TWI494341B - Epoxy resin compositions and shaped articles - Google Patents

Description

Epoxy resin composition and formed product

The present invention relates to an electrical insulation, laminated board, exothermic substrate, etc., which are excellent in reliability. An epoxy resin composition useful for an insulating material for electronic parts and a molded article using the same.

Traditionally, about the electrical properties of diodes, transistors, integrated circuits, etc. In the sealing method of an electronic component, or a semiconductor device, etc., a sealing method such as an epoxy resin or a enamel resin or the like is used; or a hermetic sealing method using glass, metal, ceramics or the like is used, but in recent years, in addition to the requirement for reliability improvement In addition to the large number of producers, that is, the resin sealing by the transfer molding which has the advantages of cost-effectiveness, has become the mainstream.

In the resin composition used in the resin sealing method by the above-mentioned transfer molding, a resin material which is an epoxy resin and a phenol resin of a curing agent as a main component of the resin component is generally used as a sealing material.

Now, an epoxy resin composition used for the purpose of protecting components such as power devices is filled with a high-density inorganic filler such as crystalline ceria because of the amount of heat released by the device.

Further, in recent years, power devices have been formed by a single wafer in which IC technology is incorporated, or a modularizer, and the like, and it is desired to further improve the heat release property and thermal expansion property of the sealing material.

In response to these requirements, in order to improve the thermal conductivity, attempts have been made to use crystalline cerium oxide, cerium nitride, aluminum nitride, and spherical alumina powder (Patent Documents 1, 2), but to enhance the inorganic filler material. When the content is high, the viscosity increases while forming, and the flow rate also decreases, which causes a problem of impaired formability. Therefore, there is a limitation in the method of increasing the content of the inorganic filler alone.

In view of the above-described background, there is a method of reviewing the high heat transfer efficiency by the matrix resin itself. For example, in Patent Document 3 and Patent Document 4, it is proposed to use a straight mesogen base. A resin composition of a liquid crystalline resin. However, these epoxy resins having a liquid crystal group are those having a high crystallinity and a high melting point of a rigid structure such as a biphenyl structure or a methylimine structure, and are treated as an epoxy resin composition. Its shortcomings. Further, in order to align the molecules in a hardened state with good efficiency, it is necessary to particularly apply a strong magnetic field to harden the operation, and the like, and therefore, it is greatly restricted to the equipment when it is widely used in industry. In addition, in the combination with the inorganic filler, the thermal conductivity of the inorganic filler is much larger than that of the matrix resin, and even if the thermal conductivity of the matrix resin itself is increased, the heat conduction of the composite material is actually achieved. The rate increase is not helpful, so the effect of improving the thermal conductivity is not obtained.

In Patent Document 5, an epoxy resin of a 4,4'-benzophenone type is disclosed, but only an example of a cured product obtained by using an acid anhydride as a curing agent is disclosed, and it is not a high degree of high thermal conductivity. Construct a controlled hardened material.

Patent Document 1: Japanese Patent Publication No. 11-147936

Patent Document 2: JP-A-2002-309067

Patent Document 3: Japanese Patent Publication No. 11-323162

Patent Document 4: JP-A-2004-331811

Patent Document 5: JP-A-2-202512

Invention disclosure

Accordingly, an object of the present invention is to provide a solution to the above problems, which is excellent in formability, has high thermal conductivity when compounded with an inorganic filler, and imparts heat resistance under low thermal expansion and An epoxy resin composition of a moisture-resistant cured product, and a molded article using the same.

The present inventors have found that when a specific epoxy resin and a specific hardener are combined, a molded article having a high-order structure after curing can be obtained, and its high thermal conductivity, low thermal expansion property, and high heat resistance are obtained. The high moisture resistance can be specifically increased to complete the present invention.

That is, the present invention relates to an epoxy resin composition characterized in that in the epoxy resin composition containing the (A) epoxy resin and the (B) hardener, 50% by weight or more of the epoxy resin is as follows. a 4,4'-benzophenone-based epoxy resin represented by the formula (1), and 50% by weight or more of the curing agent is a 4,4'-benzophenone phenol represented by the following general formula (2) Resin, and the equivalent ratio of the epoxy group in the epoxy resin and the functional group in the hardener is in the range of 0.8 to 1.5, (However, n is 0~15) (However, m is the number of 0~15).

The epoxy resin composition of the present invention may contain an inorganic filler, and the inorganic filler is preferably 50 to 95% by weight. Further, the epoxy resin composition of the present invention is suitable as an epoxy resin composition for semiconductor encapsulation.

Furthermore, the present invention relates to a prepreg characterized in that the epoxy resin composition is impregnated into a sheet-like fibrous base material and formed into a semi-hardened state.

Further, the present invention relates to a molded article characterized by subjecting the above epoxy resin composition to heat molding. The cured product is preferably one or more of the following, and 1) the thermal conductivity is 4 W/m. K or more; 2) In the differential scanning calorimetry, the peak of the melting point is in the range of 150 ° C to 300 ° C; and 3) the amount of heat absorbed by the resin component in the differential scanning calorimetry is 5 J/g or more.

The best form of implementing the invention

The 4,4'-benzophenone epoxy resin (also referred to as a benzophenone epoxy resin) represented by the above general formula (1), which can be used to make 4,4'-dihydroxydiphenyl Methyl ketone is produced by reacting with epichlorohydrin. This reaction can also be carried out in the same manner as a general epoxidation reaction. For example, 4,4'-dihydroxybenzophenone can be dissolved in excess epichlorohydrin, and then in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, 50~ The method of reacting at 150 ° C, preferably 60 to 100 ° C, for 1 to 10 hours. In this case, the amount of the alkali metal hydroxide to be used is 0.8 to 1.2 moles, preferably 0.9 to 1.0 moles, based on the hydroxyl group 1 mole in the 4,4'-dihydroxybenzophenone. Epichlorohydrin is used in excess of the hydroxyl group in 4,4'-dihydroxybenzophenone. In general, it is relative to the hydroxyl group in 4,4'-dihydroxybenzophenone. Seoul, 1.5 to 15 moles. After the completion of the reaction, the excess epichlorohydrin is distilled off, and the residue is dissolved in a solvent such as toluene or methyl isobutyl ketone, and then filtered, washed with water to remove the inorganic salt, and finally the solvent is distilled off. The standard benzophenone epoxy resin.

In the above general formula (1), n is a number from 0 to 15, but the value of n is changed by changing the epichlorohydrin used in the synthesis reaction of the epoxy resin with respect to 4,4'-dihydroxybenzophenone. Morbi can be easily adjusted. The value of n can be appropriately selected depending on the application to which it is applied. For example, in the application of semiconductor sealing for high filling rate of fillers, it is preferred to have crystallinity at a low viscosity, and the average value of n can be preferably in the range of 0.01 to 1.0. select. If it is larger than this, its viscosity will become higher, or the handleability will be lowered.

The benzophenone-based epoxy resin used in the present invention can be synthesized by mixing 4,4'-dihydroxybenzophenone with a phenolic compound of another type. The mixing ratio of 4,4'-dihydroxybenzophenone at this time was 50% by weight or more. The phenolic compound is not particularly limited, and a monofunctional one having two hydroxyl groups is preferred in the sole molecule.

The epoxy resin used in the present invention is a benzophenone-based epoxy resin represented by the general formula (1), and the epoxy resin component generally contains 50% by weight or more, preferably 80% by weight or more. The best is 90% by weight or more. The epoxy equivalent of the benzophenone-based epoxy resin is generally in the range of from 160 to 20,000, and preferably the epoxy equivalent is appropriately selected depending on the use. For example, in the case of semiconductor encapsulation, based on the viewpoint of high filling rate and fluidity improvement of the inorganic filler, it is preferable to use a low viscosity, and in the above general formula (1), n=0 body The epoxy equivalent of the main component is preferably in the range of 160 to 250. Further, in the use of a laminate or the like, it is preferably in the range of 400 to 20,000 from the viewpoint of imparting film properties and flexibility.

The benzophenone-based epoxy resin represented by the general formula (1) may be appropriately selected depending on the application. For example, in the use of semiconductor sealing, since many of them are treated with powder, they are preferably crystallized at room temperature, and have a melting point of 80 ° C or higher and 150 ° C. The melt viscosity is 0.005 to 0.2 Pa. s is ideal. Further, in the use of a laminate or the like, since many users are dissolved in a solvent, the form of the epoxy resin is not particularly limited.

The purity of the epoxy resin used in the present invention, especially the amount of water-decomposable chlorine, is preferably based on the improvement of the reliability of the applicable electronic component. Although it is not particularly limited, it is preferably 1000 ppm or less, and preferably 500 ppm or less. Further, the term "hydrolyzable chlorine" as used in the present invention means a method measured by the following method. That is, after dissolving 0.5 g of the sample in 30 ml of dioxane, adding 10 ml of 1 N-KOH, boiling and refluxing for 30 minutes, cooling to room temperature, and further adding 100 ml of 80% acetone water to 0.002 N- The AgNO ₃ aqueous solution was subjected to potentiometric titration.

In the epoxy resin composition of the present invention, in addition to the benzophenone-based epoxy resin represented by the general formula (1) which is an essential component used in the present invention, it may be used in combination with two or more epoxy groups in the molecule. Other epoxy resins. For example, there are bisphenol A, 4,4'-dihydroxydiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4 '-Dihydroxydiphenyl hydrazine, 4,4'-dihydroxydiphenyl sulfide, quinone diphenol, 4,4'-biphenyl, 3,3',5,5'-tetramethyl-4, 4'-dihydroxybiphenyl, 2,2'-biphenyl, resorcinol, catechol, t-butyl catechol, t-butylhydroquinone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2, 3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, the above dihydroxynaphthalene Divalent phenols such as allyl compounds or polyallyl compounds, allylated bisphenol A, allylated bisphenol F, allylated phenol novolac, or phenol novolac, bisphenol A Novolac, o-cresol novolac, m-cresol novolac, p-cresol novolac, xylenol novolac, poly-p-hydroxystyrene, tris-(4-hydroxyphenyl)methane, 1 1,2,2-tetrakis(4-hydroxyphenyl)ethane, fluorine Glycerol, pyrogallol, t-butyl pyrogallol, allylated pyrophenol, polyallylated pyrophenol, 1,2,4-benzenetriol, 2,3,4-tri a trivalent or higher phenol such as a hydroxybenzophenone, a phenol aralkyl resin, a naphthol aralkyl resin or a dicyclopentadiene resin, or a ring derived from a halogenated bisphenol such as tetrabromobisphenol A Oxypropyl propyl etherate and the like. These other epoxy resins may be used alone or in combination of two or more.

The epoxy resin composition of the present invention is controlled such that the blending ratio of the epoxy resin composition of the benzophenone epoxy resin represented by the general formula (1) is 50% by weight or more of the epoxy resin resin component. When it is possible to contain an epoxy resin of another type, the total amount of the difunctional epoxy resin is generally 80% by weight or more, preferably 90% by weight or more, from the viewpoint of improving the thermal conductivity when the cured product is formed. .

The epoxy resin which is other than the benzophenone type epoxy resin is the bisphenol type epoxy resin shown by the following general formula (3).

(R, R ¹ to R ³ are a halogen atom, a hydrocarbon group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms, m is a number of 0 to 5, and X is a single bond, a methyl group, an oxygen atom, a sulfonic acid group or a sulfur atom.)

The above bisphenol epoxy resin may be 4,4'-dihydroxybiphenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl, 4,4'-dihydroxy Diphenylmethane, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxy Diphenyl sulfide is used as a raw material, and is synthesized by a general epoxidation reaction. These epoxy resins can be used in the raw material stage in a mixture with 4,4'-dihydroxybenzophenone and then synthesized. Among these, epoxy resin synthesized from 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylmethane and 4,4'-dihydroxydiphenyl ether is the best. In addition to providing an epoxy resin having excellent handleability, it can also provide a molded article excellent in thermal conductivity.

In the epoxy resin composition of the present invention, a benzophenone-based phenol resin represented by the above general formula (2) is used as a curing agent. Here, the benzophenone-based phenol resin is preferably a 4,4'-dihydroxybenzophenone of 0.

Further, when the epoxy resin composition of the present invention is used as a prepreg for a laminate, in the above general formula (2), a benzophenone system having a mean value m larger than 0 is used. Phenolic resins are preferred users. The preferred m value at this time is 1 to 15 and the best is 2 to 15. In addition, the method of producing the benzophenone-based phenol resin having an increased number of m is not particularly limited, and for example, the benzophenone-based epoxy resin represented by the above general formula (1) is excessive. A method in which 4,4'-dihydroxybenzophenone is reacted. Alternatively, the hydroxyl group 1 mole of 4,4'-dihydroxybenzophenone and 4,4'-dihydroxybenzophenone is synthesized by reacting epichlorohydrin of 1 mol or less.

The hydroxyl equivalent of the benzophenone-based phenol resin represented by the general formula (2) is generally in the range of 100 to 20,000, but may be appropriately selected according to the use, as well as the epoxy resin. . For example, in the use of semiconductor encapsulation, based on the high filling rate and fluidity improvement of the inorganic filler, it is preferred to have a low viscosity, and in the above general formula (2), It is preferred that the m=0 body is a main component having a hydroxyl equivalent of from 100 to 200. Further, in the use of a laminate or the like, it is preferably in the range of 200 to 20,000 from the viewpoint of imparting film properties and flexibility. The hydroxyl equivalent is preferably one in which two or more types of epoxy resins are used, and in this case, the hydroxyl equivalent can be calculated by the total weight (g) / hydroxyl group (mole).

The hardener used in the epoxy resin composition of the present invention, in addition to the benzophenone-based phenol resin represented by the general formula (2) of the essential component of the present invention, generally, a known epoxy resin can be used as needed. The hardener is preferably combined with another phenolic hardener having a phenolic hydroxyl group. Other phenolic hardeners, specific examples thereof are: bisphenol A, bisphenol F, 4,4'-dihydroxydiphenyl ether, 1,4-bis(4-hydroxyphenoxy)benzene, 1,3- Bis(4-hydroxyphenoxy)benzene, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl fluorene, 4, 4'-dihydroxydiphenylbiphenyl, 2,2'-dihydroxybiphenyl, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphorus phenanthrene-10-oxidation , phenol novolac, bisphenol A novolac, o-cresol novolac, m-cresol novolac, p-cresol novolac, xylenol novolac, poly-p-hydroxystyrene, hydroquinone, Resorcinol, catechol, t-butyl catechol, t-butylhydroquinone, fluoroglycolol, pyrogallol, t-butyl pyrogallol, allylated pyrophenol , polyallylated pyrophenol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1 ,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4 -Dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene 2,8-dihydroxynaphthalene, allyl compound or polyallyl compound of the above dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, allylated phenol novolac, allyl Alkaloids and the like.

In the epoxy resin composition of the present invention, when the compounding ratio of the benzophenone-based phenol resin represented by the general formula (2) is, for example, 50% by weight or more based on the curing agent component, it may contain other phenolic compounds ( The resin is preferably 80% by weight or more based on the total amount of the difunctional phenolic compound (resin), and is preferably 90% by weight or more, from the viewpoint of improving the thermal conductivity when the cured product is formed.

The phenolic compound (resin) other than the benzophenone-based phenol resin is preferably, for example, 4,4'-dihydroxybiphenyl or 4,4'-dihydroxydiphenyl. Methane, 4,4'-dihydroxydiphenyl ether, 1,4-bis(4-hydroxyphenoxy)benzene, 4,4'-dihydroxydiphenyl sulfide, 1,5-naphthalenediol, 2,7-naphthalenediol, 2,6-naphthalenediol. The amount of the difunctional phenolic compound or the phenolic resin to be used is generally 50% by weight or less, preferably 20% by weight or less, based on the curing agent component.

In addition to the above-mentioned phenol-based curing agent, the curing agent used in the epoxy resin composition of the present invention may be used in combination with other curing agents conventionally known as curing agents. For example, an amine-based curing agent, an acid anhydride-based curing agent, a phenol-based curing agent, a polythiol-based curing agent, a polyamine-based amide-based curing agent, an isocyanate-based curing agent, and a blocked isocyanate-based curing agent may be used. The blending amount of these hardeners can be appropriately set in consideration of the kind of the hardener to be blended or the physical properties of the heat conductive epoxy resin molded body which can be obtained.

Specific examples of the amine-based curing agent include aliphatic amines, polyether polyamines, alicyclic amines, and aromatic amines. Aliphatic amines, for example, ethylidene diamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylenemethyl Amine, trimethylhexamethylenediamine, di-ethyltriamine, imidodipropylamine, bis(hexamethyl)triamine, tri-ethyltetramine, tetraethylidene Amine, pentaethylhexamine, N-hydroxyethylethylidene diamine, tetrakis(hydroxyethyl)ethylidene diamine, and the like. The polyether polyamines are, for example, triethylene glycol diamine, tetraethylene glycol diamine, diethylene glycol bis (propylamine), polyoxypropylene diamine, polyoxypropyltriamine, and the like. Alicyclic amines such as isophorone diamine, dicyclopentadienyl diamine, N-aminoethylpiperazine, bis(4-amino-3-methyldicyclohexyl)methane, double (Aminomethyl)cyclohexane, 3,9-bis(3-aminopropyl) 2,4,8,10-tetraoxaspiro (5,5) undecane, raw spinylene diamine, etc. . Aromatic amines, for example, tetrachloro-p-phthaldimethyldiamine, m-phthaldimethyldiamine, p-phthaldimethyldiamine, m-phenylenediamine, o-phenylene Diamine, p-phenylenediamine, 2,4-diaminoanisole, 2,4-toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodi Phenylmethane, 4,4'-diamino-1,2-diphenylethane, 2,4-diaminodiphenylanthracene, 4,4'-diaminodiphenylanthracene, m- Aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethylphenol, triethanolamine, methylbenzylamine, α-(m-aminophenyl)B Amine, α-(p-aminophenyl)ethylamine, diaminodiethyldimethyldiphenylmethane, α,α'-bis(4-aminophenyl)-p-diiso Propyl benzene and the like.

Specific examples of the acid anhydride-based hardener include, for example, dodecene succinic anhydride, polysuccinic anhydride, polysebacic anhydride, polysebacic anhydride, poly(methyloctadecanedioic acid) anhydride, poly(phenyl hexadecane) Alkanoic acid anhydride, methyltetrahydrophthalic anhydride, methyl hexahydrophthalic anhydride, hexahydrophthalic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, tetrahydrophthalic anhydride , trialkyltetrahydrophthalic anhydride, methylcyclohexene dicarboxylic anhydride, methylcyclohexene tetracarboxylic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride , ethylene glycol trimellitate, chlorohydrin anhydride, benzoic anhydride, methyl benzoic acid anhydride, 5-(2,5-dioxytetrahydro-3-furanyl)-3-methyl-3 -cyclohexane-1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalene succinic dianhydride, 1-methyl-dicarboxy-1,2 , 3,4-tetrahydro-1-naphthalene succinic dianhydride, and the like.

In the epoxy resin composition of the present invention, the blending ratio of the epoxy resin and the hardener is in the range of from 0.8 to 1.5 in terms of the equivalent ratio of the epoxy group to the functional group in the hardener. When it is outside this range, the unreacted epoxy group or the functional group in the hardener remains after hardening, and it is not preferable as the reliability of the electrical insulating material is lowered.

An inorganic filler may also be added to the epoxy resin composition of the present invention. The amount of the inorganic filler to be added is generally 50 to 95% by weight, preferably 80 to 95% by weight, based on the epoxy resin composition. If it is less than this, the effect of high thermal conductivity, low thermal expansion property, and high heat resistance cannot be fully exhibited. The effect of these is that the more inorganic fillers are preferred, but they do not increase in response to their volume fraction, but rather increase from a specific amount of addition. These physical properties are considered to be caused by the effect of controlling the high-order structure in the polymer state, and since this high-order structure is mainly formed on the surface of the inorganic filler material, a certain amount of inorganic filler material must be required. . On the other hand, when the amount of the inorganic filler to be added is more than this, the viscosity thereof may become high, or the formability may be deteriorated.

The inorganic filler is preferably spherical, and when it is also included in the cross section, it is not particularly limited as long as it is spherical, but it is based on the improvement of fluidity as much as possible. It is better to be close to a true sphere. Thereby, the closest packing structure such as a face-centered cubic structure or a hexagonal dense structure can be easily obtained, and a sufficient filling amount can be obtained. In the case of a non-spherical shape, when the filling amount is increased, the friction between the fillers is increased, so that the fluidity is extremely lowered, the viscosity is increased, and the formability is deteriorated before the above upper limit is reached. Therefore it is not ideal.

Based on the improvement of thermal conductivity, among the inorganic filler materials, the thermal conductivity is 5 W/m. It is preferable that the inorganic filler of K or more is 50% by weight or more, and aluminum oxide, aluminum nitride, crystalline cerium oxide or the like is preferably used. The best of these is spherical alumina. Further, an amorphous inorganic filler which is not related to the shape, such as molten cerium oxide, crystalline cerium oxide or the like, may be used in combination as needed.

The average particle diameter of the inorganic filler is preferably 30 μm or less. When the average particle diameter is larger than this, the fluidity of the epoxy resin composition is impaired, and the strength is also lowered, which is not preferable.

Further, as the inorganic filler, a fibrous substrate such as glass fiber or a fibrous substrate or a particulate inorganic filler may be used in combination. When the composite is mixed with a fibrous substrate, the solvent-based varnish may be, for example, impregnated into a fibrous fibrous substrate, dried, and then used as a prepreg according to the invention. The prepreg thus formed can be made of a metal substrate such as copper foil, aluminum foil, stainless steel foil, polyethylene terephthalate, polybutylene terephthalate or polyethylene naphthalene. A polymer substrate such as an acid ester, a liquid crystal polymer, a polyamine, a polyimine or a Teflon is laminated and heat-molded to be applied to a printed circuit board, a heat-releasing substrate, or the like.

In the epoxy resin composition of the present invention, a conventionally known hardening accelerator can also be used. For example, there are amines, imidazoles, organophosphines, Lewis acids, etc., specifically, for example, 1,8-diazabicyclo(5,4,0)undecene-7, tri-ethylene diamine a tertiary amine such as benzyldimethylamine, triethanolamine, dimethylaminoethanol or tris(dimethylaminomethyl)phenol, 2-methylimidazole, 2-phenylimidazole, 2-benzene Organic phosphines such as imidazoles such as 4-methylimidazole and 2-heptadecylimidazole, tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine , tetraphenyl hydrazine. Tetraphenylborate, tetraphenylphosphonium. Ethyltriphenylborate, tetrabutylphosphonium. Tetrabutyl hydride such as tetrabutyl borate. Tetrasubstituted borate, 2-ethyl-4-methylimidazole. Tetraphenylborate, N-methylmorpholine. Tetraphenylborate such as tetraphenylborate. In general, the amount added is in the range of 0.2 to 10 parts by weight based on 100 parts by weight of the epoxy resin. These can be used alone or in combination.

The amount of the above-mentioned curing catalyst is preferably 0.1 to 10.0% by mass based on the total of the epoxy resin (including the halogen-containing epoxy resin as a flame retardant) and the curing agent. If it is less than 0.1% by mass, the molding time becomes long, and the workability is lowered due to the decrease in rigidity during molding. Conversely, if it exceeds 10.0% by mass, hardening occurs during the forming process, which is liable to occur. Unfilled situation.

In the epoxy resin composition of the present invention, a wax which is generally used as a release agent in the epoxy resin composition can be used. The wax may, for example, be stearic acid, octadecanoic acid, octadecyl carbonate, phosphate or the like.

In the epoxy resin composition of the present invention, in order to improve the adhesion of the inorganic filler and the resin component, a coupling agent generally used in the epoxy resin composition can be used. As the coupling agent, for example, an epoxy decane can be used. The amount of the coupling agent added is preferably 0.1 to 2.0% by mass based on the epoxy resin composition. When the amount is less than 0.1% by mass, the blending of the resin and the substrate is deteriorated, and the formability is also deteriorated. On the other hand, when it exceeds 2.0% by mass, the molded article may be contaminated in the continuous formability.

Further, in the epoxy resin composition of the present invention, thermoplastic oligomers can be added from the viewpoint of improvement in fluidity at the time of molding and improvement in adhesion to a substrate such as a lead frame. Thermoplastic oligomers, such as C5 and C9 petroleum resins, styrene resins, enamel resins, enamel. Styrene copolymer resin, 茚. Styrene. Phenol copolymer resin, 茚. Coumarone copolymer resin, 茚. Benzothiophene copolymer resin and the like. The amount of addition is generally in the range of 2 to 30 parts by weight based on 100 parts by weight of the epoxy resin.

Further, the epoxy resin composition of the present invention can be suitably used as a general user in an epoxy resin composition. For example, there are a phosphorus-based flame retardant, a flame retardant such as a bromine compound or antimony trioxide, and a coloring agent such as carbon black or an organic dye.

In the epoxy resin composition of the present invention, an epoxy resin, a hardener, an inorganic filler, and other components other than the coupling agent may be uniformly mixed by a mixer, a coupling agent may be added, and then a heating roller may be used. It is produced by kneading a kneading machine or the like. There is no particular limitation on the order in which these ingredients are combined. Further, after the kneading, the melted kneaded material may be ground to be pulverized or tableted. The epoxy resin composition of the present invention contains an epoxy resin and a curing agent as main components of the resin component. It is preferably 60% by weight or more, more preferably 80% by weight or more, and is an epoxy resin and a hardener.

The epoxy resin composition of the present invention is useful as an electrical insulating material, and is particularly suitable for use as a sealing device in a semiconductor device.

In order to obtain a molded article using the epoxy resin composition of the present invention, for example, transfer molding, press molding, injection molding, injection molding, extrusion molding, and the like can be applied, but based on the viewpoint of mass productivity, Transfer molding is preferred. At the time of the formation, heating can be performed to cause hardening (polymerization). Therefore, the obtained molded product is also referred to as a cured product because it is a molded product of a polymer resin (thermoplastic or thermosetting resin). Therefore, the curing referred to in the present specification also means polymerization, and the cured resin contains a thermoplastic resin.

The molded article of the present invention is generally formed as a three-dimensional cross-linker, but it is not necessarily a three-dimensional cross-linked body, and may be a molded product of a thermoplastic secondary polymer. Wherein, in particular, when the difunctional epoxy resin is reacted with the difunctional hardener, the secondary hydroxyl group formed by the ring opening reaction of the epoxy group is further reacted with the epoxy group to become a cubic bond. The joint is a thermoplastic polymer molded body which can be thermoplastic by selecting a curing condition. From the viewpoint of high thermal conductivity, it is preferable to form a crystalline molded product. However, in general, since the three-dimensional crosslinked body hinders crystallinity, the crosslinking is reduced and the secondary polymer is formed as a main body. The body is preferred. The crystallinity of the molded body can be confirmed by observing the endothermic peak of the crystal melting under the differential scanning calorimetry as a melting point. Generally, the melting point ranges from 120 ° C to 320 ° C, preferably from 150 ° C to 300 ° C, and most preferably from 200 ° C to 280 ° C.

The degree of crystallization of the molded article of the present invention is preferably as high as possible, and can be evaluated by the heat absorption by melting of the crystal under differential scanning calorimetry. In general, the heat absorption amount is 5 J/g or more per unit weight of the resin component minus the filler, and preferably the heat absorption is 10 J/g or more: more preferably 20 J/g or more, and most preferably 30 J /g or more. If it is smaller than this, it has a small effect of improving the thermal conductivity of the epoxy resin molded article. Further, from the viewpoint of improvement in low thermal expansion property and heat resistance, it is preferred that the crystallinity is higher. In addition, the term "heat absorption" as used herein refers to a heat absorption amount measured by a differential thermal analyzer using a sample of about 10 mg of a fine balance and a temperature increase rate of 10 ° C /min under a nitrogen gas flow.

The molded article of the present invention can be obtained by heat molding by the above-described forming method, but in general, the molding temperature is from 80 ° C to 250 ° C, and in order to increase the degree of crystallization of the molded product, It is preferred that the melting point of the molded article is a low temperature. The preferred forming temperature is in the range of from 100 ° C to 220 ° C, and most preferably from 150 ° C to 200 ° C. Further, the forming time is preferably from 30 seconds to 1 hour, and the optimum forming time is from 1 minute to 30 minutes. Further, after forming, the degree of crystallization can be improved by post-curing. Usually, the post-cure temperature is 130 ° C to 250 ° C, and the time is in the range of 1 hour to 20 hours, preferably, at a temperature lower than the temperature of the endothermic peak by 5 ° C to 40 ° C under differential thermal analysis. It is ideal for post-cure from 1 hour to 24 hours. In addition, the preferred thermal conductivity of the shaped body is 4 W/m. Above K, the best is 6 W/m. K or above.

Example

Hereinafter, the present invention will be further specifically described by way of examples.

Reference example 1

1070 g of 4,4'-dihydroxybenzophenone was dissolved in 6500 g of epichlorohydrin, and 808 g of 48% aqueous sodium hydroxide solution was dropped under reduced pressure (about 130 Torr) at 60 ° C for 4 hours. . In the meantime, the generated water is discharged outside the system by azeotropy with epichlorohydrin, and the distilled epichlorohydrin is returned to the system. After the completion of the dropwise addition, the reaction was further continued for 1 hour, and then the epichlorohydrin was distilled off, and then 3,500 g of methyl isobutyl ketone was added, followed by washing with water to remove the salt. Thereafter, 100 g of 20% sodium hydroxide was added at 80 ° C, stirred for 2 hours, and washed with water of 1000 mL of warm water. Then, water was removed by liquid separation, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 1460 g (epoxy resin A) of a pale yellow crystalline epoxy resin.

The melting point of epoxy resin A measured by capillary method is 128 ° C to 131 ° C, while the viscosity at 150 ° C is 11.6 mPa. s. The epoxy equivalent system 179 and the water-decomposable chlorine were 270 ppm, and the ratio of each component in the general formula (1) obtained by GPC measurement of the obtained resin was 91.0% when n=0, and when n=1. The time is 8.2%. Here, the term "water-decomposable chlorine" means that 0.5 g of the sample is dissolved in 30 ml of dioxane, 10 ml of 1N-KOH is added, and the mixture is boiled for 30 minutes, cooled to room temperature, and further added with 80% acetone water. After 100 ml, the value was determined by potentiometric titration with a 0.002 N-AgNO ₃ aqueous solution. The term "melting point" refers to a value obtained by a capillary method at a temperature rising rate of 2 ° C / min. The viscosity was measured by BROOK FIELD and measured under CAP2000H, and the softening point was measured by the ring method according to JIS K-6911. In addition, the GPC measurement is based on: the device is a 515A type manufactured by Japan Waters Co., Ltd., the column is TSK-GEL2000×3 tube and TSK-GEL4000×1 tube (other than TOSOH), and the solvent is tetrahydrofuran. The flow rate is 1 ml/min, the temperature is 38 ° C, the detector is RI, and the conditions are carried out.

Examples 1 to 6 and Comparative Examples 1 to 5

The epoxy resin component used was an epoxy resin (epoxy resin A) of Reference Example 1 and an epoxide of 4,4'-dihydroxydiphenyl ether (epoxy resin B: manufactured by Toki Chemical Co., Ltd., YSLV-80DE, ring) Oxygen equivalent 174), or biphenyl epoxy resin (epoxy resin C: Nippon epoxy resin, YX-4000H, epoxy equivalent 195), and hardener used 4,4'-dihydroxydiphenyl Ketone (hardener A), 4,4'-dihydroxydiphenyl ether (hardener B), 4,4'-dihydroxydiphenylmethane (hardener C) or phenol novolac (hardener E: group Made by Rong Chemical, PSM-4261, OH equivalent 103, softening point 82 ° C). Further, triphenylphosphine was used as the hardening accelerator, and spherical alumina (average particle diameter of 12.2 μm) was used as the inorganic filler. After mixing the ingredients shown in Table 1 and thoroughly mixing them with a mixer, they were further kneaded by a heating roll for about 5 minutes, then cooled, and then ground to obtain epoxy resins of Examples 1 to 6 and Comparative Examples 1 to 5, respectively. Composition. Using the epoxy resin composition, molding and post-hardening were carried out under the conditions shown in Table 1, and the physical properties of the molded product were evaluated.

The results were compiled and shown in Tables 1 and 2. Further, the numbers of the respective complexes in the tables are parts by weight. Furthermore, the evaluation is based on the following.

(1) Thermal conductivity: The LFA447 type thermal conductivity meter manufactured by NETZSCH was used and measured by an unsteady hot line method.

(2) Measurement of melting point and heat of fusion (DSC method): Measurement was carried out by using a differential scanning calorimeter (Model DSC6200 manufactured by Seiko Instruments) at a temperature increase rate of 10 ° C /min.

(3) Linear expansion coefficient and glass transition temperature: A TMA120C type thermomechanical measuring device manufactured by Seiko Instruments Co., Ltd. was used, and the temperature was measured at a heating rate of 10 ° C / min.

(4) Water absorption rate: A disk having a diameter of 50 mm and a thickness of 3 mm was formed, and after the post-hardening, it was made to absorb moisture at 85 ° C and a relative humidity of 85% for 100 hours, and then the weight change rate was measured.

Industrial availability

The epoxy resin composition of the present invention is excellent in moldability and reliability, and is an excellent cured product capable of imparting high thermal conductivity, low water absorbability, low thermal expansion property, and high heat resistance, and is suitably used for semiconductor sealing and layering. Insulation materials for electrical and electronic parts, such as laminates and heat-dissipating substrates, can exhibit excellent heat dissipation and dimensional stability.

Claims (8)

An epoxy resin composition characterized in that, in an epoxy resin composition containing (A) an epoxy resin and (B) a phenolic curing agent having a phenolic hydroxyl group, 50% by weight or more of the epoxy resin is as follows. Formula 1) (4,4'-benzophenone-based epoxy resin represented by n-number 0 to 15), and 50% by weight or more of the curing agent is the following general formula (2) (4,4'-benzophenone-based phenol resin represented by m), and the equivalent ratio of the epoxy group in the epoxy resin and the phenolic hydroxyl group in the hardener is Within the range of 0.8~1.5. An epoxy resin composition according to claim 1 which contains 50 to 95% by weight of an inorganic filler. An epoxy resin composition according to claim 1 of the patent application, which is an epoxy resin composition for semiconductor sealing. A prepreg characterized in that the epoxy resin composition of claim 1 or 2 is impregnated into a sheet-like fibrous base material and is made into a semi-hardened state. A molded article obtained by heat-forming an epoxy resin composition according to any one of claims 1 to 3. The molded article of claim 5, wherein the thermal conductivity is 4 W/m ̇K or more. The molded article of claim 5, wherein the peak of the melting point in the differential scanning calorimetry is in the range of from 150 ° C to 300 ° C. The molded article of claim 5, wherein the amount of heat absorbed by the resin component in the differential scanning calorimetry is 5 J/g or more.