JP2017032685A - Optical filter and device with optical filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical filter that is less susceptible to warping and cracking even when a thinner support body is used, and to provide a solid-state image capturing device and camera module having the same.SOLUTION: An optical filter of the present invention includes a substrate comprising a support body having an elasticity modulus of 50-500 GPa and a resin layer formed on at least one surface of the support body, and is configured to transmit visible rays and at least partially block near-infrared rays. The resin layer preferably has an elasticity modulus of 2-8 GPa.SELECTED DRAWING: None

Description

  The present invention relates to an optical filter and an apparatus using the optical filter. Specifically, the present invention relates to an optical filter that transmits visible light and blocks a part of near infrared rays, and a solid-state imaging device and a camera module using the optical filter.

  A solid-state image pickup device such as a video camera, a digital still camera, or a mobile phone with a camera function uses a CCD or CMOS image sensor, which is a solid-state image pickup device for a color image. Silicon photodiodes that are sensitive to near infrared rays that cannot be sensed by the eyes are used. These solid-state image sensors need to be corrected for visibility so that they appear natural to the human eye. Optical filters that selectively transmit or cut light in a specific wavelength region (for example, near-infrared cut) Filter) is often used.

  As such an optical filter, what was conventionally manufactured by various methods is used. For example, a metal such as silver is deposited on the surface of a transparent substrate containing a support such as glass to reflect near infrared rays, and metal oxides with different refractive indexes are laminated alternately on a transparent substrate In addition, a transparent resin such as an acrylic resin or a polycarbonate resin to which a near-infrared absorbing dye is added has been put to practical use.

  When glass is used as a support, since the support itself has heat resistance, it can be applied to a process having a so-called solder reflow process. As a result, optical components and devices can be downsized and the manufacturing process can be simplified. Can be realized. In addition, an optical filter having a dielectric multilayer film in which metal oxides having different refractive indexes are alternately laminated on a glass support by using a vacuum deposition method, a sputtering method, a CVD method, or the like replaces the support with thin glass. It is also possible to reduce the thickness, for example, 0.1 mm (see, for example, Patent Document 1). However, in the case of a support such as glass, there is a problem that warping and cracking tend to occur when the thickness is reduced.

  On the other hand, a so-called colored glass filter that cuts near-infrared light by light absorption has a small difference in optical characteristics with respect to normal incident light and oblique incident light and is excellent in viewing angle, but obtains a predetermined optical characteristic density. Therefore, the thickness of the base material is increased, and since it is more brittle and easier to break than ordinary glass, it is difficult to reduce the size of the optical component (Non-patent Document 1).

JP 2007-197280 A

Sigma Kogyo general catalog near infrared absorption filter CCF-50S-500C

  It is an object of the present invention to provide an optical filter that is unlikely to be warped or cracked even if the thickness of a support is reduced, and a solid-state imaging device and a camera module including the optical filter.

  As a result of intensive studies to solve the above problems, the present inventors have found that an optical filter that is less likely to warp or crack even when the thickness of the support is reduced by using a support having a specific elastic modulus. As a result, the present invention was completed. Examples of embodiments of the present invention are shown below.

  [1] A substrate including a support having an elastic modulus of 50 to 500 GPa and a resin layer on at least one surface of the support, transmits visible light, and blocks at least part of near infrared rays. An optical filter characterized by

  [2] The optical filter according to item [1], wherein the resin layer has an elastic modulus of 2 to 8 GPa.

[3] The optical filter according to item [1] or [2], further satisfying the following formulas (1), (2), and (3):
Y ≧ −10500X + 540000 (1)
30 ≦ Ta ≦ 300 (2)
2 ≦ Tb ≦ 100 (3)
In the formulas (1) to (3), Y satisfies the following formula (4), X satisfies the following formula (5), Ta represents the thickness of the support (unit: μm), and Tb represents the thickness of the resin layer. (Unit: μm).
Y = (Ea × Ta) × (Eb × Tb) (4)
X = Ta (5)
In formula (4), Ea indicates the elastic modulus (unit: GPa) of the support, and Eb indicates the elastic modulus (unit: GPa) of the resin layer.

[4] The optical filter according to item [3], wherein the Y and the X satisfy the following formula (6).
Y ≧ 300X (6)

[5] The optical filter according to item [3] or [4], wherein the Y and the X satisfy the following formula (7).
Y ≤ 24000X (7)

  [6] The optical filter according to any one of items [1] to [5], wherein a dielectric multilayer film is provided on at least one surface of the substrate.

  [7] The resin layer is a cyclic (poly) olefin resin, aromatic polyether resin, polyimide resin, fluorene polycarbonate resin, fluorene polyester resin, polycarbonate resin, polyamide resin, polyarylate resin, Polysulfone resin, polyethersulfone resin, polyparaphenylene resin, polyamideimide resin, polyethylene naphthalate resin, fluorinated aromatic polymer resin, (modified) acrylic resin, epoxy resin, allyl ester resin Item [1] characterized in that it is formed of at least one resin selected from the group consisting of a curable resin, a silsesquioxane ultraviolet curable resin, an acrylic ultraviolet curable resin, and a vinyl ultraviolet curable resin. ] To [6] The optical film according to any one of [6] Over.

  [8] Any one of [1] to [7], wherein the support is formed of at least one selected from the group consisting of glass, quartz, synthetic quartz, lithium niobate, and sapphire. The optical filter according to item.

  [9] The optical filter according to any one of items [1] to [8], wherein the resin layer includes a compound (A) having an absorption maximum at a wavelength of 600 nm or more and less than 800 nm.

  [10] The optical filter according to item [8], wherein the support has an absorption maximum in a near-infrared wavelength region.

  [11] A solid-state imaging device comprising the optical filter according to any one of items [1] to [10].

  [12] A camera module comprising the optical filter according to any one of items [1] to [10].

  ADVANTAGE OF THE INVENTION According to this invention, even if it thins the thickness of a support body, the optical filter which cannot produce a curvature and a crack easily can be provided.

Hereinafter, the present invention will be specifically described.
[Optical filter]
The optical filter according to the present invention includes a support having an elastic modulus of 50 to 500 GPa and a substrate (i) having a resin layer on at least one surface of the support, and transmits visible light. It is characterized by blocking at least part of the near infrared ray. The resin layer may be formed on both sides of the support, and a plurality of resin layers may be provided on one side or both sides of the support. One side is a single layer and the other side is Multiple layers may be used. The optical filter of the present invention preferably has a dielectric multilayer film on at least one surface of the substrate (i).

  The resin layer preferably contains a compound (A) having an absorption maximum at a wavelength of 600 nm or more and less than 800 nm. The support may have an absorption maximum in the near-infrared wavelength region. Examples of such a support include glass having an absorption maximum in the near-infrared wavelength region (hereinafter referred to as “near-infrared absorption”). And a resin substrate containing the compound (A).

  The optical filter of the present invention having the configuration as described above has excellent near-infrared cut characteristics, low incidence angle dependency, and excellent transmittance characteristics in the visible wavelength region and multiple reflected light reduction effect in the near-infrared wavelength region. Optical filter.

  When the optical filter of the present invention is used for a solid-state imaging device, it is preferable that the transmittance in the near infrared wavelength region is low. In particular, it is known that the light receiving sensitivity of the solid-state imaging device is relatively high in the wavelength region of 800 to 1000 nm. By reducing the transmittance in this wavelength region, it is effective to correct the visibility of the camera image and the human eye. And excellent color reproducibility can be achieved.

  The optical filter of the present invention has an average transmittance of 5% or less, preferably 4% or less, more preferably 3% or less, particularly preferably 2 when measured from the vertical direction of the optical filter in the wavelength range of 800 to 1000 nm. % Or less. When the average transmittance at a wavelength of 800 to 1000 nm is in this range, it is preferable because near infrared rays can be sufficiently cut and excellent color reproducibility can be achieved.

  When the optical filter of the present invention is used for a solid-state imaging device or the like, it is preferable that the visible light transmittance is high. Specifically, in the wavelength range of 430 to 580 nm, the average transmittance when measured from the vertical direction of the optical filter is preferably 75% or more, more preferably 80% or more, still more preferably 83% or more, particularly preferably. 85% or more. When the average transmittance is within this range in this wavelength region, excellent imaging sensitivity can be achieved when the optical filter of the present invention is used as a solid-state imaging device.

  The optical filter of the present invention has the shortest wavelength value (Xa) at which the transmittance when measured from the vertical direction of the optical filter is 50% in the wavelength range of 560 to 800 nm and the vertical direction of the optical filter. It is preferable that the absolute value of the difference from the wavelength value (Xb) at which the transmittance when measured from an angle of 30 ° is 50% is smaller. The absolute value of the difference between (Xa) and (Xb) is preferably less than 20 nm, more preferably less than 15 nm, and particularly preferably less than 10 nm. Such an optical filter can be obtained by forming a dielectric multilayer film on the substrate (i).

  The thickness of the optical filter of the present invention may be appropriately selected according to the desired application. However, according to the recent trend of thinning and weight reduction of solid-state imaging devices, the thickness of the optical filter of the present invention is also thin. Is preferred. Since the optical filter of the present invention includes the substrate (i), it can be thinned.

  The thickness of the optical filter of the present invention is preferably, for example, preferably 200 μm or less, more preferably 180 μm or less, further preferably 150 μm or less, particularly preferably 120 μm or less, and the lower limit is not particularly limited, but for example, 20 μm It is desirable to be.

The optical filter of the present invention preferably satisfies the following formulas (1), (2) and (3) from the viewpoint of reducing warpage and cracking.
Y ≧ −10500X + 540000 (1)
30 ≦ Ta ≦ 300 (2)
2 ≦ Tb ≦ 100 (3)
In the formulas (1) to (3), Y satisfies the following formula (4), X satisfies the following formula (5), Ta represents the thickness of the support (unit: μm), and Tb represents the thickness of the resin layer. (Unit: μm).
Y = (Ea × Ta) × (Eb × Tb) (4)
X = Ta (5)
In formula (4), Ea indicates the elastic modulus (unit: GPa) of the support, and Eb indicates the elastic modulus (unit: GPa) of the resin layer.

Moreover, while said Y and said X satisfy | fill said Formula (1), it is further preferable to satisfy | fill following formula (6), it is more preferable to satisfy | fill following formula (6-1), and following formula (6- It is particularly preferable to satisfy 2).
Y ≧ 300X (6)
Y ≧ 1500X (6-1)
Y ≧ 3000X (6-2)
Moreover, it is preferable that said Y and said X satisfy | fill following formula (7) further.
Y ≤ 24000X (7)

<Support and resin layer>
The elastic modulus of the support is 50 to 500 GPa, preferably 50 to 200 GPa, more preferably 50 to 100 GPa. By using the support having the elastic modulus, it is possible to obtain an optical filter that does not easily crack or warp even if the thickness of the support is thinned. As a result, it is possible to reduce the size of various devices including the optical filter. it can. The elastic modulus of the resin layer is not particularly limited, but is preferably 2 to 8 GPa, more preferably 2 to 7 GPa, and further preferably 2 to 6 GPa. In addition, the said elasticity modulus in this specification is the value measured using "Picodenter HM500" by Fisher Instruments.

  As shown in the formula (2), the thickness of the support is preferably 30 to 300 μm, more preferably 30 to 200 μm, and further preferably 30 to 100 μm. Moreover, as shown to the said Formula (3), the thickness of the said resin layer becomes like this. Preferably it is 2-100 micrometers, More preferably, it is 2-50 micrometers, More preferably, it is 2-30 micrometers.

  The support is not particularly limited as long as it has the elastic modulus, but it is formed of at least one selected from the group consisting of glass, quartz, synthetic quartz, lithium niobate, and sapphire. It is preferable at the point which hold | maintains. The glass is not particularly limited, and examples thereof include borosilicate glass, silicate glass, soda lime glass, and near infrared absorbing glass. The near-infrared absorbing glass is preferable in that the incident angle dependency can be reduced, and specific examples thereof include fluorophosphate-based glass and phosphate-based glass.

Moreover, when the said support body is a resin-made board | substrate containing a compound (A), resin similar to the resin layer mentioned later can be used for resin used for the said resin-made board | substrate.
The resin layer can be formed using a transparent resin. As transparent resin used for the said resin layer, 1 type may be individual, and 2 or more types may be sufficient.

  The transparent resin is not particularly limited as long as it does not impair the effects of the present invention. For example, it ensures thermal stability and moldability to a film, and dielectrics are formed by high-temperature deposition performed at a deposition temperature of 100 ° C. or higher. In order to obtain a film that can form a body multilayer film, a resin having a glass transition temperature (Tg) of preferably 110 to 380 ° C, more preferably 110 to 370 ° C, and still more preferably 120 to 360 ° C. Further, it is particularly preferable that the glass transition temperature of the resin is 140 ° C. or higher because a film capable of depositing a dielectric multilayer film at a higher temperature can be obtained.

  As a transparent resin, when a resin plate having a thickness of 0.1 mm made of the resin is formed, the total light transmittance (JIS K7105) of the resin plate is preferably 75 to 95%, more preferably 78 to 95. %, Particularly preferably 80 to 95% of the resin can be used. If a resin having a total light transmittance in such a range is used, the resulting substrate exhibits good transparency as an optical film.

  The weight average molecular weight (Mw) in terms of polystyrene measured by a gel permeation chromatography (GPC) method of the transparent resin is usually 15,000 to 350,000, preferably 30,000 to 250,000. The average molecular weight (Mn) is usually 10,000 to 150,000, preferably 20,000 to 100,000.

  Examples of transparent resins include cyclic (poly) olefin resins, aromatic polyether resins, polyimide resins, fluorene polycarbonate resins, fluorene polyester resins, polycarbonate resins, polyamide (aramid) resins, and polyarylate resins. Resins, polysulfone resins, polyethersulfone resins, polyparaphenylene resins, polyamideimide resins, polyethylene naphthalate (PEN) resins, fluorinated aromatic polymer resins, (modified) acrylic resins, epoxy resins Examples thereof include resins, allyl ester curable resins, silsesquioxane ultraviolet curable resins, acrylic ultraviolet curable resins, and vinyl ultraviolet curable resins.

≪Cyclic (poly) olefin resin≫
The cyclic (poly) olefin resin is at least one monomer selected from the group consisting of a monomer represented by the following formula (X ₀ ) and a monomer represented by the following formula (Y ₀ ) And a resin obtained by hydrogenating the resin are preferred.

In the formula (X ₀ ), R ^{x1 to} R ^x4 each independently represents an atom or group selected from the following (i ′) to (ix ′), and k ^x , ^mx and p ^x are each independently 0 Or represents a positive integer.
(I ′) a hydrogen atom (ii ′) a halogen atom (iii ′) a trialkylsilyl group (iv ′) having a linking group containing an oxygen atom, a sulfur atom, a nitrogen atom or a silicon atom,
A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (v ′) A substituted or unsubstituted hydrocarbon group having 1 to 30 carbon atoms (vi ′) polar group (excluding (iv ′))
(Vii ′) an alkylidene group formed by bonding R ^x1 and R ^x2 or R ^x3 and R ^x4 to each other (provided that R ^{x1 to} R ^x4 not involved in the bonding are independently the above (i ′ )-(Vi ′) represents an atom or group selected from.
(Viii ′) R ^x1 and R ^x2 or R ^x3 and R ^x4 are bonded to each other to form a monocyclic or polycyclic hydrocarbon ring or heterocyclic ring (provided that R ^{x1 to} R not involved in the bonding) ^x4 each independently represents an atom or group selected from the above (i ′) to (vi ′).
(Ix ′) A monocyclic hydrocarbon ring or heterocycle formed by bonding R ^x2 and R ^x3 to each other (provided that R ^x1 and R ^x4 not involved in the bonding are each independently the above (i Represents an atom or group selected from ') to (vi').

In the formula (Y ₀ ), R ^y1 and R ^y2 each independently represents an atom or group selected from the above (i ′) to (vi ′), or R ^y1 and R ^y2 are bonded to each other. formed monocyclic or polycyclic alicyclic hydrocarbon, an aromatic hydrocarbon or heterocyclic, k ^y and p ^y are each independently, represent 0 or a positive integer.

≪Aromatic polyether resin≫
The aromatic polyether-based resin preferably has at least one structural unit selected from the group consisting of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2).

式（１）中、Ｒ¹〜Ｒ⁴はそれぞれ独立に、炭素数１〜１２の１価の有機基を示し、ａ〜ｄはそれぞれ独立に、０〜４の整数を示す。

In formula (1), R < ¹ > -R < ⁴ > shows a C1-C12 monovalent organic group each independently, and ad shows the integer of 0-4 each independently.

式（２）中、Ｒ¹〜Ｒ⁴およびａ〜ｄはそれぞれ独立に、前記式（１）中のＲ¹〜Ｒ⁴およびａ〜ｄと同義であり、Ｙは、単結合、−ＳＯ₂−または＞Ｃ＝Ｏを示し、Ｒ⁷およびＲ⁸はそれぞれ独立に、ハロゲン原子、炭素数１〜１２の１価の有機基またはニトロ基を示し、ｇおよびｈはそれぞれ独立に、０〜４の整数を示し、ｍは０または１を示す。但し、ｍが０のとき、Ｒ⁷はシアノ基ではない。

In the formula (2), each R ¹ to R ⁴ and a~d are independently the same meaning as R ¹ to R ⁴ and a~d of the formula (1), Y represents a single bond, -SO ₂ -Or> C = O, R ⁷ and R ⁸ each independently represent a halogen atom, a monovalent organic group having 1 to 12 carbon atoms or a nitro group, and g and h each independently represent 0 to 4 And m represents 0 or 1. However, when m is 0, R ⁷ is not a cyano group.

  The aromatic polyether resin further has at least one structural unit selected from the group consisting of a structural unit represented by the following formula (3) and a structural unit represented by the following formula (4). Is preferred.

式（３）中、Ｒ⁵およびＲ⁶はそれぞれ独立に、炭素数１〜１２の１価の有機基を示し、Ｚは、単結合、−Ｏ−、−Ｓ−、−ＳＯ₂−、＞Ｃ＝Ｏ、−ＣＯＮＨ−、−ＣＯＯ−または炭素数１〜１２の２価の有機基を示し、ｅおよびｆはそれぞれ独立に、０〜４の整数を示し、ｎは０または１を示す。

In formula (3), R ⁵ and R ⁶ each independently represent a monovalent organic group having 1 to 12 carbon atoms, Z represents a single bond, —O—, —S—, —SO ₂ —,> C═O, —CONH—, —COO— or a divalent organic group having 1 to 12 carbon atoms, e and f each independently represent an integer of 0 to 4, and n represents 0 or 1.

式（４）中、Ｒ⁷、Ｒ⁸、Ｙ、ｍ、ｇおよびｈはそれぞれ独立に、前記式（２）中のＲ⁷、Ｒ⁸、Ｙ、ｍ、ｇおよびｈと同義であり、Ｒ⁵、Ｒ⁶、Ｚ、ｎ、ｅおよびｆはそれぞれ独立に、前記式（３）中のＲ⁵、Ｒ⁶、Ｚ、ｎ、ｅおよびｆと同義である。

In formula (4), R ⁷ , R ⁸ , Y, m, g and h are each independently synonymous with R ⁷ , R ⁸ , Y, m, g and h in formula (2), and R ⁵ , R ⁶ , Z, n, e and f are each independently synonymous with R ⁵ , R ⁶ , Z, n, e and f in the formula (3).

≪Polyimide resin≫
The polyimide resin is not particularly limited as long as it is a high molecular compound containing an imide bond in a repeating unit. For example, the method described in JP-A-2006-199945 and JP-A-2008-163107 is used. Can be synthesized.

≪Fluorene polycarbonate resin≫
The fluorene polycarbonate resin is not particularly limited as long as it is a polycarbonate resin containing a fluorene moiety. For example, the fluorene polycarbonate resin can be synthesized by a method described in JP-A-2008-163194.

≪Fluorene polyester resin≫
The fluorene polyester resin is not particularly limited as long as it is a polyester resin containing a fluorene moiety. For example, the fluorene polyester resin is synthesized by a method described in JP 2010-285505 A or JP 2011-197450 A. Can do.

≪Fluorinated aromatic polymer resin≫
The fluorinated aromatic polymer resin is not particularly limited, but is selected from the group consisting of an aromatic ring having at least one fluorine atom, an ether bond, a ketone bond, a sulfone bond, an amide bond, an imide bond, and an ester bond. The polymer preferably contains a repeating unit containing at least one bond, and can be synthesized, for example, by the method described in JP-A-2008-181121.

≪Acrylic UV curable resin≫
The acrylic ultraviolet curable resin is not particularly limited, but is synthesized from a resin composition containing a compound having one or more acrylic or methacrylic groups in the molecule and a compound that decomposes by ultraviolet rays to generate active radicals. Can be mentioned.

≪Commercial product≫
The following commercial products etc. can be mentioned as a commercial item of transparent resin. Examples of commercially available cyclic (poly) olefin-based resins include Arton manufactured by JSR Co., Ltd., ZEONOR manufactured by Nippon Zeon Co., Ltd., APEL manufactured by Mitsui Chemicals, Inc., and TOPAS manufactured by Polyplastics Co., Ltd. . Examples of commercially available polyethersulfone resins include Sumika Excel PES manufactured by Sumitomo Chemical Co., Ltd. Examples of commercially available polyimide resins include Neoprim L manufactured by Mitsubishi Gas Chemical Co., Ltd. Examples of commercially available polycarbonate resins include Pure Ace manufactured by Teijin Limited. Examples of commercially available fluorene polycarbonate resins include Iupizeta EP-5000 manufactured by Mitsubishi Gas Chemical Co., Ltd. Examples of commercially available fluorene polyester resins include OKP4HT manufactured by Osaka Gas Chemical Co., Ltd. Examples of commercially available acrylic resins include NIPPON CATALYST ACRYVIEWER. Examples of commercially available silsesquioxane-based ultraviolet curable resins include Silplus manufactured by Nippon Steel Chemical Co., Ltd.

<< Compound (A) >>
The compound (A) is not particularly limited as long as it has an absorption maximum at a wavelength of 600 nm or more and less than 800 nm, but is preferably a solvent-soluble dye compound, and is a group consisting of a squarylium compound, a phthalocyanine compound, and a cyanine compound. More preferably, it is at least one selected from the above, more preferably contains a squarylium compound, more preferably contains at least one squarylium compound and another compound (A), and other compound (A). Particularly preferred are phthalocyanine compounds and cyanine compounds.

  The squarylium-based compound has excellent visible light permeability, steep absorption characteristics, and a high molar extinction coefficient, but may generate fluorescence that causes scattered light upon light absorption. In such a case, an optical filter with less scattered light and better camera image quality can be obtained by using a combination of the squarylium compound and the other compound (A). Specific examples of the squarylium-based compound include the compound (a-1) described below.

化合物（Ａ）の吸収極大波長は、好ましくは６２０ｎｍ以上７８０ｎｍ以下、さらに好ましくは６３０ｎｍ以上７７０ｎｍ以下、特に好ましくは６４０ｎｍ以上７６０ｎｍ以下である。

The absorption maximum wavelength of the compound (A) is preferably 620 nm to 780 nm, more preferably 630 nm to 770 nm, and particularly preferably 640 nm to 760 nm.

  The content of the compound (A) in the resin layer is preferably 0.01 to 5.0 parts by weight, more preferably 0.02 to 4.0 parts by weight, particularly preferably 100 parts by weight of the transparent resin. Is 0.03 to 3.0 parts by weight.

≪Other dye (X) ≫
The resin layer may further contain other dye (X) that does not correspond to the compound (A).

  Other dyes (X) are not particularly limited as long as the absorption maximum wavelength is less than 600 nm or more than 800 nm, but those having an absorption maximum wavelength of more than 800 nm are preferable. Examples of such dyes include squarylium compounds, phthalocyanine compounds, cyanine compounds, naphthalocyanine compounds, croconium compounds, octaphyrin compounds, diimonium compounds, perylene compounds, and metal dithiolate compounds. There may be mentioned at least one compound selected from the group.

≪Other ingredients≫
The resin layer may further contain additives such as an antioxidant, a near ultraviolet absorber, a fluorescence quencher, and a metal complex compound as long as the effects of the present invention are not impaired. These other components may be used alone or in combination of two or more.

Examples of the near ultraviolet absorber include azomethine compounds, indole compounds, benzotriazole compounds, and triazine compounds.
Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2′-dioxy-3,3′-di-t-butyl-5,5′-dimethyldiphenylmethane, and And tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane.

  These additives may be mixed with a resin or the like when producing a resin layer, or may be added when a resin is synthesized. The addition amount is appropriately selected according to the desired properties, but is usually 0.01 to 5.0 parts by weight, preferably 0.05 to 2.0 parts by weight, based on 100 parts by weight of the resin. Part.

<Base material (i)>
In the region of wavelength 600 nm or more and less than 800 nm, the lowest transmittance (Za) measured from the vertical direction of the substrate (i) is preferably 40% or less, more preferably 25% or less, and particularly preferably 10% or less. is there.

  The shortest wavelength (Xc) at which the transmittance measured from the vertical direction of the substrate (i) in the wavelength region of 600 nm or more is from 50% to 50% is preferably 610 to 670 nm, more preferably 620 to 665 nm. Especially preferably, it is 630-660 nm.

  If (Za) and (Xc) of the substrate (i) are within such a range, unnecessary near infrared rays can be selectively and efficiently cut, and a dielectric multilayer film can be formed on the substrate (i). When the film is formed, it is possible to reduce the incident angle dependency of the optical characteristics in the vicinity of the visible wavelength region to the near infrared wavelength region.

  The average transmittance of the substrate (i) at a wavelength of 430 to 580 nm is preferably 75% or more, more preferably 78% or more, and particularly preferably 80% or more. When a substrate having such transmission characteristics is used, high light transmission characteristics can be achieved in the visible region, and a highly sensitive camera function can be achieved.

  The thickness of the base material (i) can be appropriately selected according to a desired application, and is not particularly limited. However, it is desirable and preferably selected appropriately so as to reduce the incident angle dependency of the obtained optical filter. Is 10 to 200 μm, more preferably 15 to 180 μm, and particularly preferably 20 to 150 μm. When the thickness of the substrate (i) is in the above range, the optical filter using the substrate (i) can be thinned and reduced in weight, and can be suitably used for various applications such as a solid-state imaging device. it can.

<Manufacturing method of substrate (i)>
The solvent is removed by drying after the resin solution containing the compound (A) is melt-molded or cast-molded on the support, preferably by a method such as spin coating, slit coating, or inkjet. The substrate (i) having the resin layer formed on the support can be produced by further performing light irradiation or heating as necessary. Further, if necessary, an overcoat layer may be laminated by coating a coating agent such as an antireflection agent, a hard coating agent and / or an antistatic agent.

  Specifically, as the melt molding, a method of melt-molding pellets obtained by melt-kneading a resin and, if necessary, a compound (A) or the like; a resin and a compound (A) or the like as needed A method of melt-molding pellets obtained by removing a solvent from a resin composition containing a resin, a solvent and, if necessary, a compound (A), etc. Is mentioned. Examples of the melt molding method include injection molding, melt extrusion molding, and blow molding.

  As the cast molding, a method of removing a solvent by casting a resin composition containing a resin, a solvent and, if necessary, a compound (A) on an appropriate support; or a photocurable resin and / or heat A method in which a curable composition containing a curable resin and, if necessary, a compound (A) is cast on an appropriate support to remove the solvent, and then cured by an appropriate technique such as ultraviolet irradiation or heating. It can also be manufactured by, for example.

  The amount of residual solvent in the resin layer obtained by the above method should be as small as possible. Specifically, the amount of the residual solvent is preferably 3% by weight or less, more preferably 1% by weight or less, and further preferably 0.5% by weight or less with respect to the weight of the resin layer. When the residual solvent amount is in the above range, it is possible to obtain a resin layer that can easily exhibit a desired function, in which deformation and characteristics hardly change.

<Dielectric multilayer film>
The dielectric multilayer film in the present invention is a film having the ability to reflect near infrared rays. In the present invention, the near-infrared reflective film may be provided on one side of the substrate (i) or may be provided on both sides. When it is provided on one side, it is possible to obtain an optical filter that is excellent in production cost and manufacturability and has high strength and is less likely to warp or twist when provided on both sides. When the optical filter is applied to a solid-state imaging device application, it is preferable that the optical filter is less warped or twisted. Therefore, it is preferable to provide a dielectric multilayer film on both surfaces of the substrate (i).

  The dielectric multilayer film preferably has reflection characteristics over the entire wavelength range of 700 to 1100 nm, more preferably has reflection characteristics over the entire wavelength range of 700 to 1150 nm, and particularly preferably 700 to 1200 nm. As a form having dielectric multilayer films on both surfaces of the substrate (i), a first optical layer mainly having reflection characteristics in the vicinity of a wavelength of 700 to 950 nm when measured from an angle of 5 ° with respect to the vertical direction of the optical filter On one side of the substrate (i), and the reflection characteristic is mainly in the vicinity of 900 nm to 1150 nm when measured from the angle of 5 ° with respect to the vertical direction of the optical filter on the other surface of the substrate (i). A third optical layer mainly having reflection characteristics in the vicinity of a wavelength of 700 to 1150 nm when measured from an angle of 5 ° with respect to the vertical direction of the optical filter or a form having the second optical layer having the substrate (i) Examples thereof include a fourth optical layer which is provided on one side and has a visible region antireflection property on the other side of the substrate (i).

  Examples of the dielectric multilayer film include those in which high refractive index material layers and low refractive index material layers are alternately stacked. As a material constituting the high refractive index material layer, a material having a refractive index of 1.7 or more can be used, and a material having a refractive index of usually 1.7 to 2.5 is selected. Examples of such materials include titanium oxide, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, or indium oxide as the main components, and titanium oxide, tin oxide, and / or Or what contains a small amount (for example, 0-10 weight% with respect to a main component) of cerium oxide etc. is mentioned.

  As a material constituting the low refractive index material layer, a material having a refractive index of 1.6 or less can be used, and a material having a refractive index of usually 1.2 to 1.6 is selected. Examples of such materials include silica, alumina, lanthanum fluoride, magnesium fluoride, and sodium hexafluoride sodium.

  The method of laminating the high refractive index material layer and the low refractive index material layer is not particularly limited as long as a dielectric multilayer film in which these material layers are laminated is formed. For example, a high-refractive index material layer and a low-refractive index material layer are alternately laminated directly on the substrate (i) by CVD, sputtering, vacuum deposition, ion-assisted deposition, or ion plating. A dielectric multilayer film can be formed.

  The thicknesses of the high-refractive index material layer and the low-refractive index material layer are usually preferably 0.1λ to 0.5λ, where λ (nm) is the near infrared wavelength to be blocked. The value of λ (nm) is, for example, 700 to 1400 nm, preferably 750 to 1300 nm. When the thickness is within this range, the optical thickness obtained by multiplying the refractive index (n) by the thickness (d) (n × d) by λ / 4, the high refractive index material layer, and the low refractive index. The thicknesses of the respective layers of the refractive index material layer are almost the same value, and there is a tendency that the blocking / transmission of a specific wavelength can be easily controlled from the relationship between the optical characteristics of reflection / refraction.

  The total number of stacked high refractive index material layers and low refractive index material layers in the dielectric multilayer film is preferably 16 to 70 layers, and more preferably 20 to 60 layers as a whole. If the thickness of each layer, the thickness of the dielectric multilayer film as a whole of the optical filter, and the total number of layers are within the above ranges, a sufficient manufacturing margin can be secured, and the warpage of the optical filter and cracks in the dielectric multilayer film can be reduced. can do.

  In the present invention, the material type constituting the high refractive index material layer and the low refractive index material layer, the thickness of each layer of the high refractive index material layer and the low refractive index material layer, By properly selecting the number of layers and the number of layers, ensuring sufficient transmittance in the visible range and sufficient light-cut characteristics in the near-infrared wavelength range, and when near-infrared rays are incident from an oblique direction The reflectance can be reduced.

  Here, in order to optimize the conditions, for example, optical thin film design software (for example, manufactured by Essential Macleod, manufactured by Thin Film Center) can be used to achieve both an antireflection effect in the visible region and a light cut effect in the near infrared region. You can set the parameters as follows. In the case of the above-mentioned software, for example, in designing the first optical layer, the target transmittance at a wavelength of 400 to 700 nm is set to 100%, the target tolerance value is set to 1, and the target transmittance at a wavelength of 705 to 950 nm is set to 0%. A parameter setting method such as setting the value of Target Tolerance to 0.5 may be mentioned. These parameters can also change the value of Target Tolerance by further finely dividing the wavelength range according to various characteristics of the substrate (i).

<Other functional membranes>
As long as the optical filter of the present invention does not impair the effects of the present invention, the optical filter between the substrate (i) and the dielectric multilayer film is on the side opposite to the surface on which the dielectric multilayer film of the substrate (i) is provided. Surface, or the surface opposite to the surface on which the substrate (i) of the dielectric multilayer film is provided, the surface hardness of the substrate (i) or the dielectric multilayer film is improved, the chemical resistance is improved, the antistatic, Functional films such as an antireflection film, a hard coat film, a primer film, and an antistatic film can be appropriately provided for the purpose of improving adhesion and scratch removal.

  The optical filter of the present invention may include one layer composed of the functional film, or may include two or more layers. When the optical filter of the present invention includes two or more layers made of the functional film, it may include two or more similar layers or two or more different layers.

  The method of laminating the functional film is not particularly limited, but a coating agent such as an antireflection agent, a hard coating agent and / or an antistatic agent is melted in the base material (i) or the dielectric multilayer film as described above. Examples of the method include molding or cast molding.

  Further, the composition can also be produced by applying a curable composition containing the coating agent or the like on the substrate (i) or the dielectric multilayer film with a bar coater or the like and then curing the composition by ultraviolet irradiation or the like.

  Examples of the coating agent include ultraviolet (UV) or electron beam (EB) curable resins and thermosetting resins. Specifically, vinyl compounds, urethanes, urethane acrylates, acrylates, epoxy And epoxy acrylate resins. Examples of the curable composition containing these coating agents include vinyl, urethane, urethane acrylate, acrylate, epoxy, and epoxy acrylate curable compositions.

  Moreover, the said curable composition may contain the polymerization initiator. As the polymerization initiator, a known photopolymerization initiator or a thermal polymerization initiator can be used, and a photopolymerization initiator and a thermal polymerization initiator may be used in combination. A polymerization initiator may be used individually by 1 type, and may use 2 or more types together.

  In the curable composition, the blending ratio of the polymerization initiator is preferably 0.1 to 10% by weight, more preferably 0.5 to 10% by weight, when the total amount of the curable composition is 100% by weight. More preferably, it is 1 to 5% by weight. When the blending ratio of the polymerization initiator is within the above range, it is possible to obtain a functional film such as an antireflective film, a hard coat film or an antistatic film having excellent curing characteristics and handleability of the curable composition and having a desired hardness. it can.

  Furthermore, an organic solvent may be added as a solvent to the curable composition, and known organic solvents can be used. Specific examples of the organic solvent include alcohols such as methanol, ethanol, isopropanol, butanol and octanol; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; ethyl acetate, butyl acetate, ethyl lactate, γ-butyrolactone, propylene Esters such as glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate; Ethers such as ethylene glycol monomethyl ether and diethylene glycol monobutyl ether; Aromatic hydrocarbons such as benzene, toluene and xylene; Dimethylformamide, dimethylacetamide, N- Examples include amides such as methylpyrrolidone.

These solvents may be used alone or in combination of two or more.
The thickness of the functional film is preferably 0.1 to 20 μm, more preferably 0.5 to 10 μm, and particularly preferably 0.7 to 5 μm.

  Further, for the purpose of improving the adhesion between the base material (i) and the functional film and / or the dielectric multilayer film, and the adhesion between the functional film and the dielectric multilayer film, the base material (i), the functional film or the dielectric Surface treatment such as corona treatment or plasma treatment may be applied to the surface of the multilayer film.

[Application of optical filter]
The optical filter of the present invention has a wide viewing angle and has excellent near-infrared cutting ability and the like. Therefore, it is useful for correcting the visibility of a solid-state imaging device such as a CCD or CMOS image sensor of a camera module. In particular, digital still cameras, smartphone cameras, mobile phone cameras, digital video cameras, wearable device cameras, PC cameras, surveillance cameras, automotive cameras, TVs, car navigation systems, personal digital assistants, video game machines, and portable game machines It is useful for fingerprint authentication system, digital music player, etc. Furthermore, it is also useful as a heat ray cut filter attached to a glass plate of an automobile or a building.

[Solid-state imaging device]
The solid-state imaging device of the present invention includes the optical filter of the present invention. Here, the solid-state imaging device is an image sensor including a solid-state imaging device such as a CCD or a CMOS image sensor. Specifically, a digital still camera, a smartphone camera, a mobile phone camera, a wearable device camera, a digital camera It can be used for applications such as video cameras. For example, the camera module of the present invention includes the optical filter of the present invention.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example, this invention is not limited to these Examples at all. “Parts” means “parts by weight” unless otherwise specified. Moreover, the measurement method of each physical property value and the evaluation method of the physical property are as follows.

<Molecular weight>
The molecular weight of the resin was measured by the following method (a) or (b) in consideration of the solubility of each resin in a solvent.

  (A) Weight average molecular weight in terms of standard polystyrene using a gel permeation chromatography (GPC) apparatus (150C type, column: H type column manufactured by Tosoh Corporation, developing solvent: o-dichlorobenzene) manufactured by WATERS (Mw) and number average molecular weight (Mn) were measured.

  (B) Standard polystyrene equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) were measured using a GPC apparatus (HLC-8220 type, column: TSKgel α-M, developing solvent: THF) manufactured by Tosoh Corporation.

<Glass transition temperature (Tg)>
Using a differential scanning calorimeter (DSC6200) manufactured by SII Nano Technologies, Inc., the rate of temperature increase was measured at 20 ° C. per minute under a nitrogen stream.

<Elastic modulus>
The elastic modulus was measured under a measurement condition of 300 mN / 10 s using “Picodenter HM500” manufactured by Fisher Instruments Co., Ltd.

<Thickness>
The thickness of the support was measured using “Digimatic Indicator” manufactured by Mitutoyo Corporation, and the thickness of the resin layer was measured using “Reflected Spectral Thickness Meter FE-3000” manufactured by Otsuka Electronics Co., Ltd.

<Warpage>
A 10mm square chip-deposited deposition sheet is placed on the observation stage of “Digital Microscope VHX-600” manufactured by KEYENCE Co., Ltd. and observed from the side to measure the warp height of the tip end. It was evaluated with.
OO: Less than 20 μm XX: 20 μm ≦ warp <40 μm
○: 40 μm ≦ warp <60 μm
Δ: 60 μm ≦ warp <80 μm
×: 80 μm or more

<Break>
A 10mm square chip-cut deposition sheet is dropped 50 times onto a SUS plate from a height of 100mm, and cracks and chips are generated at 50 times using "Digital Microscope VHX-600" manufactured by KEYENCE. The situation was observed and evaluated according to the following criteria.
○○○: No cracking or chipping.
○○: 1 to 3 spots are broken or cracked.
○: 3 to 9 spots are broken or cracked.
Δ: Chipping or cracking occurs at 10 or more locations.

[Synthesis example]
The compound (A) used in the following examples was synthesized by a generally known method. As general synthesis methods, for example, Japanese Patent No. 336697, Japanese Patent No. 2846091, Japanese Patent No. 2864475, Japanese Patent No. 3703869, Japanese Patent Laid-Open No. 60-228448, Japanese Patent Laid-Open No. 1-146846 are disclosed. JP-A-1-228960, JP-A-4081149, JP-A-63-124054, “Phthalocyanine—Chemistry and Function” (IPC, 1997), JP-A-2007-169315, JP Examples include methods described in JP-A-2009-108267, JP-A 2010-241873, JP-A-3699464, JP-A-4740431, and the like.

<Resin synthesis example 1>
8-methyl-8-methoxycarbonyltetracyclo represented by the following formula (a) [4.4.0.1 ^2,5 . 1 ^7,10 ] Dodec-3-ene (hereinafter also referred to as “DNM”) 100 parts, 18 parts of 1-hexene (molecular weight regulator) and 300 parts of toluene (solvent for ring-opening polymerization reaction) were substituted with nitrogen. The vessel was charged and the solution was heated to 80 ° C. Next, 0.2 parts of a toluene solution of triethylaluminum (0.6 mol / liter) as a polymerization catalyst and a toluene solution of methanol-modified tungsten hexachloride (concentration 0.025 mol / liter) were added to the solution in the reaction vessel. 9 parts was added and this solution was heated and stirred at 80 ° C. for 3 hours to cause a ring-opening polymerization reaction to obtain a ring-opening polymer solution. The polymerization conversion rate in this polymerization reaction was 97%.

1,000 parts of the ring-opening polymer solution thus obtained was charged into an autoclave, and 0.12 part of RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opening polymer solution. Then, the hydrogenation reaction was performed by heating and stirring for 3 hours under the conditions of a hydrogen gas pressure of 100 kg / cm ² and a reaction temperature of 165 ° C. After cooling the obtained reaction solution (hydrogenated polymer solution), the hydrogen gas was released. This reaction solution was poured into a large amount of methanol to separate and recover the coagulated product, and dried to obtain a hydrogenated polymer (hereinafter also referred to as “resin A”). The obtained resin A had a number average molecular weight (Mn) of 32,000, a weight average molecular weight (Mw) of 137,000, and a glass transition temperature (Tg) of 165 ° C. Moreover, the elasticity modulus of the resin layer which consists of obtained resin A was 3 GPa.

[Example 1]
A resin solution (resin concentration 20% by weight) prepared by adding 100 parts of the resin A obtained in Resin Synthesis Example 1, 0.3 part of the compound (a-1) as the compound (A), and methylene chloride was added to glass. A substrate on which a resin layer having a thickness of 10 μm is formed on a glass support by casting on a support (“D263” manufactured by SCHOTT, thickness: 80 μm, elastic modulus 70 GPa) and drying at 150 ° C. for 1 hour. Obtained.

Subsequently, on one side of the obtained base material, a multilayer deposited film reflecting a near infrared ray at a deposition temperature of 100 ° C. [silica (SiO ₂ : film thickness 8 3 to 1 9 9 nm) layer and titania ( T i O ₂ : Thickness 10 1 to 1 25 nm) are alternately stacked, and the number of stacked layers 2 0] is further formed, and the deposition temperature is 1 on the other surface of the substrate. Multi-layer vapor-deposited film reflecting near infrared rays at 0 ° C. [silica (SiO ₂ : film thickness 7 7 to 1 89 nm) layer and titania (TiO ₂ : film thickness 8 4 to 1 1 8 nm) ) The number of laminated layers was 2 6], and a near-infrared cut filter having a total thickness of the deposited films on both sides of 0.005 mm was obtained. The multilayer deposited film was designed in consideration of the wavelength dependence of the refractive index of the substrate. The obtained near-infrared cut filter was evaluated for warpage and cracking. The results are shown in Table 1.

[Examples 2 to 9]
A near-infrared cut filter was prepared and evaluated in the same manner as in Example 1 except that the material type constituting the resin layer and the support, and the thickness of the resin layer and the support were changed as shown in Table 1. . Table 1 shows the evaluation results of the obtained near-infrared cut filter.

[Comparative Example 1]
A resin coating solution prepared by adding 0.3 part of compound (a-1) as compound (A) to 100 parts of resin B described later is applied to a PEN film with a bar coater and heated at 80 ° C. for 2 minutes. The solvent was removed by volatilization. At this time, the bar was selected so that the thickness after drying was 5 μm. Next, exposure (exposure amounts: 500 mJ / cm ² , 200 mW / cm ² ) is carried out using a conveyor-type UV exposure machine, the resin B is cured, and a substrate on which a resin layer having a thickness of 5 μm is formed on the PEN film Got. In the same manner as in Example 1, multilayer deposited films were formed on both surfaces of the obtained substrate to produce a near infrared cut filter and evaluated. The results are shown in Table 1.

[Comparative Example 2]
A near-infrared cut filter was prepared and evaluated in the same manner as in Comparative Example 1 except that Resin C was used. The results are shown in Table 1.

表１中の支持体および樹脂層の材料種は下記の通りである。

The material types of the support and the resin layer in Table 1 are as follows.

<Material type of support>
Glass A: “D263” manufactured by SCHOTT (elastic modulus: 70 GPa)
Glass B: “BS13” manufactured by Matsunami Glass Industrial Co., Ltd. (elastic modulus: 60 GPa)
Sapphire: “SA100” manufactured by Kyocera Corporation (elastic modulus; 470 GPa)
PEN: “Teonex” manufactured by Teijin DuPont Films Ltd. (elastic modulus: 6 GPa, polyethylene naphthalate)
Glass B had an absorption maximum in the near-infrared wavelength region, and the half value when the thickness was 300 μm was 597 nm, and the half value when the thickness was 100 μm was 641 nm.

<Material type of resin layer>
Resin A: Cyclic olefin resin (resin synthesis example 1)
Resin B: Acrylic ultraviolet curable resin (100 parts by weight of dipentaerythritol hexaacrylate, 5 parts by weight of 1-hydroxycyclohexyl phenyl ketone, methyl ethyl ketone (solvent, solid content concentration: 30%))
Resin C: Urethane acrylic ultraviolet curable resin (“8BR-500” manufactured by Taisei Fine Chemical Co., Ltd.) 50 parts by weight, tricyclodecane dimethanol diacrylate 50 parts by weight, 1-hydroxycyclohexyl phenyl ketone 5 parts by weight, methyl ethyl ketone (solvent , Solid content concentration: 30%))

  The optical filter of the present invention is a digital still camera, a mobile phone camera, a digital video camera, a personal computer camera, a surveillance camera, an automobile camera, a television, an in-vehicle device for a car navigation system, a portable information terminal, a video game machine, a mobile phone. It can be suitably used for game machines, fingerprint authentication system devices, digital music players, and the like. Furthermore, it can be suitably used as a heat ray cut filter or the like attached to glass or the like of automobiles and buildings.

Claims (12)

  Including a support having an elastic modulus of 50 to 500 GPa and a substrate having a resin layer on at least one surface of the support, transmitting visible light, and blocking at least part of near infrared rays. Features optical filter.   The optical filter according to claim 1, wherein the resin layer has an elastic modulus of 2 to 8 GPa. The optical filter according to claim 1 or 2, wherein the following expressions (1), (2), and (3) are satisfied.
Y ≧ −10500X + 540000 (1)
30 ≦ Ta ≦ 300 (2)
2 ≦ Tb ≦ 100 (3)
[In the formulas (1) to (3), Y satisfies the following formula (4), X satisfies the following formula (5), Ta represents the thickness of the support (unit: μm), and Tb represents the resin layer Thickness (unit: μm) is shown. ]
Y = (Ea × Ta) × (Eb × Tb) (4)
X = Ta (5)
[In Formula (4), Ea shows the elasticity modulus (unit; GPa) of a support body, and Eb shows the elasticity modulus (unit; GPa) of a resin layer. ] The optical filter according to claim 3, wherein the Y and the X satisfy the following formula (6).
Y ≧ 300X (6) The optical filter according to claim 3 or 4, wherein the Y and the X satisfy the following formula (7).
Y ≤ 24000X (7)   The optical filter according to claim 1, further comprising a dielectric multilayer film on at least one surface of the base material.   The resin layer is a cyclic (poly) olefin resin, aromatic polyether resin, polyimide resin, fluorene polycarbonate resin, fluorene polyester resin, polycarbonate resin, polyamide resin, polyarylate resin, polysulfone resin. , Polyethersulfone resins, polyparaphenylene resins, polyamideimide resins, polyethylene naphthalate resins, fluorinated aromatic polymer resins, (modified) acrylic resins, epoxy resins, allyl ester curable resins The at least one resin selected from the group consisting of a silsesquioxane ultraviolet curable resin, an acrylic ultraviolet curable resin, and a vinyl ultraviolet curable resin. The optical filter according to any one of the above.   The optical filter according to any one of claims 1 to 7, wherein the support is formed of at least one selected from the group consisting of glass, quartz, synthetic quartz, lithium niobate, and sapphire. .   The optical filter according to claim 1, wherein the resin layer includes a compound (A) having an absorption maximum at a wavelength of 600 nm or more and less than 800 nm.   The optical filter according to claim 8, wherein the support has an absorption maximum in a near infrared wavelength region.   The solid-state imaging device which comprises the optical filter of any one of Claims 1-10.   A camera module comprising the optical filter according to claim 1.