KR20100134594A - Modified epoxy resin, epoxy resin compositions and cured articles - Google Patents

Abstract

A modified epoxy resin having excellent handleability as a solid at room temperature and excellent low viscosity at molding temperature, and high thermal conductivity when used in combination with an inorganic filler, and giving a cured product excellent in heat resistance and moisture resistance with low thermal expansion. An epoxy resin composition and an epoxy resin cured product using the same are disclosed.
This modified epoxy resin is obtained by reacting a mixture of hydroquinone and 4,4'-dihydroxybiphenyl in a weight ratio of 0.1 to 10.0 with epichlorohydrin, and has crystallinity at room temperature. Moreover, the epoxy resin composition using this modified epoxy resin is obtained by using (A) epoxy resin, (B) hardening | curing agent, and (C) inorganic filler as a main component, and using this modified epoxy resin at 50 weight% or more as an epoxy resin component.

Description

Modified epoxy resin, epoxy resin composition and hardened | cured material {MODIFIED EPOXY RESIN, EPOXY RESIN COMPOSITIONS AND CURED ARTICLES}

INDUSTRIAL APPLICABILITY The present invention is a crystalline modified epoxy having excellent low-viscosity during molding while having excellent handleability as a solid at room temperature, which is useful for insulation materials for electrical and electronic components such as semiconductor encapsulation, laminates, and heat-dissipating substrates with high reliability. It is related with resin, the epoxy resin composition using this, and the hardened | cured material obtained from it.

Conventionally, as a method of encapsulating electrical, electronic components such as diodes, transistors, integrated circuits, semiconductor devices, etc., for example, a method of encapsulating with epoxy resin, silicon resin, or the like, or a hermetic seal using glass, metal, ceramic, or the like. The law has been adopted. In recent years, resin bags by transfer molding, which can be mass-produced with improved reliability and cost merit, have taken the mainstream.

In the resin composition used for the resin sealing method by transfer molding, the sealing material which consists of an epoxy resin and the resin composition which has a phenol resin as a main component of a resin component as a hardening | curing agent is generally used.

Moreover, as a method of mounting electronic components on a printed board, the transition from the conventional pin insertion method to the surface mounting method is advanced. In the surface mounting method, since the whole package is heated up to the solder temperature, package cracks due to thermal shock have been a big problem, and a strong method of preventing package cracks has been to increase the high filling rate of the inorganic filler. Moreover, in order to cope with the large amount of heat | emission which an element discharges, the epoxy resin composition used as sealing materials, such as a power device, is desired to have high density filling of an inorganic filler.

In order to overcome the above problems, an epoxy resin excellent in low viscosity is desired. As the low viscosity epoxy resin, bisphenol A type epoxy resins and bisphenol F type epoxy resins are generally widely used. However, in these epoxy resins, those having low viscosity are liquid at room temperature and difficult to handle. In addition, these epoxy resins are not sufficient in terms of heat resistance, mechanical strength, and toughness.

From the above background, many epoxy resin compositions using crystalline epoxy resins which are solid at room temperature have recently been proposed. Patent Literature 1 proposes an epoxy resin composition for semiconductor encapsulation, which is mainly a biphenyl-based epoxy resin, which has improved handling workability, heat resistance, toughness, etc., and has low water absorption and low viscosity. It is not enough in terms of curability. Patent Literature 2 also proposes a bisphenol F-type solid epoxy resin as a subject. Bisphenol F type epoxy resins have excellent properties of low viscosity, but have problems in heat resistance and curability. In addition, Patent Document 3 discloses an epoxy resin composition using an epoxy resin having a hydroquinone structure, but it has an alkyl substituent having 3 to 6 carbon atoms, and the steric hindrance of the substituent causes a decrease in the reactivity or curing of the molecule after curing. There is a problem such as a decrease in thermal conductivity due to impaired packing. In addition, although the epoxy resin composition which mix | blends the epoxy resin which has a hydroquinone structure and the epoxy resin which has a biphenyl structure is disclosed by patent document 7, it does not aim for the expression of high thermal conductivity. In Patent Document 7, tetramethyl-substituted epoxy resins are used as epoxy resins having a biphenyl structure. However, according to the inventors' experiments, it was found that having an alkyl substituent has a problem of lowering the thermal conductivity.

In addition, attempts have been made to use crystalline silica, silicon nitride, aluminum nitride, and spherical alumina powder as a method for improving the thermal conductivity (Patent Documents 4 and 5). Along with the viscosity increase, fluidity decreases, resulting in a problem that moldability is impaired. Therefore, there was a limit to how to increase the content of inorganic fillers only.

From the said background, the method by the high thermal conductivity conversion of matrix resin itself is also examined, For example, patent document 6 and patent document 8 have proposed the resin composition using liquid crystalline resin which has a rigid mesogenic group. However, since the epoxy resin having these mesogenic groups is a highly crystalline and substantially single epoxy compound having a rigid structure such as a biphenyl structure or an azomethine structure and does not have a high melting point molecular weight distribution, There was a drawback of poor workability. Moreover, in order to orientate a molecule efficiently in the hardened state, it is necessary to apply a strong magnetic field and harden | cure, and in order to use industrially widely, there existed big restrictions on the installation. In addition, in the blending system with the inorganic filler, the thermal conductivity of the inorganic filler is overwhelmingly large compared to the thermal conductivity of the matrix resin, and even if the thermal conductivity of the matrix resin itself is increased, it does not contribute significantly to the improvement of the thermal conductivity of the composite material. Was not getting. In addition, the thermal conductivity improvement of the resin is considered to improve the thermal conductivity of the resin. In the case of a mixed system with the filler, if the filler is sufficiently present, the thermal conductivity of the filler is overwhelmingly high, so even if the thermal conductivity of the resin is somewhat improved. The perception of less effect was common.

In Patent Document 9, a load applied to an electrode portion for connection of a semiconductor device in which a semiconductor element is mounted by a flip chip method or the like is efficiently dispersed and reduced in the encapsulating resin layer, and the semiconductor device is subjected to severe environmental conditions such as a temperature cycle. Epoxy resin compositions for securing the conductivity of the present invention have been disclosed. Examples of the epoxy resins include hydroquinone type epoxy resins having a tertiary butyl group and biphenyl type epoxy resins having a methyl group. Patent Document 10 discloses a high thermal conductivity epoxy resin composition containing spherical cristobalite, which has good fluidity, little mold wear, and gives a cured product having high thermal conductivity. The means is an improvement of the filler and is not intended to improve the resin. Patent document 11 discloses an epoxy resin composition in which an inorganic filler is highly charged and a molded article excellent in thermal conductivity can be obtained. The means for achieving this is to improve the filler and not to improve the resin.

Japanese Patent Publication No. 4-7365 Japanese Patent Laid-Open No. 6-345850 Japanese Patent Laid-Open No. 6-145293 Japanese Patent Laid-Open No. 11-147936 Japanese Patent Laid-Open No. 2002-309067 Japanese Patent Application Laid-Open No. 11-323162 Japanese Patent Laid-Open No. 6-184272 Japanese Unexamined Patent Publication No. 2004-331811 Japanese Unexamined Patent Publication No. 2001-207031 JP 2001-172472 A Japanese Unexamined Patent Publication No. 2001-348488

Accordingly, an object of the present invention is to solve the above problems, to have a modified epoxy resin having excellent handleability as a solid at room temperature and low viscosity at a molding temperature, and high thermal conductivity in the case of using the same as a composite with an inorganic filler. The present invention provides an epoxy resin composition having low thermal expansion properties and excellent hardening resistance and excellent hardening resistance and a cured product thereof.

As a result of various studies to solve the above problems, it was recognized that in the case of a specific resin, when a certain amount or more of inorganic filler was included, the thermal conductivity improvement of the resin was reflected in the final cured product. By reacting with a mixture of a compound having a specific phenolic hydroxyl group and epichlorohydrin, the present invention was found to have crystallinity at room temperature, excellent handling properties, and to specifically improve thermal conductivity as a composite material. .

This invention is obtained by making epichlorohydrin react with the mixture which mixed 0.1-10 weight part of 4,4'- dihydroxy biphenyls with respect to 1 weight part of hydroquinones, The modification having crystallinity at normal temperature Epoxy resin.

The present invention also provides an epoxy resin composition comprising (A) an epoxy resin, (B) hardener and (C) an inorganic filler, wherein the modified epoxy resin is used in an amount of 50 wt% or more as an epoxy resin. Composition.

The preferable form of the said epoxy resin composition is shown next.

1) The content of inorganic filler is 80 ~ 96wt%

2) Curing agent is phenolic curing agent

3) Using 50 wt% or more of bifunctional phenolic compounds as phenolic curing agent

4) The bifunctional phenolic compound is hydroquinone, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 4 , 4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylsulfide, 1,5-naphthalenediol, 2,7-naphthalenediol and 2,6-naphthalenediol Being at least one

5) Using spherical alumina as inorganic filler at least 50wt% of inorganic filler

Moreover, this invention is said epoxy resin composition characterized by the above-mentioned epoxy resin composition for semiconductor sealing.

Moreover, this invention is obtained by hardening | curing said epoxy resin composition, and is a hardened | cured material characterized by the heat conductivity being 4 W / m * K or more.

Here, it is good that the said hardened | cured material has the peak of melting | fusing point in the scanning differential thermal analysis in the range of 120 to 280 degreeC, or the endothermic amount of resin component conversion in the scanning differential thermal analysis of hardened | cured material is 10 J / g or more. .

Advantageous Effects of Invention According to the present invention, a modified epoxy resin having excellent handleability as a solid at room temperature and excellent low viscosity at molding temperature, and when used in combination with an inorganic filler, has high thermal conductivity, low thermal expansion, excellent heat resistance and moisture resistance. The epoxy resin composition which gives a hardened | cured material, and the epoxy resin hardened | cured material using the same can be provided.

The modified epoxy resin of the present invention can be produced by reacting a mixture of hydroquinone and 4,4'-dihydroxybiphenyl with epichlorohydrin. This reaction can be performed similarly to a normal epoxidation reaction. The modified epoxy resin of the present invention contains an epoxide of hydroquinone and an epoxide of 4,4'-dihydroxybiphenyl, and is derived from hydroquinone and 4,4'-dihydroxybiphenyl in one molecule. It is a mixture containing the epoxide which has a unit. And, as is well known, the epoxide obtained by reacting a dihydroxy compound with epichlorohydrin has n = 1 (di-body) and n = 2 (tri-body) in addition to an epoxide having a degree of polymerization of 0 (n = 0-body). Multimers, and the like.

The mixing ratio of hydroquinone and 4,4'-dihydroxybiphenyl is a weight ratio, hydroquinone / 4,4'- dihydroxybiphenyl = 0.1-10.0, Preferably it is 0.2-5.0. When smaller than this, handleability will fall under the influence of the high melting point of the epoxy compound of 4,4'- dihydroxy biphenyl, and when larger than this, characteristics, such as heat resistance of hardened | cured material, will fall.

For example, a mixture of hydroquinone and 4,4'-dihydroxybiphenyl is dissolved in an excess amount of epichlorohydrin in a molar ratio with respect to these phenolic hydroxyl groups and then alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. The method of making it react in 50-150 degreeC in presence, Preferably it is 60-100 degreeC for 1 to 10 hours is mentioned. The usage-amount of the alkali metal hydroxide at this time is 0.8-1.2 mol with respect to 1 mol of hydroxyl groups in hydroquinone and 4,4'- dihydroxy biphenyl, Preferably it is the range of 0.9-1.0 mol. Epichlorohydrin is used in an excess amount with respect to the hydroxyl group in hydroquinone and 4,4'- dihydroxybiphenyl, and is usually 1.5 to 15 mol with respect to 1 mol of hydroxyl groups in hydroquinone and 4,4'-dihydroxybiphenyl. . After completion of the reaction, excess epichlorohydrin is distilled off, and the residue is dissolved in a solvent such as toluene, methyl isobutyl ketone, filtered, washed with water to remove the inorganic salt, and then the solvent is distilled off. The target epoxy resin can be obtained.

In the production of the modified epoxy resin of the present invention, a mixture of hydroquinone which is an essential component as a raw material and other phenolic compounds other than 4,4'-dihydroxybiphenyl can be used. In this case, however, the total amount of hydroquinone and 4,4'-dihydroxybiphenyl is preferably 50 wt% or more, preferably 70 wt% or more, and more preferably 90 wt% or more of all the phenolic compounds.

Although the epoxy equivalent of the modified epoxy resin of this invention is the range of 110-300 normally, it is preferable that it is low viscosity from the viewpoint of the high filling rate of an inorganic filler, and fluidity improvement, and it is preferable that it is the range of 110-160 as an epoxy equivalent. .

The modified epoxy resin of the present invention has crystallinity at room temperature. The expression of crystallinity can be confirmed as an endothermic peak accompanying melting of the crystal by differential scanning calorimetry. In this case, the endothermic peak is generally observed as a plurality of peaks instead of one because the modified epoxy resin of the present invention is a mixture. The melting point observed in the differential scanning calorimetry is an endothermic peak derived from a modified epoxy resin derived from hydroquinone and 4,4'-dihydroxybiphenyl, and the lowest endothermic peak is 50 ° C. or higher, preferably 70 The endothermic peak of the highest temperature is higher than or equal to 150 ° C, preferably lower than or equal to 130 ° C. If it is lower than this, blocking will occur when it is made into powder, and handling property as a solid will fall at normal temperature, and when it is higher than this, there exists a problem of the solubility with hardening | curing agents etc. inferior. Moreover, the lower the preferable melt viscosity at 150 degreeC, the better. Usually, it is 0.1 Pa.s or less, Preferably it is 0.01 Pa.s or less, More preferably, it is 0.005 Pa.s or less.

The purity of the modified epoxy resin of the present invention, particularly the amount of hydrolyzable chlorine, is preferably less from the viewpoint of improving the reliability of the electronic component to be applied. Although not specifically limited, Preferably it is 1000 ppm or less, More preferably, it is 500 ppm or less. In addition, the hydrolysable chlorine used by this invention means the value measured by the following method. That is, 0.5 g of a sample was dissolved in 30 ml of dioxane, 1 ml of 1N-KOH and 10 ml were added thereto, and the mixture was refluxed for 30 minutes. After cooling to room temperature, 100 ml of 80% acetone water was added to the aqueous solution of 0.002N-AgNO ₃ . It is the value obtained by performing potential difference titration.

The epoxy resin composition of this invention contains (A) epoxy resin, (B) hardening | curing agent, and (C) inorganic filler as a main component, and contains 50 weight% or more of said modified epoxy resin as an epoxy resin as said epoxy resin component. That is, more than 50wt% of the total epoxy resin is the modified epoxy resin. Advantageously at least 70 wt%, more preferably at least 90 wt% of the total epoxy resin is the modified epoxy resin. When the use ratio of modified epoxy resin is less than this, the improvement effect, such as thermal conductivity at the time of using hardened | cured material, is small.

In the epoxy resin composition of this invention, in addition to the said modified epoxy resin used as an essential component of this invention, you may use together another ordinary epoxy resin which has 2 or more epoxy groups in a molecule | numerator. For example bisphenol A, bisphenol F, 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylsulfone, 4,4' -Dihydroxydiphenylsulfide, 4,4'-dihydroxydiphenylketone, fluorenebisphenol, 4,4'-biphenol, 3,3 ', 5,5'-tetramethyl-4,4' -Dihydroxybiphenyl, 2,2'-biphenol, resorcin, catechol, t-butylcatechol, 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-di Hydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, the above Divalent compounds such as allyl or polyallylate of dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, and allylated phenol novolac Phenols or phenol novolac, bisphenol A novolak, o-cresol novolak, m-cresol novolak, p-cresol novolak, xylenol novolak, poly-p-hydroxystyrene, tris- (4-hydroxy Phenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, fluoroglycinol, pyrogallol, t-butylpyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1 Trivalent or more phenols such as 2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, phenol aralkyl resin, naphthol aralkyl resin, dicyclopentadiene resin, or tetrabromobisphenol A And glycidyl ether derivatives derived from halogenated bisphenols. These epoxy resins can be used 1 type or in mixture of 2 or more types.

Although what is generally known as an epoxy resin hardener can be used as a hardening | curing agent used for the epoxy resin composition of this invention, A preferable hardening | curing agent is a phenol type hardening | curing agent. The phenolic curing agent includes a phenolic compound, and the phenolic compound contains a phenol resin in addition to the phenolic compound as a single compound.

Specific examples of the phenol curing agent include bisphenol A, bisphenol F, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, and 1,4-bis (4-hydroxyphenoxy) benzene , 1,3-bis (4-hydroxyphenoxy) benzene, 4,4'-dihydroxydiphenylsulfide, 4,4'-dihydroxydiphenylketone, 4,4'-dihydroxydi Phenylsulfone, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene -10-oxides, phenol novolacs, bisphenol A novolacs, o-cresol novolacs, m-cresol novolacs, p-cresol novolacs, xylenol novolacs, poly-p-hydroxystyrenes, hydroquinones, resorcines, Catechol, t-butylcatechol, t-butylhydroquinone, fluoroglycinol, pyrogallol, t-butylpyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydrate Cinaphthalene, 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 of the dihydroxynaphthalene Cargo or polyallylate, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, allylated pyrogallol and the like.

You may use a hardening | curing agent in mixture of 2 or more types of hardening | curing agents. Preferred curing agents include at least 50 wt%, preferably at least 70 wt% of the bifunctional phenolic compound in the curing agent. In this case, as a bifunctional phenolic compound, 4,4'- dihydroxy biphenyl, 4,4'- dihydroxy diphenyl ether, 1, 4-bis (4-hydroxy phenoxy) benzene, 4,4 '-Dihydroxydiphenylmethane, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenylsulfide, 1,5-naphthalenediol, 2,7-naphthalenediol, 2,6 Phenol compounds selected from naphthalenediol, hydroquinone, and resorcin are preferred. Among these, 4,4'- dihydroxy biphenyl, 4,4'- dihydroxy diphenyl ether, or 4,4'- dihydroxy diphenylmethane is preferable.

As a hardening | curing agent used for the epoxy resin composition of this invention, the hardening | curing agent generally known as a hardening | curing agent other than said phenolic hardening | curing agent can be used. For example, an amine hardening | curing agent, an acid anhydride type hardening | curing agent, a phenol type hardening | curing agent, a polymercaptan type hardening | curing agent, a polyaminoamide type hardening | curing agent, an isocyanate type hardening | curing agent, a block isocyanate type hardening | curing agent, etc. are mentioned. What is necessary is just to set the compounding quantity of these hardening | curing agents suitably in consideration of the physical property of the heat conductive epoxy resin molded object from which the kind of hardening | curing agent mix | blended is obtained.

Specific examples of the amine curing agent include aliphatic amines, polyether polyamines, alicyclic amines, aromatic amines, and the like. Examples of the aliphatic amines include ethylenediamine, 1,3-diaminopropane, 1,4-diaminopropane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, diethylenetriamine, iminobispropylamine, Bis (hexamethylene) triamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-hydroxyethylethylenediamine, tetra (hydroxyethyl) ethylenediamine and the like. Examples of the polyether polyamines include triethylene glycol diamine, tetraethylene glycol diamine, diethylene glycol bis (propylamine), polyoxypropylene diamine, polyoxypropylene triamine, and the like. Examples of the alicyclic amines include isophoronediamine, metacenediamine, N-aminoethylpiperazine, bis (4-amino-3-methyldicyclohexyl) methane, bis (aminomethyl) cyclohexane, 3,9-bis (3- Aminopropyl) 2, 4, 8, 10- tetraoxaspiro (5, 5) undecane, norbornene diamine, etc. are mentioned. Examples of the aromatic amines are tetrachloro-p-xylenediamine, m-xylenediamine, p-xylenediamine, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, 2,4-diaminoanisole, 2, 4-toluenediamine, 2,4-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diamino-1,2-diphenylethane, 2,4-diaminodiphenyl Sulfone, 4,4'-diaminodiphenylsulfone, m-aminophenol, m-aminobenzylamine, benzyldimethylamine, 2-dimethylaminomethyl) phenol, triethanolamine, methylbenzylamine, α- (m-aminophenyl ) Ethylamine, (alpha)-(p-aminophenyl) ethylamine, diamino diethyl dimethyl diphenylmethane, (alpha), (alpha) '-bis (4-aminophenyl) -p- diisopropyl benzene, etc. are mentioned.

Specific examples of the acid anhydride-based curing agent include dodecenyl succinic anhydride, polyadipic anhydride, polyazelanic anhydride, polycebacic anhydride, poly (ethyloctadecanoic acid) anhydride, poly (phenylhexadecane diacid) anhydride, methyltetrahydro Phthalic anhydride, methylhexahydro phthalic anhydride, hexahydro phthalic anhydride, methylhymic acid anhydride, tetrahydro phthalic anhydride, trialkyltetrahydro phthalic anhydride, methylcyclohexenedicarboxylic anhydride, methylcyclohexete tetracarboxylic anhydride, phthalic anhydride, Trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic acid anhydride, ethylene glycol bistrimellitate, het acid anhydride, nadic acid anhydride, methylnadic anhydride, 5- (2,5-dioxo Tetrahydro-3-furanyl) -3-methyl-3-cyclohexane-1,2-dicarboxylic anhydride, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid 2 Anhydride, 1-methyl-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic dianhydride, and the like.

It is preferable that the compounding ratio of an epoxy resin and a hardening | curing agent is the range of 0.8-1.5 in an equivalence ratio with the functional group in an epoxy group and a hardening | curing agent. Outside of this range, since unreacted epoxy group or functional group in a hardening | curing agent remains after hardening, since reliability regarding sealing function falls, it is unpreferable.

The amount of the inorganic filler added to the epoxy resin composition of the present invention is 80 to 96 wt% with respect to the epoxy resin composition, preferably 84 to 96 wt%. When less than this, the effect aimed at by this invention, such as high thermal conductivity, low thermal expansion property, and high heat resistance, is not fully exhibited. Although these effects are so preferable that the addition amount of an inorganic filler is large, it does not improve according to the volume fraction, but improves dramatically from a specific addition amount. These physical properties are due to the controlled effect of the higher order structure in the polymer state, and since this higher order structure is mainly achieved on the surface of the inorganic filler, it is considered that a specific amount of the inorganic filler is required. On the other hand, when the addition amount of an inorganic filler is larger than this, since a viscosity becomes high and moldability deteriorates, it is unpreferable.

It is preferable that the said inorganic filler is spherical, and if it is spherical including what is elliptical in cross section, it will not specifically limit, but from a viewpoint of fluidity improvement, it is especially preferable to be as close to a positive spherical form as possible. Thereby, it is easy to take the closest packing structure, such as a face-centered cubic structure and a hexagonal dense structure, and sufficient filling amount can be obtained. In the case of not being spherical, it is not preferable because the amount of filling increases the friction between the fillers, the fluidity is extremely lowered before the upper limit is reached, the viscosity becomes high, and the moldability deteriorates.

From the viewpoint of the thermal conductivity improvement, it is preferable to use 50 wt% or more of the thing with thermal conductivity of 5 W / m * K or more among inorganic fillers, and alumina, aluminum nitride, crystalline silica, etc. are used suitably. Particularly preferred among these is spherical alumina. In addition, you may use together an amorphous inorganic filler, for example, fused silica, crystalline silica, etc. regardless of a shape as needed.

It is preferable that the average particle diameter of an inorganic filler is 30 micrometers or less. If 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.

A well-known hardening accelerator can be mix | blended with the epoxy resin composition of this invention. For example, there are amines, imidazoles, organic phosphines, Lewis acids, and the like, specifically 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, benzyldimethylamine, triethanol Tertiary amines such as amine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecyl imida Organic phosphines such as imidazoles such as sol, tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium Tetra substituted phosphonium tetra substituted borate, such as ethyl triphenyl borate and tetrabutyl phosphonium tetrabutyl borate, 2-ethyl-4-methylimidazole tetraphenyl borate, N-methylmorpholine tetraphenyl borate, etc. Tetraphenyl boron salts; As addition amount, it is the range of 0.2-10 weight part with respect to 100 weight part of epoxy resins normally. These may be used independently and may be used together.

As for the addition amount of the said hardening accelerator, 0.1-10.Owt% is preferable with respect to the sum total of an epoxy resin (it contains this when mix | blending a halogen containing epoxy resin as a flame retardant) and a hardening | curing agent. If it is less than 0.1 wt%, the gelling time will be delayed, leading to a decrease in workability due to the decrease in rigidity at the time of curing. On the contrary, if it exceeds 10.Owt%, curing will proceed during molding and unfilling will easily occur.

In the epoxy resin composition of the present invention, wax can be used as a release agent generally used in the epoxy resin composition. As the wax, for example, stearic acid, montanic acid, montanic acid ester, phosphate ester or the like can be used.

In the epoxy resin composition of this invention, in order to improve the adhesive force of an inorganic filler and a resin component, the coupling agent generally used for an epoxy resin composition can be used. As a coupling agent, epoxysilane can be used, for example. As for the addition amount of a coupling agent, 0.1-2.wt% is preferable with respect to an epoxy resin composition. If it is less than 0.1 wt%, the resin and the substrate are poorly matched, resulting in poor moldability. On the contrary, if it exceeds 2 wt%, molded product contamination in continuous moldability occurs.

In addition, thermoplastic oligomers can be added to the epoxy resin composition of the present invention from the viewpoint of improving fluidity during molding and improving adhesion to substrates such as lead frames. Thermoplastic oligomers include C5 and C9 petroleum resins, styrene resins, indene resins, indene styrene copolymer resins, indene styrene phenol copolymer resins, indene coumarone copolymer resins, and indene benzothiophene copolymer resins. Is illustrated. As addition amount, it is the range of 2-30 weight part with respect to 100 weight part of epoxy resins normally.

Moreover, what is generally usable for an epoxy resin composition can be mix | blended suitably for the epoxy resin composition of this invention. For example, phosphorus-based flame retardants, flame retardants such as bromine compounds and antimony trioxide, and coloring agents such as carbon black and organic dyes can be used.

The epoxy resin composition of the present invention contains an epoxy resin, a curing agent, and an inorganic filler as main components. The proportion of the epoxy resin and the curing agent in the resin components other than the filler is preferably 50 wt% or more, preferably 70 wt% or more, and more preferably 80 wt% or more. In addition, the resin component except a filler means all the components used as components other than a filler after hardening. Or all components other than the filler in hardened | cured material.

The epoxy resin composition of the present invention is prepared by uniformly mixing an epoxy resin, a curing agent, an inorganic filler, and other components other than the coupling agent with a mixer or the like, and then adding the coupling agent to mix and knead with a heating roll, kneader or the like. There is no restriction | limiting in particular in the compounding order of these components. It is also possible to pulverize the molten mixed dough after mixing the dough to make it powdered or tableted.

The epoxy resin composition of the present invention is particularly suitable for sealing in semiconductor devices.

The hardened | cured material of this invention is obtained by thermosetting the said epoxy resin composition. In order to obtain hardened | cured material using the epoxy resin composition of this invention, methods, such as transfer molding, press molding, casting molding, injection molding, extrusion molding, are applied, for example, From a mass productivity viewpoint, transfer molding is preferable.

It is preferable that the hardened | cured material of this invention has crystallinity from a high thermal conductivity viewpoint. The crystallinity of the cured product can be confirmed by observing the endothermic peak accompanying melting of the crystal as the melting point in the scanning differential thermal analysis. Preferable melting | fusing point is the range of 120 to 280 degreeC, More preferably, it is the range of 150 to 250 degreeC. Moreover, the preferable thermal conductivity of hardened | cured material is 4 W / m * K or more, Especially preferably, it is 6 W / m * K or more.

The higher the crystallinity of the cured product of the present invention, the better. The degree of crystallization can be evaluated from the endothermic amount accompanying the melting of the crystal in the scanning differential thermal analysis. Preferable endothermic amount is 10 J / g or more per unit weight of the resin component excluding the filler. More preferably, it is 15 J / g or more, Especially preferably, it is 30 J / g or more. When smaller than this, the thermal conductivity improvement effect as hardened | cured epoxy resin is small. Also, from the viewpoint of low thermal expansion and heat resistance improvement, higher crystallinity is preferable. In addition, the endothermic amount here refers to the endothermic amount obtained by measuring on the conditions of the temperature increase rate of 10 degree-C / min under nitrogen stream using the sample which measured about 10 mg correctly by the differential thermal analyzer.

The cured epoxy resin of the present invention can be obtained by heat curing by the above molding method. Usually, the molding temperature is 80 ° C to 250 ° C. In order to increase the crystallinity of the cured epoxy resin, the cured epoxy resin is cured at a temperature lower than the melting point of the cured product. It is preferable. Preferable hardening temperature is the range of 100 to 200 degreeC, More preferably, it is 130 to 180 degreeC. Moreover, preferable hardening time is 30 second to 1 hour, More preferably, it is 1 to 30 minutes. In addition, the degree of crystallinity can be further increased by post cure after molding. Typically, the post cure temperature ranges from 130 ° C. to 250 ° C., and the time ranges from 1 hour to 20 hours, preferably from 1 ° C. to 40 ° C. below the endothermic peak temperature in differential thermal analysis for 1 hour to 24 hours. It is preferable to perform a post cure.

<Examples>

The present invention will be described in more detail with reference to the following Examples.

(Reference Example 1)

150.0 g of hydroquinone was dissolved in 1260 g of epichlorohydrin and 120 g of diethylene glycol dimethyl ether, and 22.7 g of 48% sodium hydroxide was added at 60 ° C and stirred for 1 hour. Then, under reduced pressure (about 130 Torr), 204.5 g of an aqueous 48% sodium hydroxide solution was added dropwise for 3 hours. The water produced in the meantime was removed out of the system by azeotroping with epichlorohydrin, and the leaked epichlorohydrin was returned to the system. After completion of the dropwise addition, the reaction was further continued for 1 hour, and after dehydration, epichlorohydrin was distilled off, 600 g of methyl isobutyl ketone was added, followed by washing with water to remove salt. Thereafter, 20.0 g of 48% sodium hydroxide was added at 85 ° C, stirred for 1 hour, and washed with 200 mL of warm water. Thereafter, water was removed by liquid separation, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 278 g of a white crystalline epoxy resin. The epoxy equivalent was 117, the melting point of 310 ppm of hydrolyzable chlorine, the capillary method was 101 to 84 degreeC, and the viscosity in 120 degreeC was 1.8 mPa * s. As for each component ratio of the epoxy resin obtained from the hydroquinone calculated | required from the GPC measurement of obtained resin, n = 0 (monomer) was 85.7%, n = 1 (diec) was 9.1%, and n = 2 (tree body) was 1.6%. Herein, hydrolyzable chlorine was dissolved 0.5 g of a sample in 30 ml of dioxane, 10 ml of 1N-KOH was added thereto, and the mixture was refluxed for 30 minutes. After cooling to room temperature, 100 ml of 80% acetone water was added. a is a value measured by carrying out potentiometric titration with -AgNO ₃ aqueous solution. In addition, melting | fusing point is a value obtained at the temperature increase rate of 2 degree-C / min by the capillary method. The viscosity was measured by BROOKFIELD, CAP2000H, and the softening point was measured by the round ball method according to JIS K-6911. GPC measurements also include devices; Nihon Waters, Form 515A, Column; TSK-GEL2000 × 3 and TSK-GEL4000 × 1 (both manufactured by Tosoh Corporation), solvents; Tetrahydrofuran, flow rate; 1 ml / min, temperature; 38 ° C., detector; Followed the terms of RI.

(Reference Example 2)

100.0 g of 4,4'-dihydroxybiphenyl was dissolved in 700 g of epichlorohydrin and 105 g of diethylene glycol dimethyl ether, and then 87.8 g of an aqueous 48% sodium hydroxide solution at 60 ° C. under reduced pressure (about 130 Torr) for 3 hours It was dripped for a while. The water produced in the meantime was removed out of the system by azeotroping with epichlorohydrin, and the leaked epichlorohydrin was returned to the system. After completion of the dropwise addition, the reaction was continued for 1 hour, and after dehydration, the mixture was cooled to room temperature and filtered to recover a precipitate. Thereafter, the precipitate was washed with water to remove salt and further dried to obtain 137 g of a crystalline powdery epoxy resin. Melting | fusing point by 163 and capillary method of epoxy equivalent was 169 degreeC and 175 degreeC. As for each component ratio in General formula (1) calculated | required from the GPC measurement of obtained resin, n = 0 was 93.7% and n = 1 was 5.9%.

(Example 1)

50.0 g of hydroquinone and 100.0 g of 4,4'-dihydroxybiphenyl were dissolved in 1000 g of epichlorohydrin and 150 g of diethylene glycol dimethyl ether, and 16.5 g of 48% sodium hydroxide was added at 60 ° C and stirred for 1 hour. Thereafter, 148.8 g of an aqueous 48% sodium hydroxide solution was added dropwise for 3 hours under reduced pressure (about 130 Torr). The water produced in the meantime was removed out of the system by azeotroping with epichlorohydrin, and the leaked epichlorohydrin was returned to the system. After completion of the dropwise addition, the reaction was further continued for 1 hour, and after dehydration, epichlorohydrin was distilled off, 600 g of methyl isobutyl ketone was added, followed by washing with water to remove salt. Thereafter, 13.5 g of 48% sodium hydroxide was added at 85 ° C, stirred for 1 hour, and washed with 200 mL of warm water. Thereafter, water was removed by liquid separation, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 224 g of a white crystalline modified epoxy resin (epoxy resin A). The epoxy equivalent was 139, the hydrolyzable chlorine was 320 ppm, the melting point by the capillary method was 104 to 141 ° C, and the viscosity at 150 ° C was 3.4 mPa · s. N = 0 (monomer) of the epoxy resin obtained from hydroquinone obtained from GPC measurement was 23.1%, and n = 1 (dimeric) was 2.2%. Further, n = 0 (monomer) of the epoxy resin obtained from 4,4'-dihydroxybiphenyl was 67.2%, and n = 1 (dimer) was 4.1%.

(Example 2)

75.0 g of hydroquinone and 75.0 g of 4,4'-dihydroxybiphenyl were dissolved in 1000 g of epichlorohydrin and 150 g of diethylene glycol dimethyl ether, and 18.1 g of 48% sodium hydroxide was added at 60 ° C, followed by stirring for 1 hour. Thereafter, 162.7 g of an aqueous 48% sodium hydroxide solution was added dropwise for 3 hours under reduced pressure (about 130 Torr). The water produced in the meantime was removed out of the system by azeotroping with epichlorohydrin, and the leaked epichlorohydrin was returned to the system. After completion of the dropwise addition, the reaction was further continued for 1 hour, and after dehydration, epichlorohydrin was distilled off, 540 g of methyl isobutyl ketone was added, followed by washing with water to remove salt. Then, 13.5g of 48% sodium hydroxide was added at 85 degreeC, it stirred for 1 hour, and it washed with 200 mL of warm water. Then, water was removed by liquid separation, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 214 g of a modified crystalline epoxy resin (epoxy resin B) in white crystal form. Epoxy equivalent was 135, 380 ppm of hydrolysable chlorine, melting | fusing point by the capillary method was 108 to 119 degreeC, and the viscosity in 150 degreeC was 2.3 mPa * s. The n = 0 (monomer) of the epoxy resin obtained from the hydroquinone obtained from the GPC measurement was 53.1%, and n = 1 (dimeric) was 34.2%. In addition, n = 0 (monomer) of the epoxy resin obtained from 4,4'- dihydroxy biphenyl was 7.2%, and n = 1 (dibody) was 4.3%.

(Example 3)

125.0 g of hydroquinone and 25.0 g of 4,4'-dihydroxybiphenyl were dissolved in 1200 g of epichlorohydrin and 180 g of diethylene glycol dimethyl ether, and 21.2 g of 48% sodium hydroxide was added at 60 ° C and stirred for 1 hour. Thereafter, 190.6 g of an aqueous 48% sodium hydroxide solution was added dropwise for 3 hours under reduced pressure (about 130 Torr). The water produced in the meantime was removed out of the system by azeotroping with epichlorohydrin, and the leaked epichlorohydrin was returned to the system. After completion of the dropwise addition, the reaction was further continued for 1 hour, after which the epichlorohydrin was distilled off, 560 g of methyl isobutyl ketones were added, followed by washing with water to remove the salt. Then, 13.5g of 48% sodium hydroxide was added at 85 degreeC, it stirred for 1 hour, and it washed with 200 mL of warm water. Thereafter, water was removed by liquid separation, and methyl isobutyl ketone was distilled off under reduced pressure to obtain 265 g of a modified epoxy resin (epoxy resin C) in white crystal form. The epoxy equivalent was 124, the hydrolyzable chlorine was 390 ppm, the melting point by the capillary method was 86 ° C to 105 ° C, and the viscosity at 150 ° C was 0.8 mPa · s. N = 0 (monomer) of the epoxy resin obtained from the hydroquinone calculated | required from the GPC measurement was 80.1%, and n = 1 (dimeric) was 2.2%. Moreover, n = 0 (monomer) of the epoxy resin obtained from 4,4'- dihydroxy biphenyl was 13.1%, and n = 1 (dimer) was 3.0%.

(Examples 4-8, Comparative Examples 1-5)

As the epoxy resin component, modified epoxy resins of Example 1 to Example 3 (called epoxy resin A, epoxy resin B, epoxy resin C in order of Example number), epoxy resin of Reference Example 1 (epoxy resin D), and reference Epoxy resin (epoxy resin E) of Example 2, biphenyl epoxy resin (epoxy resin F: product of Japan epoxy resin, YX-4000H; epoxy equivalent weight 195), phenol aralkyl resin (hardening agent A: product of Mitsui Chemicals, XL-225-LL; OH equivalent 174, softening point 75 ° C.), hydroquinone (curing agent B), 4,4′-dihydroxydiphenylether (curing agent C), triphenylphosphine as curing accelerator, spherical alumina as inorganic filler (Average particle diameter 12.2 µm), the ingredients and the amounts shown in Table 1 were mixed and thoroughly mixed with a mixer, and then mixed with a heating roll for about 5 minutes to cool and ground, followed by Examples 4 to 8 and Comparative Examples, respectively. Epoxy resin compositions of 1 to 5 were obtained. After molding under the condition of 170 ° C. for 5 minutes using this epoxy resin composition, postcure was performed at 170 ° C. for 12 hours to obtain a cured molded product, and evaluated for physical properties thereof. The result of an Example is put together in Table 1, and the result of a comparative example is shown in Table 2. In addition, the number of each compound of Table 1 and Table 2 represents a weight part. In Comparative Example 5, the physical properties of the cured molded product could not be evaluated because of poor molding.

An evaluation method is shown next.

(1) The thermal conductivity was measured by an unsteady heat ray method using a LFA447 type thermal conductivity meter manufactured by NETZSCH.

(2) Melting | fusing point and heat of melting (DSC method) were measured at the temperature increase rate of 10 degree-C / min using the differential scanning calorimetry apparatus (Seiko Instruments DSC6200 type | mold).

(3) Linear expansion coefficient and glass transition temperature were measured at the temperature increase rate of 10 degree-C / min using the Seiko Instruments TMA120C type | mold thermometer measuring apparatus.

(4) The water absorption rate was made into a 50 mm diameter, 3 mm thick disk, and the weight change rate after moisture absorption for 100 hours on 85 degreeC and 85% of the relative humidity after postcure.

The modified epoxy resin and the epoxy resin composition of the present invention are excellent in formability and reliability, and give a cured product excellent in high thermal conductivity, low water absorption, low thermal expansion, and high heat resistance, and can be applied to electrical and electronic materials such as semiconductor encapsulation, laminates, and heat dissipation substrates. It is suitably applied as an insulating material for electronic parts, and exhibits excellent heat dissipation and dimensional stability.

Claims (11)

A modified epoxy resin having crystallinity at room temperature, obtained by reacting a mixture of 0.1 to 10 parts by weight of 4,4'-dihydroxybiphenyl with 1 part by weight of hydroquinone and epichlorohydrin. An epoxy resin composition comprising (A) an epoxy resin, (B) hardener and (C) an inorganic filler as a main component, wherein the modified epoxy resin according to claim 1 is used as an epoxy resin by 50 wt% or more. . The method of claim 2,
Epoxy resin composition, characterized in that the content of the inorganic filler is 80 ~ 96wt%. The method of claim 2,
Epoxy resin composition, characterized in that the curing agent is a phenol-based curing agent. The method of claim 2,
Epoxy resin composition characterized by using 50 wt% or more of bifunctional phenolic compound as a hardening | curing agent. The method of claim 5,
Difunctional phenolic compounds include hydroquinone, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenylether, 1,4-bis (4-hydroxyphenoxy) benzene, 4,4 ' Dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylsulfide, 1,5-naphthalenediol, 2,7-naphthalenediol, 2,6-naphthalenediol and resorcin Epoxy resin composition, characterized in that at least one. The method of claim 2,
An epoxy resin composition characterized by using 50 wt% or more of spherical alumina as an inorganic filler. The method of claim 2,
Epoxy resin composition, characterized in that the epoxy resin composition for semiconductor encapsulation. The hardened | cured material obtained by hardening | curing the epoxy resin composition of Claim 2 and whose heat conductivity is 4 W / m * K or more. 10. The method of claim 9,
The hardened | cured material characterized by the peak of melting | fusing point in the scanning differential thermal analysis of hardened | cured material in the range of 120 to 280 degreeC. 10. The method of claim 9,
Hardened | cured material characterized by the endothermic amount of resin component conversion in the scanning differential thermal analysis of hardened | cured material 10 J / g or more.