JP4802666B2 - Epoxy resin adhesive composition and optical semiconductor adhesive using the same - Google Patents

Description

  The present invention relates to an epoxy resin adhesive composition and an adhesive for optical semiconductors using the same, and more specifically, it can suppress short-wave absorption, and has excellent ultraviolet resistance, weather resistance, heat resistance, reflectivity, and storage stability. The present invention relates to a light-reflective epoxy resin adhesive composition having excellent coating properties and an adhesive for an optical semiconductor using the same, which is excellent and can be used for bonding a semiconductor device mounting an optical semiconductor chip and various components.

  Optical semiconductors such as light-emitting diodes (LEDs) and laser diodes are composed of GaP-based, GaAlAs-based, GaInAlAs-based, GaInAlP-based compounds, etc., and it is necessary to flow electricity from the top and bottom surfaces of the semiconductor due to their structure. .

  When these LEDs are bonded to a lead frame or a substrate, an epoxy resin composition called a conductive adhesive is used as an adhesive that conducts electricity, and bonds the lower surface of the LED or the like to the lead frame or the substrate. Thus, light reflection, electrical and thermal conduction are obtained. Further, on the upper surface of the LED or the like, a thin conductive wire made of gold or the like called a fine wire is used to join the LED to the lead frame or the substrate to obtain electrical conduction.

These conventional LEDs can emit wavelengths from infrared to green, but it has been considered difficult to emit many wavelengths lower than green.
However, due to recent technological innovations, it has been found that GaN-based semiconductor compounds emit many wavelengths shorter than green. These GaN-based semiconductor compounds can emit wavelengths of about 550 nm or less, and can emit wavelengths such as green, blue, and ultraviolet rays.

  GaN-based semiconductor compounds have different structures from the above-mentioned GaP-based LEDs, etc., and there are those that obtain continuity from the lower surface and those that do not require continuity. Bonding is performed using a conductive adhesive or an epoxy resin composition having no electrical conductivity.

  However, conventional conductive adhesives and epoxy resin compositions use general-purpose epoxy resins such as bisphenol A type epoxy resins and phenol novolac type epoxy resins, so they will discolor when used for a long time. A problem has arisen. The cause of discoloration is considered to be that a general-purpose epoxy resin absorbs a wavelength of 500 to 450 nm or less, and the absorbed energy changes the structure of the epoxy resin. Further, since the wavelength energy is absorbed, the light emitted from the LED or the like is attenuated, and there is a problem that it cannot be brightened.

  Furthermore, in order to extract many wavelengths emitted by the GaN-based semiconductor compound to the outside, the conductive adhesive or epoxy resin composition reflects more wavelengths, or allows the wavelength to pass through the epoxy resin composition, It is necessary to reflect a lot on the bonded substrate portion.

  On the other hand, in order to solve these problems, alicyclic epoxy resins and hydrogenated epoxy resins may be used, but generally acid anhydrides such as methylhexahydrophthalic anhydride and nadic acid anhydride are used. A system curing agent will be used.

  In this case, a transparent cured product can be obtained, and a product with good permeability can be obtained. However, the one-component formulation has a short pot life and has a problem in terms of workability. In addition, by using dicyandiamide, a phenolic curing agent, etc., one-pack type compounding is possible, but the cured product is colored, absorbs wavelengths of 500 to 450 nm or less, and reflects the light emitted. There was a problem in that it decreased.

  In addition, LEDs that develop all colors from red to blue have been put into practical use, and it is expected that they will be actively used outdoors as traffic lights and information boards. Therefore, improvement in weather resistance is also strongly desired for the epoxy resin composition.

  For these reasons, an epoxy resin composition comprising a hydrogenated epoxy resin, a cationic polymerization initiator, an aromatic onium salt, a phenolic antioxidant, and a phosphorus compound has been proposed (see, for example, Patent Document 1). If this is used, the problem of coloring due to resin coloring and thermal history is avoided, and it is considered that a cured product having excellent weather resistance and toughness can be obtained.

  However, the cationic polymerization initiator contains an element that is not preferable as an electronic material, such as a sulfur compound, a phosphorus compound, a halide, or an ammonium ion. Aromatic onium salts can be problematic in that the solubility in the resin is not sufficiently high and the reactivity is not uniform, and metal ions remain in the cured resin. In addition, phenolic antioxidants are effective in improving the weather resistance, but have a problem that the yellow color changes with time. Furthermore, phosphorus compounds may ionize under certain conditions, forming compounds with semiconductors and causing defects.

  In order to solve such problems, an epoxy group-containing compound containing an alicyclic epoxy and a silanol group, or a compound containing a hydrolyzable group directly bonded to a silicon atom, and an organotin compound are contained. An epoxy resin composition is proposed. (See Patent Document 2.)

  The cured product of this epoxy resin composition is suitable for coating because it is excellent in transparency, but by using an alicyclic epoxy compound, it is excellent in weather resistance and also in storage stability. It is considered to be. However, a cured product of about 120 to 150 ° C. cannot obtain an adhesive force, and in order to obtain an adhesive force, it must be heated to 200 ° C. or higher, so that it cannot be used for an electronic component using an organic substrate. Was pointed out.

  In addition, the conductive paste comprising an organic binder, a solvent and / or a monomer, and a conductive powder, and including a silver-based powder as the conductive powder, includes at least one benzotriazole skeleton in the molecule, and has a functional group There has been proposed a conductive paste containing a compound having a methacryloyl group or a hydroxyl group in an amount of 0.1 to 10% based on the resin solid content (see, for example, Patent Document 3).

  Furthermore, as an insulating paste related to this, an insulating paste excellent in ultraviolet resistance and weather resistance has been proposed (see Patent Document 4), and a compound containing a benzotriazole skeleton as a component acts as an ultraviolet absorber, It is said that it contributes to the improvement of UV and weather resistance. However, in order to improve the reflectance of wavelength light of an optical semiconductor, it is necessary to further improve ultraviolet resistance and weather resistance without absorbing ultraviolet light.

  Therefore, the present inventor has previously developed an epoxy resin composition containing an alicyclic epoxy resin, a hydrazide-based curing agent, and a light-reflective inorganic filler as essential components (see Patent Document 5). Thereby, the short wavelength absorptivity was suppressed compared with the conventional one, and an adhesive excellent in light reflectivity, ultraviolet resistance and weather resistance could be obtained.

However, when left at a high temperature exceeding 100 ° C. for a long time, the resin component may be discolored and the light reflectivity may be lowered, and the epoxy resin composition has better heat resistance and can suppress the decrease in reflectivity. The appearance of things was anxious.
JP 2001-342240 (Claims) JP-A-8-3452 (Claims) JP2001-332124 (Claims) JP-A-2001-316596 (Claims) JP-A-2004-256603 (Claims)

  In view of the problems of the prior art described above, the object of the present invention is to suppress short wavelength absorptivity, and is excellent in adhesiveness, ultraviolet resistance, weather resistance, reflectivity, heat resistance and storage stability, and an optical semiconductor chip. An object of the present invention is to provide a light-reflective epoxy resin adhesive composition having excellent coating properties and an adhesive for optical semiconductors using the same, which can be used for the assembly of a semiconductor device to be mounted and various parts.

  As a result of intensive research to achieve the above object, the present inventor has obtained a silane compound containing a hydrolyzable group directly bonded to a silicon atom, a divalent organotin compound, and an alicyclic epoxy compound, When a specific amount of a tetravalent organotin compound and a light-reflecting inorganic filler are blended as essential components, the resulting epoxy resin composition is found not to discolor even when left at a high temperature such as 100 to 120 ° C. Furthermore, if this is used as an adhesive for optical semiconductors, short wavelength absorptivity can be suppressed, and the wavelength reflectivity, ultraviolet resistance, weather resistance, heat resistance and storage stability, and adhesion are excellent. The present invention has been completed by finding that it can be preferably applied to GaN-based LEDs that have made remarkable progress in technological development.

That is, according to the first invention of the present invention, an alicyclic epoxy compound (A), a silane compound (B) containing a hydrolyzable group directly bonded to a silicon atom, an organotin compound (C), and light An epoxy resin adhesive composition containing a reflective inorganic filler (D) as an essential component and cured at 120 to 150 ° C. , wherein the organic tin compound (C) comprises a divalent organic tin compound (c1) and 4 The organic tin compound (c2) is a mixture, and the content of each component is (A) 1 to 90% by weight and (B) 0.1 to 15% by weight based on the total amount of the composition. %, (C1) is 0.01 to 5% by weight, (c2) is 0.01 to 5% by weight, and (D) is 3 to 90% by weight. Is done.

According to the second invention of the present invention, there is provided an epoxy resin adhesive composition characterized in that, in the first invention, the silane compound (B) is a silane compound not containing a nitrogen element.
According to the third invention of the present invention, in the first or second invention, the silane compound (B) is an alkoxysilane compound containing 2 or 3 hydrolyzable groups having 1 to 3 carbon atoms. An epoxy resin adhesive composition is provided.

  According to the fourth invention of the present invention, in the first invention, the mixing amount of the divalent organic tin compound (c1) and the tetravalent organic tin compound (c2) is (c2) by weight ratio. / (C1) = 1 to 20 An epoxy resin adhesive composition is provided.

According to a fifth aspect of the present invention, in the first aspect, the light-reflective inorganic filler (D) is an inorganic particle having a band gap energy of 2.8 eV or more. An adhesive composition is provided.
Furthermore, according to a sixth aspect of the present invention, in the first aspect, the light-reflective inorganic filler (D) is one or more metal powders of Ag, Pt, or Al. An epoxy resin adhesive composition is provided.

  On the other hand, according to 7th invention of this invention, the adhesive agent for optical semiconductors which uses the epoxy resin adhesive composition in any one of 1st-6 is provided.

  The epoxy resin adhesive composition of the present invention is a cured product excellent in adhesiveness, short wavelength absorptivity, UV resistance, weather resistance, reflectivity, heat resistance, and coating properties. Is obtained. Moreover, since the adhesive for optical semiconductors using this can greatly improve the optical characteristics and reliability of a GaN-based optical semiconductor emitting a low wavelength of 550 nm or less in particular, the industrial value of the present invention is extremely great.

  Hereinafter, the epoxy resin adhesive composition of the present invention and the optical semiconductor adhesive using the same will be described in detail.

1. Epoxy resin adhesive composition The epoxy resin adhesive composition of the present invention comprises an alicyclic epoxy compound (A), a silane compound (B) containing a hydrolyzable group directly bonded to a silicon atom, and a divalent organotin compound ( c1) It contains the tetravalent organotin compound (c2) and the light-reflective inorganic filler (D) at a specific ratio. In addition, if viscosity adjustment is necessary, components (E) such as epoxy compounds other than alicyclic compounds, solvents, diluents, viscosity modifiers and the like can be added.

(A) Alicyclic epoxy compound The alicyclic epoxy compound is a thermosetting resin having an alicyclic portion such as cyclohexane and an epoxy portion. Hereinafter, the alicyclic epoxy compound may be referred to as an alicyclic epoxy resin.

  As the alicyclic epoxy compound, an aliphatic cyclic epoxy resin obtained by epoxidizing a double bond of a cyclohexene ring with peracetic acid can be used. For example, 3,4-epoxycyclohexyl-3 ', 4'-cyclohexanecarboxylate, poly (epoxidized cyclohexene oxide) and the like can be mentioned. Alicyclic epoxy resins not described here can also be used. These alicyclic epoxy compounds may be used alone or in combination.

  In the present invention, the alicyclic epoxy compound content needs to be 1 to 90% by weight. If the content of the alicyclic epoxy compound is less than 1% by weight, the adhesive force required as an adhesive cannot be obtained, and if it exceeds 90% by weight, the inorganic filler (inorganic particles or metal) which is a component of the present invention The amount of (powder) becomes relatively small, and the effect of those fillers cannot be obtained. The preferred content of the alicyclic epoxy resin is in the range of 5 to 85% by weight, more preferably 10 to 80% by weight.

(B) Silane Compound The silane compound used in the present invention refers to a compound in which a group capable of generating a silanol group by hydrolysis is directly bonded to a silicon atom. Here, the silanol group means a hydroxyl group directly bonded to a silicon atom.

Examples of such silane compounds are generally vinyl trimethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltrivinyl containing epoxy groups. Ethoxysilane, 3-methacryloxypropyltrimethoxysilane containing methacryloxy group, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, and alkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, methyl Trimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, diphenyldie Examples include xysilane, hexyltrimethoxysilane, hexyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, and chlorosilane such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, and diphenyldichlorosilane. Substances not described can be used if silanol groups can be generated by hydrolysis.
Of these, alkoxysilane compounds containing 2 or 3 hydrolyzable groups having 1 to 3 carbon atoms are particularly preferred. An alkoxysilane compound containing a hydrolyzable group having 4 or more carbon atoms or a low condensate thereof is not preferable because a desired adhesive effect cannot be expected. Further, these silane compounds containing a hydrolyzable group directly bonded to a silicon atom may be used in combination of two or more.

  In this invention, since a silane compound acts as a part of catalyst for hardening an alicyclic epoxy resin, the content shall be 0.1 to 15 weight%. If it is the range of this composition, it functions effectively as a curing catalyst according to the quantity of an epoxy resin. On the other hand, if it is 0.1% by weight or less, it does not act as a catalyst and the alicyclic epoxy resin cannot be cured. When it is 15% by weight or more, an excessive silane compound is present in the cured product, resulting in a decrease in adhesive strength.

  Further, in the present invention, it was found that when a silane compound containing no nitrogen element is used as the silane compound, the discoloration due to ultraviolet rays and the discoloration due to heat are further suppressed. The reason is not necessarily clear, but it is considered that energy by ultraviolet rays or heat breaks molecular bonds around the nitrogen element and causes coloration.

(C) Organotin Compound In the present invention, the organotin compound is composed of a divalent organotin compound (c1) and a tetravalent organotin compound (c2), and is blended at a specific ratio.

(C1) Divalent Organotin Compound In the present invention, the divalent organotin compound is not particularly limited, and any organic compound that is commercially available can be used. Specific examples include tin diacetate, tin dibutyrate, tin dioctate, tin dilaurate, tin distearate, tin dinaphthenate and the like. Two or more of these may be mixed.

  Similar to the silane compound, the divalent organotin compound acts as part of a catalyst for curing the alicyclic epoxy resin. Therefore, the content of the divalent organotin compound is set to 0.01% to 5% by weight. Within this range, any divalent organotin compound can act as a catalyst. On the other hand, if it is less than 0.01% by weight, the content is too small, so that the action as a catalyst is not exhibited, and if it is 5% by weight or more, the content is too much, the reactivity is increased and the storage is performed. Will cause problems with sex.

(C2) Tetravalent organotin compound As the tetravalent organotin compound used in the present invention, any commercially available organic compound can be used. Specific examples include tin tetraacetate, tin tetraoctate, tin tetralaurate, butyltin triacetate, butyltin tributylate, butyltin trioctate, butyltin trilaurate, octyltin triacetate, octyltin tributyrate, octyltin Trioctate, octyltin trilaurate, dibutyltin diacetate, dibutyltin dibutyrate, dibutyltin dioctate, dibutyltin dilaurate, dioctyltin diacetate, dioctyltin dibutyrate, dioctyltin dioctate, dibutyltin dilaurate, dibutyltin maleate, phenyl Tin tributyrate, phenyltin trilaurate, butyltin trimethoxy, butyltin tributoxy, octyltin trimethoxy Triphenyltin trimethoxy, dibutyltin dimethoxy, dioctyltin dimethoxy, dioctyltin versatate, dibutyl Zvi string ethoxy silicate, dibutyltin bisacetylacetonate, dibutyltin bis (o-phenyl phenoxide), dibutyltin oxide, etc. dioctyltin oxide. Two or more of these may be mixed.

  Since the tetravalent organic tin compound also acts as a part of the catalyst for curing the alicyclic epoxy resin, the content of the tetravalent organic tin compound is set to 0.01% to 5% by weight. Within this range, any tetravalent organotin compound can act as a catalyst. On the other hand, if it is less than 0.01% by weight, the content is too small, so that the action as a catalyst is not exhibited, and if it is 5% by weight or more, the content is too much, the reactivity is increased and the storage is performed. Will cause problems with sex.

  In the present invention, a divalent organotin compound and a tetravalent organotin compound are used as essential components, and these are mixed and used. When a divalent organotin compound or a tetravalent organotin compound is used alone, an adhesive cured product can be obtained. However, in the case of a divalent organotin compound, the storage stability at room temperature is inferior and is being used. On the other hand, in the case of a tetravalent organic tin compound, there are some which are inferior in storage stability at room temperature as in the case of a divalent organic tin compound, or are excellent in storage stability but have sufficient adhesion However, there is a problem that a high curing temperature of 200 ° C. or higher is required to have the above, and there is a problem that it cannot be used for an electronic component composed of an organic material substrate or the like.

  On the other hand, according to the present invention, the present epoxy resin composition is prepared by combining a divalent organotin compound and a tetravalent organotin compound at a specific ratio. In addition, it can be cured at a low temperature of 120 to 150 ° C. to obtain a cured product having high strength adhesiveness.

  The ratio of the divalent organotin compound (c1) to the tetravalent organotin compound (c2) is not particularly limited in the present invention, but the weight ratio of (c2) / (c1) is 1 to 20, particularly 1 to 10. A range of is desirable. This is when the divalent organotin compound (c1) is too much, and when the weight ratio of (c2) / (c1) is less than 1, the storage stability, which is a disadvantage of the divalent organotin compound, is gradually deteriorated. There is. On the other hand, if the tetravalent organotin compound (c2) is too much and the weight ratio exceeds 20, the reactivity may gradually decrease.

  These phenomena indicate that although the tetravalent organic tin compound is less reactive with the epoxy resin than the divalent organic tin compound, it is mixed with the divalent organic tin compound at a specific ratio. It is presumed that it is changed to a divalent organotin compound rich in reactivity by being heated at the time of adhesion. In addition, since a tetravalent organotin compound has this level of reactivity and moderate storage properties, it will have sufficient storage characteristics.

(D) Inorganic filler The inorganic filler used in the present invention is light-reflective inorganic particles. The band gap energy is not particularly limited, but is preferably 2.8 eV or more. The inorganic filler in the form of inorganic particles or metal powder improves the strength of the cured epoxy resin, contributes to adjusting the viscosity, and further has a function of reflecting light emitted from the LED or the wavelength. .

  Among these, inorganic particles of 2.8 eV or more are used when it is not necessary to obtain conduction from the lower surface of a chip such as an LED. When inorganic particles having a band gap energy of 2.8 eV or more are used, light having a wavelength emitted can be reflected more effectively by the inorganic particles. In general, wavelength absorption in an inorganic compound is mainly caused by excitation absorption of a semiconductor compound, and the band gap energy of the inorganic compound corresponds to this energy. When the band gap energy is less than 2.8 eV, the wavelength absorption range of the particles becomes 440 nm or more, and the light reflectance may be lowered in the emitted LED or the like.

In addition, the color of the inorganic particles is not particularly limited, but in order to improve the reflectance, white powder or powder having the same color as the wavelength emitted by the LED or the like to which it adheres is desirable.
Examples of such inorganic particles include zinc oxide, silicon fluoride, titanium oxide, zirconium oxide, gallium oxide, magnesium oxide, aluminum oxide, silicon dioxide, and the like. Of these, zinc oxide, titanium oxide, and zirconium oxide are preferable. These particles (powder) can be used alone, but two or more kinds may be mixed and used.

  On the other hand, the metal powder as the inorganic filler may be used either when it is necessary to obtain conduction from the lower surface of a chip such as an LED or when conduction is not necessary. If the metal powder is used, the function of obtaining electrical continuity is provided at the same time as having the function of reflecting light having the emission wavelength, as in the case of the inorganic particles. In order to further improve the reflection function, silver-like metal powder such as Ag, Pt, Al and the like is desirable.

Further, the shape may be various shapes, but if it is a flake shape, further improvement in reflectance and conductivity (for example, 1 × 10 ⁻³ Ω · cm or less) can be expected. These can be used alone, but two or more kinds may be mixed and used.

  The inorganic filler such as the inorganic powder and metal powder is not particularly limited in particle size, but the maximum particle size is 40 μm or less, particularly 20 μm or less, and the average particle size is about 1 to 10 μm, particularly 1 Those having a thickness of -5 μm are desirable. In addition, since it is used for bonding semiconductors, it is desirable to select one that does not dissolve in water or one that does not generate ionic impurities such as Na, K, or Cl.

In addition, the inorganic particles and the metal powder may be used alone as an inorganic filler, or may be mixed with each other according to required characteristics.
The amount of inorganic particles or metal powder added is 3 to 90% by weight. When the content is less than 3% by weight, the reflectance required as an inorganic filler is lowered. On the other hand, when the content is more than 90% by weight, the amount of the epoxy resin and the curing agent is relatively reduced, and the adhesive does not function. It is. A preferable content is 8 to 85% by weight, more preferably 10 to 80% by weight in the case of inorganic particles. On the other hand, if it is a metal powder, preferable content is 10 to 90 weight%, Furthermore, it is the range of 20 to 85 weight%.
In Patent Document 2, an organotin compound is blended, but it is particularly preferable to use only one tetravalent compound, and there is no specific example of an inorganic filler. Therefore, the low-temperature curing performance at 120 to 150 ° C. required by the present invention is insufficient, and the characteristics obtained from the inorganic filler are unclear, and the characteristics as a light reflective adhesive can be expected. Can not.

(E) Others In the present invention, if necessary, epoxy compounds other than alicyclic compounds and other resin components, solvents, diluents, viscosity modifiers, etc. are added within a range that does not affect the properties. It doesn't matter.

  These additives are classified into those that are incorporated into the cured product by reacting the epoxy resin with the additive or the additive itself during the curing reaction, and those that are not incorporated into the cured product. Those having no ring are desirable. In the case of a substance having a benzene ring, if it is added excessively, the benzene ring absorbs the wavelength generated by the light emission of the LED and causes a decrease in the reflectivity, etc., so the content needs attention.

  Additives that can be incorporated into the cured product include phenyl glycidyl ether, 2-ethylhexyl glycidyl ether containing an epoxy group at one end in the structure, and neo containing two or more epoxies in the structure. Pentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, non-alicyclic epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, hydrogenated bisphenol A type epoxy Examples of known epoxy resins such as resins

On the other hand, in the case of a product that is not taken into the cured product, it may have any structure as long as it is all volatile at the time of curing.
Examples of the solvent that does not react with the epoxy resin include 2,2,4-trimethyl-3-hydroxydipentaneisobutyrate, 2,2,4-trimethylpentane-1,3-isobutyrate, isobutylbutyrate, ethylene glycol monomethyl ether, Examples thereof include ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, and ethyl 2-hydroxypropanoate.

2. Adhesive for optical semiconductor The above epoxy resin adhesive composition is suitable for bonding an assembly of a semiconductor device on which an optical semiconductor chip is mounted and various components.

  The adhesive for optical semiconductors of the present invention includes light from light receiving elements such as LEDs, phototransistors, photodiodes, photocouplers, CCDs (charge coupled devices), EPROMs (erasable programmable read only memories), photosensors, and light emitting elements. It has excellent adhesiveness, hot strength, reflectance, and discoloration that are not found in conventional epoxy resin adhesive compositions for semiconductors. In particular, a large effect can be expected when used when bonding GaN-based LEDs.

  The evaluation methods (conditions) of these characteristics will be described in the following examples. The adhesiveness is 40N or more, the hot strength is 5N or more, the reflectance is 45% or more, and the color change (ΔE) is less than 5. It is excellent.

The method of using the adhesive is not particularly limited and varies depending on the composition. For example, after dropping the epoxy resin composition on the substrate and placing the optical semiconductor chip, the method is used in an oven at 50 to 250 ° C. It can be left for 20 to 300 minutes or left on a hot plate at 150 to 300 ° C. for 10 to 300 seconds to be cured.
In the case of curing in an oven, if the temperature is less than 50 ° C. or less than 20 minutes, curing of the adhesive becomes insufficient, and if the temperature exceeds 250 ° C. and exceeds 300 minutes, the resin component may be decomposed. Similarly, in the case of curing on a hot plate, the curing reaction does not proceed sufficiently at 150 ° C. or lower, resulting in insufficient curing. When the temperature exceeds 300 ° C. for 300 seconds, the resin component may be decomposed.

  EXAMPLES Hereinafter, although this invention is shown concretely using an Example and a comparative example, this invention is not limited at all by these. The raw materials used are as follows.

Epoxy compound Alicyclic epoxy resin (a): 3,4-epoxycyclohexyl-3 ′, 4′-cyclohexanecarboxylate.
Epoxy resin (b): Bisphenol A type epoxy resin.
Silane compound Silane compound (a): 3-glycidoxypropyltrimethoxysilane.
Silane compound (b): 3-methacryloxypropyltrimethoxysilane.
Silane compound (c): 3-aminopropyltrimethoxysilanesilane.
Organometallic compound Divalent organotin compound: Tin dioctate Tetravalent organotin compound: Butyltin triacetate Organoaluminum compound: Aluminum tris (ethyl acetoacetate)
Organic zirconium compound: Zirconium acetylacetonate Inorganic filler Inorganic particles (zinc oxide): Commercially available powder (band gap energy: 3.2 eV)
White powder with an average particle size of 1.2 μm.
Metal powder (silver): Flaky powder often used in conductive adhesives,
Powder with an average particle size of 1.3 μm.
Inorganic particles (copper oxide powder): Band gap energy: 2.1 eV
A reddish brown powder with an average particle size of 2.5 μm.
Other formulations Acid anhydride curing agent: MH-700, manufactured by Shin Nippon Rika Co., Ltd.
Curing catalyst: Quaternary phosphonium bromide Additive (a): Viscosity modifier for epoxy resin adhesive composition,
Butyl carbitol, which is not incorporated into the structure during the curing reaction and volatilizes.
Additive (b): viscosity adjusting agent for epoxy resin adhesive composition,
Bisphenol F-type epoxy resin incorporated into the structure during the curing reaction.

The evaluation items and evaluation methods are as follows.
Adhesive strength: An epoxy resin adhesive composition is dropped on a Cu substrate, a 1.5 mm square silicon chip is placed, and left in an oven at 120 ° C. for 60 minutes, and then left in an oven at 150 ° C. for 60 minutes. And cured. After cooling to room temperature, force was applied to the silicon chip from the horizontal direction with respect to the Cu substrate, and the force when the silicon chip was peeled was measured as adhesive strength. If the adhesive strength was 40 N or more, it was determined to be acceptable.
Hot strength: An epoxy resin adhesive composition is dropped on a Cu substrate, a 1.5 mm square silicon chip is placed, and left in an oven at 120 ° C. for 60 minutes, and then left in an oven at 150 ° C. for 60 minutes. And cured. After cooling to room temperature, the Cu substrate is allowed to stand for 20 seconds on a hot plate heated to 250 ° C., and then heated while applying force to the silicon chip from the horizontal direction with respect to the Cu substrate. The force at the time of peeling was measured as the hot strength. If the hot strength was 5N or more, it was considered acceptable.
Reflectivity: The epoxy resin adhesive composition was allowed to stand in an oven at 120 ° C. for 60 minutes, then left in an oven at 150 ° C. for 60 minutes to be cured, and then formed into a strip of 15 × 30 × 0.5 mm, A reflectance measurement sample was prepared. This sample was set in a spectrophotometer U-4001 manufactured by Hitachi, Ltd., and the light reflectance at 460 nm was measured. If the reflectance was 45% or more, it was considered acceptable.
Heat discoloration: The epoxy resin adhesive composition is printed on a glass substrate so as to have a size of 20 × 20 × 0.1 mm, left in an oven at 120 ° C. for 60 minutes, and then left in an oven at 150 ° C. for 60 minutes. And cured. After cooling to room temperature, each value of L ₁ , a ₁ , b ₁ was measured with a color difference meter. Next, after leaving the sample in an oven at 120 ° C. for 500 hours, each value of L ₂ , a ₂ , and b ₂ was measured again with a color difference meter. From these values, ΔE = √ {(L ₁ −L ₂ ) ² + (a ₁ −a ₂ ) ² + (b ₁ −b ₂ ) ² } is calculated, and ΔE is less than 5 In the case of, “◯” was given because there was little discoloration, and “X” was given if there was a lot of discoloration when 5 or more. L ₁ , a ₁ , b ₁ and L ₂ , a ₂ , b ₂ values are measured values of the L ^* a ^* b ^* color system before heating and after 500 hours of heating, respectively, and L is brightness, a and b mean chromaticity.
UV discoloration resistance: The epoxy resin adhesive composition was printed on a glass substrate so as to be 20 × 20 × 0.1 mm, left in an oven at 120 ° C. for 60 minutes, and then in an oven at 150 ° C. for 60 minutes. Allowed to cure. After cooling to room temperature, each value of L ₁ , a ₁ , b ₁ was measured with a color difference meter. Next, a 365 nm center ultraviolet lamp was applied to the sample for 1 hour, and each value of L ₂ , a ₂ , and b ₂ was measured again with a color difference meter. From these values, ΔE = √ {(L ₁ −L ₂ ) ² + (a ₁ −a ₂ ) ² + (b ₁ −b ₂ ) ² } is calculated, and ΔE is less than 5 In the case of, “◯” was given because there was little discoloration, and “X” was given if there was a lot of discoloration when 5 or more. Note that the values of L ₁ , a ₁ , and b ₁ are the same as described above.
Coating property: The epoxy resin adhesive composition filled in the syringe was continuously discharged at 1000 points from a needle having an inner diameter of 0.2 mm attached to the discharge port of the syringe. At that time, the one that is conical or hemispherical is “○”, pulls the thread to touch the adjacent point, extends linearly to the adjacent point, and the conical corner becomes higher When there were 3 or more points that were 2 mm or more, it was determined as “x”.
Storage stability: The epoxy resin adhesive composition was placed in an ointment bottle, sealed, and left at 30 ° C. for 5 days. The viscosity before and after being left was measured with a viscometer, and “○” was indicated when the viscosity after being left was within 1.2 times the viscosity before being left, and “X” was indicated when it was over 1.2 times.
Comprehensive evaluation: As a result of examining the obtained sample for adhesive strength, hot strength, reflectance, heat discoloration resistance, ultraviolet discoloration resistance, coating property, and storage stability, the adhesive strength was 40N or more, and the hot strength was 5N. As described above, only for those with a reflectance of 45% or more, heat discoloration resistance, ultraviolet discoloration resistance, applicability, and storage stability of “O”, the overall evaluation is “O”, and none of them is satisfied. When there was a characteristic, it was set as “x”.

(Examples 1-9)
Each raw material was blended according to the weight ratio in Table 1 and kneaded with a three-roll kneader to prepare a sample of the epoxy resin adhesive composition of the present invention.
Examples 1 to 3 are composed of an epoxy resin (a), a silane compound, a divalent organic tin compound, a tetravalent organic tin compound, zinc oxide, and a solvent. Is obtained by reducing the amount of zinc oxide compared to Example 2, Example 5 is obtained by increasing the silane compound more than Example 2, and increasing the ratio of divalent and tetravalent organotin compounds, Example 6 is The inorganic powder is reduced from that of Example 2 and the organic component made of epoxy resin is increased. Example 7 is a silver powder used as the inorganic powder, and conductivity is obtained. The silver powder is reduced from that in Example 7, and Example 9 uses the bisphenol F-type epoxy resin incorporated in the structure during the curing reaction as the additive (b) in Example 2. .
The obtained results are also shown in Table 1. In addition, the composition table in Table 1 is expressed in terms of% by weight with respect to the composition containing the essential component of the present invention, whereas the additive (a) and additive (b) that are not essential components are epoxy resins. Expressed in parts by weight when the adhesive composition is 100 parts by weight.

(Comparative Examples 1-9)
Each raw material was blended in the same manner as in Examples 1 to 9 and kneaded with a three-roll kneader to prepare a comparative epoxy resin adhesive composition sample. The obtained evaluation results are also shown in Table 2.
In Comparative Example 1, the organotin compound of Example 2 was changed to an organoaluminum compound, and in Comparative Example 2, the organotin compound of Example 2 was changed to an organozirconium compound.
In Comparative Example 3, a curing system using a known alicyclic epoxy resin, an acid anhydride curing agent, and a curing catalyst is used, and zinc oxide is mixed therewith.
In Comparative Example 4, a copper oxide powder having a band gap energy of 2.1 eV was used in place of the zinc oxide powder of Example 2.
In Comparative Example 5, the alicyclic epoxy resin component of Example 2 was replaced with a bisphenol A type epoxy resin.
Comparative Example 6 uses a bisphenol A type epoxy resin as in Comparative Example 5, and uses an acid anhydride curing agent and a curing catalyst.
Comparative Example 7 is a case where the amount of zinc oxide in Example 2 was significantly reduced.
In Comparative Example 8, only a divalent organotin compound was used as the organometallic compound.
Comparative Example 9 is a case where only a tetravalent organotin compound is used as the organometallic compound.

"Evaluation and Discussion"
As is apparent from Table 1, the adhesives of Examples 1 to 9 have excellent adhesive strength, and are excellent not only in low-wavelength reflectivity, deterioration against heat and ultraviolet rays, and discoloration, but also in applicability and storage stability. A cured product is obtained.
On the other hand, Comparative Example 1 is a case where an organoaluminum compound is used in place of the organotin compound, but the adhesive strength, hot strength, reflectance, heat resistance and ultraviolet discoloration resistance, and coating properties are excellent, but storage It was inferior in stability and the overall evaluation was “x”.
Comparative Example 2 is a case where an organozirconium compound is used instead of the organotin compound, but, as in Comparative Example 1, the adhesive strength, hot strength, reflectivity, heat resistance and ultraviolet discoloration resistance, and coating properties are excellent. However, the storage stability was inferior, and the overall evaluation was “x”.
In Comparative Example 3, an acid anhydride and a curing catalyst were used as the known curing agent components, so there was no problem in adhesive strength, hot strength, reflectance, heat resistance and ultraviolet discoloration resistance, and coating properties, but storage stability was improved. It was inferior and it was "x" as comprehensive evaluation.
In Comparative Example 4, since the inorganic powder filler used copper (I) having poor light reflectivity, the color of the cured product was also black and the reflectance was low. Further, although the heat resistance and ultraviolet discoloration resistance are “◯”, this is considered to be because the resin component was discolored because it was originally black so that it was not so noticeable.
Since the comparative example 5 used the bisphenol A type epoxy resin which is not preferable as this invention, the adhesive strength and the hot strength were low, the ultraviolet discoloration resistance was also inferior, and it was "x" as comprehensive evaluation. The reason why the adhesive strength is weak seems to be that although the cured product is obtained as compared with the use of the alicyclic epoxy resin, the curing reaction does not proceed sufficiently.
Comparative Example 6 uses a bisphenol A type epoxy resin as in Comparative Example 5, and uses an acid anhydride curing agent and a curing catalyst. Although these are known resin components, the curing reaction has sufficiently progressed, and sufficient adhesive strength and hot strength have been obtained. However, since the bisphenol A type epoxy resin is used, it is inferior in ultraviolet discoloration resistance, and because it uses an acid anhydride curing agent and a curing catalyst, it is inferior in storage stability. Met.
In Comparative Example 7, although the adhesive strength was sufficient, the hot strength was inferior, and the reflectance was low because the amount of zinc oxide was too small. The overall evaluation was “x”.
In Comparative Example 8, only a divalent organic tin compound was used as the organic tin compound, but the adhesive strength, reflectance, discoloration, etc. were sufficient, but the viscosity was 1.5 times the initial value. The overall evaluation was “x” because of poor storage stability.
In Comparative Example 9, only a tetravalent organotin compound was used as the organotin compound. However, since the curing temperature was not sufficient under the test conditions, it was assumed that the curing was insufficient. The strength could not be obtained as desired, and the overall evaluation was “x”.

Claims (7)

Contains alicyclic epoxy compound (A), silane compound (B) containing hydrolyzable group directly bonded to silicon atom, organotin compound (C), and light-reflective inorganic filler (D) as essential components And an epoxy resin adhesive composition that cures at 120 to 150 ° C. ,
The organotin compound (C) is a mixture of a divalent organotin compound (c1) and a tetravalent organotin compound (c2), and the content of each component is based on the total amount of the composition, A) is 1 to 90% by weight, (B) is 0.1 to 15% by weight, (c1) is 0.01 to 5% by weight, (c2) is 0.01 to 5% by weight, and (D) is An epoxy resin adhesive composition characterized by being 3 to 90% by weight.   The epoxy resin adhesive composition according to claim 1, wherein the silane compound (B) is a silane compound containing no nitrogen element.   The epoxy resin adhesive composition according to claim 1 or 2, wherein the silane compound (B) is an alkoxysilane compound containing 2 or 3 hydrolyzable groups having 1 to 3 carbon atoms.   The mixed amount of the divalent organotin compound (c1) and the tetravalent organotin compound (c2) is (c2) / (c1) = 1 to 20 in weight ratio. The epoxy resin adhesive composition as described.   The epoxy resin adhesive composition according to claim 1, wherein the light-reflective inorganic filler (D) is an inorganic particle having a band gap energy of 2.8 eV or more.   The epoxy resin adhesive composition according to claim 1, wherein the light-reflective inorganic filler (D) is one or more metal powders of Ag, Pt, or Al.   The adhesive for optical semiconductors which uses the epoxy resin adhesive composition in any one of Claims 1-6.