WO2013161492A1

WO2013161492A1 - Wavelength cut filter

Info

Publication number: WO2013161492A1
Application number: PCT/JP2013/058986
Authority: WO
Inventors: 洋介前田; 清水　正晶
Original assignee: 株式会社Adeka
Priority date: 2012-04-25
Filing date: 2013-03-27
Publication date: 2013-10-31
Also published as: TW201346350A; TWI634352B; JPWO2013161492A1; KR20150003712A; CN103930806A; CN103930806B; JP6305331B2; KR101987926B1

Abstract

The present invention provides a wavelength cut filter which has low incident angle dependency and high heat resistance and can have a reduced thickness. Specifically provided is a wavelength cut filter characterized by having such a structure that a coating layer (B) containing a dye is formed on one surface of a glass substrate (A) and an infrared ray-reflecting film (C) is laminated on the other surface of the glass substrate (A), wherein the coating layer (B) containing a dye preferably contains a dye, particularly a cyanine compound which is an acidic dye, in an amount of 0.01 to 10.0 parts by mass relative to 100 parts by mass of a resin solid content.

Description

Wavelength cut filter

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

The sensitivity of solid-state image sensors (CCD, C-MOS, etc.) used in digital still cameras, video cameras, mobile phone cameras, etc., ranges from the ultraviolet region to the infrared region of the wavelength of light. 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.

Reflective filters have problems such as changes in color 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 type filter does not change the characteristics depending on the incident angle of light, it needs a considerable thickness in order to obtain the desired characteristics.

In recent years, various devices and devices have been required to be greatly 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.

US Patent Application Publication No. 2005/253048 JP 2011-118255 A JP 2012-008532 A

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

The present invention also provides a solid-state imaging device comprising the wavelength cut filter.

The present invention also provides a camera module having the 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 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.

As shown in FIG. 1, 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 ray on the other surface of the glass substrate (A). The layer structure is formed by laminating the reflective film (C), and the side having the coating layer (B) is 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, and white plate glass, borosilicate glass, and tempered glass are easily available and have high hardness and high workability. It is preferable because it is excellent.

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

The thickness of the glass substrate (A) is not particularly limited, but is preferably 0.05 to 8 mm, and more preferably 0.05 to 1 mm from the viewpoint of weight reduction and strength.

In the present invention, since the substrate is a glass plate, it can be directly coated on the substrate, 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 a dye used in the wavelength cut filter of the present invention is prepared by dissolving or dispersing a dye, a resin, and other components to be blended as necessary in a suitable solvent to prepare a coating solution. 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, And phenol 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, Examples thereof include phenylene ethynylene compounds, 5-membered and 6-membered heterocyclic compounds, and a plurality of these compounds may be used in combination.

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, a cyanine compound is more preferable from the viewpoint of ease of synthesis and molecular design.

Examples of the cyanine compound include those represented by the following general formula (1).

(Wherein 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, 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 keeping the charge neutral. )

(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 in the above R ¹ and R ¹ ′ are a hydroxyl group, a halogen atom, a nitro group, a cyano group. Group, —SO ₃ H, carboxyl group, amino group, amide group or ferrocenyl group, and may be substituted with —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 methylene group in the alkyl group having 1 to 8 carbon atoms, the aryl group having 6 to 30 carbon atoms and the arylalkyl group having 7 to 30 carbon atoms in the above Y, Y ′ and Y ² is —O—, Even when interrupted by —S—, —CO—, —COO—, —OCO—, —SO ₂ —, —NH—, —CONH—, —NHCO—, —N═CH— or —CH═CH—. Often,
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, amido 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, nonafluorobutyl and the like. 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 above general formula (1), the cycloalkane-1,1-diyl group having 3 to 6 carbon atoms represented by X and X ′ is cyclopropane-1,1-diyl, cyclobutane-1,1- Examples thereof 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 groups exemplified in the description of R ^{1 and the} like. The hydrogen atom in these substituents is 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. _It may be interrupted with ₂ —, —NH—, —CONH—, —NHCO—, —N═CH— or —CH═CH—. 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, cinnamyl, etc. 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 is the carbon atom of the methine chain or a group that further substitutes the ring structure contained in the methine chain (for example, linking groups (Q-1) to (Q-11). ), Carbon atoms at both ends in Z), or when Z ¹⁴ or R ¹⁴ to R ¹⁹ contain a carbon atom, are not included.

Wherein R ¹⁴ , R ¹⁵ , R ¹⁶ , R ¹⁷ , R ¹⁸ , R ¹⁹ and Z ′ are each independently a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, —NRR ′, an aryl group, an arylalkyl The —NRR ′, aryl group, arylalkyl group and alkyl group may be substituted with a hydroxyl group, a halogen atom, a cyano group or —NRR ′, and —O—, —S—, May be interrupted by —CO—, —COO—, —OCO—, —SO ₂ —, —NH—, —CONH—, —NHCO—, —N═CH— or —CH═CH—,
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-sulfonate anion, 2-amino-4-methyl-5-chlorobenzenesulfonate anion, 2-amino-5-nitrobenzenesulfonate anion, JP-A-10-235999, JP-A-10-337959, Japanese Laid-Open Patent Publication No. 11-102208, Japanese Laid-Open Patent Publication No. 2000-108510, Japanese Laid-open Patent Publication No. 2000-168223, Japanese Laid-Open Patent Publication No. 2001-209969, Japanese Laid-Open Patent Publication No. 2001-248180, Japanese Laid-Open Patent Publication No. 2006-297907, Japanese Laid-Open Patent Publication No. 8-253705 In addition to organic sulfonate anions such as sulfonate anions described in JP-T-2004-503379, JP-A-2005-336150, and International Publication No. 2006/28006, chloride ions, bromide ions, and iodides. Ion, fluoride ion, chlorate ion, thiocyanate ion, perchlorate ion, hexafluorophosphate ion, hexafluoroantimonate ion, tetrafluoroborate ion, octyl phosphate ion, dodecyl phosphate ion, octadecyl phosphate ion , Phenylphosphate ion, nonylphenylphosphate ion, 2,2'-methylenebis (4,6-di-t-butylphenyl) phosphonate ion, tetrakis (pentafluorophenyl) borate ion, active molecule in excited state Is deexcited (quenched Carboxyl group or a phosphonic acid quencher anion or a cyclopentadienyl ring having the function, ferrocene having anionic groups such as sulfonic acid group, a metallocene compound anion such as Ruteosen like.

Specific examples of the cyanine compound used in the present invention include the following compound No. 1-102. 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 compound having a corresponding structure such as a route described in JP2010-209191A And a method of synthesis by reaction with 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 is 1200 nm or more of the present invention, the effect of the present invention is not exhibited, and when it is less than 650 nm, visible light is absorbed.

In the coating liquid for forming the coating layer (B) containing the dye, the content of the dye is single or a total of a plurality of types, preferably 0.01 to 50% by mass, more preferably 0.1%. ~ 30% by 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.
In the coating layer (B) containing the above dye, the content of the dye alone or in total of a plurality of types is 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 resin 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 Silica-based inorganic additives such as silica, talc, mica, minesotite, pyrophyllite, and silica; fillers such as glass fiber and calcium carbonate; crystallization agents such as nucleating agents and crystal accelerators, silane cups Examples thereof include rubber elasticity imparting agents such as a ring agent and a flexible polymer. 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, 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 can be obtained and it 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 cut filter of the present invention has a function of blocking light in a wavelength region of 700 to 1200 nm, and a low refractive index layer and a high refractive index layer are alternately laminated. It is formed of a dielectric multilayer film.

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 laminated layers is 10 to 80, and 25 to 50 is preferable from the viewpoint of process and strength.

The thickness of the low refractive index layer and the high refractive index layer is 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 reflective film (C), in addition to the above 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 upper 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 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 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, if the average value of the 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 so that it approaches human visual sensitivity.
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 use 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 conventionally known 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 FIG. 2, the wavelength cut filter 1 of the present invention may be fixed to a part other than the solid-state image sensor on the light incident side of the solid-state image sensor 2, or as shown in FIG. It may be fixed directly to the front of the.

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.

Hereinafter, the present invention relates to a camera module which is one of the solid-state imaging devices, and specifically relates to a case where the wavelength cut filter 1 of the present invention is fixed to a portion other than the solid-state imaging device on the light incident side of the solid-state imaging device 2. Explained.
FIG. 2 is a cross-sectional view showing an embodiment of the configuration of a camera module that 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) The wavelength cut filter 1 laminated in the order of the infrared reflective film (C) and the solid-state image sensor 2 are formed in a region excluding the light-receiving unit 3 on one surface, and the solid-state image sensor 2 and the wavelength cut filter 1 are bonded. Join with Agent 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 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, and is attached to the mounting substrate 8 to cover the solid-state imaging device 2. A box-shaped base portion 7 a and a cylindrical lens barrel portion 7 b that holds the lens 5 are provided. 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, the present invention will be described in more detail with reference to examples and the like, but the present invention is not limited to these examples and the like.

Production Examples 1 to 11 show preparation examples of coating solutions for forming the coating layer (B) containing the dye used in the wavelength cut filter of the present invention, and Comparative Production Examples 2 to 4 show comparative wavelengths. Examples of preparation of a comparative coating solution for forming a coating layer (B) containing a dye used for a cut filter are shown. Examples 1 to 11 show examples of production of the wavelength cut filter of the present invention. 1 to 4 show comparative wavelength cut filter manufacturing examples. In evaluation examples 1 to 11, the wavelength cut filters of the present invention manufactured in Examples 1 to 11 were evaluated, and in comparative evaluation examples 1 to 4, comparisons were made. 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 to No. Preparation of No. 4 Each component was mixed with the formulation shown in [Table 1] and [Table 2]. 1-No. 11 and comparative coating solution no. 2 to 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 are alternately laminated on one surface of a glass substrate (B) having a thickness of 100 μm by a vacuum deposition method, and the total number of layers is 30 layers. An infrared reflective film (C) having a thickness of about 3 μm was formed.
On the surface of the glass substrate (B) on which the obtained infrared reflective film (C) was formed, a surface different from the infrared reflective film (C), the coating liquid Nos. Obtained in Production Examples 1 to 11 were used. 1-No. 11 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. 1-No. 11 was produced.
The above-obtained glass substrate on which the infrared reflective film (C) was formed was compared with a comparative wavelength cut filter No. It was set to 1.
Further, on one surface of the glass substrate (B) having a thickness of 100 μm, a comparative coating solution No. 2 to 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 (A). 2 to 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 to 11 was used. 1-No. 11 and comparative wavelength cut filters 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) 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 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 [Table 1] and [Table 2]. The upper transmittance was measured with an ultraviolet-visible near-infrared spectrophotometer V-570 manufactured by JASCO Corporation.

From the results of the above [Table 1] and [Table 2], the wavelength cut filter of Comparative Example 1 having no dye-containing coating layer (B) has a high incident angle dependency and has an infrared reflection film (C). Although the wavelength cut filters of Comparative Examples 2 to 4 have low incident angle dependency, the transmittance is low in the wavelength range of 430 to 580 nm or high in the wavelength range of 800 to 1000 nm, that is, in the visible light region. Since light is not transmitted and light is not cut in the infrared region, the sensitivity cannot be corrected 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 glass substrate (A) has a coating layer (B) containing a dye on one surface, 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 (deposited film)
1. 1. Wavelength cut filter 2. Solid-state imaging device Light receiving unit 4. 4. Adhesive Lens 6. Lens cap 7. Lens holder 7a. Base part 7b. Lens barrel 8. Mounting board

Claims

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.
3. The wavelength cut filter according to claim 1, wherein the transmittance satisfies the following (i) to (iii):
(I) In the wavelength range of 430 to 580 nm, the average 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 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.
4. 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 item.
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 any one of claims 1 to 5.
A camera module comprising the wavelength cut filter according to any one of claims 1 to 5.