JP2009265562A - Optical element and method of manufacturing electronic equipment with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical element which has a functional film formed on its surface, which is not damaged nor deformed even through a reflow process. <P>SOLUTION: The optical element 16 has a functional layer on the surface of a substrate containing a curing resin, and the difference in coefficient of linear expansion between the substrate and the closest contact layer of the functional layer is not larger than 45 (×10<SP>-6</SP>/°C). The coefficient of linear expansion of the substrate is controlled by including inorganic particles in the substrate and the functional layer is an anti-reflection film. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical element and a method for manufacturing an electronic device on which the optical element is mounted.

  Information devices such as a player, a recorder, and a drive that read and record information on optical information recording media such as MO, CD, and DVD are provided with an optical pickup device. The optical pickup device includes an optical element unit that irradiates an optical information recording medium with light having a predetermined wavelength emitted from a light source, and receives the reflected light by a light receiving element. The optical element unit records these lights in an optical information recording medium. An optical element such as a lens for condensing light by a reflection layer of a medium or a light receiving element is included. In mounting electronic components and solid-state image sensors, there is a soldering process in which solder is melted in a furnace at a high temperature of about 290 ° C. called reflow. Conventionally, in order to go through this process, it has been common to use an optical element such as a lens made of glass having high heat resistance. However, in recent years, plastics such as a thermosetting resin that are not easily deformed by heat have been used. It is known to perform reflow using an optical element such as a conventional lens. Thus, it has been found that the manufacturing cost of the electronic device can be reduced by mounting the lens. Furthermore, in recent years, it has been attempted to impart various characteristics to the optical element by forming a functional film on the surface of these optical elements. In Patent Document 1, in an optical element for an optical pickup device, In order to efficiently use the laser light emitted from the light source, a technique for forming an antireflection film on the optical surface is disclosed, and the amount of light reflected from the optical surface is suppressed by using interference of light.

However, although the thermosetting resin has less problems with heat resistance, it has a large expansion and contraction due to heat compared to the conventionally used glass, and due to expansion due to high heat during the reflow process, and expansion and contraction due to cooling, It has been found that a new problem arises that the functional film of the above is damaged or deformed.
JP 2002-55207 A

  Therefore, a main object of the present invention is to provide an optical element having a functional film formed on the surface, and the functional film on the surface is not damaged or deformed even after a reflow process. .

  The above object of the present invention is achieved by the following configurations.

1. An optical element having a functional layer on the surface of a substrate containing a curable resin, wherein a difference in linear expansion coefficient between the closest surface layer of the substrate and the functional layer is 45 [× 10 ⁻⁶ / ° C.] or less. There is an optical element.

  2. 2. The optical element according to 1 above, wherein the substrate contains inorganic fine particles.

  3. 2. The optical element as described in 1 above, wherein the functional layer is an antireflection film.

  4). 4. The optical element according to any one of 1 to 3, wherein the optical element is used in an imaging device mounted on a substrate together with an electronic component by reflow processing.

  5). The step of placing the imaging device having the optical element according to any one of 1 to 4 on a substrate together with an electronic component, and subjecting the imaging device, the electronic component, and the substrate to a reflow process, A method for manufacturing an electronic device, comprising: mounting an imaging device and the electronic component on the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, it is an optical element which formed the functional film on the surface, Comprising: The optical element which a functional film on the surface does not break or deform | transform even if it passes through a reflow process can be provided.

  The best mode for carrying out the present invention will be described in detail below, but the present invention is not limited thereto.

In order to solve the above problems, the optical element of the present invention is characterized by an optical element in which a base material containing inorganic fine particles is molded into a thermosetting resin and a functional film is formed on the surface of the molded product. The optical element is characterized in that the difference in linear expansion coefficient between the closest surface layer of the substrate and the functional film is 45 [10 ⁻⁶ / ° C.] or less.

  Further, a step of placing an imaging device having the optical element on a substrate together with an electronic component, and subjecting the imaging device, the electronic component, and the substrate to a reflow process, the imaging device and the electronic component being There is provided a method for manufacturing an electronic device, comprising a step of mounting on a substrate.

  According to the present invention, by including inorganic fine particles in the curable resin, the linear expansion coefficient of the base material can be preferably controlled, and in order to match the material of the functional film, the functionality by thermal expansion and contraction There is a feature capable of suppressing breakage and deformation of the film.

  Hereinafter, preferred embodiments of the present invention will be described.

  An optical element and an electronic device according to a preferred embodiment of the present invention are: (1) a step of molding a base material containing a thermosetting resin and inorganic fine particles, and (2) a functional film on the surface of the molded product. It is formed by a step of forming and (3) a step of being mounted on an electronic device through a reflow step.

<Inorganic fine particles>
The inorganic fine particles preferably used in the present invention have an average primary particle size of 1 nm or more and 20 nm or less, and more preferably 1 nm or more and 10 nm or less. When the average primary particle size is less than 1 nm, it is difficult to disperse the resin and transparency may not be obtained on the substrate. Therefore, the average primary particle size is preferably 1 nm or more, and the average primary particle size is If it exceeds 20 nm, the resulting base material may become turbid and the transparency may be reduced, and the light transmittance may be less than 70%. Therefore, the average primary particle size is preferably 20 nm or less. The average primary particle diameter here refers to the volume average value of the diameter (sphere equivalent particle diameter) when each primary particle is converted to a sphere having the same volume. The average primary particle diameter as referred to in the present invention can be determined by measurement using TEM / EDX.

Furthermore, the metal which comprises inorganic fine particles is Li, Na, Mg, Al, Si, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, One or more selected from the group consisting of Nb, Zr, Mo, Ag, Cd, In, Sn, Sb, Cs, Ba, La, Ta, Hf, W, Ir, Tl, Pb, Bi and rare earth metals Inorganic oxide fine particles that are metals such as titanium oxide, zinc oxide, aluminum oxide, zirconium oxide, hafnium oxide, niobium oxide, tantalum oxide, magnesium oxide, calcium oxide, strontium oxide can be used. , Barium oxide, indium oxide, tin oxide, lead oxide, double oxides composed of these oxides, lithium niobate, potassium niobate, lithium tantalate Arm, magnesium aluminum oxide (MgAl ₂ O _4), and the like. In addition, rare earth oxides can also be used as oxide fine particles used in the present invention, specifically, scandium oxide, yttrium oxide, lanthanum oxide, cerium oxide, praseodymium oxide, neodymium oxide, samarium oxide, europium oxide, gadolinium oxide. Terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, lutetium oxide and the like. Furthermore, it is preferable to use core-shell particles having these particles as core particles and a silica layer formed on the surface. In particles having a primary particle diameter of 20 nm or less, the core-shell particles scatter light as particles in which the material of the core portion and the shell portion are uniformly mixed. Therefore, particles having a controlled refractive index can be achieved by adjusting the core particle diameter and the shell thickness. When considering a refractive index of 1.51 to 1.6 of a general optical resin, it is particularly preferable that the core particle is formed of aluminum oxide and the shell portion is formed of silica based on the refractive index. By using these core-shell particles, it is possible to obtain a base material that maintains high transparency even if it is contained in a resin having a refractive index of 1.51 to 1.6 that is used for general purposes. The method for producing these inorganic fine particles is not particularly limited, and any known method can be used. For example, inorganic fine particles can be formed by using a flame method, a plasma method, a sol-gel method, or the like. The core-shell particles can be easily prepared using a sol-gel method or the like.

<Hydrophobic treatment>
It is desirable that the inorganic fine particles have a hydrophobic surface in order to improve wettability with the resin. In the hydrophobization process in this patent, both dry and wet processes can be used.

  In the dry hydrophobization treatment, the inorganic fine particles are put into a high-speed stirrer such as a Henschel mixer or a super mixer, and the hydrophobization treatment is added dropwise or sprayed to the particles while stirring at high speed. The powder after adding the agent is heated.

  In the wet hydrophobization treatment, the surface is hydrophobized by adding inorganic fine particles into a solvent and adding a hydrophobization treatment agent. Examples of the solvent include ethanol, methanol, acetonitrile, THF, dioxane, dimethylformamide, water and the like, and it is preferable to mix them in some cases.

  As the hydrophobizing agent, it is preferable to use a silane coupling agent exhibiting heat resistance and high hydrophobicity. Silane coupling agents include hexamethyldisilazane, trimethylethoxysilane, trimethylmethoxysilane, trimethylsilyl chloride, methyltriethoxysilane, dimethyldiethoxysilane, decyltrimethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxy. Silane, N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, SZ6187 manufactured by Toray Dow Silicone, and the like can be suitably used.

  Among the above silane coupling agents, it is preferable to use a monofunctional silane coupling agent since the aggregation of particles in the liquid is small. Furthermore, as the particle size is reduced, the surface area relative to mass increases, and when a hydrophobic treatment is performed using a hydrophobic treatment agent having a large molecular weight, a large amount of the hydrophobic treatment agent is required. The physical properties of an optical resin material produced using particles containing a large amount of hydrophobic treatment deteriorate. Therefore, it is desirable to use a silane coupling agent having a small molecular weight and high hydrophobicity, and it is more preferable to use hexamethyldisilazane, trimethylethoxysilane, trimethylmethoxysilane, or trimethylsilyl chloride as the hydrophobizing agent.

  The addition amount of the hydrophobizing agent is preferably 50 to 400% by mass with respect to the total inorganic fine particles.

<Curable resin>
Although a curable resin is used in the substrate of the present invention, it is preferable to use a thermosetting resin or a photocurable resin. The curable resin preferably contains at least one compound having a polyfunctional alicyclic hydrocarbon skeleton having two or more reactive groups.

  Moreover, a thermoplastic resin can also be used in the range which does not inhibit an effect.

  A resin composition obtained by curing a transparent curable compound having a polymerization reactive group such as a (meth) acryl group has been used as an optical material used in an optical system of a spectacle lens or various optical instruments. In order to ensure the reliability of advanced physical properties against environmental fluctuations, which are required for optical elements used in various optical instruments, there are problems such as insufficient heat resistance and a large coefficient of linear expansion. is there. On the other hand, the curable composition containing at least one compound having a polyfunctional alicyclic hydrocarbon skeleton having two or more reactive groups is obtained by uniformly dispersing inorganic fine particles and polymerizing and curing them. It was found that excellent heat resistance was exhibited while ensuring transparency.

  In addition, both a compound having a polyfunctional alicyclic hydrocarbon skeleton having two or more reactive groups and a compound having a monofunctional alicyclic hydrocarbon skeleton having one reactive group are included. It has been found that an optical element comprising a curable composition and inorganic fine particles exhibits higher transparency and lower hygroscopicity in addition to excellent heat resistance.

(Polycyclic hydrocarbon compounds)
As the compound having an alicyclic hydrocarbon-based skeleton used in the present invention, those having an aliphatic polycyclic structure and including a three-dimensional cross-linked structure are preferable, and particularly preferable compounds include the following general formula ( 1), for example, tricyclodecane dimethanol dimethacrylate, tricyclodecane dimethanol diacrylate, compounds represented by the following general formula (2), for example, adamantyl methacrylate, adamantyl acrylate, etc. Examples of the compound represented by the general formula (3) include isobornyl methacrylate, isobornyl acrylate, and vinyl norbornene.

  In addition, an aliphatic polycyclic structure has ring-opening reactivity, and a denser cross-linked structure can be formed by adding a polyfunctional compound capable of reacting with this, but such a reaction is possible. Examples of the compound include compounds represented by the following general formulas (1) to (4). Specifically, acrylic acid (6-ethyltricyclo [2,2,1,02,6] -3-heptyl) ester And methacrylic acid (6-ethyltricyclo [2,2,1,02,6] -3-heptyl) ester. These can be produced by the method disclosed in JP-A-7-18897. As described in the above-mentioned publication, this compound has a tricyclo [2,2,1,02,6] -3-heptane ring so that an active hydrogen atom such as a hydroxyl group, a carboxyl group, or a mercapto group can be present. Since the ring-opening reaction occurs in the presence of the compound to be contained, the addition of this as a cross-linking agent improves the cross-linking density, and a cured product having high temperature durability can be obtained. In forming a crosslinked structure by this ring-opening reaction, the reaction can be accelerated by adding a ring-opening reaction catalyst to the polymerization curable composition. Examples of such a catalyst include aluminum acetylacetonate, palladium acetate. Dibutyltin laurate or the like can be used.

  These polycyclic hydrocarbon compounds may be used alone or in combination of two or more when the resin composition is formulated.

(In the general formula (1), X is a group represented by —CH ₂ —O—CO—CHR ₁ ═CH ₂ , and R ₁ represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. )

(In the general formula (2), Y is represented by —O—CO—CHR ₁ ═CH ₂ , or —CO—R ₂ —CHR ₁ ═CH ₂ , or —O—R ₂ —CHR ₁ ═CH _2. R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and R ₃ and R ₄ each independently A hydrogen atom and a C1-C10 hydrocarbon group are represented, and m represents an integer of 1-3.)

(In the general formula (3), Z is a group represented by _{-O-CO-CHR 1 = CH} 2 or -CHR ₁ = CH _2,, A is a single bond or a carbon - carbon double bonds R ₁ represents a hydrogen atom or a methyl group, and R _{5 to} R ₇ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.)

(In the general formula (4), W is a group represented by —O—CO—CHR ₁ ═CH ₂ , R ₁ represents a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, R ₈ and R ₉ represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms.)
In the resin composition of the present invention, in addition to the compound having the alicyclic hydrocarbon skeleton, it reacts with these compounds and inorganic fine particles having a reactive group to form a crosslinked structure in the resin. A suitable compound can be included. Moreover, a thermal polymerization initiator, a photopolymerization initiator, a stabilizer, a surfactant, and the like can be included as appropriate.

(Polyfunctional compound)
The polyfunctional compound used in the present invention is a compound having two or more reactive groups such as a vinyl group, a (meth) acryloyl group, an epoxy group, an oxetanyl group, a mercapto group, and the like. It reacts with inorganic fine particles having a reactive compound and a reactive compound to form a crosslinked structure in the resin.

  For example, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, tetraethylene glycol diacrylate, diethylene glycol diacrylate, trimethylolpropane triacrylate, trimethylolpropane triacrylate having two or more (meth) acryloyl groups as polyfunctional (meth) acrylate Methacrylate, pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate and the like are polyfunctional epoxy compounds, glycidyl ether type epoxy resins such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, resorcinol diglycidyl ether, diglycidyl phthalate, and Dimer acid diglycidyl ester, triglycidyl ether trif Nylmethane, tetraglycidyl ether tetraphenyl ethane, bisphenol S diglycidyl ether, cresol novolac glycidyl ether, triglycidyl isocyanurate, tetrabromobisphenol A diglycidyl ether, etc., as polyfunctional oxetane compounds, reaction of polyfunctional phenolic compounds with oxetane chloride Products, for example, bifunctional oxetane compounds such as bisphenol A type, bisphenol F type, bisphenol S type, biphenyl type and cardo type, trifunctional oxetane compounds such as trisphenol methane type and triskresol methane type, phenol novolac type, cresol Examples thereof include polyfunctional oxetane compounds such as novolak type and calixarene type.

  These polyfunctional compounds may be used not only in the resin composition but also in combination of two or more.

  The addition amount of the polyfunctional compound is preferably 1 to 80 parts by mass, and more preferably 5 to 60 parts by mass with respect to 100 parts by mass of the curable composition.

(Thermal polymerization initiator)
In the present invention, a thermal polymerization initiator such as a thermal radical generator can be added as necessary. Examples of the thermal polymerization initiator used here include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4- Azo compounds such as methoxy-2,4-dimethylvaleronitrile), organic peroxides such as benzoyl peroxide, lauroyl peroxide, t-butylperoxypivalate, 1,1′-bis (t-butylperoxy) cyclohexane, etc. It is done.

(Photopolymerization initiator)
In the present invention, a photopolymerization initiator can be added as necessary. Examples of the photopolymerization initiator used here include acetophenone, acetophenone benzyl ketal, 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, triphenylamine. , Carbazole, 3-methylacetophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoin propyl ether, benzoin ethyl ether, benzyldimethyl ketal, 1- (4-isopropylphenyl) ) Photoradical initiation of 2-hydroxy-2-methylpropan-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one, etc. Etc. The.

(Stabilizer)
In the optical element material of the present invention, one or more stabilizers selected from hindered amine stabilizers, phenol stabilizers, phosphorus stabilizers, and sulfur stabilizers may be additionally added. By appropriately selecting these stabilizers and adding them to the plastic optical element material, for example, the white turbidity when continuously irradiating light with a short wavelength such as 400 nm, and the optical characteristic fluctuations such as the refractive index fluctuations can be enhanced. Can be suppressed.

  As a preferable phenol-based stabilizer, conventionally known ones can be used, for example, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2 , 4-di-t-amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate and the like, and JP-A Nos. 63-179953 and 1-168643. Acrylate compounds described in Japanese Patent Publication No. 1; octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5 Di-t-butyl-4-hydroxybenzyl) benzene, tetrakis (methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenylpropionate) methane [ie pentaerythrmethyl-tetrakis] (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)), triethylene glycol bis (3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate), etc. Alkyl substituted phenol compounds; 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 4-bisoctylthio-1,3 Triazines such as 5-triazine, 2-octylthio-4,6-bis (3,5-di-t-butyl-4-oxyanilino) -1,3,5-triazine Jin group-containing phenolic compound; and the like.

  Preferred hindered amine stabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) succinate, bis ( 1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (N-octoxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-benzyloxy-2, 2,6,6-tetramethyl-4-piperidyl) sebacate, bis (N-cyclohexyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6) -Pentamethyl-4-piperidyl) 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1-acryloyl-2,2,6 6-tetramethyl-4-piperidyl) 2,2-bis (3,5-di-t-butyl-4-hydroxybenzyl) -2-butylmalonate, bis (1,2,2,6,6-pentamethyl) -4-piperidyldecanedioate, 2,2,6,6-tetramethyl-4-piperidyl methacrylate, 4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -1 -[2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl] -2,2,6,6-tetramethylpiperidine, 2-methyl-2- (2, 2,6,6-tetramethyl-4-piperidyl) amino-N- (2,2,6,6-tetramethyl-4-piperidyl) propionamide and the like.

  Further, the preferable phosphorus stabilizer is not particularly limited as long as it is usually used in the general resin industry. For example, triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonyl) Phenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9 Monophosphite compounds such as 1,4-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide; 4,4'-butylidenebis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite ), 4,4'-isopropylidenebis (phenyl-di-alkyl (C12-C15) phosphine) Ito) diphosphite compounds such as and the like. Among these, monophosphite compounds are preferable, and tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite and the like are particularly preferable.

  Further, preferable sulfur stabilizers include, for example, dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3- Thiodipropionate, pentaerythritol-tetrakis (β-laurylthio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane, etc. It is done.

  Although the compounding quantity of these stabilizers is suitably selected in the range which does not impair the objective of this invention, it is 0.01-2 mass parts normally with respect to 100 mass parts of resin compositions, Preferably it is 0.01-1 mass. Part.

(Surfactant)
A surfactant is a compound having a hydrophilic group and a hydrophobic group in the same molecule. The surfactant prevents white turbidity of the resin-based optical element material by adjusting the rate of moisture adhesion to the resin surface and the rate of moisture evaporation from the surface.

  Specific examples of the hydrophilic group of the surfactant include a hydroxy group, a hydroxyalkyl group having 1 or more carbon atoms, a hydroxyl group, a carbonyl group, an ester group, an amino group, an amide group, an ammonium salt, a thiol, a sulfonate, and phosphoric acid. Examples include salts and polyalkylene glycol groups. Here, the amino group may be primary, secondary, or tertiary. Specific examples of the hydrophobic group of the surfactant include an alkyl group having 6 or more carbon atoms, a silyl group having an alkyl group having 6 or more carbon atoms, and a fluoroalkyl group having 6 or more carbon atoms. Here, the alkyl group having 6 or more carbon atoms may have an aromatic ring as a substituent. Specific examples of the alkyl group include hexyl, heptyl, octyl, nonyl, decyl, undecenyl, dodecyl, tridecyl, tetradecyl, myristyl, stearyl, lauryl, palmityl, cyclohexyl and the like. Examples of the aromatic ring include a phenyl group. This surfactant only needs to have at least one hydrophilic group and one hydrophobic group as described above in the same molecule, and may have two or more groups.

  More specifically, examples of such surfactants include myristyl diethanolamine, 2-hydroxyethyl-2-hydroxydodecylamine, 2-hydroxyethyl-2-hydroxytridecylamine, 2-hydroxyethyl-2-hydroxy. Tetradecylamine, pentaerythritol monostearate, pentaerythritol distearate, pentaerythritol tristearate, di-2-hydroxyethyl-2-hydroxydodecylamine, alkyl (8 to 18 carbon atoms) benzyldimethylammonium chloride, ethylene bis Examples include alkyl (carbon number 8 to 18) amide, stearyl diethanolamide, lauryl diethanolamide, myristyl diethanolamide, palmityl diethanolamide, and the like. Among these, amine compounds or amide compounds having a hydroxyalkyl group are preferably used. In the present invention, two or more of these compounds may be used in combination.

  The surfactant is added in an amount of 0.01 to 10 parts by mass with respect to 100 parts by mass of the resin-based optical element material. When the addition amount of the surfactant is less than 0.01 parts by mass, it is not possible to effectively suppress white turbidity of the molded product due to fluctuations in temperature and humidity. On the other hand, when the addition amount exceeds 10 parts by mass, the light transmittance of the molded product becomes low, and application to the optical pickup device becomes difficult. The addition amount of the surfactant is preferably 0.01 to 5 parts by mass and more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the resin composition.

<The manufacturing method of the base material for optical elements>
The substrate made of a curable resin according to the present invention can be cured by either ultraviolet or electron beam irradiation or heat treatment, and the curable resin and inorganic fine particles are mixed in an uncured state, The base material of the present invention is obtained by curing.

  For mixing the curable resin and the inorganic fine particles, an appropriate method can be adopted. For example, after the curable resin and the core-shell particles are mixed in advance using a mortar, a rotation / revolution mixer, a dissolver mixer, or the like. It is preferable to disperse the core-shell particles uniformly using a variety of kneaders by supplying sufficient energy.

  Examples of the kneading apparatus include a closed kneading apparatus such as a lab plast mill, a Brabender, a Banbury mixer, a kneader, and a roll, or a batch kneading apparatus. Moreover, it is also possible to manufacture using a continuous melt-kneading apparatus such as a single-screw extruder or a twin-screw extruder.

  In the substrate manufacturing method according to the present invention, when the volume fraction of the inorganic fine particles in the substrate is defined as Φ, the volume fraction Φ is preferably 0.1 ≦ Φ ≦ 0.6. .

  When the content of the inorganic fine particles is small, the effect of reducing the linear expansion coefficient may be small. On the other hand, when the content of the inorganic fine particles is high, it is difficult to add the inorganic fine particles to the curable resin or the mixture. There is a risk that heat will be generated during kneading, making it difficult to uniformly disperse inorganic fine particles. From the above, the volume Φ is preferably 0.1 ≦ Φ ≦ 0.6, more preferably 0.2 ≦ Φ ≦ 0.5, and still more preferably 0.25 ≦ Φ ≦ 0.4.

  The volume fraction Φ of the core-shell particles occupying the base material is calculated by Φ = (total volume of the core-shell fine particles of the resin composition) / (volume of the resin composition).

An optical element composed of the resin composition used in the present invention can be produced by injecting the mixture obtained by the above method into a mold or the like and curing the mixture with heat or actinic rays such as ultraviolet rays or electron beams. it can. The molding method is not particularly limited, and when the curable resin is an ultraviolet ray and an electron beam curable resin, the resin composition is filled in a light-transmitting mold having a predetermined shape, or coated on the substrate, and then the ultraviolet ray and the electron beam curable resin are applied. What is necessary is just to cure by irradiating an electron beam. On the other hand, when the curable resin is a thermosetting resin, it can be cured by compression molding, transfer molding, injection molding or the like. The linear expansion coefficient of the molded substrate is adjusted by adjusting the volume fraction of the inorganic fine particles so that the difference from the material of the functional film is 45 [× 10 ⁻⁶ / ° C.] below.

<Functional film formation process>
The functional film in the functional film formation in this patent is an antireflection film, an enhanced reflection film, a half mirror film, a dichroic coat, a deflection film, an infrared cut film, a heat ray blocking film, a conductive film, a hard coat (surface protection) Film). Among these, an antireflection film is preferable.

The antireflection film can reduce reflection on the surface of the optical element due to light interference. The role of the antireflection film is listed below.
(I) Increase in transmitted light amount The reflectivity of the surface of the optical element depends on the refractive index, but it is 4% for a low refractive index glass material such as BK-7 and 8% for a high refractive index glass material. Depending on the type of film, the coated optical surface has a reflectivity of about 0.1 to 1%. Like a zoom lens, when the number of lenses is large, the transmittance of the lens varies greatly depending on the presence or absence of a film. If the antireflection film is formed on the optical element, the reflectance decreases, so that the amount of light transmitted through the optical element increases.
(Ii) Reduction of flare and ghost “Flare and ghost” refers to light that reaches the imaging plane other than the imaging light that passes through the optical system (light that forms the image of the subject), and is blurred other than the subject. May form a sharp image or reduce the contrast of the subject image. If an antireflection film is formed on the optical element, flare and ghost can be reduced.
(Iii) Adjustment of color balance In color photographs, color reproducibility (color balance) is an important evaluation factor. In particular, in a photograph using a color film, the spectral transmittance of the optical element greatly affects the color reproduction of the photograph. The spectral transmittance of the optical element can be changed somewhat depending on how the coating to be used is selected, and the color balance can be adjusted by forming an antireflection film on the optical element.
(Iv) Lens surface protection (especially in the case of glass lenses) If a lens that has been polished is left in a humid place for a long time, a whitish cloudiness is produced on the surface of the lens. This is called “discoloration” and causes a reduction in the light amount of the lens. The antireflection film is an effective means for preventing this burn. After polishing, if the lens is cleaned, it will not be burned. Since the hardness of the coating film is much higher than that of glass, it is effective in protecting the optical element from scratches. In addition, the antireflection film enhances the mechanical, physical, and chemical stability of the optical element, such as reducing the charging property and reducing the influence of the external environment change on the element.

  In order to form the antireflection film, a low refractive index material, a medium refractive index material and a high refractive index material can be appropriately selected and used. About the physical property of a film | membrane, it is published in data collections, such as an ULVAC vacuum handbook, and can utilize preferably. The linear expansion coefficient is indicated in parentheses below.

Examples of the low refractive index material include silicon oxide (5.5 × 10 ⁻⁷ / ° C.), magnesium fluoride (9.4 × 10 ⁻⁶ / ° C.), aluminum fluoride, a mixture of silicon oxide and aluminum oxide, or these Mixtures are preferably used.

As the medium refractive index material, lanthanum fluoride, neodymium fluoride, cerium fluoride, aluminum fluoride, lanthanum aluminate, lead fluoride, aluminum oxide (6.65 × 10 ₋₆ / ° C.) or a mixture thereof is used. Among these, it is preferable to use aluminum oxide, lanthanum aluminate, or a mixture thereof.

Examples of the high refractive index material include scandium oxide, lanthanum oxide, praseodymium titanate, lanthanum titanate, titanium oxide (6.86 × 10 ⁻⁶ / ° C.), lanthanum aluminate, yttrium oxide (6.56 × 10 ⁻⁶ / ° C), hafnium oxide, zirconium oxide (10.2 × 10 ⁻⁶ / ° C.) or a mixture thereof. Among these, scandium oxide, lanthanum oxide, lanthanum aluminate, yttrium oxide, hafnium oxide, zirconium oxide or It is preferable to use a mixture thereof. In particular, the high refractive index material preferably does not contain a titanium metal element.

  Examples of preferable configurations of the antireflection layer will be listed. In the following, “n1, n2,...” Represents the refractive indices of the first layer (layer directly in contact with the surface of the molded product), the second layer,. "..." represents the film thicknesses of the first layer, the second layer, ..., respectively.

<Single layer configuration: Molded product / Low refractive index material>
First layer: 1.2 ≦ n1 ≦ 1.55, 60 nm ≦ d1 ≦ 80 nm
<Two-layer configuration: molded product / medium or high refractive index material / low refractive index material>
First layer: 1.55 ≦ n1, 15 nm ≦ d1 ≦ 91 nm
Second layer: 1.2 ≦ n2 <1.55, 30 nm ≦ n2 ≦ 118
<Three-layer structure: molded product / low refractive index material / high refractive index material / low refractive index material>
First layer: 1.2 ≦ n1 <1.55, 10 nm ≦ d1 ≦ 15000 nm
Second layer: 1.7 ≦ n2, 20 nm ≦ d2 ≦ 110 nm
3rd layer: 1.2 ≦ n3 <1.55, 35 nm ≦ d3 ≦ 90 nm
<Three-layer structure: molded product / medium refractive index material / high refractive index material / low refractive index material>
First layer: 1.55 ≦ n1 <1.7, 40 nm ≦ d1 ≦ 15000 nm
Second layer: 1.7 ≦ n2, 35 nm ≦ d2 ≦ 90 nm
Third layer: 1.2 ≦ n3 <1.55, 45 nm ≦ d3 ≦ 85 nm
<5 layer configuration: low or medium refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material>
First layer: 1.2 ≦ n1 <1.7, 5 nm ≦ d1 ≦ 15000 nm
Second layer: 1.7 ≦ n2, 15 nm ≦ d2 ≦ 35 nm
Third layer: 1.2 ≦ n3 <1.55, 25 nm ≦ d3 ≦ 45 nm
4th layer: 1.7 ≦ n4, 50 nm ≦ d4 ≦ 130 nm
5th layer: 1.2 ≦ n5 <1.55, 80 nm ≦ d5 ≦ 110
<7-layer structure: molded product / low or medium refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material / high refractive index material / low refractive index material>
First layer: 1.2 ≦ n1 <1.7, 80 nm ≦ d1 ≦ 15000 nm
Second layer: 1.7 ≦ n2, 10 nm ≦ d2 ≦ 25 nm
3rd layer: 1.2 ≦ n3 <1.55, 30 nm ≦ d3 ≦ 45 nm
Fourth layer: 1.7 ≦ n4, 40 nm ≦ d4 ≦ 60 nm
5th layer: 1.2 ≦ n5 <1.55, 10 nm ≦ d5 ≦ 20 nm
6th layer: 1.7 ≦ n6, 6 nm ≦ d6 ≦ 70 nm
Seventh layer: 1.2 ≦ n7 <1.55, 60 nm ≦ d7 ≦ 100
The antireflection film is not limited to the above-described layer configuration, and may have a four-layer configuration, a six-layer configuration, an eight-layer configuration, or a layer configuration with more layers.

In this patent, the first layer in contact with the substrate is defined as the closest surface, and the difference between the layer of the closest surface and the linear expansion coefficient of the substrate is 45 [× 10 ⁻⁶ / ° C.] or less. The feature is to select and use.

(Measurement of linear expansion coefficient)
The linear expansion coefficient can be measured using a TMA measuring apparatus (for example, TMA / SS6100 manufactured by Seiko Instruments Inc.) after determining the measurement temperature range. The following measurement method is described as an example, but is not limited thereto.

Samples at 200 ° C and 240 ° C when the linear expansion coefficient was raised from room temperature to 250 ° C or higher at a load of 50mN and a heating rate of 5 ° C / min in a compression mode for a sample of about 3mm thickness and 10mmφ It is obtained from the difference in height and is defined as α _200-240 by the following formula. In the following formula, L ₂₄₀ , L ₂₀₀ , and L ₃₀ mean sample heights at 240 ° C., 200 ° C., and 30 ° C., respectively.

_{α 200-240 = (L 240 -L 200} ) / (L 30 · (240-200))
In addition, for samples in which the softening point was not observed at a temperature of 240 ° C. or lower, separate samples prepared in the same manner were prepared, and from a room temperature to 250 ° C. or higher at a load of 50 mN and a heating rate of 5 ° C./min. It can obtain | require from the difference in the sample height in 200 degreeC and 240 degreeC when it heats up to this temperature.

  As a method for forming various films including the antireflection film, a known method such as a vacuum deposition method, a sputtering method, a CVD method, a sol-gel method, an atmospheric pressure plasma method, a coating method, or a mist method can be used. For example, when an antireflection film is formed by vacuum evaporation, oxygen gas is introduced into the chamber so that the chamber is in an oxygen atmosphere or the chamber is evacuated, and the molded article has a high refractive index. A material, a medium refractive index material, and a low refractive index material are heated and vapor-deposited to form (laminate) a film on the molded product. This technique can also be used in a normal sputtering method.

  As described above, when a film is formed on the surface of the molded product of the organic-inorganic composite material, the molded product with the film is heated to strengthen the film. The heating conditions can be appropriately changed depending on the type of molded product (type of thermosetting resin, inorganic particles, etc.), the size of the molded product, application, film type, film thickness, and the like. If the heating time is about 12 to 50 hours at 150 ° C., the intended purpose can be achieved.

<Production of electronic equipment>
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the imaging apparatus 100 according to the present embodiment includes a circuit board 1 on which electronic components constituting an electronic circuit of a mobile information terminal device such as a mobile phone are mounted. A camera module 2 is mounted. The camera module 2 is a small board mounting camera in which a CCD image sensor and a lens are combined. In a completed state in which the circuit board 1 on which electronic components are mounted is incorporated in the cover case 3, the imaging provided in the cover case 3 is performed. The image to be imaged can be captured through the opening 4 for use. In FIG. 1, illustration of electronic components other than the camera module 2 is omitted.

  As shown in FIG. 2, the camera module 2 is composed of a board module 5 (see FIG. 3A) and a lens module 6 (see FIG. 3C). By mounting the board module 5 on the circuit board 1, The entire camera module 2 is mounted on the circuit board 1. The substrate module 5 is a light receiving module in which a CCD image sensor 11, which is a light receiving element for imaging, is mounted on a sub-substrate 10. The upper surface of the CCD image sensor 11 is sealed with a sealing resin 12.

  On the upper surface of the CCD image sensor 11, a light receiving portion (not shown) in which a large number of pixels that perform photoelectric conversion are arranged in a grid pattern is formed, and an optical image is formed on the light receiving portion to store each pixel. The charged charges are output as an image signal. The sub board 10 is mounted on the circuit board 1 by lead-free solder 18, whereby the sub board 10 is fixed to the circuit board 1, and connection electrodes (not shown) of the sub board 10 and circuits on the upper surface of the circuit board 1 are provided. An electrode (not shown) is electrically connected.

  The lens module 6 includes a lens case 15 that supports the imaging lens 16.

  An imaging lens 16 is held on the upper part of the lens case 15, and the upper part of the lens case 15 is a holder portion 15 a that holds the imaging lens 16. As shown in FIG. 4, an aperture stop S may be provided on the object side of the imaging lens 16, and an infrared cut filter IRCF may be provided on the image side.

  The lower portion of the lens case 15 is a mounting portion 15 b that is inserted into a mounting hole 10 a provided in the sub-board 10 and fixes the lens module 6 to the sub-board 10. For this fixing, a method of pressing and fixing the mounting portion 15b into the mounting hole 10a, a method of bonding with an adhesive, or the like is used.

  The imaging lens 16 is for imaging the reflected light from the subject on the light receiving portion of the CCD image sensor 11. The imaging lens 16 has a functional film formed on the substrate surface.

  Next, an outline of a method for manufacturing the imaging device 100 according to the present embodiment will be described with reference to FIG.

  First, the imaging resin 16 is manufactured by molding the above resin composition with a molding die (molding process), and the lens module 6 is assembled using the imaging lens 16. Here, in this molding step, the imaging lens 16 is removed from the mold before the resin composition is completely cured.

  Next, as shown in FIG. 3A, the lower end portion of the collar member 17 mounted in the lens case 15 of the lens module 6 is brought into contact with the upper surface of the sub-board 10 in the board module 5, so that the lens case 15 The mounting portion 15 b is inserted and fixed in the mounting hole 10 a of the sub-board 10 to form the camera module 2.

  Thereafter, as shown in FIG. 3B, the camera module 2 and other electronic components are placed at a predetermined mounting position of the circuit board 1 on which the solder 18 has been applied (potted) in advance (placement step).

  And as shown in FIG.3 (c), the circuit board 1 which mounted the camera module 2 and other electronic components is transferred to a reflow furnace (not shown) with a belt conveyor etc., and the said circuit board 1 is used for a reflow process. And heat at a temperature of about 260 ° C. As a result, the solder 18 is melted and the camera module 2 is mounted on the circuit board 1 together with other electronic components (mounting process). The optical element in this patent can be mounted without any problem without damage or deformation of the functional film when heated at about 260 ° C.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated concretely, this invention is not limited to these.

<Preparation of oxide fine particles>
First, 500 g of pure water and 4.8 g of ammonia water (28% Kanto Kagaku) are added to 23 g of TM-300 (Daimei Chemicals γ-alumina, primary particle diameter 7 nm) and stirred. This solution is dispersed for 4 hours at a peripheral speed of 6.8 m / sec using an Ultra Apex mill (manufactured by Kotobuki Industries Co., Ltd.). At this time, 11.5 g of tetraethoxysilane (LS-2430, manufactured by Shin-Etsu Chemical Co., Ltd.) is dropped into the solution over 2 hours.

  Dilution is performed by adding 2280 g of ethanol, 1050 g of pure water, and 20 g of ammonia water (28% Kanto Chemical) to 327 g of the fine particle dispersion. To this dispersion, 38 g of tetraethoxysilane (LS-2430, manufactured by Shin-Etsu Chemical Co., Ltd.) is dropped over 8 hours.

  Using an ultrafilter (Vivaflow Co., Ltd.), this dispersion was concentrated once for 5 minutes, added with pure water, and returned to the original liquid volume four times. Concentration to tenths yielded 400 ml of dispersion. 1200 ml of t-butanol was added to this dispersion, and freeze-dried using a freeze dryer FDU-2200 (Tokyo Rika Kikai Co., Ltd.) to obtain 25 g of white particles.

  To 25 g of the particles, 500 ml of pyridine was added, and 100 g of trimethylsilyl chloride (Shin-Etsu Chemical LS-260) was added and stirred for 1 hour. The particles were centrifuged, 100 ml of ethanol was added, and stirring and centrifugation were repeated 4 times for washing. The obtained particles were dried at 150 ° C. for 2 hours to obtain inorganic fine particles.

<Preparation of base material>
Add 15 g of isobornyl methacrylate to 15 g of tricyclodecane dimethanol dimethanol dimethacrylate, 0.3 g of Parroyl L (Nippon Yushi Co., Ltd.), stabilizer (tetrakis (1,2,2,6,6-pentamethylpiperidyl) Butanetetracarboxylate) 0.3 g, stabilizer (2,2′-methylenebis (4,6-di-t-butylphenyl) -2-ethylhexyl phosphite) 0.6 g, surfactant (pentaerythritol distearate) ) Add 0.6 g and stir to make this a curable resin. Using a lab plast mill (labor plast mill KF-6V, manufactured by Toyo Seiki Seisakusho Co., Ltd.) as a kneading device, the curable resin and the inorganic fine particles are kneaded at 10 rpm for 10 minutes to obtain a uniform resin composition. Obtained. Substrate samples 1 to 6 could be obtained by adjusting the amount of inorganic fine particles to 5 vol%, 10 vol%, 15 vol%, 20 vol%, 25 vol%, and 30 vol% in the resin.

<Production of sample piece>
The base material obtained by the above means was pressed at 160 ° C. under a reduced pressure of 13.3 Pa to obtain a molded body having an F11 mm thickness of 3 mm, and then the surface was polished to prepare a plurality of test pieces.

<Functional film formation>
The functional films 1 and 2 were formed on the substrate samples 1 to 6 by vapor deposition, respectively. The sample in which the functional film 1 (the following film forming condition 1) was formed was No. 1-No. No. 6, the sample on which the functional film 2 (the following film forming condition 2) was formed was 7-No. It was set to 12. The “film thickness” of the antireflection film was measured by observing a cross section of the film formation surface with an electron microscope.

<Evaluation>
(Reflow test)
The sample on which the functional film was formed was subjected to a reflow process at 260 ° C. for 10 minutes × 2. The conditions were determined from the module production conditions.

(Measurement of linear expansion coefficient)
Using samples TMA / SS6100 manufactured by Seiko Instruments Inc., the softening point at which the sample height is reduced by increasing the temperature from room temperature to 260 ° C. at a load of 50 mN and a temperature increase rate of 5 ° C./min. Was observed at a temperature of 240 ° C. or lower.

For samples in which the softening point was not observed at a temperature of 240 ° C. or lower, separate samples prepared in the same manner were prepared, and the temperature was from room temperature to 250 ° C. or higher at a load of 50 mN and a heating rate of 5 ° C./min. From the difference in sample height at 200 ° C. and 240 ° C. when the temperature was raised to 200 ° C., the linear expansion coefficient α _200-240 at 200 ° C. to 240 ° C. was determined according to the following formula. Table 2 shows the presence or absence of the softening point and the calculated value of α _200-240 .

_{α 200-240 = (L 240 -L 200} ) / (L 30 · (240-200))
(In the formula, L ₂₄₀ , L ₂₀₀ , and L ₃₀ mean the sample height at 240 ° C., 200 ° C., and 30 ° C., respectively.)
<Measurement of light transmittance of sample>
About the samples 1-12 of thickness 3mm, the transmittance | permeability of the thickness direction in the light of wavelength 588nm was measured with the spectrophotometer (Shimadzu Corporation UV-3150). The measurement results are shown in Table 2. The light transmittance is preferably 70% or more.

<Functional film evaluation>
(Evaluation of wiping resistance)
The surface on which the antireflection film of each sample was formed was wiped with a cotton swab soaked with isopropyl alcohol many times with a load of 5 to 10 g. Each time the sample was wiped 10 times, the film-forming surface of the antireflection film of each sample was observed with a microscope, and the presence or absence of peeling of the antireflection film was observed. And the wiping resistance of each sample was evaluated by the total number of times of wiping when the antireflection film was peeled off. The criteria for ○, △, × were as follows.

○: No peeling is observed even after wiping 100 times. Δ: No peeling is observed at the time of wiping 30 times, but peeling is observed at the time of wiping 100 times. The evaluation results are summarized in Table 2.

  From the above table, Samples 5, 6, and 10 to 12 of the present invention have excellent light transmittance and excellent wiping resistance of the functional film, and the functional film on the surface is damaged or deformed even after the reflow process. It turns out that it is an optical element which does not do.

It is a schematic perspective view of the imaging device used by preferable embodiment of this invention. 1 is an enlarged schematic cross-sectional view of a part of an imaging apparatus used in a preferred embodiment of the present invention. It is drawing for demonstrating schematically the manufacturing method of the imaging device in preferable embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Imaging device 1 Circuit board 2 Camera module 3 Cover case 4 Imaging opening 5 Board | substrate module 6 Lens module 10 Sub board | substrate 10a Mounting hole 11 CCD image sensor 12 Sealing resin 15 Lens case 15a Holder part 15b Mounting part 16 Lens 17 Color member 18 Solder

Claims (5)

An optical element having a functional layer on the surface of a substrate containing a curable resin, wherein a difference in linear expansion coefficient between the closest surface layer of the substrate and the functional layer is 45 [× 10 ⁻⁶ / ° C.] or less. There is an optical element. The optical element according to claim 1, wherein the base material contains inorganic fine particles. The optical element according to claim 1, wherein the functional layer is an antireflection film. The optical element according to claim 1, wherein the optical element is used in an imaging device mounted on a substrate together with an electronic component by reflow processing. A step of placing the imaging device having the optical element according to any one of claims 1 to 4 on a substrate together with an electronic component, and subjecting the imaging device, the electronic component, and the substrate to a reflow process, A method for manufacturing an electronic device, comprising: mounting the imaging device and the electronic component on the substrate.

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