JP2008260908A - Adhesive composition for optical waveguide, and adhesive film for optical waveguides using the same, and optical device using these - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive composition for optical waveguides and an adhesive film for optical waveguides having both transparency and heat resistance, and to provide an optical device made of these. <P>SOLUTION: The adhesive composition for optical waveguides comprises (a) an epoxy resin, (b) a curing agent, and (c) a polymer compound, wherein the total light transmittance of the cured material and light transmittance at wavelength of 700-1,600 nm are ≥80%. The adhesive composition is formed into a film to provide an adhesive film for optical waveguides. The adhesive composition or the adhesive film is used to adhere optical waveguides of an optical device. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an adhesive resin composition for an optical waveguide, an adhesive film for an optical waveguide, and an optical device using the same.

  In high-speed and high-density signal transmission between electronic devices and between wiring boards, signal transmission interference and attenuation become barriers in conventional transmission using electric wiring, and the limits of high-speed and high-density are beginning to appear. In order to overcome this problem, a technique for optically connecting electronic elements and wiring boards, so-called optical interconnection, has been studied.

  Regarding the adhesive for optical waveguides used for these optical interconnections, in addition to transparency, high heat resistance and high reliability, film thickness control of the adhesive layer, handleability, flexibility, and the like have been problems. For example, a fluorine-containing epoxy resin has been proposed (see, for example, Patent Document 1). However, it is inferior in soldering heat resistance, and since the material is liquid, it is difficult to control film thickness and handling, and since it has a high elastic modulus after curing and poor flexibility, it is satisfactory as an adhesive for optical waveguides. It is not a thing.

Japanese Patent No. 2618682

  The present invention provides an optical waveguide adhesive composition having both transparency and heat resistance, an optical waveguide adhesive film, and an optical device manufactured using the same, in view of the above-described problems of the prior art. Objective.

As a result of intensive studies, the present inventors have found that the above-described problem can be solved by the following method.
That is, the present invention
(1) An adhesive composition comprising (a) an epoxy resin, (b) a curing agent, and (c) a polymer compound, wherein the cured product has a total light transmittance and light rays at a wavelength of 700 to 1600 nm. An adhesive composition for optical waveguides having a transmittance of 80% or more,
(2) The optical waveguide according to (1), wherein the cured product has a total light transmittance of 80% or more at a wavelength of 700 to 1600 nm after three reflow tests at a maximum temperature of 265 ° C. Adhesive composition,
(3) The optical waveguide adhesive according to the above (1) or (2), wherein the reflow test at the maximum temperature of 265 ° C. is carried out three times, and the refractive index change of the cured product before and after that is within ± 0.005. Composition,
(4) After implementing the reflow test of the maximum temperature of 265 degreeC 3 times, the evaluation score of the adhesiveness by the cross cut tape method of the said hardened | cured material is 8 or more points, In any one of said (1)-(3) Adhesive composition for optical waveguide,
(5) In the repeated bending test of the optical waveguide with an adhesive using the adhesive composition, after the bending test is performed 100,000 times with a radius of curvature of 5 mm, the optical waveguide does not break mechanically. (4) Adhesive composition for optical waveguides in any one of
(6) When the total mass of (a) epoxy resin and (b) curing agent is A, and (c) the mass of the polymer compound is B, the ratio A / B is 0.24 to 1.0. The adhesive composition for optical waveguides according to any one of the above (1) to (5),
(7) The adhesive composition for an optical waveguide according to any one of the above (1) to (6), wherein the (a) epoxy resin is a solid epoxy resin having a softening point measured by ring and ball type of 50 ° C. or higher,
(8) (a) The adhesive composition for optical waveguides according to any one of the above (1) to (7), wherein the epoxy resin has no mutagenicity,
(9) (b) The adhesive composition for an optical waveguide according to any one of (1) to (8), wherein the curing agent is a phenol resin having a hydroxyl group equivalent of 150 g / eq or more,
(10) (b) The curing agent is represented by the following general formula (I):

(In the formula, each R ¹ may be the same or different and is a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, an aryl group, or a halogen atom. Represents an atom, n represents an integer of 1 to 3, and m represents an integer of 0 to 50)
The adhesive composition for optical waveguides according to the above (9), which is a phenol resin represented by
(11) The adhesive composition for an optical waveguide according to the above (10), wherein the water absorption of the phenol resin represented by the general formula (I) is 2% by mass or less,
(12) (c) The adhesive composition for an optical waveguide according to any one of the above (1) to (11), wherein the polymer compound is a functional group-containing acrylic copolymer,
(13) The adhesive composition for an optical waveguide according to (12), wherein the functional group-containing acrylic copolymer is an epoxy group-containing acrylic copolymer,
(14) The adhesive composition for an optical waveguide according to the above (13), wherein the epoxy group-containing acrylic copolymer contains 0.5 to 6% by mass of glycidyl acrylate or glycidyl methacrylate as a raw material,
(15) The adhesive composition for an optical waveguide according to any one of the above (12) to (14), wherein the weight average molecular weight of the functional group-containing acrylic copolymer is 100,000 or more,
(16) The adhesive composition for an optical waveguide according to any one of (12) to (15), wherein the glass transition temperature of the functional group-containing acrylic copolymer is −50 ° C. to 30 ° C.
(17) The adhesive composition for optical waveguides according to any one of (1) to (16), further comprising (d) a filler,
(18) (c) The polymer compound is an epoxy group-containing acrylic copolymer having a weight average molecular weight of 100,000 or more and containing 1.5 to 2.5% by mass of glycidyl acrylate or glycidyl methacrylate, and (a) an epoxy resin And (b) 1 to 50 parts by mass of (d) filler with respect to a total of 100 parts by mass of the curing agent, and (d) an inorganic filler having an average particle size of 0.01 to 0.1 μm ( 17) The adhesive composition for optical waveguides according to 17,
(19) The adhesive composition for optical waveguides according to any one of (1) to (18), further comprising (e) a curing accelerator,
(20) (e) The adhesive composition for optical waveguides according to (19), wherein the curing accelerator is an imidazole compound,
(21) An adhesive film for an optical waveguide formed by forming the adhesive composition according to any one of (1) to (20) into a film, and (22) any one of (1) to (20) Or an optical device formed by bonding an optical waveguide using the adhesive film for an optical waveguide described in (21).

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive composition for optical waveguides excellent in transparency and heat resistance, the adhesive film for optical waveguides using the same, and an optical apparatus using these can be provided.

  The optical waveguide adhesive composition of the present invention (hereinafter simply referred to as “adhesive composition”) contains (a) an epoxy resin, (b) a curing agent, and (c) a polymer compound, and a cured product thereof. The total light transmittance and light transmittance at a wavelength of 700 to 1600 nm are 80% or more. The adhesive film for optical waveguides of the present invention (hereinafter simply referred to as “adhesive film”) is characterized in that the adhesive composition is formed into a film.

In the following, the present invention will be described in more detail.
The cured product of the adhesive composition of the present invention has a total light transmittance and a light transmittance at a wavelength of 700 to 1600 nm of 80% or more, and further the light transmission after three reflow tests at a maximum temperature of 265 ° C. The rate is preferably 80% or more. When these light transmittances are 80% or more, sufficient transparency can be maintained, so that a lead-free reflow process can be applied and the application range of the adhesive composition can be expanded. From the above viewpoint, the light transmittance is more preferably 81% or more, further preferably 83% or more, and particularly preferably 85% or more. The light transmittance is the total light transmittance and the light transmittance at a wavelength of 700 to 1600 nm, and can be measured by the method described in Examples. In optical interconnection, lasers having a wavelength of 850 nm to 1300 nm are widely studied as light sources, and light transmittance in the near infrared region including this wavelength is particularly important. Note that the reflow test at the maximum temperature of 265 ° C. means a lead-free solder reflow test performed under conditions in accordance with IPC / JEDEC J-STD-020B.

  The cured product of the adhesive composition of the present invention is preferably subjected to a reflow test at a maximum temperature of 265 ° C. three times, and the refractive index change before and after that is within ± 0.005. If the change in refractive index is within this range, optical stability can be ensured, so that a lead-free reflow process can be applied, and the application range of the adhesive composition can be expanded. From the above viewpoint, the refractive index change is more preferably within ± 0.003, and further preferably within ± 0.001. The refractive index can be measured by the method described in the examples.

  The cured product of the adhesive composition of the present invention preferably has an evaluation score of 8 or more by the cross-cut tape method after performing the reflow test at the maximum temperature of 265 ° C. three times. If the adhesive evaluation score is 8 or more, sufficient adhesiveness can be maintained, so that a lead-free reflow process can be applied and the application range of the adhesive composition can be expanded. In this respect, the adhesive evaluation score is more preferably 10 points. The cross-cut tape method means an adhesion test method performed according to JIS-K5400.

In the adhesive composition of the present invention, in a repeated bending test of an optical waveguide with an adhesive using the adhesive composition, a mechanical fracture occurred in the optical waveguide after a bending test was performed 100,000 times with a radius of curvature of 5 mm. Preferably not. If mechanical breakage does not occur in the optical waveguide, stable optical transmission can be performed for a long period of time. For example, the optical waveguide can be applied to a part that is always movable, such as a hinge part of a mobile phone. In order to reduce the size of the device, it is required that the optical waveguide does not break even at a smaller radius of curvature. From this viewpoint, it is more preferable that the radius of curvature is 3 mm and no mechanical breakage occurs. More preferably it is. Mechanical breakage can be confirmed by magnifying glass, under a microscope, or by visual observation.
Here, the optical waveguide is not particularly limited as long as it can control the propagation, branching, reflection, refraction, amplification, attenuation, etc. of light, but in general, the core having a high refractive index and the refraction covering it. Consists of low rate cladding. In the present invention, a polymer optical waveguide having flexibility is preferably used from the viewpoint that a flexible optical waveguide having flexibility can be manufactured.

Hereinafter, each component will be described more specifically.
The (a) epoxy resin used in the present invention is not particularly limited as long as it is cured and exhibits an adhesive action. Epoxy resins having at least two functional groups and preferably having a molecular weight of less than 5000, more preferably less than 3000 can be used. For example, a bifunctional epoxy resin such as a bisphenol A type epoxy resin or a bisphenol F type epoxy resin, a novolak type epoxy resin such as a phenol novolac type epoxy resin or a cresol novolac type epoxy resin, or the like can be used. Moreover, what is generally known, such as a polyfunctional epoxy resin and a heterocyclic ring-containing epoxy resin, can also be applied.

  As such an epoxy resin, commercially available products include, for example, Epicoat 807, Epicoat 815), Epicoat 825, Epicoat 827, Epicoat 828, Epicoat 834, Epicoat 1001, Epicoat 1002, Epicoat 1003, Epicoat 1055, Epicoat 1004, Epicoat. 1004AF, Epicoat 1007, Epicoat 1009, Epicoat 1003F, Epicoat 1004F (above, trade name, manufactured by Japan Epoxy Resin Co., Ltd.), DER-330, DER-301, DER-361, DER-661, DER-662, DER-663U , DER-664, DER-664U, DER-667, DER-642U, DER-672U, DER-673MF, DER-668, DER-669 (above, Bichemical phenol type epoxy resin such as YDF-2004 (manufactured by Toto Kasei Co., Ltd., trade name), etc. Resin, Epicoat 152, Epicoat 154 (above, Japan Epoxy Resin Co., Ltd., trade name), EPPN-201 (Nippon Kayaku Co., Ltd., trade name), DEN-438 (Dow Chemical Co., trade name), etc. Phenol novolac type epoxy resin, Epicoat 180S65 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.), Araldite ECN1273, Araldite ECN1280, Araldite ECN1299 (above, manufactured by Ciba Specialty Chemicals, Inc.), YDCN-701, YDCN-702 DCN-703, YDCN-704 (trade name, manufactured by Toto Kasei Co., Ltd.), EOCN-102S, EOCN-103S, EOCN-104S, EOCN-1012, EOCN-1020, EOCN-1025, EOCN-1027 (above, Nippon Kayaku Co., Ltd., trade name), ESCN-195X, ESCN-200L, ESCN-220 (above, Sumitomo Chemical Co., Ltd., trade name) and other cresol novolac epoxy resins, Epon 1031S, Epicoat 1032H60, Epicoat 157S70 (above, Japan Epoxy Resin Co., Ltd., trade name), Araldite 0163 (Ciba Specialty Chemicals, trade name), Denacol EX-611, Denacol EX-614, Denacol EX-614B, Denacol EX-622 Denacol EX-512, Denacol EX-521, Denacol EX-421, Denacol EX-411, Denacol EX-321 (above, manufactured by Nagase Chemical Co., Ltd., trade name), EPPN501H, EPPN502H (above, manufactured by Nippon Kayaku Co., Ltd., Multifunctional epoxy resin such as (trade name), Epicoat 604 (trade name, manufactured by Japan Epoxy Resin Co., Ltd.), YH-434 (trade name, manufactured by Toto Kasei Co., Ltd.), TETRAD-X, TETRAD-C (above, Mitsubishi Gas) Chemical-made, trade name), amine-type epoxy resins such as ELM-120 (Sumitomo Chemical Co., trade name), and hetero ring-containing epoxy resins such as Araldite PT810 (trade name, manufactured by Ciba Specialty Chemicals), ERL4234, ERL4299, ERL4221, ERL4206 It can be used UCC Co., and alicyclic epoxy resin trade name) or the like. These epoxy resins can be used alone or in combination of two or more.

  In the present invention, from the viewpoint of heat resistance, it is preferable to use an epoxy resin that is solid at room temperature (25 ° C.) and has a softening point of 50 ° C. or higher measured by a ring and ball method of 20% by mass or more of the entire epoxy resin. , 40% by mass or more is more preferable, and 60% by mass or more is more preferable. Examples of such epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, alicyclic epoxy resins, aliphatic chain epoxy resins, phenol novolac type epoxy resins, and cresol novolac types. Epoxy resin, bisphenol A novolak type epoxy resin, diglycidyl etherified product of biphenol, diglycidyl etherified product of naphthalenediol, diglycidyl etherified product of phenol, diglycidyl etherified product of alcohol, and alkyl substitution products thereof , Halides, hydrogenated substances and the like. These may be used alone or in combination of two or more, and components other than the epoxy resin may be contained as impurities. It is preferable to use an epoxy resin having a large molecular weight and a softening point of 50 ° C. or higher, or a combination of epoxy resin and rubber having a large difference in polarity, which is not compatible with each other.

  As described later, the epoxy resin is preferably incompatible with the polymer compound. When two or more epoxy resins are used in combination as the epoxy resin, the mixture and the polymer compound are incompatible. The mixture is preferably soluble, and the mixture may contain a compatible epoxy resin. For example, in the case where a single incompatible epoxy resin YDCN703 having a softening point of 50 ° C. or higher and a single compatible epoxy resin Epicoat 828 having a softening point of less than 50 ° C. are combined, they are combined at 1: 0 to 1: An epoxy resin mixture mixed at a mass ratio of 10 becomes incompatible.

  The (b) curing agent used in the present invention is not particularly limited as long as it can cure the epoxy resin. Examples of such curing agents include polyfunctional phenols, amines, imidazole compounds, acid anhydrides, organic phosphorus compounds and their halides, polyamides, polysulfides, boron trifluoride, and the like.

  Examples of polyfunctional phenols include hydroquinone, resorcinol, catechol, monocyclic bifunctional phenols, bisphenol A, bisphenol F, bisphenol S, naphthalenediols, biphenols, and halides thereof. And alkyl group-substituted products. Moreover, phenol resins such as phenol novolac resins, resol resins, bisphenol A novolac resins and cresol novolac resins, which are polycondensates of these phenols and aldehydes. Preferable phenol resin curing agents on the market include, for example, Phenolite LF2882, Phenolite LF2822, Phenolite TD-2090, Phenolite TD-2149, Phenolite VH4150, Phenolite VH4170 (above, Dainippon Ink & Chemicals, Inc.) Company name, product name).

(B) As the curing agent, a phenol resin having a hydroxyl group equivalent of 150 g / eq or more is preferably used. Such a phenolic resin is not particularly limited as long as it has the above-mentioned value, but it is preferable to use a novolak-type or resol-type resin because it is excellent in moisture resistance reliability.
Specific examples of the phenol resin described above include, for example, the following general formula (I):

(In the formula, each R ¹ may be the same or different and is a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, an aryl group, or a halogen atom. Represents an atom, n represents an integer of 1 to 3, and m represents an integer of 0 to 50)
The phenol resin shown by these is mentioned. Such a phenolic resin is not particularly limited as long as it conforms to the general formula (I). However, from the viewpoint of moisture resistance, the water absorption rate after introduction into a constant temperature and humidity chamber of 85 ° C. and 85% RH is 48 hours. It is preferable that it is 2 mass% or less.
Further, it is preferable to use a material having a heating weight reduction rate (heating rate: 5 ° C./min, atmosphere: nitrogen) at 350 ° C. of less than 5% measured by a thermogravimetric analyzer (TGA). When the heating weight reduction rate is less than 5%, the reliability of various properties such as heat resistance and moisture resistance is increased by suppressing the volatile matter during heating processing, etc., and during heating processing, etc. It is preferable because contamination of equipment due to the volatile matter can be reduced.

The phenol resin represented by the general formula (I) can be obtained, for example, by reacting a phenol compound and a xylylene compound which is a divalent linking group in the absence of a catalyst or an acid catalyst. Examples of the phenol resin as described above include Milex XLC-series and XL series (above, trade name, manufactured by Mitsui Chemicals, Inc.).
When the phenol resin represented by the general formula (I) is used in combination with an epoxy resin, the amount of the epoxy equivalent and the hydroxyl equivalent is 0.70 / 0.30 to 0.30 / 0.70, respectively. It is preferable to be 0.65 / 0.35 to 0.35 / 0.65, more preferably 0.60 / 0.30 to 0.30 / 0.60, It is particularly preferably 0.55 / 0.45 to 0.45 / 0.55. When the blending ratio is within the above range, the curability when the adhesive is used can be improved.

Examples of the phenol compound used in the production of the phenol resin of the general formula (I) include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, p-ethylphenol, on-propylphenol, mn-propylphenol, pn-propylphenol, o-isopropylphenol, m-isopropylphenol, p-isopropylphenol, on-butylphenol, mn-butylphenol, pn-butylphenol, o-isobutyl Phenol, m-isobutylphenol, p-isobutylphenol, octylphenol, nonylphenol, 2,4-xylenol, 2,6-xylenol, 3,5-xylenol, 2,4,6-trimethylphenol, resorcin, catechol, Idroquinone, 4-methoxyphenol, o-phenylphenol, m-phenylphenol, p-phenylphenol, p-cyclohexylphenol, o-allylphenol, p-allylphenol, o-benzylphenol, p-benzylphenol, o-chloro Examples include phenol, p-chlorophenol, o-bromophenol, p-bromophenol, o-iodophenol, p-iodophenol, o-fluorophenol, m-fluorophenol, p-fluorophenol and the like. Particularly preferred are phenol, o-cresol, m-cresol, p-cresol and the like.
These phenol compounds may be used alone or in admixture of two or more.

  The following xylylene dihalide, xylylene diglycol and derivatives thereof can be used as the xylylene compound which is a divalent linking group used in the production of the phenol resin of the general formula (I). Α, α′-dichloro-p-xylene, α, α′-dichloro-m-xylene, α, α′-dichloro-o-xylene, α, α′-dibromo-p-xylene, α, α ′ -Dibromo-m-xylene, α, α'-dibromo-o-xylene, α, α'-diiodo-p-xylene, α, α'-diiodo-m-xylene, α, α'-diiodo-o-xylene Α, α′-dihydroxy-p-xylene, α, α′-dihydroxy-m-xylene, α, α′-dihydroxy-o-xylene, α, α′-dimethoxy-p-xylene, α, α′- Dimethoxy-m-xylene, α, α'-dimethoxy-o-xylene, α, α'-diethoxy-p-xylene, α, α'-diethoxy-m-xylene, α, α'-diethoxy-o-xylene, α, α′-di-n-propoxy-p-xylene, α α'-n-propoxy-m-xylene, α, α'-di-n-propoxy-o-xylene, α, α'-diisopropoxy-p-xylene, α, α'-diisopropoxy-m- Xylene, α, α'-diisopropoxy-o-xylene, α, α'-di-n-butoxy-p-xylene, α, α'-di-n-butoxy-m-xylene, α, α'- Di-n-butoxy-o-xylene, α, α'-diisobutoxy-p-xylene, α, α'-diisobutoxy-m-xylene, α, α'-diisobutoxy-o-xylene, α, α'-di- Examples thereof include tert-butoxy-p-xylene, α, α′-di-tert-butoxy-m-xylene, α, α′-di-tert-butoxy-o-xylene, and the like. Of these, α, α'-dichloro-p-xylene, α, α'-dichloro-m-xylene, α, α'-dichloro-o-xylene, α, α'-dihydroxy-p-xylene , Α, α'-dihydroxy-m-xylene, α, α'-dihydroxy-o-xylene, α, α'-dimethoxy-p-xylene, α, α'-dimethoxy-m-xylene, α, α'- Dimethoxy-o-xylene. These xylylene compounds are used alone or in admixture of two or more.

When the phenol compound and the xylylene compound are reacted, the reaction is performed using an acidic catalyst until the xylylene compound as a raw material substantially disappears at 50 to 250 ° C. and the reaction composition becomes constant.
Examples of acidic catalysts include mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid and polyphosphoric acid; organic carboxylic acids such as dimethyl sulfuric acid, diethyl sulfuric acid, p-toluenesulfonic acid, methanesulfonic acid and ethanesulfonic acid; trifluoromethanesulfonic acid and the like Super strong acids; strong acid ion exchange resins such as alkane sulfonic acid type ion exchange resins; super strong acid ion exchange resins such as perfluoroalkane sulfonic acid type ion exchange resins (trade name: Nafion, Nafion) , Manufactured by DuPont); natural and synthetic zeolites; activated clay (acid clay), and the like.
Although the reaction time depends on the raw materials and the reaction temperature, it is generally about 1 to 15 hours. In practice, it may be determined while tracking the reaction composition by GPC (gel permeation chromatography) or the like. In exceptional cases, when a halogenoxylene derivative such as α, α'-dichloro-p-xylene is used, an acid catalyst is required because the reaction proceeds without a catalyst while generating the corresponding hydrogen halide gas. And not. In other cases, the reaction proceeds in the presence of an acid catalyst to produce the corresponding water or alcohol. In addition, the reaction molar ratio of a phenol compound and a xylylene compound usually uses a phenol compound excessively, and collect | recovers an unreacted phenol compound after reaction. At this time, the average molecular weight is determined by the amount of the phenol compound, and the phenol compound having a lower average molecular weight can be obtained as the phenol compound is more excessive. In addition, the phenol resin whose phenol compound part is allylphenol is obtained by, for example, producing a non-allylated phenol resin, reacting it with allyl halide, allyl ether, and then allylating by Claisen transition. Can do.

  Examples of amines include aliphatic or aromatic primary amines, secondary amines, tertiary amines, quaternary ammonium salts and aliphatic cyclic amines, guanidines, urea derivatives, and the like. Examples of these compounds include N, N-benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, tetramethylguanidine, triethanolamine, N, N '-Dimethylpiperazine, 1,4-diazabicyclo [2.2.2] octane, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [4.4.0] -5 -Nonene, hexamethylenetetramine, pyridine, picoline, piperidine, pyrrolidine, dimethylcyclohexylamine, dimethylhexylamine, cyclohexylamine, diisobutylamine, di-n-butylamine, diphenylamine, N-methylaniline, tri-n-propylamine, tri -N-octylamine, tri- - butylamine, triphenylamine, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, triethylenetetramine, diaminodiphenylmethane, diaminodiphenyl ether, dicyandiamide, tolylbiguanide, guanylurea, dimethylurea and the like.

  Examples of imidazole compounds include imidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 1-benzyl-2-methylimidazole, 2- Heptadecylimidazole, 4,5-diphenylimidazole, 2-methylimidazoline, 2-phenylimidazoline, 2-undecylimidazoline, 2-heptadecylimidazoline, 2-isopropylimidazole, 2,4-dimethylimidazole, 2-phenyl-4 -Methylimidazole, 2-ethylimidazoline, 2-phenyl-4-methylimidazoline, benzimidazole, 1-cyanoethylimidazole and the like.

  Examples of the acid anhydride include phthalic anhydride, hexahydrophthalic anhydride, pyromellitic dianhydride, benzophenone tetracarboxylic dianhydride, and the like.

  As the organic phosphorus compound, any phosphorus compound having an organic group can be used without particular limitation. For example, hexamethylphosphoric triamide, tri (dichloropropyl) phosphate, tri (chloropropyl) phosphate, phosphorous acid Examples include triphenyl, trimethyl phosphate, phenylphosphonic acid, triphenylphosphine, tri-n-butylphosphine, diphenylphosphine, and the like. These curing agents can be used alone or in combination.

  The amount of these curing agents is not particularly limited as long as the curing reaction of the epoxy group can proceed, but preferably in the range of 0.01 to 5.0 equivalents per 1 mol of the epoxy group, Particularly preferably, it is used in the range of 0.8 to 1.2 equivalents.

  In addition, in an epoxy resin and a hardening | curing agent, the compound which does not have mutagenicity, for example, the thing which does not use bisphenol A is preferable since the influence on an environment or a human body is small.

  The polymer compound (c) used in the present invention is preferably incompatible with an epoxy resin from the viewpoint of low elasticity, adhesiveness, and high temperature reliability. For example, an acrylic copolymer, an acrylic rubber , Rubbers such as acrylonitrile butadiene rubber and silicone rubber, silicone modified resins such as silicone resin and silicone modified polyamideimide, polyurethane, polyimide, polyimide amide and the like. The term “incompatible with the epoxy resin” means a property that separates from the epoxy resin and separates into two or more phases.

(C) The polymer compound preferably has a reactive group (functional group) and a weight average molecular weight of 100,000 or more.
Examples of the reactive group include a carboxylic acid group, an amino group, a hydroxyl group, and an epoxy group. Among these, when the functional group monomer is a carboxylic acid type acrylic acid, the crosslinking reaction is likely to proceed, causing gelation in the varnish state and lowering of the adhesive strength due to an increase in the degree of cure in the B stage state. Sometimes. Therefore, from the viewpoint that these are not generated or the period until the generation is long, glycidyl acrylate or glycidyl methacrylate having an epoxy group (hereinafter collectively referred to as “glycidyl (meth) acrylate”) (c) It is more preferable to use it as a raw material for the polymer compound. As the polymer compound (c) used in the present invention, it is more preferable to use an epoxy group-containing acrylic copolymer having a weight average molecular weight of 100,000 or more. The component (c) used in the present invention is obtained by polymerization so that unreacted monomers remain in the polymerization reaction for obtaining the polymer compound, or after the polymer compound is obtained, the reactive group-containing monomer is added. Can also be obtained. In addition, a weight average molecular weight is a polystyrene conversion value using the calibration curve by standard polystyrene by GPC method.

Examples of the acrylic copolymer include acrylic rubber that is a copolymer of acrylate, methacrylate, acrylonitrile, and the like. Moreover, since adhesiveness and heat resistance are high, 0.5 to 6 mass% of glycidyl (meth) acrylate is included as a functional group, and a glass transition temperature (hereinafter abbreviated as “Tg”) is −50 ° C. or more and 30 ° C. In the following, an acrylic copolymer having a weight average molecular weight of not less than −10 ° C. and not more than 30 ° C. and a weight average molecular weight of not less than 100,000 is particularly preferred.
As an acrylic copolymer containing 0.5 to 6% by mass of glycidyl (meth) acrylate, having a Tg of −10 ° C. or more and 30 ° C. or less and a weight average molecular weight of 100,000 or more, for example, HTR-860P-3 ( Teikoku Chemical Industry Co., Ltd., trade name).
The amount of glycidyl (meth) acrylate used as the functional group monomer is more preferably a copolymer ratio of 2 to 6% by mass. When it is 2% by mass or more, higher adhesive force can be obtained, and when it is 6% by mass or less, gelation can be suppressed. The balance may be an alkyl (meth) acrylate having an alkyl group having 1 to 8 carbon atoms such as methyl (meth) acrylate, and a mixture of styrene or acrylonitrile. Among these, ethyl (meth) acrylate and / or butyl (meth) acrylate are particularly preferable.
The mixing ratio is preferably adjusted in consideration of the Tg of the copolymer. When Tg is −10 ° C. or higher, the tackiness of the adhesive layer or adhesive film in the B-stage state can be reduced, and the handleability can be improved. There is no restriction | limiting in particular in a polymerization method, For example, pearl polymerization, solution polymerization, etc. are mentioned, A copolymer is obtained by these methods. In addition, (meth) acrylate means an acrylate and a methacrylate.

  The weight average molecular weight of the epoxy group-containing acrylic copolymer is preferably 300,000 to 3,000,000, and more preferably 500,000 to 2,000,000. When the weight average molecular weight is 300,000 or more, the strength and flexibility in sheet form and film form can be improved, and an increase in tackiness can be suppressed. On the other hand, when it is 3 million or less, the flowability is improved, and the followability to the unevenness of the adherend can be improved.

  The blending amount of the above (c) polymer compound is such that the total mass of (a) epoxy resin and (b) curing agent is A, and (c) polymer When the mass of the compound is B, the ratio A / B is preferably 0.24 to 1.0. When the blending ratio is 0.24 or more, a reduction in elastic modulus and an effect of suppressing flowability during molding can be obtained. On the other hand, when the blending ratio is 1.0 or less, handleability at high temperatures can be improved.

  The adhesive composition of the present invention may further contain (d) a filler and / or (e) a curing accelerator as necessary.

Examples of the filler (d) include inorganic fillers and organic fillers, and it is preferable to add inorganic fillers from the viewpoints of improving handleability, improving thermal conductivity, adjusting melt viscosity, and imparting thixotropic properties.
There are no particular restrictions on the inorganic filler. For example, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, aluminum nitride, aluminum borate whisker, nitriding Examples thereof include boron, crystalline silica, and amorphous silica. These may be used alone or in combination of two or more. From the viewpoint of improving thermal conductivity, aluminum oxide, aluminum nitride, boron nitride, crystalline silica, amorphous silica and the like are more preferable. From the viewpoint of adjusting melt viscosity and imparting thixotropic properties, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, aluminum oxide, crystalline silica, non-crystalline A crystalline silica or the like is more preferable.
Examples of the organic filler include various rubber fillers such as acrylonitrile butadiene rubber filler and silicone rubber filler. These are effective in improving flexibility and lowering the elastic modulus at low temperatures.

(D) As for a filler, it is more preferable that a contact angle with water is 100 degrees or less. When the contact angle with water is 100 ° or less, the effect of filler addition can be improved, and when the contact angle is 60 ° or less, the effect of improving the reflow resistance is particularly high, which is further preferable.
(D) It is preferable that the average particle diameter of a filler is 0.005-0.1 micrometer, and it is more preferable that it is 0.01-0.1 micrometer. When the average particle size is 0.005 μm or more, dispersibility and fluidity can be improved, and when it is 0.1 μm or less, adhesiveness can be improved. The contact angle of the filler with water is measured by the following method. A filler is compression-molded to produce a flat plate, a water droplet is dropped on it, and the angle at which the water droplet contacts the flat plate is measured with a contact angle meter. For the value of the contact angle, this measurement is performed 10 times and the average value is used.

Examples of such filler include silica, alumina, antimony oxide and the like. As silica, nanotech SiO ₂ (trade name, manufactured by CII Kasei Co., Ltd., contact angle: 43 degrees, average particle size: 0.012 μm), and Aerosil R972 (trade name, manufactured by Nippon Aerosil Co., Ltd., contact angle: 43 degrees) As an alumina, Nanotech Al ₂ O ₃ (trade name, manufactured by CI Kasei Co., Ltd., contact angle: 55 degrees, average particle size: 0.033 μm), as antimony trioxide, , PATOX-U (trade name, manufactured by Nippon Seiko Co., Ltd., contact angle: 43 degrees, average particle size: 0.02 μm) are commercially available.

  (D) It is preferable that the compounding quantity of a filler is 1-50 mass parts with respect to 100 mass parts of (a) epoxy resin and (b) hardening | curing agent. When the blending amount is 50 parts by mass or less, the storage elastic modulus of the adhesive can be reduced and the adhesiveness can be improved. In this respect, the amount is more preferably 5 to 40 parts by mass, and particularly preferably 10 to 30 parts by mass. However, since the exposure light beam at the time of optical waveguide formation is scattered and reflected by the filler, it may affect the resolution of the optical waveguide. It is preferable to appropriately adjust the filler content in consideration.

(E) There is no restriction | limiting in particular as a hardening accelerator, For example, a tertiary amine, imidazoles, a quaternary ammonium salt etc. can be used.
Examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, and the like. Species or two or more can be used in combination. As the imidazoles, for example, 2E4MZ, 2PZ-CN, 2PZ-CNS (both trade names, manufactured by Shikoku Kasei Kogyo Co., Ltd.) are commercially available.

  Moreover, it is preferable that it is a hardening accelerator which has the potential in the point that the use period of a film becomes long. Typical examples include dihydrazide compounds such as dicyandiamide and adipic acid dihydrazide, guanamic acid, melamic acid, addition compound of epoxy compound and imidazole compound, addition compound of epoxy compound and dialkylamine, addition compound of amine and thiourea And an addition compound of an amine and an isocyanate. Moreover, what has taken the adduct type structure from the point which can reduce activity at room temperature (25 degreeC) is preferable.

  (E) It is preferable that the compounding quantity of a hardening accelerator shall be 5.0 mass parts or less with respect to 100 mass parts of total amounts of (a) epoxy resin and (b) hardener, and 0.05-3.0 masses. More preferably, it is more preferably 0.2 to 3.0 parts by mass. When the blending amount is 5.0 parts by mass or less, storage stability is improved and a good pot life is obtained.

  From the viewpoint of improving flexibility and reflow crack resistance, a high molecular weight resin compatible with an epoxy resin can be added to the adhesive composition of the present invention. The high molecular weight resin compatible with the epoxy resin is not particularly limited. For example, phenoxy resin, high molecular weight epoxy resin, ultra high molecular weight epoxy resin, highly polar functional group-containing rubber, and highly polar functional group-containing reactive rubber. Etc. can be used.

As the phenoxy resin, phenototo YP-40, phenototo YP-50 (both trade names, manufactured by Tohto Kasei Co., Ltd.), PKHC, PKHH, and PKHJ (all trade names, manufactured by Phenoxy Associate) are commercially available.
Examples of the high molecular weight epoxy resin include a high molecular weight epoxy resin having a molecular weight of 30,000 to 80,000, and an ultrahigh molecular weight epoxy resin having a molecular weight exceeding 80,000 (Japanese Patent Publication No. 7-59617 and Japanese Patent Publication No. 7-59618). No. 7-59619, No. 7-59620, No. 7-64911, No. 7-68327, etc.).
As a functional group-containing reactive rubber having a large polarity, PNR-1 (trade name, manufactured by JSR Corporation) is commercially available as a carboxyl group-containing acrylonitrile butadiene rubber.
The amount of the high molecular weight resin compatible with the epoxy resin is preferably 40 parts by mass or less with respect to 100 parts by mass of the epoxy resin. Tg of an epoxy resin layer can be improved as it is 40 mass parts or less.

In addition, various coupling agents can be added to the adhesive composition of the present invention in order to improve interfacial bonding between different materials.
Examples of the coupling agent include silane-based, titanium-based, and aluminum-based, and silane-based coupling agents are most preferable.
The silane coupling agent is not particularly limited, and examples thereof include vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacrylate. Roxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxy Silane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ- Aminopro Rutrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-ureidopropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-aminopropyltri Methoxysilane, 3-aminopropyl-tris (2-methoxy-ethoxy-ethoxy) silane, N-methyl-3-aminopropyltrimethoxysilane, triaminopropyl-trimethoxysilane, 3- (4,5-dihydro) imidazole -1-yl-propyltrimethoxysilane, 3-methacryloxypropyl-trimethoxysilane, 3-mercaptopropyl-methyldimethoxysilane, 3-chloropropyl-methyldimethoxysilane, 3-chloropropyl-dimethyl Xylsilane, 3-cyanopropyl-triethoxysilane, hexamethyldisilazane, N, O-bis (trimethylsilyl) acetamide, methyltrimethoxysilane, methyltriethoxysilane, ethyltrichlorosilane, n-propyltrimethoxysilane, isobutyltrimethoxy Silane, amyltrichlorosilane, octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltri (methacryloyloxyethoxy) silane, methyltri (glycidyloxy) silane, N-β- (N-vinylbenzylaminoethyl) -γ -Aminopropyltrimethoxysilane, octadecyldimethyl [3- (trimethoxysilyl) propyl] ammonium chloride, γ-chloropropylmethyldichlorosilane, γ-chloro Use of propylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, trimethylsilyl isocyanate, dimethylsilyl isocyanate, methylsilyl triisocyanate, vinylsilyl triisocyanate, phenylsilyl triisocyanate, tetraisocyanate silane, ethoxysilane isocyanate, etc. These can be used alone or in combination of two or more.

  The titanium-based coupling agent is not particularly limited. For example, isopropyl trioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, Isopropyltricumylphenyl titanate, isopropyltris (dioctylpyrophosphate) titanate, isopropyltris (n-aminoethyl) titanate, tetraisopropylbis (dioctylphosphite) titanate, tetraoctylbis (ditridecylphosphite) titanate, tetra (2, 2-Diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titane , Dicumylphenyloxyacetate titanate, bis (dioctylpyrophosphate) oxyacetate titanate, tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetate Nitrate, Titanium Octylene Glycolate, Titanium Lactate Ammonium Salt, Titanium Lactate, Titanium Lactate Ethyl Ester, Titanium Chileethanol Aminate, Polyhydroxy Titanium Stearate, Tetramethyl Orthotitanate, Tetraethyl Orthotitanate, Tetarapropyl Orthotitanate, Tetraisobutyl Ortho Titanate, stearyl titanate, cresyl titanate monomer, cresyl Nate polymer, diisopropoxy-bis (2,4-pentadionate) titanium (IV), diisopropyl-bis-triethanolamino titanate, octylene glycol titanate, tetra-n-butoxytitanium polymer, tri-n-butoxytitanium A monostearate polymer, tri-n-butoxytitanium monostearate, etc. can be used, and these 1 type (s) or 2 or more types can also be used together.

The aluminum coupling agent is not particularly limited. For example, ethyl acetoacetate aluminum diisopropylate, aluminum toys (ethyl acetoacetate), alkyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetate bis (ethyl acetoacetate), Aluminum tris (acetylacetonate), aluminum monoisopropoxy monooleoxyethyl acetoacetate, aluminum di-n-butoxide mono-ethyl acetoacetate, aluminum di-iso-propoxide mono-ethyl acetoacetate, etc. Aluminum chelate compound, aluminum isopropylate, mono-sec-butoxyaluminum diisopropylate, aluminum-sec- Chireto, aluminum alcoholates of aluminum ethylate or the like can be used, may be used in combination one or more of them.
The blending amount of the coupling agent is preferably 10 parts by mass or less with respect to 100 parts by mass in total of (a) the epoxy resin and (b) the curing agent, from the viewpoints of the effect, heat resistance, and cost.

Furthermore, an ion scavenger can also be mix | blended with the adhesive composition of this invention from a viewpoint of adsorb | sucking an ionic impurity and improving moisture resistance reliability.
As the ion scavenger, there is no particular limitation, and a compound known as a copper damage preventive agent to prevent copper from ionizing and dissolving, for example, a triazine thiol compound, a bisphenol-based reducing agent, etc. can be used. Inorganic ion adsorbents such as zirconium-based and antimony bismuth-based magnesium aluminum compounds can also be used. The addition amount of the ion scavenger is preferably 10 parts by mass or less with respect to 100 parts by mass of the adhesive composition from the viewpoints of the effect of addition, heat resistance, cost, and the like.

The cured product of the adhesive composition of the present invention preferably has a tensile modulus of 1 to 20 MPa at 240 ° C. When the tensile modulus is 20 MPa or less, the stress relaxation property can be improved, and warpage or the like hardly occurs. On the other hand, when it is 1 MPa or more, the occurrence of reflow cracks can be reduced.
In addition, the measurement of the tensile elastic modulus at 240 ° C. is performed as follows. First, an adhesive composition having an initial length of 20 mm (L) and a thickness of about 50 μm is cured at 170 ° C. for 1 hour to produce a cured film. A constant load of 1 to 10 kg (W) is applied to the cured film, and the cured film is put into a constant temperature bath at 240 ° C. After the addition, after the temperature of the cured film reaches 240 ° C., the elongation amount (ΔL) and the cross-sectional area (S) of the cured film are obtained, and the tensile elastic modulus (E ′) is calculated from the following formula.
E ′ = L · W / (ΔL · S)

  The weight reduction rate when the adhesive composition of the present invention is heated at 270 ° C. is preferably 2% or less, more preferably 1.5%, and further preferably 1%. When the weight reduction rate during heating is 2% or less, contamination of peripheral devices can be reduced during use.

  The adhesive composition and adhesive film of the present invention preferably have components separated into two phases in the cross section of the cured product. The term “two phases” as used herein means that the cured product has a sea / island structure.

  The sea / island structure refers to a case where a cross-section of the cured adhesive composition is polished and observed using a scanning electron microscope or the like, for example, “New Polymer One Point Polymer Alloy” published by Kyoritsu Shuppan. As described on page 16, it means that the observed image has a non-uniform structure consisting of a continuous phase (referred to as “the sea”) and a dispersed phase (referred to as “islands”).

  Adhesive compositions and adhesive films having such properties include, for example, epoxy resins and their curing agents, and polymer compounds that are incompatible with them, such as allyl rubber, acrylonitrile butadiene rubber, silicone rubber, polyurethane, polyimide , Polyamide imide, and the like, and copolymers or mixtures thereof, and, if necessary, a composition comprising a filler and / or a curing accelerator, or a film-like product thereof (adhesive film).

From the viewpoint of improving the adhesion between the sea phase and the island phase, the outer peripheral length S of the island phase is preferably S / (V ^1/2 )> 4.0 with respect to the cross-sectional area V, and S / ( More preferably, V ^1/2 )> 3.6. The adhesive composition and the adhesive film having such characteristics include, for example, an epoxy resin and its curing agent, and a polymer compound incompatible with them, such as a phenoxy resin, and a filler and a curing accelerator. It is achieved by the composition or its film-like material (adhesive film). In particular, those containing a filler are preferred, and those containing a filler having an average particle diameter of 0.005 to 0.1 μm are particularly preferred. Moreover, the filler is silica and the surface is preferably coated with an organic substance.

  Further, the cured product of the adhesive composition preferably has a storage elastic modulus at 240 ° C. of 1 to 20 MPa. The adhesive composition having such properties is achieved, for example, by a composition comprising an epoxy resin and its curing agent, a polymer compound that is incompatible with them, and a filler and a curing accelerator. In particular, those containing a filler are preferred, and those containing a filler having an average particle diameter of 0.005 to 0.1 μm are particularly preferred.

  The cured product of the adhesive composition or adhesive film of the present invention preferably has pores, the average diameter of the pores is 0.01 to 2 μm, and the volume content of the pores is 0.1 to 20% by volume. Preferably there is. More preferably, the cured product has pores having an average diameter of 0.03 to 0.1 μm. The pores mean voids, spaces, gaps, etc., and the average diameter of the pores means the diameter when the volume of the pores is roughly converted to a sphere. When the average diameter of the pores is in the above range, PCT resistance (adhesion strength) can be improved.

When the volume content of the pores is 0.1% by volume or more, the presence effect of the pores can be obtained and the PCT resistance can be improved. Reflow resistance and PCT resistance can be improved as it is 20 volume% or less. More preferably, the pores are uniformly dispersed. The volume content measurement of pores is calculated by the following method.
(1) A place having a square area with a length of 100 times the average particle diameter of the filler used in the scanning electron microscope (SEM) as one side and having 50 holes is set.
(2) The square area and the area of 50 holes are obtained by the following method.
A transparent film having a uniform density and film thickness is placed on the SEM photograph, traced with a pen along the shape of all 50 holes, and the trace portion is cut off.
(3) After tracing a certain area portion (including 50 hole portions) with a pen as in (2), the trace portion is cut off.
(4) The masses of the separated (2) and (3) are measured to obtain (2) / (3).
(5) V = [(2) / (3)] ^3/2 is obtained.
(6) (1) to (5) are repeated 5 times, and the average value of the obtained V is defined as the volume content.

  The adhesive composition and adhesive film of the present invention contain (a) an epoxy resin, (b) a curing agent and (c) a polymer compound, and (d) a filler and (e) a curing accelerator as necessary. It may be made of a cured product of the adhesive composition that has pores with an average diameter of 0.01 to 2.0 μm, and the volume content of the pores is 0.1 to 20% by volume.

Using the adhesive composition of the present invention, for example, an adhesive film having a flow reduction amount of 50% or less after 60 ° C. and 72 hours can be produced. When the amount of decrease in the flow of the adhesive film is 50% or less, it is preferable because the storage period of the adhesive film at 25 ° C. or 5 ° C. is long and long-term storage is possible.
The amount of flow decrease can be measured by the following procedure.
First, an adhesive film punched into a size of 1 cm × 2 cm is pressed under the conditions of 160 ° C., 1 MPa, and 18 seconds. The length of the sample protruding from the end of the four samples was measured for each sample at two points with an optical microscope, the average length was determined, and this was taken as the flow amount.
From the initial flow amount F (0) and the flow amount F (72) after 60 ° C. and 72 hours, the flow decrease amount after 60 ° C. and 72 hours is obtained by the following equation.
Flow reduction amount (%) = (F (0) −F (72)) / F (0) × 100

The adhesive film of the present invention is a cured product of an adhesive composition containing (a) an epoxy resin, (b) a curing agent, (c) a polymer compound, (d) a filler, and (e) a curing accelerator. And the components (a) to (e) are
0.75> a / b
Here, a represents the contact angle of (d) the filler with water, and b represents the water of the product obtained by applying and drying the blends of (a), (b), (c) and (e). Represents the contact angle,
It is preferable that the relationship is satisfied.

  The adhesive film having the above characteristics includes, for example, epoxy resins and curing agents thereof, and polymer compounds that are incompatible with them, such as allyl rubber, acrylonitrile butadiene rubber, silicone rubber, polyurethane, polyimide, polyamideimide, and the like. This is achieved by a composition comprising a copolymer or a mixture thereof, and, if necessary, a filler and / or a curing accelerator, or a film thereof. In particular, an epoxy group-containing acrylic copolymer having a weight average molecular weight of 100,000 or more, containing 1.5 to 2.0% by mass of an epoxy resin, a curing agent thereof, and glycidyl (meth) acrylate that is incompatible with the epoxy resin, And an adhesive film comprising a filler and a curing accelerator. In particular, it is preferable to use an epoxy resin having a softening point of 50 ° C. or higher. Moreover, it is preferable that a hardening | curing agent is a phenol resin shown by the said general formula (I).

In the adhesive film of the present invention, the adhesive composition is applied and dried, and the components (a) to (e) are 0.75> a / b (where a and b are as described above). ) Is preferably selected so as to satisfy the relationship.
0.75> a / b, that is, a / b is preferably less than 0.75, more preferably less than 0.66, and particularly preferably less than 0.50. The lower limit of a / b is about 0.25.
Adhesiveness after moisture absorption can be improved as a / b is less than 0.75. The contact angle a between the filler and water is measured by the method described above. The contact angle b with water of the coating and drying of the blends (a), (b), (c) and (e) is also measured in the same manner.

In the adhesive composition and adhesive film of the present invention, the blending ratio of the components (a) to (e)
(A) total of epoxy resin and (b) curing agent; 17.0-49.5% by mass,
(C) polymer compound; 50.0-70.0 mass%,
(D) Filler: 0.45 to 10.0% by mass and (e) Curing accelerator: 0.05 to 3.0% by mass are preferable.

  When the total amount of (a) epoxy resin and (b) curing agent is 17.0% by mass or more, adhesiveness, moldability (flowability) and the like are sufficient, while 49.5% by mass or less. If it is, the elastic modulus will not be too high. Here, the ratio [(a) :( b)] of (a) epoxy resin and (b) curing agent is preferably 33:67 to 75:25. At this ratio, if there are too many (a) epoxy resins, heat resistance, moldability (flowability), etc. tend to be insufficient, and (b) if there are too many curing agents, moldability (flowability), etc. There is a tendency to become insufficient. By using the composition having the above-described composition, an adhesive film excellent in heat resistance after moisture absorption, reflow resistance, adhesiveness after moisture absorption, and the like can be obtained.

  In the adhesive film of the present invention, (a) the total mass of the epoxy resin and (b) the phenol resin represented by the formula (I) is A, and (c) 0.5 to 6% by mass of a reactive group-containing monomer is used. When the mass of the acrylic copolymer having a weight average molecular weight of 100,000 or more is B, the ratio A / B is preferably an adhesive composition having a ratio of 0.24 to 1.0.

Using the adhesive composition of the present invention, an adhesive film comprising a laminated cured product of the adhesive composition and a polyimide film and having a peel strength of 50 N / m or more measured at 240 ° C. of the laminated cured product is produced. can do.
Further, by using the laminated cured product, an adhesive film having a diameter of 2 mm or more in the laminated cured product can be produced in a heat treatment at 260 ° C. for 120 seconds after the moisture absorption treatment.
Furthermore, when the adhesive composition of the present invention was used, after passing through a reflow oven at 260 ° C. for 120 seconds after moisture absorption treatment at 85 ° C. and 85% relative humidity (RH) for 168 hours, the adhesive layer and the optical waveguide were Thus, an optical device having a diameter of 1 mm or more that does not cause peeling can be produced.

  The above-mentioned adhesive film and optical device are, for example, an epoxy resin and its curing agent, and preferably a polymer compound having a crosslinkable functional group that is incompatible with them, and, if necessary, a filler and / or curing. It is achieved by an adhesive composition comprising an accelerator or an optical device in which the adhesive composition is applied to a film-like product and an optical waveguide. In particular, an epoxy group-containing acrylic copolymer having a weight average molecular weight of 100,000 or more, containing 1.5 to 6.0% by mass of an epoxy resin, its curing agent, and glycidyl (meth) acrylate that is incompatible with them, and This is achieved by an adhesive film comprising a filler and a curing accelerator. In particular, it is preferable to use an epoxy resin having a softening point of 50 ° C. or higher. Moreover, it is preferable that a hardening | curing agent is a phenol resin shown by the said general formula (I). In particular, those containing a filler having an average particle diameter of 0.005 to 0.1 μm are preferable. Moreover, the filler is silica and the surface is preferably coated with an organic substance.

  The adhesive composition of the present invention has an excellent moisture absorption resistance due to the use of the low hygroscopic phenol resin represented by the formula (I), and has an appropriate cross-linked structure using an acrylic copolymer containing a reactive group-containing monomer. Excellent reflow crack resistance and heat resistance due to the formation of a clear sea-island structure after curing by using an acrylic copolymer that is incompatible with the epoxy resin. Is obtained. Furthermore, the addition of an inorganic filler increases the high-temperature elastic modulus, increases the high-temperature peel strength, works to prevent reflow cracks, and provides an adhesive composition with excellent reflow crack resistance.

  The adhesive film of the present invention is a support for a polytetrafluoroethylene film, a polyethylene terephthalate film whose surface has been subjected to mold release treatment, by dissolving or dispersing the adhesive composition of the present invention in a solvent such as methyl ethyl ketone, toluene, or cyclohexanone. It is obtained as an adhesive layer formed on the support film by coating, heating and drying on the body film, and removing the solvent, and a protective film may be provided if necessary (see FIG. 1). . As heating conditions in this case, for example, it is preferable that the temperature is about 80 to 250 ° C. and about 10 minutes to 20 hours.

  As the support film, a plastic film such as a polytetrafluoroethylene film, a polyethylene terephthalate film, a polyethylene film, a polypropylene film, a polymethylpentene film, or a polyimide film can be used. Can also be used. The support film can be peeled off at the time of use and only the adhesive layer can be used, or it can be used together with the support film and removed later.

  As a method for applying the varnish to the support film, a known method can be used, and examples thereof include a knife coating method, a roll coating method, a spray coating method, a gravure coating method, a bar coating method, and a curtain coating method. .

  The thickness of the adhesive layer (that is, the adhesive film) is not particularly limited, but is preferably 3 to 100 μm, more preferably 5 to 50 μm, and still more preferably 7 to 25 μm. 9 to 15 μm is particularly preferable. If it is 3 μm or more, the stress relaxation effect is sufficient, and if it is 100 μm or less, it is economical and the light transmittance can be improved.

  The varnishing solvent is not particularly limited, but considering the volatility during film production, methyl ethyl ketone, acetone, methyl isobutyl ketone, 2-ethoxyethanol, toluene, xylene, butyl cellosolve, methanol, ethanol, It is preferable to use a solvent having a relatively low boiling point such as 2-methoxyethanol. In addition, for the purpose of improving the coating property, a solvent having a relatively high boiling point such as dimethylacetamide, dimethylformamide, N-methylpyrrolidone, cyclohexanone can be added.

  In the production of the varnish when the filler is added to the adhesive composition of the present invention, it is preferable to use a raking machine, a three roll, a ball mill and a bead mill in consideration of the dispersibility of the filler. It can also be used in combination. Moreover, the mixing time can be shortened by mixing the filler and the low molecular weight compound in advance and then blending the high molecular weight compound. In addition, after forming the varnish, it is preferable to remove bubbles in the varnish by vacuum degassing or the like.

  In addition, when a filler is added to the adhesive composition in the present invention, an epoxy resin, a curing agent, and a filler are mixed, and then the mixture is preferably a rubber compound such as acrylic rubber as a polymer compound incompatible with the epoxy resin. It is preferable to employ a method for producing an adhesive composition by mixing. By this method, an epoxy resin film is formed at the filler interface, so that a large amount of filler remains in the epoxy resin phase even after the rubber and epoxy resin are phase-separated and cured. This increases the reinforcement and hardening of the interface and improves the heat resistance. The ratio VA / VB of the volume VA of the filler contained in the cured epoxy resin phase and the volume VB of the filler contained in the rubber component phase is preferably 1.2 or more. When VA / VB is 1.2 or more, the reinforcing effect of the A and B interfaces can be obtained, and the heat resistance can be improved. VA / VB is particularly preferably 2 or more, and more preferably 4 or more. VA / VB can be measured by the following procedure. The fracture surface of the film is observed with a scanning electron microscope, and the peak of atoms forming a filler is measured with XMA in each of the regions mainly composed of A and B. VA / VB is determined by the ratio of the peak heights.

  In addition, two or more adhesive layers in the adhesive film of the present invention can be bonded together in order to obtain a desired thickness. In this case, it is necessary to have a bonding condition that does not cause peeling between the adhesive layers.

By using the optical waveguide adhesive composition or the optical waveguide adhesive film of the present invention, an optical device formed by adhering an optical waveguide can be produced.
An example of manufacturing an optical device using the adhesive film of the present invention will be described with reference to FIG. First, when there is a protective film, it is peeled off, the adhesive surface of the adhesive layer 1 and the adherend member 21 are bonded together (see FIG. 2-A (a)), and then the support substrate 2 is peeled off (see FIG. 2-A (b)). Subsequently, the member to be bonded 21 holding the adhesive and the optical waveguide 11 are laminated via the adhesive layer 1, and then the adhesive is heated and cured to manufacture the target optical device 40 (FIG. 2). A (c)). Here, an example in which the adhesive film is first laminated on the member to be bonded and then bonded to the optical waveguide is shown, but this order may be changed as shown in FIG. As a method of affixing the adhesive film, a method of cutting the adhesive film into a predetermined shape and thermocompression bonding the cut adhesive film to a desired position of the optical waveguide or the bonded member is common. It is not limited. Here, the member to be bonded is not particularly limited as long as it is used for a target optical device. For example, a glass epoxy substrate, an organic wiring substrate using polyimide, a ceramic wiring substrate such as an alumina substrate, an aluminum nitride substrate, or the like. And semiconductor wafers such as silicon, metals such as copper and aluminum, and glass materials such as quartz.

  In the above description, a method for bonding an optical waveguide prepared in advance to a member to be bonded using an adhesive film for an optical waveguide has been described. In addition to this method, an adhesive film is first laminated on the member to be bonded, and an optical waveguide layer, specifically, a lower clad layer, a core layer, and an upper clad layer are sequentially stacked on the adhesive film. An optical device in which an optical waveguide is bonded using a receiving sheet can be manufactured. According to this method, an optical waveguide can be produced on a member to be bonded by build-up, which is advantageous in pattern accuracy and alignment accuracy of the optical waveguide.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

Example 1
[Preparation of adhesive film]
(A) YDCN-703 (trade name, manufactured by Toto Kasei Co., Ltd., cresol novolak type epoxy resin, epoxy equivalent 210) as an epoxy resin, 55 parts by mass, (b) Millex XLC-LL (trade name, manufactured by Mitsui Chemicals, Inc.) as a curing agent , Phenol resin, hydroxyl group equivalent 175, water absorption rate 1.8% by mass, heating weight reduction rate at 350 ° C. 4%) 45 parts by mass, NUC A-189 (trade name, γ-made by Nihon Unicar Co., Ltd.) as the silane coupling agent 1.7 parts by mass of mercaptopropyltrimethoxysilane) and 3.2 parts by mass of NUC A-1160 (trade name, γ-ureidopropyltriethoxysilane manufactured by Nihon Unicar Co., Ltd.), (d) Aerosil R972 (on the silica surface) as a filler Methyl coated with dimethyldichlorosilane and hydrolyzed in a reactor at 400 ° C. A cyclohexanone is added to a composition comprising 32 parts by mass of a filler having an organic group on the surface thereof, a product name manufactured by Nippon Aerosil Co., Ltd., silica, and an average particle size of 0.016 μm. Kneaded for minutes. (C) 280 parts by mass of acrylic rubber HTR-860P-3 (trade name, weight average molecular weight 800,000 manufactured by Teikoku Chemical Industry Co., Ltd.) containing 3% by mass of glycidyl acrylate or glycidyl methacrylate as a polymer compound, and (e ) Curazole 2PZ-CN (trade name, 1-cyanoethyl-2-phenylimidazole manufactured by Shikoku Kasei Kogyo Co., Ltd.) as a curing accelerator was added in an amount of 0.5 parts by mass, stirred and mixed, and vacuum degassed. This adhesive varnish is applied on a 75 μm-thick polyethylene terephthalate (PET) film that has been subjected to a release treatment, and heated and dried at 140 ° C. for 5 minutes to form a B-stage coating film having a thickness of 10 μm. The adhesive film provided with the body film was produced.

  The storage elastic modulus of the adhesive composition obtained by curing the adhesive film at 170 ° C. for 1 hour was measured using a dynamic viscoelasticity measuring device (DVE-V4, manufactured by Rheology) (sample size: length 20 mm, width 4 mm). And a film thickness of 80 μm, a heating rate of 5 ° C./min, a tensile mode, 10 Hz, and an automatic static load), the result was 380 MPa at 25 ° C. and 5 MPa at 260 ° C.

[Preparation of resin film for forming optical waveguide]
[Production of resin film for clad layer formation]
As binder polymer, 50 parts by mass of phenoxy resin (trade name: Phenotote YP-70, manufactured by Toto Kasei Co., Ltd.) and as a photopolymerizable compound, alicyclic diepoxycarboxylate (trade name: KRM-2110, molecular weight: 252) Asahi Denka Kogyo Co., Ltd.) 50 parts by mass, as a photopolymerization initiator, triphenylsulfonium hexafluoroantimonate salt (trade name: SP-170, Asahi Denka Kogyo Co., Ltd.) 4 parts by mass, as a sensitizer, SP-100 (trade name, manufactured by Asahi Denka Kogyo Co., Ltd.) 0.4 parts by weight, 40 parts by weight of propylene glycol monomethyl ether acetate as an organic solvent was weighed into a wide-mouthed plastic bottle, using a mechanical stirrer, shaft and propeller, The mixture was stirred for 6 hours under the conditions of a temperature of 25 ° C. and a rotational speed of 400 rpm, and the clad layer forming resin It was formulated a scan. After that, using a polyflon filter (trade name: PF020, manufactured by Advantech Toyo Co., Ltd.) with a pore diameter of 2 μm, the mixture is filtered under pressure at a temperature of 25 ° C. and a pressure of 0.4 MPa, and further the degree of vacuum using a vacuum pump and a bell jar. Degassed under reduced pressure for 15 minutes under the condition of 50 mmHg.

  The above-obtained resin varnish for forming a clad layer was coated on a corona-treated surface of a polyamide film (trade name: Miktron, manufactured by Toray Industries, Inc., thickness: 12 μm) (Multicoater TM-MC, Hirano Tech Seed Co. And then dried at 80 ° C. for 10 minutes, then at 100 ° C. for 10 minutes, and then released from the release PET film (trade name: A31, Teijin DuPont Films, Inc., thickness: 25 μm) as a protective film. Affixed so that the mold surface was on the resin side to obtain a resin film for forming a clad layer. At this time, the thickness of the resin layer can be arbitrarily adjusted by adjusting the gap of the coating machine. In this embodiment, the thickness after curing is 30 μm for the lower cladding layer and 80 μm for the upper cladding layer. Adjusted.

[Production of resin film for core layer formation]
As binder polymer, 26 parts by mass of phenoxy resin (trade name: Phenototo YP-70, manufactured by Toto Kasei Co., Ltd.) and 9,9-bis [4- (2-acryloyloxyethoxy) phenyl] fluorene as a photopolymerizable compound (Product name: A-BPEF, manufactured by Shin-Nakamura Chemical Co., Ltd.) 36 parts by mass, and bisphenol A type epoxy acrylate (trade name: EA-1020, manufactured by Shin-Nakamura Chemical Co., Ltd.), 36 parts by mass, photopolymerization initiator 2 parts by mass of bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (trade name: Irgacure 819, manufactured by Ciba Specialty Chemicals Co., Ltd.), and 40 parts by mass of propylene glycol monomethyl ether acetate as an organic solvent The resin film for forming the cladding layer was made Examples and was formulated resin varnish for forming a core layer by the same method and conditions were pressure filtered further vacuum degassing.

  The core layer-forming resin varnish obtained above is prepared on the non-treated surface of a PET film (trade name: Cosmo Shine A1517, manufactured by Toyobo Co., Ltd., thickness: 16 μm). After applying and drying in the same manner as in the example, a release PET film (trade name: A31, Teijin DuPont Films Co., Ltd., thickness: 25 μm) is pasted as a protective film so that the release surface is on the resin side. A resin film for layer formation was obtained. In this example, the gap of the coating machine was adjusted so that the film thickness after curing was 50 μm.

[Fabrication of optical waveguide]
The release PET film (A31), which is a protective film for the resin film for forming the lower cladding layer obtained above, is peeled off, and the resin side (base film) is obtained using an ultraviolet exposure machine (EXM-1172, manufactured by Oak Manufacturing Co., Ltd.). The lower cladding layer 32 was formed by irradiating ultraviolet rays (wavelength 365 nm) with 1 J / cm ² from the opposite side, followed by heat treatment at 80 ° C. for 10 minutes (see FIG. 3A).

  Next, a roll laminator (HLM-1500, manufactured by Hitachi Chemical Technoplant Co., Ltd.) is used on the lower clad layer 32 under the conditions of pressure 0.4 MPa, temperature 50 ° C., laminating speed 0.2 m / min. After laminating the layer-forming resin film, and using a vacuum pressurization type laminator (manufactured by Meiki Seisakusho Co., Ltd., MVLP-500) as a flat plate laminator, vacuuming to 500 Pa or less, pressure 0.4 MPa, temperature 50 ° C., The core layer 33 was formed by thermocompression bonding under conditions of a pressurization time of 30 seconds (see FIG. 3B).

Next, through the negative photomask 35 having a width of 50 μm, the above ultraviolet exposure machine was irradiated with ultraviolet rays (wavelength 365 nm) at 0.6 J / cm ² (see FIG. 3C), and then exposed at 80 ° C. for 5 minutes. Post heating was performed. Thereafter, the PET film as the support film was peeled off, and the core pattern 36 was developed using a developer (propylene glycol monomethyl ether acetate / N, N-dimethylacetamide = 8/2, mass ratio) (FIG. 3D )reference). Then, it wash | cleaned using the washing | cleaning liquid (isopropanol), and heat-dried at 100 degreeC for 10 minute (s).

Next, the above clad layer forming resin film was laminated as the upper clad layer 37 under the same laminating conditions as described above. Furthermore, a flexible optical waveguide in which an upper clad layer 37 is formed and a base film is disposed on the outside is obtained by performing ultraviolet treatment (wavelength 365 nm) on both surfaces for a total of 25 J / cm ^{2 and} then heat-treating at 160 ° C. for 1 hour. It produced (refer FIG.3 (e)). Furthermore, in order to peel the polyamide film, the flexible optical waveguide was treated for 100 hours at a high temperature and high humidity of 85 ° C./85% to produce a flexible optical waveguide from which the base film 38 was removed (see FIG. 3F). Thereafter, a flexible optical waveguide having a waveguide length of 5 cm was cut out using a dicing saw (manufactured by DISCO Corporation, DAD-341).

  In addition, when the refractive index of the core layer and the clad layer was measured by a prism coupler (Model2010) manufactured by Metricon, the core layer was 1.584 and the clad layer was 1.550 at a wavelength of 830 nm. In addition, the propagation loss of the manufactured optical waveguide was measured by using a 850 nm surface emitting laser ((EXFO, FLS-300-01-VCL) as a light source, Advantest Co., Ltd., Q82214 as a light receiving sensor, and a cut-back method ( Measurement waveguide length: 10, 5, 3, 2 cm, incident fiber: GI-50 / 125 multimode fiber (NA = 0.20), output fiber: SI-114 / 125 (NA = 0.22)) However, it was 0.1 dB / cm.

[Evaluation of adhesive film]
(1) Evaluation of adhesion [Preparation of test sample]
Various members (Glass epoxy substrate (trade name: MCL-E-679F, thickness 0.6 mm, manufactured by Hitachi Chemical Co., Ltd.), polyimide film (trade name: Kapton EN, thickness 25 μm, manufactured by Toray DuPont Co., Ltd.) Copper foil (trade name: GTS-35, thickness 35 μm, glossy surface used, manufactured by Furukawa Circuit Foil Co., Ltd.), aluminum foil (trade name: AIN30H-H, glossy surface used, thickness 30 μm, Takeuchi Metal Foil Co., Ltd.) Manufactured), silicon substrate (thickness 0.625 mm, manufactured by Mitsubishi Materials Corporation), silicon substrate with oxide film (thickness 0.625 μm, with oxide film 1 μm, manufactured by Mitsubishi Materials Corporation) at 60 ° C., 0.5 MPa, The adhesive film was roll-laminated at a feed rate of 0.2 m / min, and then the support film was peeled off, and the feed rate was 80 ° C., 0.5 MPa. The flexible optical waveguide prepared above was roll-laminated under the condition of a degree of 0.5 m, followed by heat curing at 180 ° C. for 1 hour to prepare a test sample for evaluating adhesiveness.

[Evaluation methods and results]
The adhesiveness (number of peeled cells) before and after the reflow test was examined by a cross-cut tape method (based on JIS-K5400). The results are shown in Table 1. The reflow test was conducted using a reflow test machine (Furukawa Electric Co., Ltd., Salamanda XNA-645PC) and a lead solder-free reflow test at a maximum temperature of 265 ° C. under the conditions in accordance with IPC / JEDEC J-STD-020B. 3 times. Detailed reflow conditions are shown in Table 2, and the temperature profile in the reflow furnace is shown in FIG.
The same was done in the following reflow test.

(2) Evaluation of light transmittance [production of test sample]
An adhesive film is roll-laminated on a slide glass having a thickness of 1 mm at 60 ° C., 0.5 MPa, and a feed rate of 0.5 m / min. After that, the substrate film is peeled off by UV irradiation, and then heated at 180 ° C. for 1 hour. It hardened | cured and produced the test sample for light transmittance evaluation.
[Evaluation methods and results]
The light transmittance at a wavelength of 700 to 1600 nm before and after the reflow test was measured using a spectrophotometer “U-3410” manufactured by HITACHI. The results are shown in FIG. The total light transmittance was measured using a color difference / turbidity measuring device “COH-300A” manufactured by Nippon Denshoku Industries Co., Ltd. according to JIS-K7105. The results are shown in Table 1.

(3) Evaluation of refractive index [production of test sample]
A test sample for refractive index measurement was produced in the same manner as the transmittance evaluation test sample of (2).
[Evaluation methods and results]
The refractive index at a wavelength of 830 nm before and after the reflow test was measured using a Metricon prism coupler (Model 2010). The results are shown in Table 1. The refractive index change after the reflow test was found to be 0.001.

(4) Evaluation of insertion loss after bonding of optical waveguide [Preparation of test sample]
A silicon substrate (thickness: 0.625 mm, manufactured by Mitsubishi Materials Corporation) was used as the member to be bonded, and the optical waveguide was bonded to the silicon substrate by the method shown in the preparation of the test sample for the above-described adhesion evaluation. This was processed with a dicing saw (dicing saw “DAD-341” manufactured by DISCO) so as to have a waveguide length of 10 cm, and a test sample for insertion loss evaluation was produced.
[Evaluation methods and results]
A cut-back method (measurement waveguide length 10, 5, 3, 2 cm) using a surface-emitting laser (850 nm manufactured by EXFO, FLS-300-01-VCL) as a light source and Q82214 manufactured by Advantest Co., Ltd. as a light receiving sensor. , Incident fiber; GI-50 / 125 multimode fiber (NA = 0.20), output fiber: SI-114 / 125 (NA = 0.22)), and the insertion loss of the optical waveguide before and after the reflow test was measured. The results are shown in Table 1.

(5) Repeated bending test [Preparation of test sample]
A polyimide film (trade name: Kapton EN, thickness 25 μm, manufactured by Toray DuPont Co., Ltd.) is used as a member to be bonded, and the optical waveguide is bonded to the polyimide by the method shown in the preparation of the test sample for evaluation of adhesiveness described above. Then, this was processed with a dicing saw (dicing saw “DAD-341” manufactured by DISCO) so as to have a waveguide length of 10 cm and a width of 5 mm to produce an optical device.
(Evaluation method and results)
Using a bending durability tester (manufactured by Daisho Electronics Co., Ltd.), a bending test was repeated 100,000 times under the conditions of a radius of curvature of 2 mm and a bending frequency of 2 times / second, and the sample after the test was observed under a microscope with a magnification of 200 times. did. As a result, even after the completion of 100,000 times, no breakage was observed in the core and clad of the optical waveguide. Further, the optical device in which the optical waveguide was bonded to the polyimide film did not peel off at any interface of polyimide / adhesive / optical waveguide, and had good flexibility.

  As described above, good results were obtained in any evaluation, and the adhesive film of the present invention has good transparency and heat resistance, and an optical device in which an optical waveguide is bonded to a polyimide film Was found to have good flexibility.

  The adhesive composition and adhesive film of the present invention have good flexibility in addition to excellent transparency and heat resistance due to the above configuration. For this reason, optical devices using these can be applied to a wide range of fields such as optical interconnection.

It is a cross-sectional schematic diagram which shows the adhesive film of this invention. It is a cross-sectional schematic diagram which shows an example of the usage method of the adhesive film of this invention, and an optical apparatus. It is a cross-sectional schematic diagram which shows an example of an optical waveguide production process. It is a temperature profile of the reflow test used for evaluation of the adhesive film of this invention. It is the light transmittance before and behind reflow in the wavelength of 700-1600 nm of the adhesive film of Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Adhesive layer 2; Support film 3; Protective film 4; Adhesive film 11; Optical waveguide 21; Adhered member 31, 38;
32; lower clad layer 33; core layer 34; base film (for core layer formation)
35; photomask 36; core pattern 37; upper clad layer 40; optical device

Claims (22)

  An adhesive composition comprising (a) an epoxy resin, (b) a curing agent, and (c) a polymer compound, wherein the cured product has a total light transmittance and a light transmittance at a wavelength of 700 to 1600 nm. The adhesive composition for optical waveguides which is 80% or more.   The adhesive composition for an optical waveguide according to claim 1, wherein after the reflow test at a maximum temperature of 265 ° C is carried out three times, the total light transmittance of the cured product and the light transmittance at a wavelength of 700 to 1600 nm are 80% or more. .   3. The adhesive composition for an optical waveguide according to claim 1, wherein a reflow test at a maximum temperature of 265 ° C. is carried out three times, and the refractive index change of the cured product before and after that is within ± 0.005.   The adhesive for optical waveguides according to any one of claims 1 to 3, wherein the cured product has an adhesive evaluation score of 8 or more by a cross-cut tape method after three reflow tests at a maximum temperature of 265 ° C. Composition.   In the repeated bending test of the optical waveguide with an adhesive using the adhesive composition, mechanical fracture does not occur in the optical waveguide after performing a bending test 100,000 times with a radius of curvature of 5 mm. An adhesive composition for optical waveguides according to claim 1.   When the total mass of (a) the epoxy resin and (b) the curing agent is A and (c) the mass of the polymer compound is B, the ratio A / B is 0.24 to 1.0. Item 6. An adhesive composition for an optical waveguide according to any one of Items 1 to 5.   (A) The adhesive composition for optical waveguides in any one of Claims 1-6 whose epoxy resin is a solid epoxy resin whose softening point measured by the ring and ball type is 50 degreeC or more.   (A) Adhesive composition for optical waveguides in any one of Claims 1-7 whose epoxy resin does not have mutagenicity.   (B) The adhesive composition for optical waveguides according to any one of claims 1 to 8, wherein the curing agent is a phenol resin having a hydroxyl group equivalent of 150 g / eq or more. (B) The curing agent is represented by the following general formula (I):

(In the formula, each R ¹ may be the same or different and is a hydrogen atom, a linear or branched alkyl group having 1 to 10 carbon atoms, a cyclic alkyl group, an aralkyl group, an alkenyl group, a hydroxyl group, an aryl group, or a halogen atom. Represents an atom, n represents an integer of 1 to 3, and m represents an integer of 0 to 50)
The adhesive composition for optical waveguides of Claim 9 which is a phenol resin shown by these.   The adhesive composition for optical waveguides of Claim 10 whose water absorption of the phenol resin shown by the said general formula (I) is 2 mass% or less.   (C) The polymer compound is a functional group-containing acrylic copolymer, The adhesive composition for an optical waveguide according to any one of claims 1 to 11.   The adhesive composition for an optical waveguide according to claim 12, wherein the functional group-containing acrylic copolymer is an epoxy group-containing acrylic copolymer.   The adhesive composition for optical waveguides of Claim 13 whose epoxy group containing acrylic copolymer contains 0.5-6 mass% of glycidyl acrylate or glycidyl methacrylate as the raw material.   The adhesive composition for optical waveguides in any one of Claims 12-14 whose weight average molecular weights of a functional group containing acrylic copolymer are 100,000 or more.   The adhesive composition for optical waveguides in any one of Claims 12-15 whose glass transition temperature of a functional group containing acrylic copolymer is -50 degreeC-30 degreeC.   Furthermore, the adhesive composition for optical waveguides in any one of Claims 1-16 containing a filler (d). (C) The high molecular compound is an epoxy group-containing acrylic copolymer having a weight average molecular weight of 1.5 to 2.5% by mass of glycidyl acrylate or glycidyl methacrylate and having a weight average molecular weight of 100,000 or more. 1) 50 to 50 parts by mass with respect to a total of 100 parts by mass of epoxy resin and (b) curing agent, and (d) an inorganic filler having an average particle diameter of 0.01 to 0.1 μm. The adhesive composition for optical waveguides of 17.   Furthermore, the adhesive composition for optical waveguides in any one of Claims 1-18 containing (e) hardening accelerator.   (E) The adhesive composition for optical waveguides of Claim 19 whose hardening accelerator is an imidazole compound.   The adhesive film for optical waveguides formed by forming the adhesive composition in any one of Claims 1-20 in a film form.   An optical device obtained by bonding an optical waveguide using the adhesive composition for an optical waveguide according to any one of claims 1 to 20 or the adhesive film for an optical waveguide according to claim 21.

Images