JPWO2015119195A1 - Epoxy resin composition, cured product thereof, and semiconductor device - Google Patents

Abstract

An object of this invention is to provide the epoxy resin composition excellent in heat resistance and a flame retardance, its hardened | cured material, and a semiconductor device using them. The epoxy resin composition of the present invention has an epoxy resin represented by the following formula (1) and an epoxy compound represented by the following formula (2) whose softening point (according to ASTM D 3104) is 100 to 120 ° C. Contains a mixture, a biphenyl aralkyl type phenolic resin and an inorganic filler. (In the formula (1), n is an average value and represents a number of 5 to 20.)

Description

  The present invention relates to an epoxy resin composition that provides a cured product excellent in heat resistance and flame retardancy.

  Furthermore, the present invention relates to an electrical and electronic material application that requires high functionality, in particular, an epoxy resin composition suitable as a semiconductor sealant and a thin film substrate material, a cured product thereof, and a semiconductor device using them.

  Epoxy resin compositions are widely used in the fields of electrical and electronic parts, structural materials, adhesives, paints, etc. due to their workability and excellent electrical properties, heat resistance, adhesion, moisture resistance (water resistance), etc. It has been.

However, in recent years, with the development in the electric / electronic field, moisture resistance, adhesion, dielectric properties, low viscosity for high filling of filler (inorganic or organic filler) as well as high purity of resin composition, There is a need for further improvements in various properties such as increased reactivity to shorten the molding cycle. Further, as a structural material, there is a demand for a material that is lightweight and has excellent mechanical properties in applications such as aerospace materials and leisure / sports equipment. In particular, in recent years, attention has been focused on power devices from the viewpoint of energy saving (Non-Patent Document 1).
In the past, power devices were mainly sealed with silicon gel, but in the future, conversion to thermosetting resins will continue to make significant progress in terms of productivity and cost, as well as strength and reliability. Yes. Furthermore, the driving temperature of this power device tends to increase year by year. For example, silicon-based semiconductors are designed assuming a driving temperature of 150 ° C. or higher, and have heat resistance to very high temperatures exceeding 150 ° C. (Non-Patent Document 2).

“2008 STRJ Report Semiconductor Roadmap Technical Committee 2008 Report”, Chapter 8, p1-17, [online], March 2009, JEITA Japan Electronics and Information Technology Industries Association Semiconductor Technology Roadmap Specialist Association, [May 30, 2012 search], Internet <URL: http: // strj-jeita. eliasp. net / strj / nenjihoukoku-2008. cfm> Nobuyuki Takakura et al., Matsushita Electric Engineering Technical Report Car-related device technology High-temperature operation IC for vehicles, 74, Japan, May 31, 2001, pp. 35-40

An epoxy resin having high heat resistance generally becomes an epoxy resin having a high crosslinking density.
An epoxy resin having a high crosslinking density has a high water absorption rate, is brittle, and deteriorates thermal decomposition characteristics. In addition, the electrical characteristics tend to deteriorate. In the case of a semiconductor driven at high temperature, the use of an epoxy resin having a high crosslinking density is not preferable because not only thermal decomposition characteristics are important but also electrical characteristics are important. Lowering the crosslinking density improves these disadvantageous properties, but lowers heat resistance and lowers the glass transition point (Tg). When the driving temperature exceeds the glass transition point, the volume resistivity is generally lowered at a temperature exceeding Tg, so that the electrical characteristics are deteriorated.
When trying to improve these characteristics, a technique of improving the heat resistance by increasing the molecular weight of the resin itself may be used, but the viscosity becomes very high. Therefore, it is necessary to cleanly cover the entire semiconductor when sealing the semiconductor. However, when the viscosity is high, it is difficult to cleanly cover the semiconductor, and thus unfilled portions such as voids are formed, which is not suitable as a semiconductor sealing material.
In general, a cured product having high heat resistance tends to have poor flame retardancy.
In particular, many compounds having Tg with thermomechanical properties of 150 ° C. or higher have poor flame retardancy, and both are required to be compatible.
That is, the present invention provides an epoxy resin composition having fluidity suitable for semiconductor encapsulation and having excellent heat resistance and flame retardancy, a cured product thereof, and a semiconductor device using them. With the goal.

As a result of intensive studies in view of the actual situation as described above, the present inventors have completed the present invention.
That is, the present invention relates to the following [1] to [4].
[1] An epoxy resin mixture of an epoxy resin represented by the following formula (1) and an epoxy compound represented by the following formula (2) having a softening point (according to ASTM D 3104) of 100 to 120 ° C., biphenylaralkyl type An epoxy resin composition containing a phenol resin and an inorganic filler.

(In formula (1), n represents an average value of 5 to 20)

[2] The epoxy resin represented by the formula (1) is an epoxy resin obtained by reacting an orthocresol novolak with an epihalohydrin,
The epoxy resin composition according to [1], wherein the total content of the binuclear body and the trinuclear body in the orthocresol novolak is 10 area% or less in terms of area percentage of gel permeation chromatography (GPC).
[3] A cured product obtained by curing the epoxy resin composition according to [1] or [2].
[4] A semiconductor device formed by covering a semiconductor chip with the epoxy resin composition according to [1] or [2] molded into a granular or tablet shape and molded at 175 to 250 ° C.

According to the present invention, there are provided an epoxy resin composition having fluidity suitable for semiconductor encapsulation and excellent in heat resistance and flame retardancy, a cured product thereof, and a semiconductor device using them. Can do.
In particular, the epoxy resin composition of the present invention is used for semiconductor sealing, particularly for sealing semiconductor elements for power devices, and can provide a highly reliable semiconductor device having high heat resistance and flame retardancy.

  The epoxy resin composition of the present invention contains a specific epoxy resin mixture, a specific curing agent, and an inorganic filler. In this specification, the softening point is a value measured according to ASTM D 3104 (Metra method) unless otherwise specified.

The epoxy resin mixture in the present invention contains an ortho-cresol novolac type epoxy resin and 4,4′-bisglycidyloxybiphenyl. The epoxy resin mixture in the present invention contains an ortho-cresol novolac type epoxy resin as a main component. In the epoxy resin mixture, the content of 4,4′-bisglycidyloxybiphenyl is 10 to 25 area% (gel permeation chromatography (hereinafter referred to as GPC) (detector: RI)). Calculation) is preferable, more preferably 10 to 23 area%, and particularly preferably 10 to 20 area%. A preferred ratio of 4,4′-bisglycidyloxybiphenyl to orthocresol novolac type epoxy resin is 9: 1 to 3: 1 in terms of area percentage of GPC (orthocresol novolac type epoxy resin: 4,4′-bisglycidyloxy Biphenyl), and a particularly preferred ratio is 9: 1 to 4: 1.
4,4'-bisglycidyloxybiphenyl is effective in improving fluidity when contained in 10% by area or more, and effective in maintaining heat-resistant decomposition characteristics and water-resistant characteristics when the content is 25% by area or less. is there.
In the epoxy resin mixture in the present invention, an ortho-cresol novolak type epoxy resin is a main component as described above, and such an ortho-cresol novolak type epoxy resin is an epoxy resin represented by the following formula (1).

(In formula (1), n represents an average value of 5 to 20)
The ortho cresol novolac type epoxy resin in the epoxy resin mixture in the present invention has an average value of 5 to 20, and preferably 5 to 10. Further, such an ortho-cresol novolak type epoxy resin has a number average molecular weight of preferably from 100 to 10,000, more preferably from 1000 to 5,000, particularly preferably from 1,300 to 2,000, particularly in measurement by GPC. preferable. Moreover, the softening point of the ortho cresol novolak type epoxy resin in the epoxy resin composition of the present invention is 100 to 120 ° C, preferably 100 to 115 ° C. The heat resistance and thermal decomposition characteristics of the epoxy resin composition which has been made to be a resin having a softening point lower than 100 ° C. are reduced, and in the case of an epoxy resin having a temperature higher than 120 ° C. The melt viscosity does not decrease, and there is a problem in fluidity in applications such as semiconductor sealing, which causes voids.

As the shape of the epoxy resin mixture in the present invention, it is preferable to have a solid resin shape with crystallinity when homogeneously mixed, and the softening point (according to ASTM D 3104) is handling property and molding at the time of curing. From the problem of property, it is preferable that it is 100-120 degreeC, More preferably, it is 100-110 degreeC. General resins tend to be sticky when handled at room temperature, and are preferably used at least at a softening point of 50 ° C. or lower. In particular, electronic materials can be produced in Southeast Asia, so it is assumed that the room will exceed 40 ° C. Therefore, the softening point exceeding 100 ° C will not only make the handling at room temperature very convenient. , Excellent crushing and kneading properties. However, when the softening point is too high, there is a problem that it does not dissolve cleanly at the time of kneading, and there is a high possibility that a reaction will occur at the time of kneading if the temperature is too high for melting. Therefore, a softening point of 120 ° C. or lower is preferable.
In addition, the resin having crystallinity is itself crystalline and does not become a cloudy resin, and it is allowed to stand at 25-100 ° C. for 8 hours or more even if it does not express crystallinity at first glance. It means a resin that becomes cloudy from a transparent resin.

The epoxy resin mixture in the present invention preferably has a melt viscosity at 150 ° C. of 0.11 Pa to 1.0 Pa · s, more preferably 0.11 Pa · s to 0.8 Pa · s, particularly 0. It is preferably 11 Pa · s or more and 0.7 Pa · s or less.
Especially in a power device, since the wire is thick, it can be sealed even if the viscosity is high, but if it exceeds 1.0 Pa · s, there may be a problem in moldability. On the other hand, if it is too low, there is a problem such as forming a weld void that hardens while entraining the air. It is preferable because it can be easily pushed out of the glass.

The epoxy resin mixture in the present invention may be obtained by uniformly mixing the respective epoxy resins, but in the present invention, it is preferably obtained by mixing cresol novolak and 4,4′-biphenol and reacting with epihalohydrin. The cresol novolak is preferably an ortho cresol novolak.
Further, in the cresol novolak or orthocresol novolak to be used, the content of the binuclear body and the trinuclear body is preferably 15 area% or less in total as measured by GPC, and particularly preferably 10 area% or less. preferable. The binuclear body is preferably 10 area% or less, particularly preferably 5 area% or less. Furthermore, the trinuclear body is preferably 10 area% or less, and particularly preferably 5 area% or less.

For simple mixing, the epoxidation of cresol novolac and the epoxidation of 4,4′-biphenol are performed separately. In this case, a reaction occurs in which cresol novolacs are partially bonded to each other and 4,4′-biphenols are partially bonded to each other during epoxidation. In this case, the partial polymerization of cresol novolacs is markedly increased in viscosity. In addition, those in which 4,4′-biphenols are bonded to each other have very high crystallinity and poor compatibility, so that it is difficult to dissolve them uniformly. It also induces a decrease in heat resistance.
In contrast, in the case of epoxidizing a mixture of cresol novolak and 4,4′-biphenol, the formation of a compound in which cresol novolak and biphenol are partially bonded can suppress polymerization between cresol novolacs and promote low viscosity. it can. Furthermore, this compound has the characteristics of both cresol novolac and biphenol, is excellent in compatibility, and can further suppress a decrease in heat resistance.

The cresol novolak that can be used in the present invention may be a commercially available one, but can also be produced by the reaction of cresol and formaldehyde (Japanese Patent Laid-Open No. 2002-179750, Japanese Patent Laid-Open No. 2004-131585). Issue no.). As the cresol novolak resin, the softening point (according to ASTM D 3104) is preferably 120 to 150 ° C, more preferably 120 to 145 ° C, and particularly preferably 120 to 140 ° C.
The structure is preferably ortho-cresol novolak, and particularly preferably bifunctional biscresol F is 5 area% or less in GPC measurement, and trifunctional cresol novolac is 5 area% or less.
The Mw (average molecular weight) is preferably 1000 or more and less than 10,000, and particularly preferably 1000 or more and less than 5000. It exists in the tendency for the balance of fluidity | liquidity, compatibility, heat resistance, and thermal decomposition resistance to be excellent because it exists in this range. Moreover, in molecular weight distribution (Mw / Mn), it is preferable to use a thing of 1.8-2.5. Particularly preferred is 1.85 to 2.15.

  With respect to 4,4'-biphenol, the purity is preferably 99% or more. This is because, when it has been partially oxidized by oxidation or the like, it becomes monofunctional and may cause a decrease in heat resistance.

  The method for reacting a mixture of cresol novolak, 4,4'-biphenol and epihalohydrin is not particularly limited, but an example of the synthesis method is described below.

  In the reaction for obtaining an epoxy resin mixture in the present invention, an epoxy resin mixture can be obtained by simultaneously reacting cresol novolac (CN) and 4,4'-biphenol (BP) with epihalohydrin. Here, the ratio (weight ratio) of (CN) to (BP) is preferably CN / BP = 3 to 9, more preferably 3.5 to 5.7, and particularly preferably 3.5 to 4.5. . This range is preferable from the viewpoint of the balance of heat resistance, flame retardancy, and fluidity. Hereinafter, a mixture of (CN) and (BP) is referred to as a phenol mixture in the present invention.

In the reaction for obtaining the epoxy resin mixture in the present invention, the epihalohydrin is preferably epichlorohydrin which is industrially easily available. The amount of epihalohydrin used is usually 3.0 to 15 mol, preferably 3.0 to 10 mol, more preferably 3.5 to 8.5 mol, particularly preferably 1 mol per mol of the hydroxyl group of the phenol mixture of the present invention. It is 4.0-6.0 mol.
When the amount is less than 3.0 mol, the epoxy equivalent may be increased, and the workability of the resulting epoxy resin may be deteriorated. When the amount exceeds 15 mol, the amount of the solvent may be increased.
In particular, in the present invention, since the reaction product of cresol novolac and biphenol contributes to the characteristics, the amount of epichlorohydrin is preferably 6.0 mol or less. This adjusts the bond between cresol novolac and biphenol.
At this time, the amount of biphenol taken into the cresol novolac is preferably 1 to 10%, particularly preferably 1 to 8%. This amount can be calculated from the number of moles of biphenol and cresol and GPC data by NMR or the like, and can also be calculated from the theoretical reaction ratio and GPC area% when charged during synthesis. A specific calculation method is as follows. The theoretical amount of diglycidyloxybiphenyl is confirmed from the charged amount. On the other hand, the content is confirmed by the peak area of diglycidyloxybiphenyl (detector: RI) from the area ratio of GPC. This subtraction is taken in and becomes the amount. When only biphenol is used, the binding between biphenols is preferential, but under the condition where the amount of cresol novolak is large, it is preferentially incorporated into cresol novolac from the probability theory, so the difference is judged to be the amount incorporated. Judge that there is no problem. On the other hand, in the NMR measurement, the molar ratio is calculated from the proton or carbon peak area ratio of each benzene nucleus. The theoretical amount of diglycidyloxybiphenyl is confirmed from the molar ratio. The rest is the same as above. In addition, it is also possible to roughly calculate based on the difference between the actual epoxy equivalent and the theoretical epoxy equivalent calculated from the charging ratio.

In the above reaction, it is preferable to use an alkali metal hydroxide for the reaction with epihalohydrin. Examples of the alkali metal hydroxide that can be used include sodium hydroxide, potassium hydroxide, and the like, and a solid substance may be used, or an aqueous solution thereof may be used. From the viewpoint of property and handling, it is preferable to use a solid material molded into a flake shape.
The amount of alkali metal hydroxide used is usually 0.90 to 1.5 mol, preferably 0.95 to 1.25 mol, more preferably 0.99 to 1. mol, per mol of hydroxyl group in the phenol mixture. 15 moles.

  In order to accelerate the reaction, a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide or trimethylbenzylammonium chloride may be added as a catalyst. The amount of the quaternary ammonium salt used is usually 0.1 to 15 g, preferably 0.2 to 10 g, per 1 mol of the hydroxyl group of the phenol mixture of the present invention.

In this reaction, in addition to the above epihalohydrin, a nonpolar proton solvent (dimethylsulfoxide, dioxane, dimethylimidazolidinone, etc., dimethylsulfoxide and dioxane are preferred in the present invention) and an alcohol having 1 to 5 carbon atoms are used in combination. Is preferred. Examples of the alcohol having 1 to 5 carbon atoms include alcohols such as methanol, ethanol and isopropyl alcohol (methanol is preferred in the present invention). The usage-amount of a nonpolar protic solvent or a C1-C5 alcohol is 2-50 weight% normally with respect to the usage-amount of an epihalohydrin, Preferably it is 4-25 weight%. Moreover, epoxidation may be performed while controlling the moisture in the system by a technique such as azeotropic dehydration.
When the water content in the reaction system is large, the electrical reliability of the obtained epoxy resin mixture may be lowered, and it is preferable to synthesize with the water content controlled to 5% or less. Moreover, when an epoxy resin mixture is obtained using a nonpolar proton solvent, an epoxy resin mixture having excellent electrical reliability can be obtained, and therefore a nonpolar proton solvent can be suitably used.

The reaction temperature is usually 30 to 90 ° C, preferably 35 to 80 ° C. In particular, in the present invention, 60 ° C. or higher is preferable for higher-purity epoxidation, and reaction under conditions close to reflux conditions is particularly preferable. The reaction time is usually 0.5 to 10 hours, preferably 1 to 8 hours, particularly preferably 1 to 3 hours. If the reaction time is short, the reaction cannot proceed, and if the reaction time is long, a by-product may be formed.
After the reaction product of these epoxidation reactions is washed with water or without washing with water, the epihalohydrin, the solvent and the like are removed under heating and reduced pressure. Furthermore, in order to obtain an epoxy resin mixture with less hydrolyzable halogen, the recovered epoxy resin mixture is a ketone compound having 4 to 7 carbon atoms (for example, methyl isobutyl ketone, methyl ethyl ketone, cyclopentanone, cyclohexanone, etc.). Is dissolved as a solvent, and the reaction is carried out by adding an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide to ensure ring closure. In this case, the amount of alkali metal hydroxide used is usually 0.01 to 0.3 mol, preferably 0.05 to 0.2 mol, based on 1 mol of the hydroxyl group of the phenol mixture of the present invention used for epoxidation. . The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 2 hours.

  After completion of the reaction, the produced salt is removed by filtration, washing with water, etc., and the solvent is distilled off under heating and reduced pressure to obtain the epoxy resin mixture in the present invention. In addition, after distilling off the solvent under heating and decompression, after maintaining at 110 to 170 ° C., a plate-like body (plate shape, sheet shape, belt shape or the like having a temperature of 100 ° C. or less, more preferably 80 ° C. or less ) It is preferable to form and take out a plate shape, a water droplet shape (marble shape) or the like by casting or dropping on the surface. Note that a stepwise cooling method of cooling at 60 ° C. or lower after cooling at 80 ° C. or lower may be used. The solid material obtained in this step shows a transparent amorphous state or a cloudy shape in which crystals are dispersed. Even if the solid material is a transparent amorphous state, it is heated at 50 to 100 ° C. for 30 minutes to 10 hours. By doing so, it becomes a cloudy shape in which crystals are dispersed.

  As a preferable resin characteristic of the epoxy resin mixture in the present invention, an epoxy equivalent is 175 to 215 g / eq. And more preferably 175 to 210 g / eq. It is. When the epoxy equivalent is within the above range, an epoxy resin mixture excellent in heat resistance and electrical reliability of the cured product can be obtained more easily. Epoxy equivalent is 215 g / eq. In the case where it exceeds the upper limit, the ring of the epoxy is not completely closed, and many compounds having no functional group may be contained, and the epoxy equivalent may not be lowered. Many of these compounds that could not be ring-closed often contain chlorine, and as an electronic material application, the release of chlorine ions under high-temperature and high-humidity conditions and the resulting corrosion of wiring may occur.

  The total chlorine remaining in the epoxy resin mixture is preferably 1500 ppm or less, more preferably 1200 ppm or less, and particularly preferably 900 ppm or less. In addition, about chlorine ion and sodium ion, 5 ppm or less is preferable respectively, More preferably, it is 3 ppm or less. Chlorine ions are described above. Needless to say, cations such as sodium ions are also very important factors particularly in power device applications, and contribute to a defective mode when a high voltage is applied.

The epoxy resin composition of the present invention contains a biphenyl aralkyl type phenol resin as an essential component as a curing agent.
The curing agent in the present invention is not particularly limited as long as it is a structure in which phenols are bonded with a biphenylenediyl group. Specifically, 4,4′-bis (chloromethyl) -1,1′-biphenyl, 4,4 Substituted methylene biphenyl compounds such as' -bis (methoxymethyl) -1,1'-biphenyl, 4,4'-bis (hydroxymethyl) -1,1'-biphenyl, and phenols: phenol, carbon number of 1-2 A phenol resin obtained by a reaction with an alkyl-substituted phenol (cresol, ethylphenol, etc.), dihydroxybenzene (resorcin, hydroquinone, catechol, etc.) and trihydroxybenzene (phloroglicinol, etc.). Examples of suitable specific structures include the following.

(In the above formula, R independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a hydroxyl group, and n represents a number of 1 to 10 in terms of the number of repetitions.)

In the present invention, the biphenyl aralkyl type phenol resin is preferably a resin having a softening point (based on JIS K-7234) of 50 to 120 ° C, more preferably 55 to 90 ° C, and particularly preferably 50 to 84 ° C. is there. When the softening point is below 50 ° C., the stickiness at room temperature is severe and handling may be difficult. Moreover, when it exceeds 120 degreeC, there exists a possibility that reaction of a hardening | curing agent and an epoxy resin may advance at the time of kneading | mixing.
Furthermore, the melt viscosity at 150 ° C. is preferably 0.01 to 1.0 Pa · s, particularly preferably 0.01 to 0.5 Pa · s. Exceeding 1.0 Pa · s is not preferable because the fluidity is deteriorated and the number of unfilled portions may increase. In addition, a compound having a molecular weight of less than 0.01 Pa · s has a low molecular weight, or a phenol monomer may remain, which may make it difficult to obtain a homogeneous composition due to volatilization and crystallinity problems. It is not preferable.

In the epoxy resin composition of the present invention, the preferred range of the amount of the curing agent used in the present invention is preferably the epoxy resin in the present invention: the curing agent in the present invention = 0.5: 1 to 2: 1 in weight ratio, 7: 1 to 1.1: 1 are more preferable, and 0.7: 1 to 0.9: 1 are particularly preferable. In addition, as for content of a hardening | curing agent, 0.7-1.2 equivalent is preferable with respect to 1 equivalent of epoxy groups of all the epoxy resins. When less than 0.7 equivalent or more than 1.2 equivalent with respect to 1 equivalent of epoxy group, curing may be incomplete and good cured properties may not be obtained.
Here, in the case of the biphenyl aralkyl type phenol resin, the biphenyl aralkyl type phenol resin is preferably from 0.8 to 1.1, particularly preferably from 0.85 to 1.05 with respect to 1 mol of the epoxy resin mixture.

The epoxy resin composition of the present invention contains an inorganic filler. Examples of inorganic fillers include crystalline silica, fused silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, titania, talc, and the like. Examples thereof include, but are not limited to, spherical beads. Here, in order to improve cured properties such as water absorption and linear expansion coefficient, crystalline silica, fused silica or alumina is preferred as a filler to be combined with the epoxy resin mixture in the present invention and the curing agent in the present invention. These may be used alone or in combination of two or more. The content of these inorganic fillers is usually 60 to 95% by weight, preferably 70 to 90% by weight in the epoxy resin composition of the present invention.
If it is less than 60% by weight, the water absorption rate and the linear expansion coefficient may be too high, and if it exceeds 95% by weight, there may be a problem that uniform kneading cannot be performed. In addition, there is a problem in fluidity, and it may be difficult to seal without filling.

  Hereinafter, the blending ratio of the epoxy resin composition of the present invention and other blends will be described.

  Specific examples of the curing accelerator that can be used (also referred to as a curing catalyst or a polymerization catalyst) include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, and 2- (dimethyl Aminomethyl) phenol, tertiary amines such as 1,8-diaza-bicyclo [5.4.0] undecene-7, phosphines such as triphenylphosphine, tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyl Quaternary ammonium salts such as decanylammonium salt and cetyltrimethylammonium salt, quaternary phosphonium salts such as triphenylbenzylphosphonium salt, triphenylethylphosphonium salt and tetrabutylphosphonium salt (quaternary salt) Counter ions are halogen, organic acid ions, An oxide ion, particularly specification is not, in particular organic acid ion, a hydroxide ion.) Include metal compounds such as tin octylate. When using a hardening accelerator, 0.01-5.0 weight part is used as needed with respect to 100 weight part of epoxy resins.

  In the epoxy resin composition, other epoxy resins can be used in combination with the epoxy resin mixture in the present invention. When used in combination, the proportion in the total epoxy resin is preferably 30% by weight or more, particularly preferably 40% by weight or more.

  Specific examples of other epoxy resins include novolac type epoxy resins, bisphenol A type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, phenol aralkyl type epoxy resins, and the like. Specifically, bisphenol A, bisphenol S, thiodiphenol, fluorene bisphenol, terpene diphenol, 4,4′-biphenol, 2,2′-biphenol, 3,3 ′, 5,5′-tetramethyl- [ 1,1′-biphenyl] -4,4′-diol, hydroquinone, resorcin, naphthalenediol, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol (Phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hydroxyacetate Enone, o-hydroxyacetophenone, dicyclopentadiene, furfural, 4,4′-bis (chloromethyl) -1,1′-biphenyl, 4,4′-bis (methoxymethyl) -1,1′-biphenyl, 1, Glycidyl ethers derived from polycondensates with 4-bis (chloromethyl) benzene, 1,4-bis (methoxymethyl) benzene and the like, modified products thereof, halogenated bisphenols such as tetrabromobisphenol A, and alcohols , Cycloaliphatic epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin, silsesquioxane epoxy resin (chain structure, cyclic structure, ladder structure, or a mixed structure of at least two of them) Glycidyl group and / or epoxycyclohexane structure Solid or liquid epoxy resin having an epoxy resin) and the like having, but not limited thereto.

As a hardening | curing agent which the epoxy resin composition of this invention contains, you may contain hardening | curing agents other than a biphenyl aralkyl type phenol resin. Examples thereof include a phenol resin, a phenol compound, an amine compound, an acid anhydride compound, an amide compound, and a carboxylic acid compound. When used in combination, the proportion of the curing agent is preferably 30% by weight or more, particularly preferably 40% by weight or more.
Specific examples of the curing agent that can be used are as follows.
Phenol resin, phenol compound; bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, terpene diphenol, 4,4′-biphenol, 2,2′-biphenol, 3,3 ′, 5,5′-tetramethyl- [ 1,1′-biphenyl] -4,4′-diol, hydroquinone, resorcin, naphthalenediol, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol (Phenol, alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, dihydroxynaphthalene, etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hy Loxyacetophenone, o-hydroxyacetophenone, dicyclopentadiene, furfural, polycondensates with 1,4′-bis (chloromethyl) benzene, 1,4′-bis (methoxymethyl) benzene, etc., and modified products thereof, Examples thereof include, but are not limited to, halogenated bisphenols such as tetrabromobisphenol A and polyphenols such as terpene and phenol condensates. These may be used alone or in combination of two or more.

  Preferable phenol resins in combination include phenol aralkyl resins (resins having an aromatic alkylene structure), particularly preferably a structure having at least one selected from phenol, naphthol, and cresol, and an alkylene portion serving as a linker thereof. And a resin characterized by at least one selected from a benzene structure and a naphthalene structure (specific examples include zylock, naphthol zylock, and phenol-naphthalene novolak resin).

  Amine compounds, amide compounds; diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, nitrogen-containing compounds such as polyamide resins synthesized from linolenic acid and ethylenediamine, It is not limited to these. These may be used alone or in combination of two or more.

  Acid anhydride compounds, carboxylic acid compounds; phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, hexahydro Phthalic anhydride, methylhexahydrophthalic anhydride, butanetetracarboxylic anhydride, bicyclo [2.2.1] heptane-2,3-dicarboxylic anhydride, methylbicyclo [2.2.1] heptane-2, Acid anhydrides such as 3-dicarboxylic acid anhydride and cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride; by addition reaction of various alcohols, carbinol-modified silicone, and the above-mentioned acid anhydrides Although the obtained carboxylic acid resin is mentioned, it is not limited to these. These may be used alone or in combination of two or more.

Other curing agents that can be used in combination include, but are not limited to, imidazole, trifluoroborane-amine complexes, guanidine derivative compounds, and the like. These may be used alone or in combination of two or more.
In the present invention, it is particularly preferable to use a phenol resin from the viewpoint of reliability.

  In the epoxy resin composition of the present invention, the amount of the curing agent used is preferably 0.7 to 1.2 equivalents relative to 1 equivalent of the epoxy groups of all epoxy resins. When less than 0.7 equivalent or more than 1.2 equivalent with respect to 1 equivalent of epoxy group, curing may be incomplete and good cured properties may not be obtained.

  In the epoxy resin composition of the present invention, a curing accelerator may be used in combination with the curing agent. Specific examples of the curing accelerator that can be used include those described above. When using a hardening accelerator, 0.01-5.0 weight part is used as needed with respect to 100 weight part of epoxy resins.

  The epoxy resin composition of the present invention may contain a phosphorus-containing compound as a flame retardant component. The phosphorus-containing compound may be a reactive type or an additive type. Specific examples of phosphorus-containing compounds include trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixylylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixylylenyl phosphate, 1,3-phenylenebis ( Phosphoric acid esters such as dixylylenyl phosphate), 1,4-phenylenebis (dixylylenyl phosphate), 4,4′-biphenyl (dixylylenyl phosphate); 9,10-dihydro-9-oxa Phosphanes such as -10-phosphaphenanthrene-10-oxide, 10 (2,5-dihydroxyphenyl) -10H-9-oxa-10-phosphaphenanthrene-10-oxide; epoxy resin and active hydrogen of the phosphanes Contains phosphorus obtained by reacting with Poxy compounds, red phosphorus and the like can be mentioned, and phosphoric esters, phosphanes or phosphorus-containing epoxy compounds are preferable, and 1,3-phenylenebis (dixylylenyl phosphate), 1,4-phenylenebis (dixylylene). Nyl phosphate), 4,4′-biphenyl (dixylylenyl phosphate) or phosphorus-containing epoxy compounds are particularly preferred. The phosphorus-containing compound content is preferably phosphorus-containing compound / total epoxy resin = 0.1 to 0.6 (weight ratio). If it is 0.1 or less, the flame retardancy is insufficient, and if it is 0.6 or more, the hygroscopicity and dielectric properties of the cured product may be deteriorated.

  Furthermore, you may add antioxidant to the epoxy resin composition of this invention as needed. Antioxidants that can be used include phenol-based, sulfur-based, and phosphorus-based antioxidants. Antioxidants can be used alone or in combination of two or more. The usage-amount of antioxidant is 0.008-1 weight part normally with respect to 100 weight part with respect to the resin component in the epoxy resin composition of this invention, Preferably it is 0.01-0.5 weight part. is there.

  Specific examples of phenolic antioxidants include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β- (3 , 5-di-t-butyl-4-hydroxyphenyl) propionate, isooctyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, 2,4-bis- (n-octylthio)- Monophenols such as 6- (4-hydroxy-3,5-di-t-butylanilino) -1,3,5-triazine, 2,4-bis [(octylthio) methyl] -o-cresol; 2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 4,4′-thiobis (3- Til-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) ) Propionate], 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-t) -Butyl-4-hydroxy-hydrocinnamamide), 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 3,5-di-t -Butyl-4-hydroxybenzylphosphonate-diethyl ester, 3,9-bis [1,1-dimethyl-2- {β- (3-t-butyl-4-hydroxy-5- Bisphenols such as (tilphenyl) propionyloxy} ethyl] 2,4,8,10-tetraoxaspiro [5.5] undecane, bis (3,5-di-t-butyl-4-hydroxybenzylsulfonate) ethyl 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t- Butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane, bis [3,3′-bis- (4 '-Hydroxy-3'-tert-butylphenyl) butyric acid] glycol ester, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -iso Anureate, 1,3,5-tris (3 ′, 5′-di-t-butyl-4′-hydroxybenzyl) -S-triazine-2,4,6- (1H, 3H, 5H) trione, tocophenol And the like.

  Specific examples of the sulfur antioxidant include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, and the like. The

  Specific examples of phosphorus antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris (2,4-di-t- Butylphenyl) phosphite, cyclic neopentanetetrayl bis (octadecyl) phosphite, cyclic neopentanetetraylbi (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbi (2,4 -Di-t-butyl-4-methylphenyl) phosphite, bis [2-t-butyl-6-methyl-4- {2- (octadecyloxycarbonyl) ethyl} phenyl] hydrogen phosphite, etc. 9,10-dihydro 9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3,5-di-tert-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10 -Oxaphosphaphenanthrene oxides such as 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are exemplified.

  These antioxidants can be used alone, but two or more of them may be used in combination. In the present invention, a phosphorus-based antioxidant is particularly preferable.

Furthermore, you may add a light stabilizer to the epoxy resin composition of this invention as needed.
As the light stabilizer, hindered amine-based light stabilizers, particularly HALS and the like are suitable. HALS is not particularly limited, but representative examples include dibutylamine, 1,3,5-triazine, N, N′-bis (2,2,6,6-tetramethyl-4- Polycondensate of piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy succinate -2,2,6,6-tetramethylpiperidine polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], bis (1,2,2, 6,6-pentamethyl-4-pi Peridyl) [[3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl] methyl] butyl malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis (1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate, 2- (3,5-di -T-butyl-4-hydroxybenzyl) -2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), etc. Only one HALS is used. Two or more types may be used in combination.

  Furthermore, a binder resin can also be mix | blended with the epoxy resin composition of this invention as needed. Examples of the binder resin include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, polyamide resins, polyimide resins, and silicone resins. However, it is not limited to these. The blending amount of the binder resin is preferably in a range that does not impair the flame retardancy and heat resistance of the cured product, and is usually 0.05 to 50 parts by weight, preferably 0.05 to 100 parts by weight with respect to 100 parts by weight of the epoxy resin component. 20 parts by weight are used as needed.

Further, the epoxy resin composition of the present invention may be blended with a resin for improving heat resistance such as cyanate resin, maleimide resin, benzoxazine, etc., if necessary. The amount is usually 10 to 50 parts by weight, preferably 15 to 40 parts by weight based on the parts by weight.
Furthermore, the epoxy resin composition of the present invention contains various combinations of a silane coupling agent, a release agent such as stearic acid, palmitic acid, zinc stearate, and calcium stearate, a surfactant, a dye, a pigment, and an ultraviolet absorber. An agent and various thermosetting resins can be added, and the amount used is generally 0.05% to 1.5% by weight, preferably 0.05 to 1.0%, based on the total amount of the epoxy resin composition. % By weight.

  The epoxy resin composition of this invention is obtained by mixing each component uniformly. The epoxy resin composition of the present invention can be easily made into a cured product by a method similar to a conventionally known method. For example, a modified epoxy resin and a curing agent and / or a curing accelerator, a phosphorus-containing compound, a binder resin, an inorganic filler and a compounding agent are pulverized as necessary, and then mixed using an extruder, kneader, roll, etc. A resin composition is obtained, and the epoxy resin composition is further pulverized, tableted or granulated and molded at 140 to 220 ° C. using a transfer molding machine or compression molding machine, and further at 100 to 220 ° C. for 1 to 10 hours. The cured product of the present invention can be obtained by heating.

  The semiconductor device of the present invention is obtained by mounting a semiconductor element on a printed wiring board and sealing it with the epoxy resin composition of the present invention. The mounting method and the sealing method of the semiconductor element are not particularly limited. For example, a flip chip bonder or the like is used to align the connection electrode portions on the multilayer printed wiring board and the solder bumps of the semiconductor element. Thereafter, the solder bumps are heated to the melting point or more, and the printed wiring board and the solder bumps are connected by fusion bonding. Next, a liquid sealing resin is filled between the printed wiring board and the semiconductor element and cured. Thereby, a semiconductor device is obtained. Since the semiconductor device thus obtained has excellent heat resistance and heat decomposition resistance, it is particularly useful for an in-vehicle power device.

  EXAMPLES Next, the present invention will be described more specifically with reference to examples. In the following, parts are parts by weight unless otherwise specified. The present invention is not limited to these examples. Moreover, area% shows the area percentage computed from the measured value by gel permeation chromatography (GPC) unless there is particular notice after that.

The various analysis methods used in the examples are described below.
Epoxy equivalent: JIS K 7236 (ISO 3001) compliant ICI melt viscosity: JIS K 7117-2 (ISO 3219) compliant Softening point: ASTM D 3104 compliant GPC:
Column (Shodex KF-603, KF-602.5, KF-602, KF-601x2)
The coupled eluent is tetrahydrofuran. The flow rate is 0.5 ml / min.
Column temperature is 40 ° C
Detection: RI (differential refraction detector)

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.

(Synthesis Example 1)
A flask equipped with a stirrer, a reflux condenser, and a stirrer was purged with nitrogen while orthocresol novolak (softening point 138 ° C. 2.5 nuclei 2.5 area% 3 nuclei 3.4 area% hydroxyl equivalent 120 g / eq. 92.6 parts, 21.2 parts of 4,4′-biphenol, 416 parts of epichlorohydrin and 95.8 parts of dimethyl sulfoxide were added and dissolved under stirring, and the temperature was raised to 45 ° C. Next, 42 parts of flaky sodium hydroxide were added in portions over 90 minutes, and then reacted at 45 ° C. for 2 hours and at 70 ° C. for 75 minutes. After completion of the reaction, excess solvents such as epichlorohydrin were distilled off from the oil layer under reduced pressure using a rotary evaporator. The residue was dissolved by adding 352 parts of methyl isobutyl ketone, washed with water, and heated to 75 ° C. Under stirring, 13 parts of a 30% by weight aqueous sodium hydroxide solution was added and the reaction was performed for 1 hour, followed by washing with water until the washing water of the oil layer became neutral. From the resulting solution, the pressure was reduced using a rotary evaporator. Methyl isobutyl ketone and the like were distilled off below to obtain 153 parts of an epoxy resin mixture (EP1) in the present invention. The epoxy equivalent of the obtained epoxy resin was 187 g / eq. The ICI melt viscosity at a softening point of 108 ° C. and 150 ° C. was 0.60 Pa · s.
The theoretical amount of diglycidyloxybiphenyl calculated from the raw material is 20%. On the other hand, the amount of diglycidyloxybiphenyl calculated from gel permeation chromatography was 16.2%. This indicates that 3.8% of the biphenol structure was incorporated into the cresol novolac structure. The average molecular weight Mw was 2517.

(Synthesis Example 2)
A flask equipped with a stirrer, a reflux condenser, and a stirrer was purged with nitrogen while orthocresol novolak (softening point 138 ° C. dinuclear 1.8 area% trinuclear 3.0 area% hydroxyl equivalent 120 g / eq. 92.6 parts, 21.2 parts of 4,4′-biphenol, 602 parts of epichlorohydrin and 95.8 parts of dimethyl sulfoxide were added and dissolved under stirring, and the temperature was raised to 45 ° C. Next, 42 parts of flaky sodium hydroxide were added in portions over 90 minutes, and then reacted at 45 ° C. for 2 hours and at 70 ° C. for 75 minutes. After completion of the reaction, excess solvents such as epichlorohydrin were distilled off from the oil layer under reduced pressure using a rotary evaporator. The residue was dissolved by adding 352 parts of methyl isobutyl ketone, washed with water, and heated to 75 ° C. Under stirring, 13 parts of a 30% by weight aqueous sodium hydroxide solution was added and the reaction was performed for 1 hour, followed by washing with water until the washing water of the oil layer became neutral. From the resulting solution, the pressure was reduced using a rotary evaporator. Methyl isobutyl ketone and the like were distilled off below to obtain 158 parts of an epoxy resin mixture (EP2) in the present invention. The epoxy equivalent of the obtained epoxy resin is 185 g / eq. The ICI melt viscosity at a softening point of 118 ° C. and 150 ° C. was 0.53 Pa · s.
The theoretical amount of diglycidyloxybiphenyl calculated from the raw material is 20%. On the other hand, the amount of diglycidyloxybiphenyl calculated from gel permeation chromatography was 18.7%. This indicates that 1.3% of the biphenol structure was incorporated into the cresol novolac structure. The average molecular weight Mw was 2368.

(Synthesis Example 3)
An orthocresol novolak (softening point 139 ° C. dinuclear 1.7 nuclei 1.7 nuclei 2.9 nuclei 2.9 area% hydroxyl equivalent 120 g / eq. ) 90.0 parts, 4,4'-biphenol 23.3 parts, epichlorohydrin 416 parts, dimethyl sulfoxide 95.8 parts were added and dissolved under stirring, and the temperature was raised to 45 ° C. Next, 42 parts of flaky sodium hydroxide were added in portions over 90 minutes, and then reacted at 45 ° C. for 2 hours and at 70 ° C. for 75 minutes. After completion of the reaction, excess solvents such as epichlorohydrin were distilled off from the oil layer under reduced pressure using a rotary evaporator. The residue was dissolved by adding 352 parts of methyl isobutyl ketone, washed with water, and heated to 75 ° C. Under stirring, 13 parts of a 30% by weight aqueous sodium hydroxide solution was added and the reaction was performed for 1 hour, followed by washing with water until the washing water of the oil layer became neutral. From the resulting solution, the pressure was reduced using a rotary evaporator. Methyl isobutyl ketone and the like were distilled off below to obtain 149 parts of an epoxy resin mixture (EP3) in the present invention. The epoxy equivalent of the obtained epoxy resin was 179 g / eq. The ICI melt viscosity at a softening point of 111 ° C. and 150 ° C. was 0.43 Pa · s.
The theoretical amount of diglycidyloxybiphenyl calculated from the raw material is 22%. On the other hand, the amount of diglycidyloxybiphenyl calculated from gel permeation chromatography was 19.3%. This indicates that 2.7% of the biphenol structure was incorporated into the cresol novolac structure. The average molecular weight Mw was 2410.

(Synthesis Example 4)
An orthocresol novolak (softening point 100 ° C. dinuclear body 8.2 area% trinuclear body 9.1 area% hydroxyl group equivalent 120 g / eq. Was added to a flask equipped with a stirrer, reflux condenser and stirrer while purging with nitrogen. ) 96 parts, 18.6 parts of 4,4′-biphenol, 416 parts of epichlorohydrin and 95.8 parts of dimethyl sulfoxide were added and dissolved under stirring, and the temperature was raised to 45 ° C. Next, 42 parts of flaky sodium hydroxide were added in portions over 90 minutes, and then reacted at 45 ° C. for 2 hours and at 70 ° C. for 75 minutes. After completion of the reaction, excess solvents such as epichlorohydrin were distilled off from the oil layer under reduced pressure using a rotary evaporator. The residue was dissolved by adding 352 parts of methyl isobutyl ketone, washed with water, and heated to 75 ° C. Under stirring, 13 parts of a 30% by weight aqueous sodium hydroxide solution was added and the reaction was performed for 1 hour, followed by washing with water until the washing water of the oil layer became neutral. From the resulting solution, the pressure was reduced using a rotary evaporator. By distilling off methyl isobutyl ketone and the like, 165 parts of a comparative epoxy resin mixture (EP4) was obtained. The epoxy equivalent of the obtained epoxy resin was 187 g / eq. The ICI melt viscosity at a softening point of 95 ° C. and 150 ° C. was 0.05 Pa · s.
The theoretical amount of diglycidyloxybiphenyl calculated from the raw material is 17.5%. On the other hand, the amount of diglycidyloxybiphenyl calculated from gel permeation chromatography was 15.9%. This indicates that 1.6% of the biphenol structure was incorporated into the cresol novolac structure. The average molecular weight Mw was 1087.

(Synthesis Example 5)
A flask equipped with a stirrer, a reflux condenser, and a stirrer was purged with nitrogen while orthocresol novolak (softening point 138 ° C. dinuclear 2.2 area% trinuclear 3.6 area% hydroxyl equivalent 120 g / eq. ) 120 parts, epichlorohydrin 600 parts and dimethyl sulfoxide 95.8 parts were added, dissolved under stirring, and the temperature was raised to 45 ° C. Next, 42 parts of flaky sodium hydroxide were added in portions over 90 minutes, and then reacted at 45 ° C. for 2 hours and at 70 ° C. for 75 minutes. After completion of the reaction, excess solvents such as epichlorohydrin were distilled off from the oil layer under reduced pressure using a rotary evaporator. The residue was dissolved by adding 352 parts of methyl isobutyl ketone, washed with water, and heated to 75 ° C. Under stirring, 13 parts of a 30% by weight aqueous sodium hydroxide solution was added and the reaction was performed for 1 hour, followed by washing with water until the washing water of the oil layer became neutral. From the resulting solution, the pressure was reduced using a rotary evaporator. Methyl isobutyl ketone and the like were distilled off to obtain 166 parts of an epoxy resin (EP-A). The epoxy equivalent of the obtained epoxy resin is 202 g / eq. The ICI melt viscosity at a softening point of 103 ° C. and 150 ° C. was 3.1 Pa · s. The average molecular weight Mw was 3073.

(Synthesis Example 6)
In Synthesis Example 5, “orthocresol novolak (softening point 138 ° C. dinuclear 2.2 area% trinuclear 3.6 area% hydroxyl group equivalent 120 g / eq.) 120 parts” was changed to “orthocresol novolak (softening point 130 ° C. It was synthesized in the same manner except that it was changed to “2 nuclei <5%, 3 nuclei <5%, hydroxyl equivalent 130 g / eq.) 130 parts”. The resulting epoxy resin (EP-B) had an epoxy equivalent of 202 g / eq. The ICI melt viscosity at a softening point of 101 ° C. and 150 ° C. was 2.9 Pa · s. The average molecular weight Mw was 2980.

(Synthesis Example 7)
In Synthesis Example 5, “orthocresol novolak (softening point 138 ° C. dinuclear 2.2 area% trinuclear 3.6 area% hydroxyl group equivalent 120 g / eq.) 120 parts” It was synthesized in the same manner except that it was changed to "2 parts 8.2% trinuclear 9.1% hydroxyl equivalent 120 g / eq.) 120 parts".
The obtained epoxy resin (EP-C) had an epoxy equivalent of 196 g / eq. The ICI melt viscosity at a softening point of 61 ° C. and 150 ° C. was 0.1 Pa · s (EOCN-1020-62). The average molecular weight Mw was 1526.

Examples 1, 2, 3 Comparative Examples 1-3
<Various cured property tests>
The epoxy resins obtained above were blended in the proportions (parts by weight) shown in Table 1 below, and uniformly mixed and kneaded using a mixing roll to obtain the epoxy resin compositions of the present invention and comparative examples. This epoxy resin composition was pulverized with a mixer and further tableted with a tablet machine. The tableted epoxy resin composition was transfer-molded (175 ° C. × 60 seconds), and after demolding, cured under the conditions of 160 ° C. × 2 hours + 180 ° C. × 6 hours to obtain a test piece for evaluation.
The evaluation method for each evaluation is described below. The evaluation results are shown in Table 1 below.

Heat resistance (TMA): Measured according to JIS K 7244.
Flame retardance: Performed according to UL94. However, the test was conducted with a sample size of 12.5 mm wide × 150 mm long and a thickness of 0.8 mm.
・ Afterflame time: Total afterflame time after 10 times of contact with 5 samples. ・ Heat resistance (DMA)
Dynamic viscoelasticity measuring device: TA-instruments, DMA-2980
Measurement temperature range: -30 to 280 ° C
Temperature rate: 2 ° C./min Test piece size: 5 mm × 50 mm cut out (thickness is about 800 μm)
Tg: Tan-δ peak point is defined as Tg

* EP5: Trisphenol methane type epoxy resin (EPPN 501H, softening point (conforms to JIS K-7234) 52 ° C.)

  From the above results, it was confirmed that the epoxy resin composition of the present invention can provide a cured product having both high heat resistance and flame retardancy.

Although the invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.
In addition, this application is based on the Japan patent application (Japanese Patent Application No. 2014-021880) for which it applied on February 7, 2014, The whole is used by reference. Also, all references cited herein are incorporated as a whole.

  Since the epoxy resin composition of the present invention is particularly excellent in heat resistance and flame retardancy, it is useful as an electrical and electronic material application, particularly as a semiconductor sealant and a thin film substrate material.

Claims (4)

An epoxy resin mixture of an epoxy resin represented by the following formula (1) and an epoxy compound represented by the following formula (2) having a softening point (according to ASTM D 3104) of 100 to 120 ° C., a biphenyl aralkyl type phenol resin, and An epoxy resin composition containing an inorganic filler.

(In formula (1), n represents an average value of 5 to 20)

The epoxy resin represented by the formula (1) is an epoxy resin obtained by reacting an orthocresol novolak with an epihalohydrin,
2. The epoxy resin composition according to claim 1, wherein the total content of the binuclear body and the trinuclear body in the orthocresol novolak is 10 area% or less in terms of gel permeation chromatography (GPC) area percentage.   A cured product obtained by curing the epoxy resin composition according to claim 1.   A semiconductor device formed by covering the semiconductor chip with the epoxy resin composition according to claim 1 or 2 molded into a granular or tablet shape and molding at 175 to 250 ° C.