filter described in Patent Document 1 is obtained by vapor-depositing a reflective IR cut film (dielectric multilayer film) on a substrate. Such a reflective filter has a light blocking performance. Although it is excellent, it has an incident angle dependency in which the reflection characteristic changes depending on the incident angle of light, and the reduction thereof has been a problem. An example of a filter that does not depend on the incident angle is an absorptive filter composed of a transparent material containing a light absorber. However, a considerable thickness is required to achieve sufficient absorption characteristics. .

In addition, an attempt has been made to make the optical filter have better performance by using a reflection type filter and an absorption type filter having different characteristics.
For example, in Patent Document 2, a light absorption film obtained by applying and drying a pigment ink containing a near infrared absorber on a glass substrate and a film having a higher refractive index than that of the light absorption film are alternately multilayered. A laminated light absorption filter is disclosed. The light absorption filter of Patent Document 2 is intended to realize a reduction in thickness while reducing the angle dependency.
Patent Document 3 discloses a heat ray cut filter in which a heat ray reflective film and a heat ray absorption film made of an optical multilayer film are formed on a glass substrate. The heat ray cut filter disclosed in Patent Document 3 provides a broadband heat ray cut filter that can generate a heat ray sharply and almost completely in a wide band from a near infrared region to a far infrared region generated from a lamp. The objective is to block infrared rays in a short wavelength region (for example, a wavelength of 2 μm or less) with a heat ray reflecting film and to block infrared rays in a long wavelength region (for example, a wavelength of 2 μm or more) with a heat ray absorbing film.

By the way, when a multilayer film is formed by vapor deposition on a glass substrate, it has a high transmittance in a wavelength region (for example, visible region) to be transmitted and a high wavelength region (for example, near-infrared region) to be blocked. If the number of layers of the multilayer film is increased in order to achieve the cutting performance, stress may be generated between the layers due to heating / cooling in the vapor deposition process, and cracks or cracks may occur. Thus, it has been proposed to reduce the number of layers of the multilayer film by using absorption glass as a base material (see, for example, Non-Patent Document 1). However, if the absorption glass concentration of the absorption glass is increased, cracks are generated, and the absorption glass concentration cannot be reduced, so that the absorption pigment concentration must be lowered. For this reason, in order to exhibit sufficient absorption performance, it is necessary to use the absorption glass of considerable thickness (for example, about 2 mm).

JP 2008-181121 A JP 2006-106570 A JP-A-8-329719

Mitsunobu Kominato, “Optical Thin Film Filter Design”, Optronics, October 5, 2006, p. 213-219

As described above, although the reflection type filter is excellent in light blocking performance, there is a problem that it has incident angle dependency. On the other hand, although the absorption filter has no dependency on the incident angle, it is necessary to increase the thickness in order to exhibit sufficient absorption performance. In addition, when using a glass substrate, there is a problem that if it is made thin, it becomes easy to break, and there is a limit to thinning. Thus, in order to obtain a light selective transmission filter that can effectively block the light of a specific wavelength by reducing the dependency of the blocking performance on the incident angle, and meet the demand for a thin film. There was room for ingenuity.

The present invention has been made in view of the above-described situation, and the light selective transmission filter in which the dependency on the incident angle of the light blocking property is sufficiently reduced, the light selective transmission is excellent, and the film can be sufficiently thinned, It is an object of the present invention to provide a resin sheet used for a light selective transmission filter and a solid-state imaging device having the light selective transmission filter.

The present inventor has made various studies on a light selective transmission filter that selectively reduces the light transmittance. As a result, a reflection type filter (reflection layer) and an absorption type filter (absorption layer) are used in combination. Reduction and sufficient blocking performance. In addition, if the absorption layer is a resin layer, the dye as an absorbent can be uniformly dispersed in the layer even at a high concentration, and the absorption layer can be made much thinner than when glass is used like absorption glass. I found out that I can. Furthermore, the light selective transmission filter has a structure in which an optical multilayer film as a reflection film is formed on the surface of the resin sheet having the above-described absorption layer (resin layer), thereby comparing with the case of using glass as the base material. We have also found that the entire filter can be made much thinner. And it has also been found that such a light selective transmission filter can be suitably applied to optical applications such as solid-state imaging devices (camera modules), optical device applications, and the like, and has reached the present invention.

That is, the present invention is a light selective transmission filter including a resin sheet and an optical multilayer film formed on at least one surface thereof, wherein the resin sheet has a maximum absorption in a wavelength range of 600 to 800 nm. It is a light selective transmission filter which has a resin layer containing.
The present invention is also a resin sheet for a light selective transmission filter used for the light selective transmission filter.
The present invention is also a solid-state imaging device having at least the light selective transmission filter, a lens unit portion, and a sensor portion.
The present invention is described in detail below. In addition, what combined two or three or more of the preferable forms of this invention described in a paragraph below is also a preferable form of this invention.

The resin sheet which comprises the light selective transmission filter of this invention has a resin layer containing the pigment | dye which has an absorption maximum in the wavelength range of 600-800 nm. Thereby, especially when the said light selective transmission filter is applied to the infrared cut filter which reduces infrared light of 780 nm-10 micrometers, the incident angle dependence of a light-shielding characteristic can fully be reduced. In addition, by using an absorbent resin layer as described above in combination with an optical multilayer film, the number of layers of the optical multilayer film can be reduced, and stress in the multilayer film can be relieved. Can be prevented. Such a resin sheet for a light selective transmission filter used in the light selective transmission filter of the present invention is also one aspect of the present invention.

The dye in the present invention means a substance that absorbs light of a specific wavelength.
The dye is not particularly limited as long as it has an absorption maximum in a wavelength range of 600 to 800 nm, and a dye that can be mixed and kneaded with a resin can be used. The absorption maximum is preferably present in the wavelength range of 620 to 780 nm. More preferably, it exists in a wavelength range of 650 to 750 nm.
It is also preferable that the dye does not substantially have an absorption maximum in a wavelength region of 400 nm or more and less than 600 nm.

Examples of the dye include phthalocyanine dyes, cyanine dyes, porphyrin dyes, pyromethene dyes, azo dyes, and quinones because of their high solubility in solvent-soluble resins, solvent-soluble resin raw materials, or liquid resin raw materials described later. Of these, dyes based on dyes, squarylium dyes, triarylmethane dyes, indigo dyes and copper ion dyes are suitable. Also, phthalocyanine dyes, cyanine dyes, porphyrin dyes, and copper ion dyes are preferred because of their high transmittance in the visible light region. Furthermore, phthalocyanine dyes and porphyrin dyes are preferred because of excellent light resistance. Furthermore, phthalocyanine dyes are preferred because they have a particularly high transmittance in the visible light region and no absorption in the visible light region. In addition, phthalocyanine dyes are preferred because of their excellent heat resistance. Thus, the form in which the dye is at least one selected from the group consisting of a phthalocyanine dye, a cyanine dye, a porphyrin dye, and a copper ion dye is one of the preferred embodiments in the present invention. is there.

Examples of the phthalocyanine dyes include metal phthalocyanines. Examples of the central metal include copper, zinc, cobalt, vanadium, iron, nickel, tin, silver, magnesium, sodium, lithium, lead and the like. Especially, since light resistance is more excellent, copper, vanadium, and zinc are preferable, and copper is more preferable. The phthalocyanine using copper is not deteriorated by light even when dispersed in any binder resin, and has very excellent light resistance.
Examples of the cyanine dyes, I ^- salts cyanine, ClO ₄ ^- salt cyanine, Br ^- salts ^cyanine, - OAc salt cyanine, BF ₄ ^- salt cyanine and the like.
Examples of the porphyrin pigment include tetraazaporphyrin.
Examples of the copper ion dye include compounds containing copper ions in which polar groups such as acids such as acrylic acid, carboxylic acid and phosphoric acid, and ketone groups and ester groups are coordinated and / or bonded.

It is preferable that the pigment is uniformly dispersed or dissolved in the resin layer. In this embodiment, it is preferable that the haze in the visible light region of the resin layer containing the pigment is 10% or less. More preferably, it is 5% or less, more preferably 3% or less, and most preferably 1% or less. In this embodiment, the transmittance of the resin layer containing a dye at a visible light wavelength of 500 nm is preferably 60% or more, more preferably 70% or more, still more preferably 80% or more, and most preferably 85% or more. .
In the above-described embodiment, it is preferable that the light selective transmission filter including the resin layer containing the dye also has the haze in the visible light region and the transmittance at 500 nm of visible light in the above-described ranges.

The concentration (content) of the pigment in the resin sheet is preferably 0.0001% by mass or more and less than 15% by mass with respect to 100% by mass of the total amount of the resin sheet. More preferably, it is 0.001 mass% or more and less than 10 mass%. More preferably, it is 0.001 mass% or more and less than 0.5 mass%.
The concentration (content) of the pigment in the resin layer is preferably 0.0001% by mass or more and less than 15% by mass with respect to 100% by mass of the total amount of the resin layer. More preferably, it is 0.001 mass% or more and less than 10 mass%. More preferably, they are 0.1 mass% or more and less than 10 mass% with respect to 100 mass% of total amounts of a resin layer, Most preferably, they are 0.5 mass% or more and less than 10 mass%.
When the resin sheet is composed of a resin layer containing the dye and a support film as described later, the concentration (content) of the dye in the resin layer is 100% by mass of the total amount of the resin layer. The content is preferably 1% by mass or more and less than 15% by mass. More preferably, it is 3 mass% or more and less than 15 mass%.

The resin layer is preferably a resin layer formed of at least one of a solvent-soluble resin, a solvent-soluble resin raw material, and a liquid resin raw material in which a pigment is dispersed. Since such a resin layer can be formed (film formation) by a solvent casting method to be described later, the pigment can be uniformly dispersed at a high concentration, and the resin layer can be formed at a relatively low temperature. In addition, by appropriately selecting a resin forming component (binder resin) for forming the resin layer, high transmittance in a wavelength region (for example, visible region) to be transmitted and a wavelength region (for example, infrared) to be blocked. It is possible to achieve both high absorbency in the region).

In the present specification, the solvent-soluble resin material refers to a solvent-soluble resin material, that is, a resin material that is solvent-soluble. For example, it is preferable to dissolve 1 part by mass or more with respect to 100 parts by mass of dimethylacetamide or N-methylpyrrolidone. The liquid resin material means a liquid resin material, that is, a resin material that is liquid. Here, the term “liquid” means that the viscosity of the product itself is 100 Pa · s or less at room temperature (25 ° C.). The viscosity can be measured with a B-type viscometer.
The solvent-soluble resin in which a pigment is dispersed means a composition containing at least a solvent-soluble resin and a pigment, in which the pigment is dispersed in the composition. Similarly, the solvent-soluble resin raw material in which a dye is dispersed means a composition containing at least a solvent-soluble resin raw material and a dye, wherein the dye is dispersed in the composition. The dispersed liquid resin raw material means a composition containing at least a liquid resin raw material and a pigment, and the pigment is dispersed in the composition.
The resin raw material includes a precursor of the resin, a raw material of the precursor, and a monomer (such as a curable monomer) for forming the resin.
As described above, the resin layer is preferably a resin layer formed of at least one of a solvent-soluble resin, a solvent-soluble resin raw material, and a liquid resin raw material in which a pigment is dispersed. The solvent itself may be solvent-soluble or insoluble.

The solvent-soluble resin is not particularly limited as long as it is soluble in an organic solvent. For example, it is preferably a resin that dissolves 1 part by mass or more with respect to 100 parts by mass of dimethylacetamide or N-methylpyrrolidone. Specific examples include fluorinated aromatic polymers, poly (amide) imide resins, polyamide resins, aramid resins, polycycloolefin resins, and the like. Preferred are fluorinated aromatic polymers and polyimide resins.
These solvent-soluble resins are reactive groups that can undergo a crosslinking reaction (curing reaction) (for example, ring-opening polymerizable groups such as epoxy groups, oxetane rings, and ethylene sulfide groups, acrylic groups, methacrylic groups, vinyl groups). Or a radical curable group such as an addition curable group).
When the solvent-soluble resin is used as a resin-forming component for forming the resin layer, the resin-forming component may be used as it is to form a resin component constituting the obtained resin layer. What changed by the above may become a resin component constituting the resin layer.

The fluorinated aromatic polymer includes an aromatic ring having at least one fluorine group and at least one bond selected from the group consisting of an ether bond, a ketone bond, a sulfone bond, an amide bond, an imide bond, and an ester bond. Specifically, for example, a polyimide having a fluorine atom, polyether, polyetherimide, polyetherketone, polyethersulfone, polyamide ether, polyamide, polyether A nitrile, polyester, etc. are mentioned. Among these, it is preferable that it is a polymer which has as an essential part the repeating unit containing the aromatic ring which has an at least 1 or more fluorine group, and an ether bond, and the following general formula (1-1) or (1- A polyether ketone having a fluorine atom containing the repeating unit represented by 2) is more preferred. Among these, fluorinated polyether ketone (FPEK) is particularly preferable.
In addition, the repeating unit represented by the general formula (1-1) or (1-2) may be the same or different, and may be in any form such as a block shape or a random shape.

In the general formula (1-1), R ¹ represents a divalent organic chain having an aromatic ring having ¹ to 150 carbon atoms. Z represents a divalent chain or a direct bond. x and y are integers of 0 or more, satisfy x + y = 1 to 8, and represent the number of fluorine atoms that are the same or different and are bonded to the aromatic ring. n ¹ represents a degree of polymerization, preferably in the range of 2 to 5000, and more preferably in the range of 5 to 500.
In General Formula (1-2), R ² may have a substituent, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkylamino having 1 to 12 carbon atoms. Group, an alkylthio group having 1 to 12 carbon atoms, an aryl group having 6 to 20 carbon atoms, an aryloxy group having 6 to 20 carbon atoms, an arylamino group having 6 to 20 carbon atoms, or an arylthio group having 6 to 20 carbon atoms. . R ³ represents a divalent organic chain having an aromatic ring having 1 to 150 carbon atoms. z is the number of fluorine atoms bonded to the aromatic ring and is 1 or 2. n ¹ represents a degree of polymerization, preferably in the range of 2 to 5000, and more preferably in the range of 5 to 500.

In the general formula (1-1), x + y is preferably in the range of 2 to 8, and more preferably in the range of 4 to 8. Further, the position at which the ether structure moiety (—O—R ¹ —O—) is bonded to the aromatic ring is preferably para to Z.

In the general formulas (1-1) and (1-2), R ¹ and R ³ are divalent organic chains. For example, any one represented by the following structural formula group (2): Or it is preferable that it is the organic chain of the combination.

In the structural formula group (2), Y ^{1 to} Y ⁴ are the same or different and each represents a hydrogen group or a substituent, and the substituent is a halogen atom or an alkyl which may have a substituent. A group, an alkoxy group, an alkylamino group, an alkylthio group, an aryl group, an aryloxy group, an arylamino group or an arylthio group;
More preferable specific examples of R ¹ and R ³ include organic chains represented by the following structural formula group (3).

In the general formula (1-1), Z represents a divalent chain or a direct bond. For example, the divalent chain is preferably a chain represented by the following structural formula group (4) (structural formulas (4-1) to (4-13)).

In the structural formula group (4), X is a divalent organic chain having 1 to 50 carbon atoms. Examples thereof include the organic chain represented by the structural formula group (3) described above, and among them, diphenyl ether. A chain, a bisphenol A chain, a bisphenol F chain, and a fluorene chain are preferred.

In R ² in the general formula (1-2), examples of the alkyl group include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, An isopentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, dodecyl group, 2-ethylhexyl group and the like are preferable.
Examples of the alkoxy group include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, pentyloxy group, hexyloxy group, 2-ethylhexyloxy group, octyloxy group, nonyloxy group, decyloxy group, undecyloxy group. , Dodecyloxy group, furfuryloxy group, allyloxy group and the like are preferable.
As the alkylamino group, methylamino group, ethylamino group, dimethylamino group, diethylamino group, propylamino group, n-butylamino group, sec-butylamino group, tert-butylamino group and the like are preferable.
As the alkylthio group, methylthio group, ethylthio group, propylthio group, n-butylthio group, sec-butylthio group, tert-butylthio group, iso-propylthio group and the like are preferable.

As the aryl group, phenyl group, benzyl group, phenethyl group, o-, m- or p-tolyl group, 2,3- or 2,4-xylyl group, mesityl group, naphthyl group, anthryl group, phenanthryl group, A biphenylyl group, a benzhydryl group, a trityl group, a pyrenyl group, and the like are preferable.
Examples of the aryloxy group include groups derived from a phenoxy group, a benzyloxy group, hydroxybenzoic acid and esters thereof (for example, methyl ester, ethyl ester, methoxyethyl ester, ethoxyethyl ester, furfuryl ester, and phenyl ester). A naphthoxy group, o-, m- or p-methylphenoxy group, o-, m- or p-phenylphenoxy group, phenylethynylphenoxy group, a group derived from cresotinic acid and esters thereof, and the like are preferable.
The arylamino group includes an anilino group, o-, m- or p-toluidino group, 1,2- or 1,3-xylidino group, o-, m- or p-methoxyanilino group, anthranilic acid and its Groups derived from esters are preferred.
The arylthio group is preferably a phenylthio group, a phenylmethanethio group, an o-, m- or p-tolylthio group, a group derived from thiosalicylic acid and esters thereof, and the like.
Among these, R ² is preferably an alkoxy group, an aryloxy group, an arylthio group, or an arylamino group, which may have a substituent. However, R ² may or may not contain a double bond or a triple bond.

Examples of the substituent for R ² in the general formula (1-2) include an alkyl group having 1 to 12 carbon atoms as described above; a halogen atom such as fluorine, chlorine, bromine and iodine; a cyano group, a nitro group, and a carboxy group. An ester group or the like is preferred. Moreover, hydrogen of these substituents may or may not be halogenated. Among these, preferably, a halogen atom, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group, a hexyl group, and a carboxy ester, which may or may not be halogenated. It is a group.

The above poly (amide) imide resin is a narrowly defined polyimide resin (resin that contains an imide bond and does not contain an amide bond, and the amide bond here refers to an amide bond that cannot form an imide bond by a dehydration reaction of an amic acid. And a polyamide-imide resin (resin containing an amide bond and an imide bond that cannot form an imide bond by a dehydration reaction of an amic acid).
The imide bond in the polyimide resin is usually a bond chain having an amide bond and a carboxyl group adjacent thereto (in the present invention, this bond chain is also referred to as an amic acid. Usually, adjacent to the carbon atom to which the amide bond is bonded. The structure is formed by dehydration reaction between an amide bond and a carboxyl group.
When a polyimide resin is produced from a polyamic acid by a dehydration reaction, a slight amount of amic acid can remain in the molecule. Therefore, in the present invention, the term “polyimide resin” includes an imide bond and does not include an amide bond that cannot form an imide bond by a dehydration reaction of an amic acid, but can form an imide bond by a dehydration reaction of an amic acid. It may contain no amide bond or some amount.
As the solvent-soluble resin used in the present invention, the imide bond content in the polyimide resin (ratio of the number of imide bonds that can be imidized by imidization reaction and the total amount of imide bonds of 100 mol%) is 80 mol% or more. A polyimide resin is preferred.

The poly (amide) imide resin is a poly (amide) imide resin raw material (poly (amide) imide precursor) obtained by reacting a polyvalent carboxylic acid compound with a polyvalent amine compound and / or a polyvalent isocyanate compound. Can be obtained by imidization reaction.
The poly (amide) imide resin also preferably has transparency. In order to improve transparency, it is preferable that there are few aromatic rings. Among them, it is more preferable to have a structure in which the aromatic ring is replaced with an alicyclic ring or a fatty chain. More preferably, the weight of the aromatic ring in the total weight of 100% is 65% or less, more preferably 45% or less, and particularly preferably 30% or less.

Although it will not specifically limit as said poly (amide) imide resin if it is a compound which has an imide bond, For example, following General formula (5):

A compound having a repeating unit represented by the formula (wherein R ⁴ represents a divalent organic group having 2 to 39 carbon atoms) is preferable.
R ⁴ in the general formula (5) is preferably an organic group having 2 to 39 carbon atoms, divalent aliphatic, alicyclic, aromatic, or a combination thereof. The organic group represented by R ⁴ may be directly bonded to a nitrogen atom, and as a bonding group, —O—, —SO ₂ —, —CO—, —CH ₂ —, —C (CH ₃ ). _{2 -, - Si (CH 3} ) 2 -, - C 2 H 4 O -, - S- , etc. may be included.
The repeating units represented by the general formula (5) may be the same or different, and may be in any form such as block or random.

Preferable specific examples of the poly (amide) imide resin include, for example, Neoprim L-3430 (thickness 50 μm, 100 μm, 200 μm, etc.) manufactured by Mitsubishi Gas Chemical Company. In addition, although this product is a film shape, since it is soluble in an organic solvent, it is preferably used as the solvent-soluble resin of the present invention.

Examples of the solvent-soluble resin raw material or the liquid resin raw material include epoxy resins (compounds), acrylic resins (compounds), vinyl monomers ((meth) acrylic compounds, styrene compounds, etc.), poly (amides), and the like. Examples include imide precursors. An epoxy resin (compound) and an acrylic resin (compound) are preferable.
The said epoxy resin is a hardened | cured material of the curable composition containing the compound (epoxy compound) which has an epoxy group. Examples of the form of the cured product include a form obtained by curing the epoxy compound with light and / or heat in the presence of a cationic curing catalyst, a form of a cured product obtained by reacting the epoxy compound with an additional curing agent, and the like. In the latter case, a conventionally known curing accelerator can be used in combination for accelerating the curing reaction. Examples of the additional curing agent include acid anhydrides, polyhydric phenol compounds, and polyvalent amines. Among them, acid anhydrides are preferable.

As said epoxy compound, an aromatic epoxy compound, an aliphatic epoxy compound, an alicyclic epoxy compound, a hydrogenated epoxy compound etc. are suitable, For example, Osaka Gas Chemical Co., Ltd. fluorene epoxy (Oncoat EX-1); Bisphenol A type epoxy resin (Epicoat 828EL) manufactured by Japan Epoxy Resin; Hydrogenated bisphenol A type epoxy resin (Epicoat YX8000) manufactured by Japan Epoxy Resin; Alicyclic liquid epoxy resin (Celoxide 2021) manufactured by Daicel Industries, Ltd. Can be preferably used.
In addition, in this specification, an epoxy group includes an oxirane ring that is a three-membered ether, and includes a glycidyl group (including a glycidyl ether group and a glycidyl ester group) in addition to a narrowly defined epoxy group. Means.

In the epoxy resin, it is preferable that the curable composition before curing includes a flexible component (flexible component). By including a flexible component, it is possible to obtain a resin composition having a sense of unity, such as not cracking, not losing shape, being easily peeled off, and having flexibility when being removed from molding or from a substrate or mold.
The flexible component may be a compound different from the epoxy compound, or at least one of the epoxy compounds may be a flexible component.

The acrylic resin is a cured product of a curable composition containing a compound having a (meth) acryloyl group ((meth) acryloyl group-containing compound).
Specific examples of the acrylic resin include urethane acrylate, polyester acrylate, epoxy acrylate, (co) polymers of (meth) acrylate monomers, and the like. In terms of facilitating film formation, it is preferable to cure a composition comprising the above resin (oligomer, polymer) and (meth) acrylate monomer.

The poly (amide) imide precursor is a raw material for forming a poly (amide) imide resin, that is, a compound that is subjected to an imidization reaction. For example, a polyamic acid is preferable. Specifically, for example, HPC-7000-30 manufactured by Hitachi Chemical Co., Ltd. is preferably used.

As described above, the resin forming component (binder resin) for forming the resin layer is preferably at least one of a solvent-soluble resin, a solvent-soluble resin raw material, and a liquid resin raw material in which a pigment is dispersed. From the viewpoint of visible light transmittance, it is preferable to use a poly (amide) imide resin, a fluorinated aromatic polymer such as FPEK, and / or a poly (amide) imide precursor as the binder resin.
Among the solvent-soluble resins, solvent-soluble resin raw materials, and liquid resin raw materials described above, when a solvent-soluble resin is used as a resin-forming component (binder resin), light resistance is higher than when solvent-soluble resin raw materials and liquid resin raw materials are used. Excellent in properties. This is because the solvent-soluble resin is less likely to cause deterioration in the absorption performance of the dispersed dye than the solvent-soluble resin material and the liquid resin material. The reason is that the solvent-soluble resin is prepared from its monomers and precursors to complete the polymerization and reaction. Further purification may be performed. It is considered that the solvent-soluble resin thus obtained has almost no unreacted substances, reactive ends, ionic groups, catalysts, acid / basic groups, etc. that promote the deterioration and decomposition of the dye. On the other hand, solvent soluble resin raw materials and liquid resin raw materials still have many factors that promote the deterioration and decomposition of such pigments. Therefore, even if the same pigment is dispersed, the light resistance of the resin layer varies depending on the resin forming component (binder resin). From the viewpoint of light resistance, it is preferable to use at least a solvent-soluble resin. Among these, FPEK and poly (amide) imide resin are preferable from the viewpoint of superior light resistance. More preferred is a poly (amide) imide resin, and particularly preferred is a polyimide resin.

In the form in which the pigment is uniformly dispersed in the resin layer, the method for forming the resin layer in which the pigment is dispersed is not particularly limited, and for example, a kneading method or a solvent casting method can be employed. . Among these, it is preferable to employ a solvent casting method. Thereby, since a pigment | dye can be disperse | distributed more uniformly, the light absorption film excellent in light selective absorptivity can be formed. In addition, since the pigment can be dispersed at a high concentration, it is possible to reduce the thickness of the pigment and meet demands for reducing the height of members such as an imaging lens element. Furthermore, since the resin layer can be formed at a relatively low temperature, a dye having a relatively low heat resistance can also be used. Thus, the form in which the said resin layer is formed by the solvent cast method is one of the suitable embodiment in this invention.
On the other hand, in the kneading method, since the resin is melted and used at a high temperature (for example, 200 ° C. or more), the dye having low heat resistance is decomposed and there is a possibility that sufficient light absorption cannot be obtained. is there. In addition, the dispersibility of the dye may not be sufficiently high.

The solvent (organic solvent) used in the solvent casting method is not particularly limited as long as it can dissolve the resin-forming component for forming the resin layer, and can be appropriately selected depending on the type of resin. Ketones such as methyl ethyl ketone (2-butanone), methyl isobutyl ketone (4-methyl-2-pentanone), cyclohexanone; PGMEA (2-acetoxy-1-methoxypropane), ethylene glycol mono-n-butyl ether, ethylene glycol monoethyl Glycol derivatives such as ether and ethylene glycol ethyl ether acetate (ether compounds, ester compounds and ether ester compounds); Amides such as N, N-dimethylacetamide; Esters such as ethyl acetate, propyl acetate and butyl acetate; N- Methyl-pyrrolidone More specifically, pyrrolidones such as 1-methyl-2-pyrrolidone); aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as cyclohexane and heptane; ethers such as diethyl ether and dipyl ether Etc. are preferred. More preferred are methyl ethyl ketone, ethyl acetate, and N, N-dimethylacetamide.

The amount of the solvent used is 150% by mass or more with respect to 100% by mass of the total amount of resin forming components (solvent-soluble resin, solvent-soluble resin raw material, and liquid resin raw material) for forming the resin layer. Moreover, 1900 mass% or less is preferable. More preferably, it is 200 mass% or more, and is 1400 mass% or less.

In the solvent casting method, a dispersion in which a pigment is uniformly dispersed in a solution obtained by dissolving a resin forming component (binder resin) for forming a resin layer in a solvent is applied onto a substrate and dried (cured). ) To form a resin layer (film formation). When a liquid resin raw material is used as the resin forming component, the dye may be directly dispersed in the resin raw material, or the dye may be dispersed after the resin raw material is diluted with a solvent.

As the form of the resin sheet constituting the light selective transmission filter of the present invention, (i) the resin sheet is composed of a resin layer containing a pigment and a support film, and an optical multilayer film (reflection film) described later is the resin layer. And / or the form formed on the surface (one side or both sides) of the support film, and (ii) the resin sheet is composed of a resin layer containing a dye, and an optical multilayer film (reflective film) described later is formed on the resin layer. Although the form (form which consists of a support body film and a pigment | dye is contained in this support body film) formed in the surface (one side or both surfaces) can be mentioned, it is preferable to set it as the form of (i).
In the case of the form (i), even if the support film is difficult to disperse the pigment, the effect of the present invention can be imparted by coating the surface with a resin layer. Since the absorption characteristics can be controlled by changing the pigment concentration of the resin layer and the coating thickness of the resin layer, the present invention does not substantially change the film thickness of the support film by, for example, coating the resin layer very thinly. These effects can be imparted, the thickness of the support film can be adjusted, or the resin layer can be used for surface modification such as reduction of surface scratches on the support film.
Moreover, it is also preferable to set it as the resin sheet which pinched | interposed the resin layer with the support body film.

In the form (i), it is preferable to use a resin having excellent transparency as the support film. Specifically, for example, (meth) acrylic resin, epoxy resin, polycarbonate resin, polyester resin, fluorinated aromatic polymer, poly (amide) imide resin, polyamide resin, aramid resin, polycycloolefin resin, etc. may be used. it can. Among these, fluorinated aromatic polymer, poly (amide) imide resin, polyamide resin, aramid resin, polycycloolefin resin, epoxy resin, and acrylic resin are excellent in heat resistance when the optical multilayer film is formed by vapor deposition. preferable. Thus, the support film is formed of at least one selected from the group consisting of a fluorinated aromatic polymer, a poly (amide) imide resin, a polyamide resin, an aramid resin, a polycycloolefin resin, an epoxy resin, and an acrylic resin. The form that is to be done is one of the preferred embodiments of the present invention.

Furthermore, since the dispersibility of the dye is high, it is possible to form a light-absorbing film excellent in light selective absorption, and because the dye can be dispersed at a high concentration, it is possible to reduce the thickness of the dye. More preferably, the resin corresponds to a resin formed from at least one of a solvent-soluble resin, a solvent-soluble resin raw material, and a liquid resin raw material. Furthermore, what corresponds to the solvent soluble resin mentioned above is especially preferable at the point which is excellent in flexibility.

As a suitable combination of the material of the support film and the material of the resin layer containing the pigment, support film: polyimide resin / resin layer: polyimide resin, support film: polyimide resin / resin layer: acrylic resin, support film : Polyimide resin / resin layer: fluorinated aromatic polymer, support film: polyamide resin / resin layer: acrylic resin, support film: aramid resin / resin layer: acrylic resin, support film: cycloolefin resin / resin layer: An acrylic resin etc. are mentioned. Of these, support film: polyimide resin / resin layer: polyimide resin, support film: polyimide resin / resin layer: acrylic resin are most preferable.
In the form (i), the method for producing the resin sheet is not particularly limited, but a method of forming a resin layer on the surface (one side or both sides) of the support film by the solvent casting method described above is preferable.

In the form (ii), the resin layer containing the pigment also serves as the support film. About a suitable form, it is as having already stated in description of the said resin layer.
In the form of (ii), the method for producing the resin sheet is not particularly limited, but by forming a resin layer on the surface of an arbitrary base material (resin film or glass plate) by the above-described solvent casting method and peeling it off. The manufacturing method is preferred.

The resin sheet constituting the light selective transmission filter of the present invention preferably has a transmittance of 60% or less at the absorption maximum wavelength of the dye. Thereby, the light near the absorption maximum wavelength can be effectively blocked. The transmittance is more preferably 50% or less, still more preferably 40% or less, and particularly preferably 30% or less.
The transmittance can be measured using a spectrophotometer (Shimadzu UV-3100, manufactured by Shimadzu Corporation).

The resin sheet preferably has a thickness of 1 mm or less. As a result, the light selective transmission filter can be sufficiently thinned to meet the demand for lowering the height of optical members and the like. More preferably, it is 200 micrometers or less as a thickness of a resin sheet, More preferably, it is 100 micrometers or less.
Moreover, in the form in which the resin sheet includes a resin layer containing a pigment and a support film, the thickness of the resin layer is preferably 10 μm or less and the thickness of the support film is preferably 100 μm or less.

As the optical multilayer film constituting the light selective transmission filter of the present invention, an inorganic multilayer film or the like that can control the refractive index of each wavelength is suitable in that it has excellent heat resistance. As the inorganic multilayer film, a refractive index control multilayer film in which a low refractive index material and a high refractive index material are alternately laminated on a base material or other functional material layers by a vacuum deposition method, a sputtering method or the like is preferable. . The optical multilayer film is also preferably a transparent conductive film. As the transparent conductive film, a transparent conductive film as a film that reflects infrared rays, such as indium-tin oxide (ITO), is preferable. Among these, an inorganic multilayer film is preferable.

As the inorganic multilayer film, a dielectric multilayer film in which dielectric layers A and dielectric layers B having a refractive index higher than that of the dielectric layer A are alternately stacked is preferable.
<Dielectric layer A>
As the material constituting the dielectric layer A, a material having a refractive index of 1.6 or less can be generally used, and a material having a refractive index range of 1.2 to 1.6 is preferably selected.
As the material, for example, silica, alumina, lanthanum fluoride, magnesium fluoride, sodium hexafluoride sodium, and the like are suitable.

<Dielectric layer B>
As a material constituting the dielectric layer B, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index range of 1.7 to 2.5 is preferably selected.
Examples of the material include titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, indium oxide as a main component, and small amounts of titanium oxide, tin oxide, cerium oxide, and the like. What was contained is suitable.

<Thickness of each layer>
In general, the thickness of each of the dielectric layer A and the dielectric layer B is preferably 0.1λ to 0.5λ when the wavelength of light to be blocked is λ (nm). When the thickness is out of the above range, the product (n × d) of the refractive index (n) and the film thickness (d) is significantly different from the optical film thickness calculated by λ / 4, and the optical characteristics of reflection and refraction are different. May be lost, and control for blocking / transmitting a specific wavelength may not be possible.

<Lamination method>
The method for laminating the dielectric layer A and the dielectric layer B is not particularly limited as long as a dielectric multilayer film in which these material layers are laminated is formed. For example, CVD, sputtering, vacuum deposition Thus, a dielectric multilayer film can be formed by alternately laminating the dielectric layers A and B.

The optical multilayer film such as the inorganic multilayer film can be suitably formed by the above method or the like, but in order to reduce the possibility that the light selective transmission filter is deformed and curled by the vapor deposition, or cracking occurs. The following method can be used. Specifically, a multilayer film in which a vapor deposition layer is formed on a temporary base material such as glass that has been subjected to mold release treatment, and the vapor deposition layer is transferred to a resin sheet that is a base material of a light selective transmission filter to form a multilayer film. This transfer method is preferred. In this case, it is preferable to form an adhesive layer on the resin sheet.
When the resin sheet is formed of an organic material, specifically, a resin composition, the dielectric layer and the like are vapor-deposited on an uncured and semi-cured resin sheet (resin composition). A method of curing the sheet is preferred. When such a method is used, the substrate becomes fluid and becomes in a liquid state during cooling after multi-layer deposition, so the difference in thermal expansion coefficient between the resin composition and the dielectric layer does not matter. The deformation (curl) of the light selective transmission filter can be suppressed.

As described above, the vapor deposition method is preferably used for forming the optical multilayer film (preferably the inorganic multilayer film) on the resin sheet, but the vapor deposition temperature is preferably 100 ° C. or higher. More preferably, it is 120 degreeC or more, More preferably, it is 150 degreeC or more. When vapor deposition is performed at such a high temperature, the inorganic film (inorganic film constituting the inorganic multilayer film) becomes dense and hard, and there are advantages such as improving various resistances and improving the yield. Therefore, it is very meaningful to use a resin sheet and a dye that can withstand such a deposition temperature. In addition, for such high temperature vapor deposition, it is preferable to use a resin layer or support film having a low linear expansion coefficient as the resin layer or support film constituting the resin sheet. Thereby, the inorganic layer crack by the difference of an inorganic and organic linear expansion coefficient can be suppressed. In addition, when a resin layer or a support film having a low linear expansion coefficient is used, not only can it be deposited at a high temperature, but even if it is deposited at a low temperature, the difference in the linear expansion coefficient from the inorganic film is small. Even in a heating environment or a severe use environment in a manufacturing process such as a reflow process adopted when manufacturing a solid-state imaging device including a filter, an inorganic layer crack due to a difference in inorganic and organic linear expansion coefficients does not occur.

As the resin layer or support film having a low linear expansion coefficient, those having a linear expansion coefficient of 60 ppm or less are preferable. More preferably, it is 50 ppm or less, More preferably, it is 30 ppm or less, Most preferably, it is 10 ppm or less.
Specifically, as the resin layer or the support film having a low linear expansion coefficient, for example, a poly (amide) imide resin, an aramid resin, a polyamide resin, an epoxy resin, a polyester resin, an organic-inorganic hybrid resin, and the like are preferable. The form in which the resin layer or the support film is formed of at least one selected from the group consisting of these is one of the preferred forms of the present invention. The linear expansion coefficient can also be reduced by stretching the resin; dispersing inorganic fine particles; using glass cloth; increasing the crosslinking density; compositing; crystallizing;

The optical multilayer film is formed on at least one surface of the resin sheet. The optical multilayer film may be formed on only one surface of the resin sheet or may be formed on both surfaces of the resin sheet, but is preferably formed on both surfaces. Thereby, the curvature of the light selective transmission filter which concerns on this invention, and the crack of an optical multilayer film can be reduced. Moreover, in the form in which the resin sheet is composed of the resin layer containing the dye and the support film, the optical multilayer film is preferably formed on the surface of the resin layer.

When the optical multilayer film has the optical multilayer film only on one surface of the resin sheet, the number of laminated optical multilayer films is preferably in the range of 10 to 80 layers, more preferably in the range of 25 to 50 layers. On the other hand, when it has the said optical multilayer film on both surfaces of a resin sheet, the range of 10-80 layers is preferable as a total of the lamination | stacking number of the said optical multilayer film on both surfaces of a resin sheet, More preferably, it is 25-50. The range of layers.
The optical multilayer film preferably has a thickness of 0.5 to 10 μm. More preferably, it is 2-8 micrometers. In the form in which the optical multilayer film is formed on both surfaces of the resin sheet, the total thickness of the optical multilayer films on both surfaces is preferably within the above range.

As another preferred embodiment of the light selective transmission filter according to the present invention, an optical multilayer film is formed on at least one surface of a resin film different from the resin sheet, and the resin sheet is further formed on the surface of the optical multilayer film. The form in which (preferably the resin layer containing a pigment | dye) is formed can be mentioned. That is, on the surface of the resin film, an optical multilayer film and the resin sheet (a resin sheet composed only of a resin layer containing a dye, or a resin sheet composed of a resin layer containing a dye and a support film) are laminated in this order. It is a form that is made. The optical multilayer film is preferably provided on both surfaces of the resin film. In that case, the resin sheet may be laminated on the surface of one optical multilayer film or may be laminated on the surfaces of two optical multilayer films. In this case, the resin film can use the same thing as the support film mentioned above, and it is the same as that of the support film also about a suitable form.

The light selective transmission filter of the present invention may have various other functions other than the function of selectively reducing desired light transmittance. For example, in the case of an infrared cut filter which is one of the preferred forms as a light selective transmission filter, the form having various functions other than the infrared cut such as the function of shielding ultraviolet rays, and the infrared cut filter such as toughness and strength The form which has the function to improve the physical property of can be mentioned.
In such a form in which the light selective transmission filter of the present invention has the other function, the optical multilayer film is formed on one surface of the resin sheet and the other function is imparted to the other surface. It is preferable to form a functional material layer.
The functional material layer is, for example, a functional material formed directly on the resin sheet or on a temporary base material subjected to a release treatment by the above-described CVD method, sputtering method, or vacuum deposition method. It can be obtained by laminating the layer on the resin sheet with an adhesive. Moreover, it can obtain also by apply | coating the liquid composition containing a raw material substance to a resin sheet, drying and forming a film.

The light selective transmission filter of the present invention preferably has a thickness (total thickness of the resin sheet and the optical multilayer film) of 1 mm or less. Here, the thickness of the light selective transmission filter refers to the maximum thickness of the light selective transmission filter. More preferably, the thickness of the light selective transmission filter is 200 μm or less, more preferably 150 μm or less, particularly preferably 120 μm or less, and most preferably 60 μm or less in that it can meet the demand for thinning. . In addition, the thickness of the light selective transmission filter is preferably 1 μm or more, more preferably 10 μm or more, and even more preferably 30 μm or more in terms of excellent reflow resistance, particularly heat resistance at a temperature of 260 ° C. . The range of the thickness of the light selective transmission filter is preferably 1 to 150 μm, more preferably 10 to 120 μm, still more preferably 30 to 120 μm, and particularly preferably 30 to 60 μm.

By setting the thickness of the light selective transmission filter to 1 mm or less, the light selective transmission filter can be reduced in size and weight, and can be suitably used for various applications. In particular, it can be suitably used in optical applications such as optical members. In optical applications, as with other optical members, the light selective transmission filter is strongly required to be small and light. The light selective transmission filter of the present invention can achieve a reduction in thickness by setting the thickness to 1 mm or less, and in particular, when used in a lens unit such as an imaging lens, it is possible to reduce the height of the lens unit. In other words, when a thin light selective transmission filter of 1 mm or less is used as the optical member, the optical path can be shortened and the optical member can be made small. Specifically, the camera module includes a lens, a light selective transmission filter, and a sea moss sensor.

19 and 20 schematically show an example of the camera module. Note that these figures refer to materials from the Electronic Journal 81st Technical Seminar (Electronic Journal 81st Technical Seminar).
As shown in FIG. 19, the light selective transmission filter has a role of cutting light of a desired wavelength (in the camera module, for example, light having a wavelength of 700 nm or more) to prevent malfunction of the sea moss sensor. When a light selective transmission filter is inserted into the camera module, the focal length is extended, so that the back focus is extended and the module is enlarged. When the thickness of the light selective transmission filter is t and the refractive index n is about 1.5, as shown in FIG. 20, the back focus is extended by about t / 3 and the module is enlarged, but the light selective transmission filter is thinned. Thus, the focal length can be shortened and the module can be made smaller. Thereby, for example, the optical path length of an optical size of 1/10 inch is preferably 120% or less when there is no light selective transmission filter. More preferably, it is 110% or less, More preferably, it is 105% or less.

The light selective transmission filter of the present invention selectively reduces the light transmittance. The light to be reduced may be between 10 nm and 100 μm, and can be selected depending on the application to be used. Depending on the wavelength of light to be reduced, it can be an infrared cut filter, an ultraviolet cut filter, an infrared / ultraviolet cut filter, etc. Among them, it reduces infrared light of 650 nm to 10 μm and ultraviolet light of 200 to 350 nm. It is preferable that other light is transmitted. That is, the light selective transmission filter is preferably an infrared / ultraviolet cut filter. Thereby, the effect of this invention of reducing the incident angle dependence of a light-shielding characteristic can be exhibited more fully.
The infrared cut filter may be a filter having a function of selectively reducing light of any wavelength (range) among light having a wavelength of 650 nm to 10 μm that is an infrared region. The wavelength range to be selectively reduced is preferably 650 nm to 2.5 μm, 650 to 1000 nm, or 800 nm to 1 μm. A filter that selectively reduces at least one of wavelengths in these ranges is also included in the infrared cut filter. The range of the wavelength to be selectively reduced is more preferably 650 nm to 1 μm in the near infrared region.
The ultraviolet cut filter is a filter having a function of blocking ultraviolet rays. The wavelength range to be selectively reduced is preferably 200 to 350 nm.
The infrared / ultraviolet cut filter is a filter having a function of blocking both ultraviolet rays and infrared rays. The wavelength range to be selectively reduced is preferably the same as described above.

In the embodiment in which the light selective transmission filter of the present invention is an infrared cut filter, it is preferable to selectively reduce the infrared transmittance of 650 to 1000 nm to 5% or less. The transmittance in other wavelength regions is preferably 75% or more, but only the transmittance in a specific wavelength region may be high depending on the use of the filter. For example, when the infrared cut filter is used as a camera module, it is preferable that the transmittance of infrared light is 5% or less and the transmittance of visible light (400 to 600 nm) is 80% or more. More preferably, it is 85% or more. Moreover, it is preferable that the transmittance | permeability of the light of the wavelength range of 450-550 nm is 85% or more among visible light, and it is more preferable that it is 90% or more. In the infrared cut filter, the transmittance of other wavelengths (other than the infrared region) is more preferably 85% or more, and still more preferably 90% or more. That is, the light selective transmission filter is preferably an infrared cut filter having a light transmittance of 80% or more at a wavelength of 400 to 600 nm and a transmittance of 5% or less at 800 to 1000 nm.
The transmittance can be measured using a spectrophotometer (Shimadzu UV-3100, manufactured by Shimadzu Corporation).

In the embodiment in which the light selective transmission filter of the present invention is an ultraviolet cut filter, it is preferable to selectively reduce the transmittance of ultraviolet light of 200 to 350 nm to 5% or less. The transmittance in other wavelength regions is preferably 75% or more.
In the embodiment in which the light selective transmission filter of the present invention is an infrared / ultraviolet cut filter, a filter that selectively reduces infrared light of 650 nm to 10 μm and ultraviolet light of 200 to 350 nm to 5% or less is preferable. The transmittance in the wavelength region is preferably 75% or more.

The light selective transmission filter is formed by forming an optical multilayer film on at least one surface of a resin sheet having a resin layer containing a dye having an absorption maximum in a wavelength range of 600 to 800 nm. The incident angle dependence of the light blocking characteristic can be sufficiently reduced. The incident angle dependency of the light blocking characteristic is a transmittance (for example, 0 °, 20 °, 25 °, 30 °, etc.) with the incident angle changed using a spectrophotometer (Shimadzu UV-3100, manufactured by Shimadzu Corporation). The transmittance at an incident angle of 0 ° is a transmittance measured so that light enters from the thickness direction of the light selective transmission filter, and the transmittance at an incident angle of 20 ° is the thickness direction of the light selective transmission filter. It can be evaluated from the amount of change in the spectrum.
The incident angle dependency of the light blocking characteristic needs to be sufficiently reduced by the absorption of the resin sheet, and the transmittance spectrum does not change or the degree of the change is small with respect to the change of the incident angle. preferable. Specifically, even when the incident angle is changed from 0 ° to 20 ° (more preferably to 25 °), it is preferable that the transmittance spectrum does not change in the region where the transmittance is 80% or more, more preferably The transmittance spectrum does not change in the region where the transmittance is 70% or more, and more preferably, the transmittance spectrum does not change in the region where the transmittance is 60% or more. Most preferably, the spectrum does not change in any transmittance region.

As described above, the light selective transmission filter of the present invention can sufficiently reduce the incident angle dependency of the light blocking characteristic and can be sufficiently thinned, so that it can be applied to glass of automobiles and buildings. It is useful not only as a heat ray cut filter to be mounted, but also as a filter for blocking optical noise and correcting visibility in camera module (also referred to as a solid-state imaging device) application. Among these, the light selective transmission filter of the present invention is useful as a filter for use in camera modules such as digital still cameras and mobile phone cameras that are becoming thinner and lighter. The camera module usually includes a lens unit (imaging lens) unit, a light selective transmission filter, and a sensor unit such as a CCD or CMOS. Further, as described above, the camera module using the light selective transmission filter of the present invention is usually disposed between a lens unit (imaging lens) unit and a sensor unit such as a CCD or CMOS. Thus, the solid-state imaging device having at least the light selective transmission filter, the lens unit portion, and the sensor portion of the present invention is also one aspect of the present invention. Normally, in a solid-state imaging device using a reflective light selective transmission filter, a lens unit using a large number of lenses is used to suppress the influence caused by the incident angle dependency (such as the occurrence of color unevenness due to the incident angle). However, in the solid-state imaging device of the present invention, the use of the above-described light selective transmission filter sufficiently eliminates the influence due to the incident angle dependency, so that the number of lenses constituting the lens unit portion Thus, a reduction in thickness and weight can be realized.
In addition, about a lens unit part, the form as described in WO2008 / 081892 can be employ | adopted preferably.

The light selective transmission filter of the present invention is a light selective transmission filter having the above-described configuration, which can effectively block light of a desired wavelength, and has a sufficiently reduced incident angle dependency of light blocking characteristics. is there. Therefore, the solid-state imaging device (camera module) using the light selective transmission filter of the present invention captures an image in which the occurrence of color unevenness due to the incident angle, which is a problem by using the reflective light selective transmission filter, is suppressed. be able to. Furthermore, since sufficient thinning is possible, it can be used particularly suitably in applications that require reduction in thickness and weight. Specifically, it can be suitably used for various applications such as optical device applications, display device applications, mechanical parts, electrical / electronic parts, and the like, and is particularly useful as an IR cut filter for camera modules.

: The transmittance spectrum of the resin sheet (1) obtained in Production Example 1. : The transmittance spectrum of the resin sheet (2) obtained in Production Example 2. : The transmittance spectrum of the resin sheet (3) obtained in Production Example 3. : The transmittance spectrum of the resin sheet (4) obtained in Production Example 4. : The transmittance spectrum of the resin sheet (5) obtained in Production Example 5. : The transmittance spectrum of the resin sheet (6) obtained in Production Example 6. : The transmittance spectrum of the resin sheet (7) obtained in Production Example 7. : The transmittance spectrum of the resin sheet (8) obtained in Production Example 8. : The transmittance spectrum of the resin sheet (9) obtained in Production Example 9. : The transmittance spectrum of the resin sheet (10) obtained in Production Example 10. : The transmittance spectrum of the resin sheet (11) obtained in Production Example 11. : The transmittance spectrum of the resin sheet (12) obtained in Production Example 12. : The transmittance spectrum of the resin sheet (13) obtained in Production Example 13. : It is a conceptual diagram which shows the transmittance | permeability measuring method. : A transmittance spectrum of the light selective transmission filter obtained in Comparative Example 1. : A transmittance spectrum of the light selective transmission filter obtained in Example 1. : A transmittance spectrum of the light selective transmission filter obtained in Example 2. : A transmittance spectrum of the light selective transmission filter obtained in Example 3. : It is a cross-sectional schematic diagram which shows the structure of a camera module. : It is a schematic diagram which shows expansion | extension of the back focus by the presence or absence of a light selective transmission filter.

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” means “part by weight” and “%” means “mass%”.

<Synthesis of FPEK>
Synthesis example 1
In a reactor equipped with a thermometer, a cooling pipe, a gas introduction pipe, and a stirrer, 16.74 parts of BPDE (4,4′-bis (2,3,4,5,6-pentafluorobenzoyl) diphenyl ether), 10.5 parts of HF (9,9-bis (4-hydroxyphenyl) fluorene), 4.34 parts of potassium carbonate, and 90 parts of DMAc (dimethylacetamide) were charged. The mixture was warmed to 80 ° C. and reacted for 8 hours. After completion of the reaction, the reaction solution was poured into a 1% aqueous acetic acid solution with vigorous stirring with a blender. The precipitated reaction product was separated by filtration, washed with distilled water and methanol, and then dried under reduced pressure to obtain a fluorinated aromatic polymer (FPEK). The polymer had a glass transition temperature (Tg) of 242 ° C., a number average molecular weight (Mn) of 70770, and a surface resistance value of 1.0 × 10 ¹⁸ Ω / cm ² or more.

In addition, the number average molecular weight in the said synthesis example was measured with the following method.
<Number average molecular weight>
Two gel permeation chromatography (column: TSKgel SuperMultipore HZ-N 4.6 ^* 150, eluent: tetrahydrofuran, standard sample: TSK polystyrene standard) were used for measurement.

<Preparation of dye-containing resin composition>
Preparation Example 1
To 10 parts of FPEK obtained in Synthesis Example 1 above, 0.3 parts of SDA3039 (trade name, absorption maximum wavelength 670 nm, manufactured by HW SANDS) and 70 parts of MIBK (methyl isobutyl ketone) are added and dissolved uniformly. A contained resin composition (1) was obtained.

Preparation Example 2
In 1 part of FPEK, 1H-Benzindolinium, 3-butyl-2- [5- (3-butyl-1,3-dihydro-1,1-dimethyl-2H-benzindol-2-ylidene) -1,3-pentadiene-1- yl] -1,1-dimethyl-tetrafluoroborate (1-) (HBFB, cyanine dye, absorption maximum wavelength 680 nm) 0.08 parts and MIBK 70 parts are added and uniformly dissolved to obtain a dye-containing resin composition (2) Got.

Preparation Example 3
0.004 part of HBFB and 40 parts of MIBK were added to 10 parts of FPEK and dissolved uniformly to obtain a dye-containing resin composition (3).

Preparation Example 4
To 10 parts of FPEK, 0.3 part of TX-EX-609K (development product name, phthalocyanine dye, absorption maximum wavelength 650 nm, manufactured by Nippon Shokubai Co., Ltd.) and 70 parts of MIBK are uniformly dissolved, and the dye-containing resin composition (4) Got.

Preparation Example 5
0.01 parts of TX-EX-609K (development product name, phthalocyanine dye, absorption maximum wavelength 650 nm, manufactured by Nippon Shokubai Co., Ltd.) and 40 parts of MIBK are uniformly dissolved in 10 parts of FPEK, and the dye-containing resin composition (5) Got.

Preparation Example 6
To 65 parts of FPEK, 0.0065 parts of TX-EX-609K (development product name, phthalocyanine dye, absorption maximum wavelength 650 nm, manufactured by Nippon Shokubai Co., Ltd.) and 40 parts of MIBK are uniformly dissolved, and the dye-containing resin composition (6) Got.

Preparation Example 7
0.01 parts of TX-EX-708K (development product name, phthalocyanine dye, absorption maximum wavelength 750 nm, manufactured by Nippon Shokubai Co., Ltd.) and 40 parts of MIBK are uniformly dissolved in 10 parts of FPEK, and the dye-containing resin composition (7) Got.

Preparation Example 8
Denacol EX-121 (trade name, 2-ethylhexyl glycidyl ether, epoxy equivalent 187, manufactured by Nagase ChemteX Corp.) 7.5 parts, Celoxide 2021P (trade name, 3,4-epoxycyclohexenylmethyl-3 ′, 4′- Epoxycyclohexene carboxylate, manufactured by Daicel Chemical Industries, Ltd.) 2.5 parts, Sun Aid SI100L (trade name, polymerization initiator, manufactured by Sanshin Chemical Industry Co., Ltd.) 0.1 parts, 0.1 part HBFB, 6 parts MIBK It was made to melt | dissolve uniformly and the pigment | dye containing resin composition (8) was obtained.

Preparation Example 9
10 parts of purple light UV-6630B (trade name, UV curable urethane acrylate ligomer, manufactured by Nippon Synthetic Chemical Co., Ltd.), 0.1 part of perhexyl D (trade name, polymerization initiator, manufactured by NOF Corporation) is added with 0.05 HBFB. 1 part and 6 parts of MIBK were added and dissolved uniformly to obtain a dye-containing resin composition (9).

Preparation Example 10
A poly (amido) imide precursor solution (solvent: DMAc, solid content concentration 30% HPC-7000-30 manufactured by Hitachi Chemical Co., Ltd.) 50 parts of 0.0125 part of HBFB was added and uniformly dissolved to obtain a dye-containing resin. A composition (10) was obtained.

Preparation Example 11
90 parts of DMAc was added to 10 parts of Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness), and stirred at 120 ° C. for 1 hour to dissolve. To this solution, 0.3 part of TX-EX-609K (trade name, phthalocyanine dye, absorption maximum wavelength 650 nm, manufactured by Nippon Shokubai Co., Ltd.) was added and dissolved uniformly to obtain a dye-containing resin composition (11).

Preparation Example 12
A flask is charged with 5 parts of 1,2,4,5-cyclohexanetetracarboxylic acid (manufactured by Aldrich, purity 95%) and 44 parts of acetic anhydride (manufactured by Wako Pure Chemical Industries), and the reactor is filled with nitrogen gas while stirring. Replaced. The temperature was raised to the reflux temperature of the solvent under a nitrogen gas atmosphere, and the solvent was refluxed for 10 minutes. While stirring, the mixture was cooled to room temperature to precipitate crystals. The precipitated crystals were separated into solid and liquid and dried to obtain crystals of the desired product (1,2,4,5-cyclohexanetetracarboxylic dianhydride). In a flask equipped with a thermometer, a stirrer, a nitrogen introducing tube, a dropping funnel with a side tube, Dean Stark, and a cooling tube, 0.89 part of 4,4′-diaminodiphenyl ether (manufactured by Wako Pure Chemical Industries, Ltd.) under a nitrogen stream, After dissolving 7.6 parts of N-methyl-2-pyrrolidone as a solvent and dissolving it, 1 part of 1,2,4,5-cyclohexanetetracarboxylic dianhydride was separated at room temperature over 1 hour. The mixture was added and stirred at room temperature for 2 hours. 2.6 parts of xylene as an azeotropic dehydrating agent was added and reacted at 180 ° C. for 3 hours, and the product water refluxed by Dean Stark was azeotropically separated. Xylene was distilled off while the temperature was raised to 190 ° C., followed by cooling to obtain an N-methyl-2-pyrrolidone solution of polyimide. To this solution, 0.045 parts of TX-EX-609K (trade name, phthalocyanine dye, absorption maximum wavelength 650 nm, manufactured by Nippon Shokubai Co., Ltd.) was added and dissolved uniformly to obtain a dye-containing resin composition (12).

Preparation Example 13
In Preparation Example 12, instead of 0.89 g of 4,4′-diaminodiphenyl ether, 1.08 g of α, α′-bis (4-aminophenyl) -1,4-diisopropylbenzene (manufactured by Tokyo Chemical Industry) and 4,4 An N-methyl-2-pyrrolidone solution was obtained in the same manner except that 0.49 g of '-bis (4-aminophenoxy) biphenyl (manufactured by Wako Pure Chemical Industries, Ltd.) was used. To this solution, 0.0068 parts of TX-EX-609K (trade name, phthalocyanine dye, absorption maximum wavelength 650 nm, manufactured by Nippon Shokubai Co., Ltd.) was added and dissolved uniformly to obtain a dye-containing resin composition (13).

<Creation of resin sheet>
Production Example 1
On Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness) as a support film, the dye-containing resin composition (1) obtained in Preparation Example 1 was applied at a thickness of 20 μm and dried at 150 ° C. for 60 minutes. And 52 micrometer of resin sheets (1) were obtained. The transmittance spectrum of the resin sheet (1) is shown in FIG.

Production Example 2
On Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness) as a support film, the dye-containing resin composition (2) obtained in Preparation Example 2 was applied at a thickness of 30 μm and dried at 150 ° C. for 60 minutes. And 53 micrometer of resin sheets (2) were obtained. The transmittance spectrum of the resin sheet (2) is shown in FIG.

Production Example 3
The pigment-containing resin composition (3) obtained in Preparation Example 3 was applied at a thickness of 380 μm and dried at 150 ° C. for 180 minutes to obtain a resin sheet (3) of 60 μm. The transmittance spectrum of the resin sheet (3) is shown in FIG.

Production Example 4
On Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness) as a support film, the dye-containing resin composition (4) obtained in Preparation Example 4 was applied at a thickness of 30 μm and dried at 150 ° C. for 60 minutes. And 53 micrometer of resin sheets (4) were obtained. The transmittance spectrum of the resin sheet (4) is shown in FIG.

Production Example 5
The dye-containing resin composition (5) obtained in Preparation Example 5 was applied at a thickness of 420 μm and dried at 150 ° C. for 180 minutes to obtain 65 μm of a resin sheet (5). The transmittance spectrum of the resin sheet (5) is shown in FIG.

Production Example 6
The pigment-containing resin composition (6) obtained in Preparation Example 6 was applied at a thickness of 650 μm and dried at 150 ° C. for 180 minutes to obtain a resin sheet (6) of 100 μm. The transmittance spectrum of the resin sheet (6) is shown in FIG.

Production Example 7
The dye-containing resin composition (7) obtained in Preparation Example 7 was applied at a thickness of 320 μm and dried at 150 ° C. for 180 minutes to obtain a resin sheet (7) of 50 μm. The transmittance spectrum of the resin sheet (7) is shown in FIG.

Production Example 8
On Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness) as a support film, the dye-containing resin composition (8) obtained in Preparation Example 8 was applied at a thickness of 12 μm and cured at 140 ° C. for 30 minutes. And dried to obtain 57 μm of a resin sheet (8). The transmittance spectrum of the resin sheet (8) is shown in FIG.

Production Example 9
On Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness) as a support film, the dye-containing resin composition (9) obtained in Preparation Example 9 was applied at a thickness of 8 μm, and the temperature was 150 ° C. in a nitrogen atmosphere. And cured for 60 minutes to obtain 54 μm of a resin sheet (9). The transmittance spectrum of the resin sheet (9) is shown in FIG.

Production Example 10
The pigment-containing resin composition (10) obtained in Preparation Example 10 was applied at a thickness of 130 μm and dried at 200 ° C. for 60 minutes to obtain 20 μm of a resin sheet (10). The transmittance spectrum of the resin sheet (10) is shown in FIG.

Production Example 11
The dye-containing resin composition (11) obtained in Preparation Example 11 was applied at a thickness of 30 μm onto Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness) as a support film, and dried at 150 ° C. for 60 minutes. Then, the pigment | dye containing resin composition (11) was similarly apply | coated to the back surface of a support film by 30 micrometers thickness, and it dried at 150 degreeC for 60 minutes, and obtained resin sheet (11) 56 micrometers. The transmittance spectrum of the resin sheet (11) is shown in FIG.

Production Example 12
The dye-containing resin composition (12) obtained in Preparation Example 12 was applied at a thickness of 30 μm onto Neoprim L-3430 (Mitsubishi Gas Chemical Co., Ltd., 50 μm thickness) as a support film, and dried at 200 ° C. for 60 minutes. Then, the pigment | dye containing resin composition (12) was similarly apply | coated to the back surface of a support body film by 30 micrometers thickness, and it dried at 150 degreeC for 60 minutes, and obtained resin sheet (12) 56 micrometers. The transmittance spectrum of the resin sheet (12) is shown in FIG.

Production Example 13
The pigment-containing resin composition (13) obtained in Preparation Example 13 was applied at a thickness of 400 μm and dried at 200 ° C. for 60 minutes to obtain a resin sheet (13) of 45 μm. The transmittance spectrum of the resin sheet (13) is shown in FIG.

1 to 13, the horizontal axis of the graph indicates the wavelength (nm), and the vertical axis indicates the transmittance (%).

<Creation of light selective transmission filter>
Examples 1 to 9 and Comparative Example 1
Resin sheets prepared by cutting the resin sheets (1) to (9) obtained in the respective production examples into a rectangle having a width of 60 mm and a length of 100 mm were prepared.
A multilayer film [silica (SiO ₂ : film thickness 120 to 190 nm) layer and titania (TiO ₂ : film thickness 70 to 120 nm) reflecting infrared rays at a vapor deposition substrate temperature of 150 ° C. on both surfaces of the resin sheet. ) Layers were alternately stacked, and the number of layers was 20 layers on one side deposited on both sides: a total of 40 layers] by vapor deposition to produce a light selective transmission filter (optical filter).
The resin sheets used in each example are as follows.
Example 1: Resin sheet (2) obtained in Production Example 2
Example 2: Resin sheet (3) obtained in Production Example 3
Example 3: Resin sheet (4) obtained in Production Example 4
Example 4: Resin sheet (1) obtained in Production Example 1
Example 5: Resin sheet (5) obtained in Production Example 5
Example 6: Resin sheet obtained in Production Example 6 (6)
Example 7: Resin sheet (7) obtained in Production Example 7
Example 8: Resin sheet (8) obtained in Production Example 8
Example 9: Resin sheet (9) obtained in Production Example 9
Comparative Example 1: With respect to each light selective transmission filter obtained from a resin sheet made of an FPEK film (thickness: 50 μm) containing no dye, the transmittance and incidence angle dependency were measured and evaluated by the following methods.

<Measurement of transmittance and evaluation of incidence angle dependency>
The transmittance at 200 to 1100 nm was measured using Shimadzu UV-3100 (manufactured by Shimadzu Corporation). As shown in FIG. 14, when the light selective transmission filter is installed so that the transmittance is perpendicular to the incident light (the transmittance spectrum measured in this way is also referred to as a 0 ° spectrum. Light selective transmission). Measured when light enters from the thickness direction of the filter) and when the 25 ° light selective transmission filter is tilted with respect to the incident light (the transmittance spectrum thus measured is 25 °). It is also referred to as a spectrum, which is measured in such a manner that light enters from a direction inclined by 25 ° with respect to the thickness direction of the light selective transmission filter.

The transmittance spectra of the light selective transmission filters obtained in Examples 1 to 3 and Comparative Example 1 are shown in FIGS. 16 to 18 and FIG. 15, respectively.
In each figure, 0 ° means a 0 ° spectrum, and 25 ° means a 25 ° spectrum.
The horizontal axis of the graph represents wavelength (nm), and the vertical axis represents transmittance (%).

The following can be said from the above Examples and Comparative Examples.
In the light selective transmission filter (Comparative Example 1) that does not have the resin layer containing the dye, the slope of the transmittance change near the absorption edge of the transmittance spectrum in the near infrared region is steep, but in all transmittance regions. It was found that the 0 ° and 25 ° spectra were shifted, and the light blocking property was highly dependent on the incident angle. In contrast, in the light selective transmission filter (Examples 1, 2, and 3) having the resin layer containing the dye, the slope of the transmittance spectrum in the near-infrared region becomes gentle, but the transmission in Example 1 In the region where the transmittance is 60% or more, in the region where the transmittance is 80% or more in Example 2, the spectrum of 0 ° and 25 ° is not changed in the region where the transmittance is 70% or more in Example 3, and the light blocking characteristic is It was found that the incident angle dependency was reduced. Although not shown in the figure, as a result of performing transmittance measurement and viewing angle dependency evaluation of the light selective transmission filters obtained in Examples 4 to 9, comparison was made as in Examples 1 to 3. Compared to Example 1, it was confirmed that the viewing angle dependency was improved. The transmittance spectrum, incident angle dependency, and slope in the near-infrared region required for the light selective transmission filter vary depending on the camera module (configuration and sensor) used and the application. From the examples, when a resin sheet containing a dye having an absorption maximum in the wavelength region of 600 to 800 nm is used, the transmittance spectrum, the incident angle dependency, and the slope in the near-infrared region are adjusted by adjusting the absorption wavelength and absorption intensity. Was found to be adjustable as needed.

1: Lens 2: Light selective transmission filter 3: Sensor 4: Light source 5: Light selective transmission filter 6: Light receiving unit

Claims (8)

A light selective transmission filter comprising a resin sheet and an optical multilayer film formed on at least one surface thereof,
The light selective transmission filter, wherein the resin sheet has a resin layer containing a pigment having an absorption maximum in a wavelength region of 600 to 800 nm. The resin layer containing the pigment is a resin layer formed of at least one of a solvent-soluble resin, a solvent-soluble resin material, and a liquid resin material in which the pigment is dispersed. The light selective transmission filter described. The light selective transmission filter according to claim 1, wherein the resin sheet has a transmittance of the dye at an absorption maximum wavelength of 60% or less. 4. The photoselection according to claim 1, wherein the dye is at least one selected from the group consisting of a phthalocyanine dye, a cyanine dye, a porphyrin dye, and a copper ion dye. Transmission filter. 5. The resin sheet according to claim 1, wherein the resin sheet comprises a resin layer containing the dye and a support film, and the optical multilayer film is formed on a surface of the resin layer containing the dye. The light selective transmission filter according to any one of the above. The support film is formed of at least one selected from the group consisting of a fluorinated aromatic polymer, a poly (amide) imide resin, a polyamide resin, an aramid resin, a polycycloolefin resin, an epoxy resin, and an acrylic resin. The light selective transmission filter according to claim 5, wherein: A resin sheet for a light selective transmission filter, which is used in the light selective transmission filter according to claim 1. A solid-state imaging device comprising at least the light selective transmission filter according to any one of claims 1 to 6, a lens unit portion, and a sensor portion.

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