JP5570453B2 - Epoxy resin composition and cured product - Google Patents

Description

  The present invention relates to an epoxy resin composition that provides a cured product that is excellent in flame retardancy and also excellent in moisture resistance, adhesion, and reflow resistance, and the cured product.

  In recent years, particularly with the advancement of the advanced material field, development of higher performance base resins has been demanded. For example, in the field of semiconductor encapsulation, the problem of package cracking has become serious due to the reduction in the size and area of packages corresponding to recent high-density mounting, and the spread of surface mounting methods. There is a strong demand for improvement in moisture resistance, heat resistance, adhesion to metal substrates, and the like. Furthermore, from the viewpoint of reducing the environmental load, there is a movement to eliminate halogen-based flame retardants, and there is a demand for a base resin that is more excellent in flame retardancy.

  However, it is not yet known that conventional epoxy resin-based materials sufficiently satisfy these requirements. For example, the well-known bisphenol type epoxy resin is in a liquid state at room temperature and is widely used because it is excellent in workability and easy to mix with a curing agent, an additive, etc. There is a problem in terms of moisture resistance. Also, phenol novolac type epoxy resins are known as improved heat resistance, but there are problems with moisture resistance and impact resistance. JP-A-63-238,122 proposes an epoxy compound of a phenol aralkyl resin for the purpose of improving moisture resistance and impact resistance, but it is not sufficient in terms of heat resistance and flame retardancy.

  JP-A-9-235449, JP-A-10-182792 and the like disclose a method for adding a phosphate ester-based flame retardant as a measure for improving flame retardancy without using a halogen-based flame retardant. Has been. However, the method using a phosphate ester flame retardant does not have sufficient moisture resistance. In addition, the phosphoric acid ester is hydrolyzed under a high temperature and humidity environment, and there is a problem that the reliability as an insulating material is lowered.

JP-A-11-140166 JP 2004-57992 A Japanese Patent Laid-Open No. 4-173831 JP 2000-129092 A Japanese Patent Laid-Open No. 3-90075 JP-A-3-281623 JP-A-8-120039 Japanese Patent Laid-Open No. 5-140265 Japanese Patent Laid-Open No. 9-249794

  Patent Documents 1, 3, and 4 disclose an example in which an aralkyl epoxy resin having a biphenyl structure is applied to a semiconductor sealing material as an element that improves flame retardancy without containing a halogen atom or a phosphorus atom. Yes. Patent Document 2 discloses an example in which an aralkyl type epoxy resin having a naphthalene structure is used. However, these epoxy resins have insufficient performance in any of flame retardancy, moisture resistance, and heat resistance. Patent Documents 5 and 6 disclose a naphthol-based aralkyl epoxy resin and a semiconductor sealing material containing the naphthol-based aralkyl epoxy resin, but nothing focuses on flame retardancy. On the other hand, Patent Document 7 discloses benzylated polyphenol and its epoxy resin as an example focusing on improving heat resistance, moisture resistance and crack resistance, but these do not focus on flame retardancy. Furthermore, Patent Document 8 discloses an epoxy resin composition containing a styrenated phenol novolac type epoxy resin, which is excellent in low water absorption and low stress, but this also focuses on flame retardancy. There wasn't. Furthermore, Patent Document 9 discloses an epoxy resin composition containing an indene-based oligomer, but it does not focus on improving flame retardancy and reflow resistance.

  Therefore, the object of the present invention is to ensure non-halogen-based flame retardancy and to have excellent performance in moisture resistance, adhesion and reflow resistance, and for applications such as lamination, molding, casting and adhesion. It is an object to provide an epoxy resin composition useful for the above and a cured product thereof.

（ここで、Ｇはグリシジル基を示し、Ｒ₁は水素又は炭素数１〜６の炭化水素基を示し、Ｒ₂は式（ａ）で表される置換基を示し、ｎは１〜２０の数を示す。また、ｐは０．１〜２．５の数を示す。Ｒ₃は水素又は炭素数１〜６の炭化水素基を示す。） That is, the present invention is an epoxy resin composition containing an epoxy resin, a phenolic curing agent, an inorganic filler, and an indene oligomer, wherein the epoxy resin component contains an epoxy resin represented by the following general formula (1). It is an epoxy resin composition characterized by being.

(Here, G represents a glycidyl group, R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, R ₂ represents a substituent represented by the formula (a), and n represents 1 to 20) (P represents a number of 0.1 to 2.5, and R ₃ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms.)

  Moreover, this invention is said epoxy resin composition in which a phenol type hardening | curing agent component contains at least 1 sort (s) chosen from an aralkyl type phenol type hardening | curing agent and a novolak type phenol hardening agent.

  Moreover, this invention is said epoxy resin composition whose content rate of an inorganic filler is 60 to 94 weight%.

  Moreover, this invention is said epoxy resin composition whose content of an indene type oligomer is 5-30 weight part with respect to 100 weight part of epoxy resins. Furthermore, the present invention provides an indene-based oligomer obtained by copolymerizing an oligomer obtained by copolymerizing a monomer containing indene, styrene and phenol, or a monomer containing indene and benzothiophene. It is said epoxy resin composition characterized by being an oligomer obtained.

  Furthermore, this invention is said epoxy resin composition characterized by being an epoxy resin composition for semiconductor sealing materials, and is an epoxy resin hardened | cured material formed by hardening | curing these epoxy resin compositions. Furthermore, this invention is a semiconductor device which sealed the semiconductor element with said epoxy resin composition for semiconductor sealing materials.

  The epoxy resin composition of the present invention is excellent in flame retardancy and gives a cured product excellent in moisture resistance, adhesion and reflow resistance, and is suitable for use as a sealing material for electrical and electronic parts. Is possible. In particular, the use of a flame retardant having an environmental load is made unnecessary or reduced while ensuring excellent reflow resistance.

  The epoxy resin composition of the present invention comprises an epoxy resin component, a phenolic curing agent component, an inorganic filler component, and an indene oligomer component as essential components. Advantageously, these essential components are contained in an amount of 50% by weight or more, preferably 80% by weight or more, more preferably 95% by weight or more.

  First, the epoxy resin represented by the general formula (1) which is the first type of epoxy resin component in the epoxy resin composition of the present invention will be described. The epoxy resin (also referred to as StPNE) represented by the general formula (1) is obtained by epoxidizing a styrene-added polyvalent hydroxy resin represented by the following general formula (3). Further, the styrene-added polyvalent hydroxy resin (also referred to as StPN) represented by the general formula (3) is composed of a polyvalent hydroxy compound (also referred to as the polyvalent hydroxy compound (4)) represented by the following general formula (4) and styrenes. Can be obtained by addition reaction. Since StPNE can be easily epoxidized using a glycidylating agent such as epichlorohydrin, StPN will be described.

（一般式（３）及び（４）において、Ｒ₁、Ｒ₂、ｎ、及びｐは一般式（１）と同じ意味を有する。）

(In General Formulas (3) and (4), R ₁ , R ₂ , n, and p have the same meaning as in General Formula (1).)

  In the styrene-added polyvalent hydroxy resin represented by the general formula (3), the hydroxyl equivalent can be arbitrarily adjusted by adding styrene to the basic structure of the polyvalent hydroxy compound (4). . Here, the addition of styrenes refers to the substitution of hydrogen on the benzene ring of the polyvalent hydroxy compound (4) with the substituent represented by the formula (a) (α-methylbenzyl group). In other words, in the epoxy resin cured product, the hydroxypropyl group generated by the reaction between the epoxy group and the hydroxyl group is said to burn easily, but by increasing the hydroxyl equivalent, aliphatic carbon of the flammable component derived from the epoxy group The rate is low and a high degree of flame retardancy can be expressed. Moreover, by adding styrene rich in aromaticity, the aromaticity is further improved, and it is effective in improving moisture resistance in addition to flame retardancy.

  Therefore, a highly flame-retardant epoxy resin composition, especially an epoxy resin composition for semiconductor encapsulation is obtained using these. In other words, high flame retardancy, moisture resistance and low elasticity are exhibited in addition to excellent curability in these compositions, and highly reliable sealing of electrical and electronic parts and circuits using this material A substrate material or the like is obtained.

  StPN is obtained by addition reaction of the polyvalent hydroxy compound (4) represented by the general formula (4) and styrenes. At this time, as a ratio of the polyhydroxy compound (4) and the styrene, in consideration of a balance between flame retardancy and curability of the obtained cured product, styrene is used with respect to 1 mol of the phenol ring in the polyhydroxy compound. The use ratio of the class is preferably in the range of 0.1 to 2.5 mol, more preferably in the range of 0.1 to 1.0 mol, and still more preferably in the range of 0.3 to 0.8 mol. When the amount is less than this range, the properties of the starting polyvalent hydroxy compound are not improved. When the amount is more than this range, the functional group density tends to be too low and the curability tends to decrease. This molar ratio is related to p in the general formula (1).

In general formulas (3), (4) and general formula (1), common symbols have the same meaning. R ₁ represents a group represented by the above formula (a). p represents a number of 0.1 to 2.5, which means the average number (number average) of α-methylbenzyl groups substituted by one phenol ring (or benzene ring) in the formula. p is preferably in the order of 0.1 to 2, 0.1 to 1.0, 0.3 to 1, and 0.3 to 0.8. In addition, up to 4 α-methylbenzyl groups can be substituted on the phenol ring (or benzene ring) at both ends, and up to 3 α-methylbenzyl groups can be substituted on the intermediate phenol ring (or benzene ring). Therefore, when n is 1, a maximum of 8 α-methylbenzyl groups can be substituted.
From another point of view, the StPNE used in the present invention preferably has a substitution number (number average) of α-methylbenzyl groups per molecule of 1 or more, more preferably 2 or more, still more preferably 2 .6-4.

In formula (a), R ₃ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, preferably hydrogen or an alkyl group having 1 to 3 carbon atoms, and more preferably hydrogen. This R ₃ is determined by the styrenes used as reaction raw materials.

  In the general formula (1), n represents a number of 1 to 20, preferably 1.5 to 5.0 as an average (number average).

Next, a method for manufacturing StPN will be described.
The StPN production method is carried out by reacting 0.1 to 2.5 mol of styrene in the presence of an acid catalyst with respect to 1 mol of the hydroxy group of the polyvalent hydroxy compound represented by the general formula (4). . Typical examples of the polyvalent hydroxy compound represented by the general formula (4) include phenol novolac and cresol novolak. Although the usage-amount of styrene is 0.1-2.5 with respect to 1 mol of hydroxy groups, 0.1-1.0 are preferable and 0.3-0.8 are more preferable.

  The phenols used to obtain the polyvalent hydroxy compound (4) are phenols or phenols substituted with a hydrocarbon group having 1 to 6 carbon atoms, preferably phenol or alkyl having 1 to 4 carbon atoms. Phenols substituted with a group, more preferably phenol. When phenol is used as the phenol, it may contain a small amount of other phenol components. For example, when phenol is used as a phenol, a small amount of other phenol components include o-cresol, m-cresol, p-cresol, ethylphenols, isopropylphenols, tertiary butylphenols, allylphenols, phenyl Phenols, 2,6-xylenol, 2,6-diethylphenol, hydroquinone, resorcin, catechol, 1-naphthol, 2-naphthol, 1,5-naphthalenediol, 1,6-naphthalenediol, 1,7-naphthalenediol 2,6-naphthalenediol, 2,7-naphthalenediol, and the like. These phenols or naphthols may contain 2 or more types.

  The styrene used for the reaction with the polyvalent hydroxy compound (4) is styrene or styrene substituted with a hydrocarbon group having 1 to 6 carbon atoms, and is preferably styrene. These styrenes may contain a small amount of other reaction components, and other reaction components include unsaturated bond-containing components such as α-methylstyrene, divinylbenzene, indene, coumarone, benzothiophene, indole, and vinylnaphthalene. Can do. In this case, the resulting StPN includes a compound in which a group derived therefrom is substituted on the aromatic ring.

  The reaction of polyvalent hydroxy compounds with styrenes can be carried out in the presence of an acid catalyst, and the amount of the catalyst used is in the range of 10 to 1000 ppm, preferably in the range of 100 to 500 ppm. If it is more than this, the methylene crosslinks of phenol novolac will be easily cleaved, and the unit price phenol component by-produced by the cleavage reaction will lower the curability and heat resistance. On the other hand, if it is less than this, the reactivity is lowered, and a large amount of unreacted styrene monomer remains.

  The acid catalyst can be appropriately selected from known inorganic acids and organic acids. For example, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, organic acids such as formic acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, dimethyl sulfuric acid, diethyl sulfuric acid, zinc chloride, aluminum chloride, iron chloride, trifluoride. Examples thereof include Lewis acids such as boron fluoride or ion exchange resins, activated clays, silica-alumina, solid acids such as zeolite, and the like.

  Moreover, the reaction temperature in this reaction is performed in the range of 40-120 degreeC. If it is lower than this, the reactivity is lowered and the reaction time is prolonged. On the other hand, if it is higher than this, a part of the methylene cross-linked bond of the polyvalent hydroxy compound (4) is likely to be cleaved, and the curability and heat resistance are lowered by the unit price phenol component by-produced by the row opening reaction.

  Moreover, this reaction is normally performed for 1 to 20 hours. Further, during the reaction, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, ethyl cellosolve, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethyl ether, diethyl ether, diisopropyl ether, Ethers such as tetrahydrofuran and dioxane, aromatic compounds such as benzene, toluene, chlorobenzene, and dichlorobenzene can be used as the solvent.

  As a specific method for carrying out this reaction, all raw materials are charged in a lump and reacted at a predetermined temperature as it is, or a polyvalent hydroxy compound and a catalyst are charged and maintained at a predetermined temperature while maintaining styrenes. A method of reacting while dropping is generally used. At this time, the dropping time is preferably 5 hours or less, and usually 1 to 10 hours. After the reaction, if a solvent is used, the catalyst component can be removed if necessary, and then the solvent can be distilled off to obtain a resin for use in the present invention. By doing so, the target StPN can be obtained.

The epoxy resin (StPNE) represented by the general formula (1) can be obtained by epoxidizing the above StPN. In the general formula (1), symbols common to the general formula (3) have the same meaning, but G represents a glycidyl group, which is generated by the reaction of the hydroxyl group of the general formula (3). R ₁ is an α-methylbenzyl group.

  StPNE used in the present invention is advantageously produced by reacting StPN represented by the general formula (3) with epichlorohydrin, but is not limited to this reaction.

  In addition to the reaction of reacting StPN with epichlorohydrin, StPN and allyl halide can be reacted to form an allyl ether compound and then reacted with peroxide. The reaction of reacting StPN with epichlorohydrin can be performed in the same manner as a normal epoxidation reaction.

  For example, after the above StPN is dissolved in excess epichlorohydrin, in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, it is 20 to 150 ° C., preferably 30 to 80 ° C. The method of making it react for time is mentioned. The amount of alkali metal hydroxide used in this case is in the range of 0.8 to 1.5 mol, preferably 0.9 to 1.2 mol, relative to 1 mol of StPN hydroxyl group. In addition, epichlorohydrin is used in excess with respect to 1 mol of hydroxyl group in StPN, but is usually in the range of 1.5 to 30 mol, preferably 2 to 15 mol, relative to 1 mol of hydroxyl group in StPN. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene, methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the target epoxy is removed by distilling off the solvent. A resin can be obtained.

  In the epoxy resin composition of the present invention, the epoxy resin represented by the above general formula (1) is used as an essential epoxy resin as an epoxy resin component, but other epoxy resins are used in combination as long as the object of the present invention is not impaired. You can also.

  Examples of such other epoxy resins include bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl. Epoxidized products of divalent phenols such as resorcin, naphthalenediols, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolac, o-cresol Epoxides of trivalent or higher phenols such as novolak, epoxidized products of cocondensation resins obtained from dicyclopentadiene and phenols, epoxidized products of cocondensation resins obtained from cresols, formaldehyde and alkoxy-substituted naphthalenes, phenols And paraxilile Epoxy product of phenol aralkyl resin obtained from dichloride, etc., Epoxy product of biphenyl aralkyl type phenol resin obtained from phenols and bischloromethylbiphenyl, etc., Epoxy of naphthol aralkyl resins synthesized from naphthols and paraxylylene dichloride, etc. And the like. These epoxy resins may be used alone or in combination of two or more. Although these compounding quantities should just be a range which does not impair the objective of this invention, it is less than 50 weight% with respect to the sum total of StPNE and the said resin. Preferably, StPNE is used in an amount of 60% by weight or more, more preferably 75% by weight or more based on the total epoxy resin.

  Specific examples of the phenolic curing agent used in the epoxy resin composition of the present invention include bivalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, hydroquinone, resorcin, catechol, biphenols, and naphthalenediols. Phenols, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak, naphthol novolak, dicyclopentadiene type phenol resin, Trivalent or higher phenols typified by phenol aralkyl resins and the like, further phenols, naphthols, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphe , 2,2'-biphenol, hydroquinone, resorcin, catechol, naphthalenediols, and the like, and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, p-xylylene glycol, p-xylylene glycol dimethyl ether Obtained from polyphenolic compounds synthesized by reaction with crosslinking agents such as divinylbenzene, diisopropenylbenzene, dimethoxymethylbiphenyls, divinylbiphenyl, diisopropenylbiphenyls, phenols and bischloromethylbiphenyl, etc. Examples thereof include biphenyl aralkyl type phenol resins, naphthol aralkyl resins synthesized from naphthols and paraxylylene dichloride and the like.

  The softening point range of the phenolic curing agent is preferably 40 to 150 ° C, more preferably 50 to 120 ° C. If it is lower than this, there is a problem of blocking during storage, and if it is higher than this, there is a problem in kneadability and moldability during preparation of the epoxy resin composition. Further, the melt viscosity at 150 ° C. is preferably 1 Pa · s or less, more preferably 0.5 Pa · s or less. When higher than this, there exists a problem in the kneadability at the time of preparation of an epoxy resin composition, and a moldability.

  In the epoxy resin composition of the present invention, the mixing ratio of the epoxy resin and the curing agent is preferably in the range of 0.8 to 1.5 in terms of an equivalent ratio of the epoxy group and the functional group in the curing agent. Outside this range, unreacted epoxy groups or functional groups in the curing agent remain even after curing, and physical properties such as reliability and water absorption when the cured product is reduced. Moreover, it is preferable that the equivalent ratio of the epoxy group of an epoxy resin and the phenolic OH of a phenol type hardening | curing agent is the range of 0.8-1.5.

  Examples of the inorganic filler used in the present invention include silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, mullite, and titania. Preferred are metal oxides, carbonates, silicates, carbides or nitrides. Although these 1 type (s) or 2 or more types may be combined, it is preferable to have a fused silica as a main component, and the form includes a crushed shape or a spherical shape. Usually, silica is used in combination with those having several kinds of particle size distributions. The range of the average particle diameter of the silica to be combined is preferably 0.5 to 100 μm. The content of the inorganic filler is preferably in the range of 60 to 94% by weight, preferably 78 to 86% by weight, more preferably 80 to 86% by weight. If it is smaller than this, the content of the organic component becomes high, and the flame retardancy is not sufficiently exhibited. On the other hand, if it is larger than this, the thermal conductivity of the molded product will increase, so that the decomposition rate of the organic component will increase, and the amount of heat-insulating carbonized layer will decrease, making it difficult to exhibit flame retardancy.

Furthermore, a metal hydroxide flame retardant can be used in the epoxy resin composition of the present invention as necessary. The metal hydroxide flame retardant is not particularly limited as long as it contains a metal element and an OH group or H ₂ O in the chemical formula or composition formula and acts as a flame retardant, but the following composition formula (I ) Is preferred.

m (M ¹ aOb) · n (M ² cOd) · l (H ₂ O) (I)
(Here, M ¹ and M ² represent different metal elements, and a, b, c, d, m, n, and l represent positive numbers.)
Is not particularly limited as long as M ¹ and M ² in the above formula (I) is a different metal elements from each other, from the viewpoint of the flame retardancy, the M ¹ as M ¹ and M ² are not the same first 3 cycles of metal elements, alkaline earth elements of group IIA, IVB, group IIB group, VII group, IB group, selected from metal elements belonging to group IIIA and group IVA, transition metal elements M ² are IIIB~IIB group Is preferably selected from. M ¹ is preferably selected from magnesium, calcium, aluminum, tin, titanium, iron, cobalt, nickel, copper and zinc, and M ² is preferably selected from iron, cobalt, nickel, copper and zinc. From the viewpoint of fluidity, it is preferable that M ¹ is magnesium and M ² is zinc. The molar ratio of m and n is not particularly limited as long as the effect of the present invention is obtained, but m / n is preferably 99/1 to 50/50. The content of the metal hydroxide flame retardant in the epoxy resin composition is preferably in the range of 1 to 10% by weight. Preferably it is 2-9 weight%, More preferably, it is 5-9 weight%. If it is smaller than this, the content of the organic component becomes high, and the flame retardancy is not sufficiently exhibited. On the other hand, if it is larger than this, the volume resistivity of the molded product is deteriorated, so that the insulation reliability is lowered and the fluidity is deteriorated. Since the metal hydroxide flame retardant acts also as an inorganic filler, in the calculation of the blending amount of the inorganic filler, it is calculated by including it in the inorganic filler.

  The epoxy resin composition of the present invention can reduce the high-temperature elastic modulus and improve the reflow resistance by containing an indene oligomer.

  The indene oligomer used in the present invention is obtained by copolymerizing monomers containing indene, styrenes and phenols. Examples of indenes include hydrocarbon-substituted indenes such as indene, methylindene, ethylindene, propylindene, and phenylindene. Among these, indene is preferable. Examples of styrenes include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, o-propylstyrene, m-propylstyrene, p Examples include alkyl-substituted styrene such as -propylstyrene and on-butylstyrene, and α-alkylstyrene such as α-methylstyrene, α-ethylstyrene, and α-propylstyrene. Of these, styrene is preferred. Examples of phenols include alkylphenols such as phenol and cresols, dialkylphenols such as xylenol, bisphenols such as naphthols, bisphenol A and bisphenol F, and polyfunctional phenol resins such as phenol novolac and phenol aralkyl resins. Is mentioned. Of these, phenol is preferred.

  In addition to the above indenes, styrenes and phenols, other monomers may be included, such as benzothiophene, methylbenzothiophenes, benzofuran, methylbenzofurans, vinylnaphthalene, vinylbiphenyl, acenaphthylene, acrylic acid, Examples thereof include monomers containing unsaturated bonds such as acrylic acid esters, methacrylic acid, methacrylic acid esters, maleic anhydride, fumaric acid, divinylbenzenes and diisopropenylbenzenes.

  The monomer mixture used to make an indene-based oligomer by copolymerization includes monomers containing indene, styrenes and phenols, and monomers containing indene and benzothiophenes.

  The content of each monomer is appropriately selected, but it is desirable to contain 60% by weight or more of indene per the total weight of the monomer. If the indenes are less than 60% by weight, there is a tendency that the effect of reducing the high temperature elastic modulus and improving the adhesion to copper and silver cannot be sufficiently obtained.

  Examples of the method for copolymerizing monomers containing indene, styrenes and phenols include radical polymerization, cationic polymerization, anionic polymerization and the like, and cationic polymerization is preferable. Cationic polymerization is usually carried out in the presence of an acidic catalyst. Examples of the acid catalyst include inorganic acids such as hydrochloric acid, sulfuric acid and phosphoric acid, formic acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, methanesulfone. Examples thereof include organic acids such as acids, Lewis acids such as zinc chloride, aluminum chloride, iron chloride, and boron trifluoride, solid acids such as activated clay, silica alumina, and zeolite.

  The number average molecular weight of the indene oligomer is preferably 300 to 1000, more preferably 500 to 800. The softening point of the indene oligomer is preferably 50 to 160 ° C, more preferably 70 to 120 ° C.

  As commercial products of indene oligomers, trade names manufactured by Nippon Steel Chemical Co., Ltd .; I-100, I-120, IP-100, IP-120, IS-100BT, and the like are available.

  The content of the indene oligomer is preferably 5 to 30 parts by weight, more preferably 10 to 25 parts by weight, and particularly preferably 10 to 20 parts by weight with respect to 100 parts by weight of the epoxy resin. If the content is 5 parts by weight or more, the reflow resistance tends to be improved by reducing the high temperature elastic modulus, and if it is 30 parts by weight or less, the decrease in hot hardness and the decrease in fluidity tend to be suppressed. It is in.

  Furthermore, a curing accelerator can be used in the epoxy resin composition of the present invention as necessary. Examples include amines, imidazoles, organic phosphines, Lewis acids, etc., specifically 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, benzyldimethylamine, Tertiary amines such as ethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2- Imidazoles such as heptadecylimidazole, organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenyl Tetraphenyl such as ruphosphonium / ethyltriphenylborate, tetrabutylphosphonium / tetrabutylborate, tetrasubstituted phosphonium / tetrasubstituted borate, 2-ethyl-4-methylimidazole / tetraphenylborate, N-methylmorpholine / tetraphenylborate, etc. There is boron salt. Of these, triphenylphosphine is preferable from the viewpoint of flame retardancy and curability, and an adduct of a third phosphine compound and a quinone compound is preferable from the viewpoint of flame retardancy, fluidity, and mold release. Of these, an adduct of triphenylphosphine and p-benzoquinone and an adduct of tris (4-methylphenyl) phosphine and p-benzoquinone are more preferable from the viewpoints of storage stability and releasability. The addition amount is usually in the range of 0.2 to 5 parts by weight with respect to 100 parts by weight of the epoxy resin.

  The epoxy resin composition of the present invention is made into a varnish in which an organic solvent is dissolved, and then impregnated into a fibrous material such as glass cloth, aramid nonwoven fabric, polyester nonwoven fabric such as liquid crystal polymer, etc., and then the solvent is removed, It can be. Moreover, it can be set as a laminated body by apply | coating on sheet-like materials, such as copper foil, stainless steel foil, a polyimide film, and a polyester film depending on the case.

  If the epoxy resin composition of the present invention is cured by heating, an epoxy resin cured product can be obtained, and this cured product is excellent in terms of flame retardancy, low hygroscopicity, low elasticity, and the like. This cured product can be obtained by molding the epoxy resin composition by a method such as casting, compression molding, transfer molding or the like. The temperature at this time is usually in the range of 120 to 220 ° C.

  In addition, in the epoxy resin composition of the present invention, an oligomer or a polymer compound such as polyester, polyamide, polyimide, polyether, polyurethane, phenoxy resin, or the like may be appropriately blended, pigment, You may mix | blend additives, such as a natural agent, a thixotropic agent, a coupling agent, and a fluid improvement agent. Examples of the pigment include organic or inorganic extender pigments and scaly pigments. Examples of the thixotropic agent include silicon-based, castor oil-based, aliphatic amide wax, oxidized polyethylene wax, and organic bentonite-based. Moreover, you may mix | blend hardening accelerators, such as amines, imidazoles, organic phosphines, and Lewis acid, as needed. As a compounding quantity, it is 0.2-5 weight part normally with respect to 100 weight part of epoxy resins. Furthermore, if necessary, the resin composition of the present invention includes a release agent such as carnauba wax and OP wax, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a colorant such as carbon black, and trioxide. A flame retardant such as antimony, a low stress agent such as silicone oil, a lubricant such as calcium stearate, and the like can be blended.

  The cured product of the present invention can be obtained by curing the epoxy resin composition by a molding method such as casting, compression molding, transfer molding or the like. The temperature at which the cured product is generated is usually 120 to 220 ° C.

  If the epoxy resin composition of the present invention is heat-cured by the above method, it can be made into a cured epoxy resin, and this epoxy composition is excellent in terms of flame retardancy, moisture resistance, adhesion, reflow resistance, and the like. An epoxy resin composition for semiconductor encapsulation can be obtained.

  Hereinafter, based on a synthesis example, an Example, and a comparative example, this invention is demonstrated concretely.

Synthesis example 1
(Synthesis of polyvalent hydroxy resin)
A phenol novolak (manufactured by Showa Polymer; BRG-555, hydroxyl group equivalent: 105 g / eq., Softening point: 67 ° C., melt viscosity at 150 ° C .: 0.08 Pa · s) is added to a 1 L 4-neck flask as a polyvalent hydroxy compound component. 105 g, 5.3 g of toluene, and 0.055 g (300 ppm) of p-toluenesulfonic acid as an acid catalyst were charged and the temperature was raised to 100 ° C. Next, with stirring at 100 ° C., 73 g (0.7 mol) of styrene was dropped over 3 hours to be reacted. Further, after reacting at 100 ° C. for 2 hours, 0.049 g of 30% Na ₂ CO ₃ was added for neutralization. Next, it was dissolved in 330 g of MIBK and washed 5 times with water at 80 ° C. Subsequently, after MIBK was distilled off under reduced pressure, 170 g of a polyvalent hydroxy resin was obtained. Its hydroxyl equivalent is 178 g / eq. The softening point was 78 ° C., and the melt viscosity at 150 ° C. was 0.13 Pa · s. From the hydroxyl equivalent, p of this polyvalent hydroxy resin was calculated to be 0.7. This resin is referred to as StPN-A.

Synthesis example 2
(Synthesis of epoxy resin)
In a four-neck separable flask, 150 g of StPN-A obtained in Synthesis Example 1, 468 g of epichlorohydrin, and 70 g of diethylene glycol dimethyl ether were added and dissolved by stirring. After uniformly dissolving, maintaining at 65 ° C. under a reduced pressure of 130 mmHg, 70.3 g of 48% aqueous sodium hydroxide solution was added dropwise over 4 hours, and the water and epichlorohydrin distilled off during the addition were separated in a separation tank, and epichlorohydrin was The mixture was returned to the reaction vessel, and water was removed from the system to react. After completion of the reaction, the salt produced by filtration was removed, and after further washing with water, epichlorohydrin was distilled off to obtain 185 g of an epoxy resin (StPNE-A). The epoxy equivalent of the obtained resin was 246 g / eq. The softening point was 56 ° C. and the melt viscosity at 150 ° C. was 0.10 Pa · s.

Examples 1-5, Comparative Examples 1-5
Formulation shown in Tables 1-2 for the epoxy resin (StPNE-A) obtained in Synthesis Example 2 above, curing agents, inorganic fillers and indene oligomers, triphenylphosphine as a curing accelerator, and other additives An epoxy resin composition was prepared by kneading at a ratio. The numerical value in a table | surface shows the weight part in a mixing | blending.

In addition, as a comparative epoxy resin,
Epoxy resin A: o-cresol novolac type epoxy resin (epoxy equivalent 200, softening point 65 ° C., manufactured by Nippon Steel Chemical Co., Ltd.)
Epoxy resin B: A phenol aralkyl type epoxy resin (epoxy equivalent 238, softening point 51 ° C., melt viscosity at 150 ° C. 0.12 Pa · s) was used.
As a hardener component,
PA: phenol aralkyl resin (MEH-7800SS (Maywa Kasei), OH equivalent 175, softening point 67 ° C.),
PN: phenol novolak (PSM-4261 (manufactured by Gunei Chemical Co., Ltd.), OH equivalent 103, softening point 82 ° C.) was used.
As an inorganic filler, spherical fused silica FB-60 (average particle size 21 μm) manufactured by Denki Kagaku Kogyo was used.
As an indene oligomer component,
I-100 (manufactured by Nippon Steel Chemical; copolymer of indene, styrene and phenol, softening point 100 ° C.),
IP-100 (manufactured by Nippon Steel Chemical; polymer of indene, softening point 98 ° C.),
IS-100BT (manufactured by Nippon Steel Chemical Co., Ltd .; copolymer of indene and benzothiophene, softening point 92 ° C.) was used.

  This epoxy resin composition was molded at 175 ° C., and further post-cured at 175 ° C. for 12 hours to obtain a cured product test piece, which was then subjected to various physical property measurements. The results are shown in Tables 3-4.

1) Measurement of epoxy equivalent Using a potentiometric titrator, methyl ethyl ketone was used as a solvent, a brominated tetraethylammonium acetic acid solution was added, and the potential was measured using a 0.1 mol / L perchloric acid-acetic acid solution.

2) Softening point It measured by the ring and ball method according to JIS-K-2207 using the automatic softening point apparatus (Mingfeng Co., Ltd. make, ASP-M4SP).

3) Melt viscosity The viscosity was measured at 150 ° C. using a CAP2000H rotational viscometer manufactured by BROOKFIELD.

4) Glass transition point (Tg)
Tg was determined under the condition of a temperature increase rate of 10 ° C./min using a TMA120C thermomechanical measuring device manufactured by Seiko Instruments.

5) Water absorption rate The conditions of 25 ° C. and 50% relative humidity were taken as the standard state, and the weight change rate after 100 hours of moisture absorption at 85 ° C. and 85% relative humidity.

6) Adhesiveness Adhesiveness was obtained by molding a 25 mm x 12.5 mm x 0.5 mm molded product between two 194 alloy plates at 175 ° C with a compression molding machine and post-curing at 175 ° C for 12 hours. The tensile shear strength was evaluated.

7) Flame retardance A test piece having a thickness of 1/16 inch was molded, evaluated according to the UL94V-0 standard, and represented by the total burning time of five test pieces.
8) Reflow resistance An 80-pin flat package (QFP) having an outer dimension of 20 mm × 14 mm × 2 mm mounted with a silicon chip with a volume of 8 mm × 10 mm × 0.4 mm is molded at 175 ° C. using an epoxy resin composition, Further, post-curing was performed at 175 ° C. for 12 hours, humidified under the conditions of 85 ° C., 85% RH and 168 hours, then subjected to reflow treatment at 235 ° C. for 10 seconds, and observed for the presence or absence of cracks. Evaluation was made based on the number of crack-generating packages with respect to the number of packages (5).

Claims (6)

In an epoxy resin composition containing an epoxy resin, a phenolic curing agent, an inorganic filler, and an indene oligomer, the epoxy resin component contains 60% by weight or more of an epoxy resin represented by the following general formula (1) , phenol The system curing agent component contains at least one selected from aralkyl type phenolic curing agents and novolac type phenolic curing agents, and the blending ratio of the epoxy resin and the phenolic curing agent is an epoxy group and a curing agent. The equivalent ratio of phenolic OH groups in the range is 0.8 to 1.5, the content of the inorganic filler in the epoxy resin composition is 60 to 94% by weight, and indene The epoxy resin composition, wherein the oligomer content is 5 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin.

(Here, G represents a glycidyl group, R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, R ₂ represents a substituent represented by the formula (a), and n represents 1 to 20) And p represents a number of 0.1 to 2.5, and R ₃ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms.) 2. The epoxy resin composition according to claim 1 , wherein the indene oligomer is an oligomer obtained by copolymerizing a monomer containing indene, styrene and phenol . The epoxy resin composition according to claim 1 or 2 , wherein the indene oligomer is an oligomer obtained by copolymerizing a monomer containing indene and benzothiophene . It is an epoxy resin composition for semiconductor sealing materials, The epoxy resin composition in any one of Claims 1-3 characterized by the above-mentioned. The epoxy resin hardened | cured material formed by hardening | curing the epoxy resin composition in any one of Claims 1-4 . The semiconductor device which sealed the semiconductor element with the epoxy resin composition of Claim 4 .