JP2016090781A - Wavelength cut filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wavelength cut filter which has low incident angle dependency, has high heat resistance, and can reduce thickness.SOLUTION: A wavelength cut filter has a coating layer (B) containing a dye on one surface of a glass substrate (A), and has an infrared reflection film (C) laminated on the other surface of the glass substrate (A). The coating layer (B) containing the dye preferably contains 0.01-10.0 pts.mass of a cyanine compound which is a dye, particularly, an acid dye with respect to 100 pts.mass of a resin solid content.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wavelength cut filter formed by laminating a coating layer containing a dye, a glass substrate, and an infrared reflective film.

  The sensitivity of a solid-state imaging device (CCD, C-MOS, etc.) used for a digital still camera, a video camera, a mobile phone camera or the like ranges from the ultraviolet region to the infrared region of the light wavelength. On the other hand, human visibility is only in the visible region of the wavelength of light. Therefore, by providing an infrared cut filter between the imaging lens and the solid-state imaging device, the sensitivity of the solid-state imaging device is corrected so as to approach human visibility (see, for example, Patent Documents 1 to 3).

  Conventionally, an infrared cut filter is a reflection type filter using a combination of layers containing substances having no absorption characteristics and laminated in multiple layers and utilizing the difference in refractive index, or a light absorber is contained in a transparent substrate, or It was a combined absorption filter.

  The reflection type filter has a problem that the color changes between the center and the periphery of the screen because the characteristics change depending on the incident angle of light. In addition, the reflected light becomes stray light in the optical path, leading to a problem that causes a reduction in resolution, image spots, unevenness, multiple images called ghosts, and the like.

On the other hand, although the absorption filter has no change in characteristics due to the incident angle of light, a considerable thickness is required to obtain the desired characteristics.

  In recent years, various devices and apparatuses have been required to be significantly reduced in size, and conventional absorption filters cannot meet the requirements for downsizing. In addition, it is difficult for the reflection type filter to reach the required characteristics, particularly due to the incident angle dependency.

JP 2004-354735 A JP 2011-118255 A JP 2012-008532 A

  Accordingly, an object of the present invention is to provide a wavelength cut filter that has low incidence angle dependency, high heat resistance, and can be thinned.

  As a result of intensive studies, the inventor has a coating layer (B) containing a dye on one surface of the glass substrate (A), and an infrared reflective film (on the other surface of the glass substrate (A)). The present inventors have found that a wavelength cut filter characterized by being formed by laminating C) has low incident angle dependency, and has reached the present invention.

  The present invention comprises a coating layer (B) containing a dye on one surface of a glass substrate (A) and an infrared reflection film (C) laminated on the other surface of the glass substrate (A). The wavelength cut filter characterized by this is provided.

  Moreover, this invention provides the solid-state imaging device which comprises the said wavelength cut filter.

  Moreover, this invention provides the camera module which comprises the said wavelength cut filter.

  The wavelength cut filter of the present invention is excellent in that the incident angle dependency is low. The wavelength cut filter of the present invention is suitable for a solid-state imaging device and a camera module.

It is sectional drawing which shows the outline of the layer structure of the wavelength cut filter of this invention. It is sectional drawing which shows the outline of the layer structure of the wavelength cut filter of this invention. It is sectional drawing which shows one form of a structure of the camera module of this invention. It is sectional drawing which shows one form of a structure of the camera module of this invention. It is sectional drawing which shows another one form of a structure of the camera module of this invention. It is sectional drawing which shows another one form of a structure of the camera module of this invention.

  Hereinafter, the wavelength cut filter of the present invention will be described based on preferred embodiments.

  The wavelength cut filter of the present invention has a coating layer (B) containing a dye on one surface of a glass substrate (A), and an infrared reflective film (C) is laminated on the other surface of the glass substrate (A). As shown in FIG. 1, the side having the coating layer (B) containing the dye may be used as the light incident side, and as shown in FIG. 2, it has the infrared reflection film (C). The side may be the light incident side. Hereinafter, each layer will be described in order.

<Glass substrate (A)>
As the glass substrate (A) used for the wavelength cut filter of the present invention, it can be used by appropriately selecting from a glass material transparent in the visible range, but soda lime glass, white plate glass, borosilicate glass, tempered glass, Quartz glass, phosphate glass, and the like can be used. Among them, soda lime glass is preferable because it is inexpensive and easily available. White plate glass, borosilicate glass, and tempered glass are easily available, have high hardness, and excellent workability. Therefore, it is preferable.

  Furthermore, after pre-treating the glass substrate (A) with a silane coupling agent or the like, a coating liquid is applied to form a coating layer (B) containing a dye described later. Adhesiveness to the glass substrate of the coating layer (B) containing bismuth increases.

  Examples of the silane coupling agent include epoxy functional alkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane. Amino-functional alkoxysilanes such as N-β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxy Examples include mercapto functional alkoxysilanes such as silane.

  Moreover, you may have a base layer between a glass substrate (A) and a coating layer (B). The undercoat layer is a coating liquid in which aggregates of metal oxide fine particles having an average secondary particle diameter of 20 to 250 nm in which primary particles having an average primary particle diameter of 5 to 100 nm are aggregated are dispersed in a solvent shown below. It is obtained by coating by the coating method shown below, and the thickness is 30 to 1000 nm. The aggregate of the metal oxide fine particles is preferably 0.1 to 50% by mass with respect to the total amount of the coating liquid.

  Although the thickness of a glass substrate (A) is not specifically limited, 0.05-8 mm is preferable and 0.05-1 mm is more preferable from the point of weight reduction and intensity | strength.

  In the present invention, since the base material is a glass plate, it can be directly coated on the base material, dried and then cut, and the structure and process are simplified. Moreover, since a board | substrate is a glass plate, heat resistance (260 degreeC reflow tolerance) is higher than the case where it is a plastic.

<Coating layer (B)>
The coating layer (B) containing the dye used in the wavelength cut filter of the present invention adjusts the coating liquid by dissolving or dispersing the dye, binder and other components to be blended as necessary in an appropriate solvent. It can form by apply | coating the obtained coating liquid on a glass substrate (A).
Application methods include spin coating, dip coating, spray coating, bead coating, air knife coating, curtain coating, roller coating, wire bar coating, gravure coating, die coating, and hopper. Examples include the extrusion coating method.

  The dye is not particularly limited, and known dyes can be used. For example, oxazole and oxadiazole compounds, coumarin compounds, quinolinol compounds, phthalocyanine compounds, naphtholactam compounds, fluorenes and derivatives thereof, anthracene and derivatives thereof, xanthene compounds ( (Pyronine, rhodamine, fluorescein), stilbene compounds, cyanine compounds, azo compounds, azomethine compounds, indigo compounds, thioindigo compounds, oxonol compounds, squarylium compounds, indole compounds, styryl compounds, porphine compounds, azurenium compounds, croconic methine compounds , Pyrylium compounds, thiopyrylium compounds, triarylmethane compounds, diphenylmethane compounds, tetrahydrocholine compounds, Dophenol compounds, anthraquinone compounds, naphthoquinone compounds, thiazine compounds, spiropyran compounds, benzylidene compounds, indane compounds, azulene compounds, perylene compounds, phthaloperine compounds, azine compounds, acridine compounds, thiazine compounds, oxazine compounds, polyacetylene compounds, phenylene vinylene compounds, A phenylene ethynylene compound, a 5-membered ring, a 6-membered ring heterocyclic compound, etc. are mentioned, These may mix and use.

Among the above dyes, acidic dyes such as xanthene compounds, phthalocyanine compounds, cyanine compounds, azo compounds, oxonol compounds, and anthraquinone compounds are preferable from the viewpoint of solubility.
Among the acid dyes, cyanine compounds are more preferable from the viewpoint of ease of synthesis and molecular design.

  As said cyanine compound, what is represented by following General formula (1) is mentioned, for example.

(In the formula, A represents a group selected from (a) to (m) of the following group I, A ′ represents a group selected from (a ′) to (m ′) of the following group II,
Q represents a methine chain having 1 to 9 carbon atoms, and represents a linking group that may contain a ring structure in the chain, and the hydrogen atom in the methine chain is a hydroxyl group, a halogen atom, a cyano group, —NRR ′, aryl Group, an arylalkyl group or an alkyl group may be substituted, and the -NRR ', aryl group, arylalkyl group and alkyl group may be further substituted with a hydroxyl group, a halogen atom, a cyano group or -NRR'. , —O—, —S—, —CO—, —COO—, —OCO—, —SO ₂ —, —NH—, —CONH—, —NHCO—, —N═CH— or —CH═CH—. May be interrupted,
R and R ′ represent an aryl group, an arylalkyl group or an alkyl group,
An ^-q represents a q-valent anion, q represents 1 or 2, and p represents a coefficient for maintaining a neutral charge. )

(Wherein, ring C and ring C ′ represent a benzene ring, a naphthalene ring, a phenanthrene ring or a pyridine ring,
R ¹ and R ¹ ′ are a hydroxyl group, a halogen atom, a nitro group, a cyano group, —SO ₃ H, a carboxyl group, an amino group, an amide group, a ferrocenyl group, an aryl group having 6 to 30 carbon atoms, or a carbon atom number of 7 Represents an arylalkyl group of ˜30 or an alkyl group of 1 to 8 carbon atoms,
The aryl group having 6 to 30 carbon atoms, the arylalkyl group having 7 to 30 carbon atoms and the alkyl group having 1 to 8 carbon atoms are a hydroxyl group, a halogen atom, a nitro group, a cyano group, —SO ₃ H, carboxyl Group, amino group, amide group or ferrocenyl group, which may be substituted, —O—, —S—, —CO—, —COO—, —OCO—, —SO ₂ —, —NH—, —CONH— , -NHCO-, -N = CH- or -CH = CH-
R ^{2 to} R ⁹ and R ² ′ to R ⁹ ′ represent the same group or hydrogen atom as R ¹ and R ¹ ′,
X and X ′ represent an oxygen atom, a sulfur atom, a selenium atom, —CR ⁵¹ R ⁵² —, a cycloalkane-1,1-diyl group having 3 to 6 carbon atoms, —NH— or —NY ² —;
R ⁵¹ and R ⁵² represent the same group or hydrogen atom as R ¹ and R ¹ ′,
Y, Y ′ and Y ² are each a hydrogen atom, or a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, an amino group, an amide group, a ferrocenyl group, —SO ₃ H or a nitro group, which may be substituted with 1 carbon atom. Represents an alkyl group having ˜20, an aryl group having 6 to 30 carbon atoms, or an arylalkyl group having 7 to 30 carbon atoms,
The alkyl group, the aryl group and the methylene group in the arylalkyl group in Y, Y ′ and Y ² are —O—, —S—, —CO—, —COO—, —OCO—, —SO ₂ —, -NH-, -CONH-, -NHCO-, -N = CH- or -CH = CH- may be interrupted,
r and r ′ are 0 or (a) to (e), (g) to (j), (l), (m), (a ′) to (e ′), (g ′) to (j ′) ), (L ′) and (m ′) represent the number that can be substituted. )

Examples of the halogen atom represented by R ⁵¹ and R ⁵² in R ^{1 to} R ⁹ and R ¹ ′ to R ⁹ ′ and X and X ′ in the general formula (1) include fluorine, chlorine, bromine and iodine. And
Examples of the aryl group having 6 to 30 carbon atoms include phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-iso-propylphenyl, 4-iso-propylphenyl, 4-butylphenyl, 4-iso-butylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 4-stearylphenyl, 2, 3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert-butylphenyl 2,5-di-tert-butylphenyl, 2,6-di-tert-butyl Ruphenyl, 2,4-di-tert-pentylphenyl, 2,5-di-tert-amylphenyl, 2,5-di-tert-octylphenyl, 2,4-dicumylphenyl, 4-cyclohexylphenyl, (1 , 1′-biphenyl) -4-yl, 2,4,5-trimethylphenyl, ferrocenyl and the like,
Examples of the arylalkyl group having 7 to 30 carbon atoms include benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, triphenylmethyl, styryl, cinnamyl, ferrocenylmethyl, ferrocenylpropyl and the like. ,
Examples of the alkyl group having 1 to 8 carbon atoms include methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, tert-butyl, iso-butyl, amyl, iso-amyl, tert-amyl, hexyl, 2- Examples include hexyl, 3-hexyl, cyclohexyl, 1-methylcyclohexyl, heptyl, 2-heptyl, 3-heptyl, iso-heptyl, tert-heptyl, 1-octyl, iso-octyl, tert-octyl and the like.
The aryl group having 6 to 30 carbon atoms, the arylalkyl group having 7 to 30 carbon atoms and the alkyl group having 1 to 8 carbon atoms are a hydroxyl group, a halogen atom, a nitro group, a cyano group, —SO ₃ H, carboxyl Group, amino group, amide group or ferrocenyl group, which may be substituted, —O—, —S—, —CO—, —COO—, —OCO—, —SO ₂ —, —NH—, —CONH— , —NHCO—, —N═CH—, or —CH═CH—, and the number and position of these substitutions and interruptions are arbitrary.
For example, examples of the group in which the alkyl group having 1 to 8 carbon atoms is substituted with a halogen atom include chloromethyl, dichloromethyl, trichloromethyl, fluoromethyl, difluoromethyl, trifluoromethyl, and nonafluorobutyl. And
Examples of the group in which the alkyl group having 1 to 8 carbon atoms is interrupted by —O— include methyloxy, ethyloxy, iso-propyloxy, propyloxy, butyloxy, pentyloxy, iso-pentyloxy, hexyloxy, heptyl Alkoxy groups such as oxy, octyloxy, 2-ethylhexyloxy, 2-methoxyethyl, 2- (2-methoxy) ethoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, 4-methoxybutyl, 3-methoxybutyl, etc. An alkoxyalkyl group of
Examples of the group in which the alkyl group having 1 to 8 carbon atoms is substituted with a halogen atom and interrupted by -O- include, for example, chloromethyloxy, dichloromethyloxy, trichloromethyloxy, fluoromethyloxy, difluoromethyloxy , Trifluoromethyloxy, nonafluorobutyloxy and the like.

  In the general formula (1), the cycloalkane-1,1-diyl group having 3 to 6 carbon atoms represented by X and X ′ includes cyclopropane-1,1-diyl, cyclobutane-1,1- Examples include diyl, 2,4-dimethylcyclobutane-1,1-diyl, 3,3-dimethylcyclobutane-1,1-diyl, cyclopentane-1,1-diyl, cyclohexane-1,1-diyl and the like.

In the general formula (1), a halogen atom represented by Y, Y ′ and Y ² , an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms and an aryl having 7 to 30 carbon atoms Examples of the alkyl group include the groups exemplified in the description of R ^{1 and the} like, and hydrogen atoms in these substituents are a hydroxyl group, a halogen atom, a cyano group, a carboxyl group, an amino group, an amide group, a ferrocenyl group,- Any number of SO ₃ H or nitro groups may be substituted.
In addition, the alkyl group, the aryl group and the methylene group in the arylalkyl group in Y, Y ′, and Y ² are —O—, —S—, —CO—, —COO—, —OCO—, —SO. _2- , -NH-, -CONH-, -NHCO-, -N = CH- or -CH = CH- may be interrupted. For example, methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, tert-butyl, iso-butyl, amyl, iso-amyl, tert-amyl, hexyl, 2-hexyl, 3-hexyl, cyclohexyl, 1- Methylcyclohexyl, heptyl, 2-heptyl, 3-heptyl, iso-heptyl, tert-heptyl, 1-octyl, iso-octyl, tert-octyl, 2-ethylhexyl, nonyl, iso-nonyl, decyl, dodecyl, tridecyl, tetradecyl Alkyl groups such as pentadecyl, hexadecyl, heptadecyl, octadecyl; phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-iso-propylphenyl, 4-iso-propi Phenyl, 4-butylphenyl, 4-iso-butylphenyl, 4-tert-butylphenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 4-stearylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 2,4-di-tert- Aryl groups such as butylphenyl and cyclohexylphenyl; arylalkyl groups such as benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, triphenylmethyl, styryl, and cinnamyl are interrupted by ether bonds, thioether bonds, etc. Such as 2-methoxye 3-methoxypropyl, 4-methoxybutyl, 2-butoxyethyl, methoxyethoxyethyl, methoxyethoxyethoxyethyl, 3-methoxybutyl, 2-phenoxyethyl, 3-phenoxypropyl, 2-methylthioethyl, 2-phenylthio And ethyl.

Examples of the linking group constituting the methine chain having 1 to 9 carbon atoms represented by Q in the general formula (1) and including a ring structure in the chain include the following (Q-1) to (Q-11). The group represented by any of the above is preferable because it is easy to produce. The number of carbon atoms in the methine chain having 1 to 9 carbon atoms includes the methine chain and the carbon atom of the group that further substitutes the ring structure in the chain (for example, both of the linking groups (Q-1) to (Q-11)). The terminal carbon atom, Z ′ or R ^{14 to} R ¹⁹ when the carbon atom contains a carbon atom) is not included.

Wherein R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and Z ′ are each independently a hydrogen atom, hydroxyl group, halogen atom, cyano group, —NRR ′, aryl group, arylalkyl Represents a group or an alkyl group, and the -NRR ', aryl group, arylalkyl group and alkyl group may be substituted with a hydroxyl group, a halogen atom, a cyano group or -NRR', -O-, -S-, -CO -, - COO -, - OCO -, - SO 2 -, - NH -, - CONH -, - NHCO -, - N = CH- or -CH = CH- may be interrupted by,
R and R ′ represent an aryl group, an arylalkyl group or an alkyl group. )

Examples of the halogen atom, aryl group, arylalkyl or alkyl group represented by R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and Z ′ include those exemplified in the description of R ^{1 and the} like. As the aryl group, arylalkyl group or alkyl group represented by R and R ′, those exemplified in the description of R ^{1 and the} like can be mentioned.

Examples of the q-valent anion represented by pAn ^-q in the general formula (1) include methanesulfonate anion, dodecylsulfonate anion, benzenesulfonate anion, toluenesulfonate anion, trifluoromethanesulfonate anion, naphthalenesulfone. Acid anion, diphenylamine-4-sulfonic acid anion, 2-amino-4-methyl-5-chlorobenzenesulfonic acid anion, 2-amino-5-nitrobenzenesulfonic acid anion, JP-A-10-235999, JP-A-10-337959 No. 1, JP-A No. 11-102808, JP-A No. 2000-108510, JP-A No. 2000-168223, JP-A No. 2001-209969, JP-A No. 2001-322354, and JP-A No. 2006-248180. , JP 2 Organic sulfonic acids such as sulfonate anions described in Japanese Patent Application Laid-Open No. 06-297907, Japanese Patent Application Laid-Open No. 8-253705, Japanese Patent Application Publication No. 2004-503379, Japanese Patent Application Laid-Open No. 2005-336150, International Publication No. 2006/28006, etc. In addition to anions, chloride ions, bromide ions, iodide ions, fluoride ions, chlorate ions, thiocyanate ions, perchlorate ions, hexafluorophosphate ions, hexafluoroantimonate ions, tetrafluoroborate ions, Octyl phosphate ion, dodecyl phosphate ion, octadecyl phosphate ion, phenyl phosphate ion, nonylphenyl phosphate ion, 2,2'-methylenebis (4,6-di-t-butylphenyl) phosphonate ion, tetrakis (penta Fluorophenyl) borate ion, excitation Quencher anions that have the function of deexciting (quenching) active molecules in the state, ferrocene, luteocene, etc. having an anionic group such as a carboxyl group, phosphonic acid group, or sulfonic acid group on the cyclopentadienyl ring And metallocene compound anions.

  Specific examples of the cyanine compound used in the present invention include the following compound Nos. 1-102 may be mentioned. In the following examples, cyanine cations without anions are shown.

  The production method of the cyanine compound is not particularly limited, and can be obtained by a method using a well-known general reaction. For example, a corresponding structure such as a route described in JP 2010-209191 A can be obtained. And a method of synthesizing the compound by a reaction between the compound having the compound and an imine derivative.

  The dye used in the present invention preferably has a maximum absorption wavelength (λmax) of the coating film of 650 to 1200 nm, and more preferably 650 to 900 nm. When the maximum absorption wavelength (λmax) of the coating film exceeds 1200 nm, the effect of the present invention is not exhibited, and when it is less than 650 nm, visible light is absorbed, which is not preferable.

In the coating liquid for forming the coating layer (B) containing the dye, the content of the dye is single or the total of a plurality of types, preferably 0.01 to 50% by mass, more preferably 0.1. -30 mass%. When the content of the dye is less than 0.01% by mass, sufficient characteristics may not be obtained. When the content is more than 50% by mass, the dye may precipitate in the coating layer.
Moreover, in the coating layer (B) containing the said dye, the content of the dye is a single or a total of a plurality of types, and preferably 0.01 to 10.0 parts by mass with respect to 100 parts by mass of the resin solid content. More preferably, it is 0.25 to 5.0 parts by mass.

  Examples of the binder include natural polymer materials such as gelatin, casein, starch, cellulose derivatives, and alginic acid, or polymethyl methacrylate, polyvinyl butyral, polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl chloride, styrene-butadiene copolymer, polystyrene, Synthetic polymer materials such as polycarbonate and polyamide are used.

  Other components that may be blended as necessary include benzotriazole, triazine, and benzoate UV absorbers; phenol, phosphorus, and sulfur antioxidants; cationic surfactants and anionic surfactants Agents, nonionic surfactants, amphoteric surfactants, etc .; halogen compounds, phosphate ester compounds, phosphate amide compounds, melamine compounds, fluororesins or metal oxides, (poly) phosphorus Flame retardants such as melamine acid, piperazine phosphate (poly); hydrocarbon-based, fatty acid-based, aliphatic alcohol-based, aliphatic ester-based, aliphatic amide-based or metal soap-based lubricants; fumed silica, fine particle silica, silica Stone, diatomaceous earth, clay, kaolin, diatomaceous earth, silica gel, calcium silicate, sericite, kaolinite, flint, feldspar powder Silica-based inorganic additives such as meteorite, attapulgite, talc, mica, minnesite, pyrophyllite and silica; fillers such as glass fiber and calcium carbonate; crystallization agents such as nucleating agents and crystallization accelerators, silane couplings Examples thereof include rubber elasticity imparting agents such as agents and flexible polymers. The amount of these other components used is 50% by mass or less in total in the coating liquid for forming the coating layer (B) containing the dye.

  The solvent is not particularly limited and various known solvents can be used as appropriate. Examples thereof include alcohols such as isopropanol; ether alcohols such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and butyl diglycol; acetone, Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and diacetone alcohol; esters such as ethyl acetate, butyl acetate and methoxyethyl acetate; acrylic acid esters such as ethyl acrylate and butyl acrylate; Fluorinated alcohols such as 3-tetrafluoropropanol; hydrocarbons such as hexane, benzene, toluene and xylene; chlorinated hydrocarbons such as methylene dichloride, dichloroethane and chloroform. These organic solvents can be used alone or in combination.

  The thickness of the coating layer (B) containing the dye is preferably 1 to 200 μm because a uniform film is obtained and is advantageous for thinning. If the thickness is less than 1 μm, the function cannot be sufficiently exhibited, and if it exceeds 200 μm, the solvent may remain during coating.

<Infrared reflective film (C)>
The infrared reflective film (C) used in the wavelength cut filter of the present invention has a function of blocking light in a wavelength range of 700 to 1200 nm, and low refractive index layers and high refractive index layers are alternately laminated. The dielectric multilayer film is formed.

  As a material constituting the low refractive index layer, a material having a refractive index of 1.2 to 1.6 can be used. For example, silica, alumina, lanthanum fluoride, magnesium fluoride, aluminum hexafluoride sodium, etc. Can be mentioned.

  As the material constituting the high refractive index layer, a material having a refractive index of 1.7 to 2.5 can be used. For example, titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, oxidation Examples thereof include yttrium, zinc oxide, zinc sulfide, indium oxide, and the like, and those containing these as main components and containing a small amount of titanium oxide, tin oxide, cerium oxide, and the like.

The method for laminating the low refractive index layer and the high refractive index layer is not particularly limited as long as a dielectric multilayer film in which these layers are laminated is formed. For example, a CVD method, a sputtering method on a glass substrate. And a method of forming a dielectric multilayer film in which a low refractive index layer and a high refractive index layer are alternately laminated by a vacuum deposition method or the like. It is also possible to form a dielectric multilayer film in advance and attach it to the glass substrate with an adhesive.
The number of layers is 10 to 80, and 25 to 50 is preferable from the viewpoint of process and strength.

  The thicknesses of the low refractive index layer and the high refractive index layer are usually 1/10 to 1/2 of the wavelength λ (nm) of the light beam to be blocked. When the thickness is less than 0.1λ or greater than 0.5λ, the product (nd) of the refractive index (n) and the physical film thickness (d) is significantly different from the optical film thickness expressed as a multiple of λ / 4. There is a risk that the wavelength cannot be blocked or transmitted.

  As the infrared reflection film (C), in addition to the dielectric multilayer film, a film containing a dye having a maximum absorption wavelength of 700 to 1100 nm, a film in which a polymer is laminated, or a film formed by applying a cholesteric liquid crystal The thing using organic materials, such as these, can also be used.

The wavelength cut filter of the present invention preferably has a transmittance satisfying the following (i) to (iii). The transmittance was measured with an ultraviolet-visible near-infrared spectrophotometer V-570 manufactured by JASCO Corporation.
(I) In the wavelength range of 430 to 580 nm, the average value of the transmittance when measured from the vertical direction of the wavelength cut filter is 75% or more.
(Ii) At a wavelength of 800 to 1000 nm, the average value of transmittance when measured from the vertical direction of the wavelength cut filter is 5% or less.
(Iii) In the wavelength range of 560 to 800 nm, the wavelength value (Ya) at which the transmittance is 80% when measured from the vertical direction of the wavelength cut filter, and an angle of 35 ° with respect to the vertical direction of the wavelength cut filter The absolute value of the difference in wavelength value (Yb) at which the transmittance is 80% when measured from is 30 nm or less.
In the wavelength cut filter, when the average value of transmittance in the wavelength range of 430 to 580 nm of (i) is less than 75%, light in the visible light region is hardly transmitted, and the wavelength 800 of (ii) above. If the average value of transmittance at ˜1000 nm exceeds 5%, light in the infrared region is hardly cut, so that it may be difficult to correct the sensitivity to approach human visibility.
If the absolute value of the difference between Ya and Yb in (iii) exceeds 30 nm, the dependence on the incident angle of light increases, and the characteristics of the wavelength cut filter change depending on the incident angle of light. There is a risk of adverse effects such as a change in color around.

  As a specific application of the wavelength cut filter of the present invention, a heat ray cut filter mounted on a window glass of an automobile or a building; a digital still camera, a digital video camera, a surveillance camera, an in-vehicle camera, a web camera, a mobile phone For example, for a visibility correction for a solid-state imaging device such as a CCD or CMOS in a solid-state imaging device such as a camera; an automatic exposure meter; a display device such as a plasma display.

Next, the solid-state imaging device and camera module of the present invention will be described.
The solid-state imaging device of the present invention is configured in the same manner as a conventional solid-state imaging device except that the wavelength cut filter of the present invention is provided on the front surface of the imaging element. As shown in FIGS. 3 and 4, the wavelength cut filter 1 of the present invention may be fixed to a portion other than the solid-state image sensor on the light incident side of the solid-state image sensor 2, or as shown in FIGS. 5 and 6. Alternatively, it may be directly fixed to the front surface of the solid-state imaging device 2.

  In the solid-state imaging device of the present invention, an optical low-pass filter, an antireflection filter, a color filter, and the like can be arranged as necessary, and the order of stacking these is not particularly limited.

As shown in FIG. 3 and FIG. 4, the wavelength cut filter 1 of the present invention is laminated on the solid-state image sensor 2 on the light incident side of the solid-state image sensor 2 in the camera module which is one of the solid-state image sensors of the present invention. A specific case will be described.
3 and 4 are cross-sectional views showing one embodiment of the configuration of a camera module which is one of the solid-state imaging devices of the present invention. The camera module includes a solid-state imaging device 2 formed in a rectangular shape in plan view on a semiconductor substrate, and a coating layer (B) / glass substrate containing a dye from the light incident side on the opposite side of the light-receiving unit 3 of the solid-state imaging device 2 Wavelength cut filter 1 (FIG. 3) / infrared reflective film (C) / glass substrate (A) / dye-containing coating layer (B) laminated in the order of (A) / infrared reflective film (C) The formed wavelength cut filter 1 (FIG. 4) and the solid-state image pickup device 2 are formed on a surface of the solid-state image pickup device 2 except for the light receiving unit 3, and the solid-state image pickup device 2 and the wavelength cut filter 1 are joined with an adhesive 4. A camera module, which is a solid-state imaging device, takes in light from the outside through the wavelength cut filter 1 and receives it with a light receiving element disposed in the light receiving unit 3 of the solid-state imaging element 2.

As shown in FIG. 5 and FIG. 6, the wavelength cut filter 1 of the present invention relates to a camera module that is one of the solid-state image pickup devices of the present invention, and the wavelength cut filter 1 of the present invention The case where it is fixed will be specifically described.
5 and 6 are cross-sectional views showing one embodiment of the configuration of a camera module which is one of the solid-state imaging devices of the present invention. The camera module includes a solid-state imaging device 2 formed in a rectangular shape in plan view on a semiconductor substrate, and a coating layer (B) / glass substrate containing a dye from the light incident side on the opposite side of the light-receiving unit 3 of the solid-state imaging device 2 (A) Wavelength cut filter 1 (FIG. 5) laminated in the order of the infrared reflection film (C) / or the infrared reflection film (C), the glass substrate (A), and the coating layer (B) containing the dye. The wavelength cut filter 1 (FIG. 6) and the solid-state imaging device 2 are formed in a region excluding the light receiving portion 3. A camera module, which is a solid-state imaging device, takes in light from the outside through the wavelength cut filter 1 and receives the light with a light-receiving element disposed in the light-receiving unit 3 of the solid-state imaging element 2.

  As the adhesive 4, a UV curable adhesive such as an acrylic resin or an epoxy resin, or a thermosetting resin can be used. After the adhesive 4 is uniformly applied, a known photolithography may be used as necessary. The adhesive 4 is patterned using a technique and bonded by thermosetting. When joining, vacuum pressurization may be performed after bonding in a vacuum environment.

The mounting substrate 8 is a rigid substrate using a glass epoxy substrate, a ceramic substrate, or the like, and is provided with a control circuit for controlling the solid-state imaging device 2.
The solid-state imaging device 2 is disposed on the mounting substrate 8, and then the adhesive 4 is applied in advance to a position where the lens holder 7 of the mounting substrate 8 is fixed.
The lens cap 6 protects the lens 5. The lens holder 7 holds the lens 5. The lens holder 7 is attached to the mounting substrate 8 to cover the solid-state imaging device 2. A box-shaped base portion 7 a that holds the lens 5, and a cylindrical lens barrel portion 7 b that holds the lens 5. It has.

  Subsequently, the lens holder 7 is disposed on the mounting substrate 8 so that the lower end surface of the lens holder 7 is in contact with the applied adhesive 4, and the light receiving unit 3 of the solid-state imaging device 2 and the lens 5 in the lens holder 7 are arranged. The position of the lens holder 7 is adjusted such that the distance of the lens 5 coincides with the focal length of the lens 5.

After adjusting the position of the lens holder 7, the adhesive 4 can be irradiated with ultraviolet rays to cure the adhesive 4, and a camera module can be manufactured.
The entire mounting substrate 8 to which the lens holder 7 is fixed may be heated at about 85 ° C. and the adhesive 4 may be sufficiently cured by thermal curing.

  Since the camera module manufacturing method includes a step of heating the entire mounting substrate 8 after the step of irradiating ultraviolet rays, the lens holder 7, the lens 5 and the wavelength cut filter 1 are all materials having high heat resistance. Is required. Specifically, in addition to heating for thermosetting the adhesive 4 as described above, a plurality of solders disposed on the lower surface of the mounting substrate 8 are heated and melted at about 260 ° C. to be soldered to other substrates. For this reason, it is desirable that the material is made of a material having reflow resistance.

  Hereinafter, although an example etc. are given and the present invention is explained still in detail, the present invention is not limited to these examples.

  Manufacture examples 1-11 show the adjustment example of the coating liquid for forming the coating layer (B) containing the dye used for the wavelength cut filter of this invention, and the comparative manufacture examples 2-4 are comparative wavelengths. The adjustment example of the comparative coating liquid for forming the coating layer (B) containing the dye used for a cut filter is shown, Examples 1-11 show the manufacture example of the wavelength cut film of this invention, and a comparative example 1-4 show the manufacture example of a comparative wavelength cut filter, In evaluation examples 1-11, the wavelength cut filter of this invention manufactured in Examples 1-11 is evaluated, In comparative evaluation examples 1-4, it compares The comparative wavelength cut filters produced in Examples 1-4 were evaluated.

[Production Examples 1 to 11 and Comparative Production Examples 2 to 4] Coating liquid No. 1-No. 11 and comparative coating solution no. 2-No. Preparation of 4
Each component was mixed with the composition shown in [Table 1] and [Table 2]. 1-No. 11 and comparative coating solution no. 2-No. 4 was obtained.

[Examples 1 to 11 and Comparative Examples 1 to 4] Wavelength cut filter No. 1-No. 11 and comparative wavelength cut filter No. 1-No. Production of 4 A silica (SiO ₂ ) layer and a titanium oxide (TiO ₂ ) layer were alternately laminated on one surface of a glass substrate (A) having a thickness of 100 μm by a vacuum deposition method, and the total number of layers was 30 layers. An infrared reflective film (C) having a thickness of about 3 μm was formed.
On the surface different from the infrared reflective film of the glass substrate (A) to which the obtained infrared reflective film (C) was applied, the coating liquids No. 1 obtained in Production Examples 1 to 11 were used. 1-No. 11 was applied by a bar coater # 30 (film thickness: 10 μm) and dried at 100 ° C. for 10 minutes. 1-No. 11 was produced.
The above-obtained glass substrate provided with the infrared reflective film (C) was compared with a comparative wavelength cut filter No. It was set to 1.
Further, on one surface of the glass substrate (A) having a thickness of 100 μm, a comparative coating solution No. 2-No. 4 was coated with a bar coater # 30 (film thickness 10 μm), and then dried at 100 ° C. for 10 minutes to form a coating layer (B). 2-No. 4 was produced.

[Evaluation Examples 1 to 11 and Comparative Evaluation Examples 1 to 4]
The wavelength cut filter No. 1 of the present invention obtained in Examples 1-11. 1-No. 11 and comparative wavelength cut filter No. 1 obtained in Comparative Examples 1 to 4. 1-No. 4) i) Average transmittance when measured from the vertical direction of the wavelength cut filter in the wavelength range of 430 to 580 nm, ii) Transmission when measured from the vertical direction of the wavelength cut filter at the wavelength of 800 to 1000 nm Average value of the rate and iii) With respect to the wavelength value (Ya) at which the transmittance is 80% when measured from the vertical direction of the wavelength cut filter in the wavelength range of 560 to 800 nm, and the vertical direction of the wavelength cut filter The absolute value of the difference in wavelength value (Yb) at which the transmittance was 80% when measured from an angle of 35 ° was determined. The results are shown in Tables 1 and 2. The upper transmittance was measured with an ultraviolet-visible near-infrared spectrophotometer V-570 manufactured by JASCO Corporation.

From the results of Tables 1 and 2, the wavelength cut filter of Comparative Example 1 having no coating layer (B) containing a dye has high incident angle dependency and Comparative Examples 2 to 4 having no infrared reflective film (C). The wavelength cut filter has a low incident angle dependency, but has a low transmittance in the wavelength range of 430 to 580 nm or a high transmittance in the wavelength range of 800 to 1000 nm, that is, does not transmit light in the visible light region, and is infrared. Since light is not cut in the region, the sensitivity cannot be corrected so as to approach human visibility.
On the other hand, the wavelength cut filter of the present invention has high transmittance in the wavelength range of 430 to 580 nm, low transmittance in the wavelength range of 800 to 1000 nm, and low incident angle dependency.

  From the above results, the coating layer (B) containing the dye is formed on one surface of the glass substrate (A), and the infrared reflection film (C) is laminated on the other surface of the glass substrate (A). The wavelength cut filter according to the present invention, which is characterized by this, has low incident angle dependency. Therefore, the wavelength cut filter of the present invention is useful for a solid-state imaging device and a camera module.

(A) Glass substrate (B) Coating layer (C) Infrared reflective film (deposition film)
DESCRIPTION OF SYMBOLS 1 Wavelength cut filter 2 Solid-state image sensor 3 Light-receiving part 4 Adhesive agent 5 Lens 6 Lens cap 7 Lens holder 7a Base part 7b Lens barrel part 8 Mounting board

Claims (7)

  It has a coating layer (B) containing a dye on one surface of a glass substrate (A), and an infrared reflective film (C) is laminated on the other surface of the glass substrate (A). Wavelength cut filter.   The wavelength cut filter according to claim 1, wherein the dye is an acid dye. The wavelength cut filter according to claim 1 or 2, wherein the transmittance satisfies the following (i) to (iii).
(I) In the wavelength range of 430 to 580 nm, the average value of the transmittance when measured from the vertical direction of the wavelength cut filter is 75% or more.
(Ii) At a wavelength of 800 to 1000 nm, the average value of transmittance when measured from the vertical direction of the wavelength cut filter is 5% or less.
(Iii) In the wavelength range of 560 to 800 nm, the wavelength value (Ya) at which the transmittance is 80% when measured from the vertical direction of the wavelength cut filter, and an angle of 35 ° with respect to the vertical direction of the wavelength cut filter The absolute value of the difference in wavelength value (Yb) at which the transmittance is 80% when measured from is 30 nm or less.   The coating layer (B) containing the dye contains 0.01 to 10.0 parts by mass of the dye with respect to 100 parts by mass of the resin solid content. The wavelength cut filter according to 1.   The wavelength cut filter according to any one of claims 1 to 4, wherein the dye is a cyanine compound.   A solid-state imaging device comprising the wavelength cut filter according to claim 1.   A camera module comprising the wavelength cut filter according to claim 1.

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