JP2017071705A - Epoxy resin mixture, epoxy resin composition and cured product thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition which is excellent in flowability, and contributes to curability when formed into a compound, and heat resistance, flame retardancy and thermal decomposition characteristics of the cured product; an epoxy resin composition; and a cured product.SOLUTION: An epoxy resin composition contains a bifunctional or higher epoxy resin (A) and a bifunctional or higher maleimide resin (B), where a content of the epoxy resin (A) is 10 to 90 wt.% with respect to the total amount of the resin and a content of the maleimide resin is 10-90 wt.%, an ICI melt viscosity (cone plate method) at 150°C is 0.01 to 0.9 Pa s, and a softening point by the ring and ball method is 50 to 160°C.SELECTED DRAWING: None

Description

  The present invention relates to an epoxy resin mixture, an epoxy resin composition, and a cured product thereof suitable for electrical and electronic material applications requiring heat resistance.

  Epoxy resins 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. Yes.

In recent years, with the development in the electrical and electronic field, moisture resistance, adhesion, dielectric properties, low viscosity for high filling of filler (inorganic or organic filler), molding, etc., as well as high purity of resin composition There is a need for further improvements in various characteristics such as increased reactivity to shorten the cycle. In addition, as a structural material, a lightweight material with excellent mechanical properties is required for aerospace materials and leisure / sports equipment applications. Especially in the field of semiconductor encapsulation and substrates (substrate itself or its peripheral materials), as the semiconductor transitions, it becomes increasingly complex with thinning, stacking, systematization, and three-dimensionalization. Required characteristics such as heat resistance and high fluidity are required (Non-Patent Document 1). In particular, with the expansion of plastic packages to in-vehicle applications, demands for improving heat resistance are becoming more severe. Specifically, heat resistance of 150 ° C. or higher has been required due to an increase in semiconductor driving temperature (Non-patent Document 2).
In general, epoxy resins with a high softening point tend to have high heat resistance, but on the other hand, there is a tendency for viscosity to increase, making it difficult to use as a sealing material in terms of workability and storage stability. It becomes. In order to deal with this problem, a proposal has been made to provide heat resistance by introducing a naphthalene structure (Patent Document 2), but this has a problem that it becomes brittle and mechanical strength is lowered. Moreover, although the polyfunctional epoxy resin is examined, the subject that a flame retardance falls remarkably occurred.

On the other hand, maleimide resins have been conventionally studied as having high heat resistance. Particularly in applications such as substrates, it is partially used in the form of BT resin. However, maleimide resins show properties like organic fillers due to their high crystallinity in fields such as semiconductor encapsulants, and cannot contain a lot of inorganic fillers. Also, it takes a long time from molding to demolding. There is a problem with such productivity. In order to deal with such problems, a technique of modifying maleimide resin with an amine and using it has been studied.

International Publication No. 2010/110433 Japanese Patent No. 2503814

“2008 STRJ Report Semiconductor Roadmap Technical Committee 2008 Report”, Chapter 8, p1-1, [online], March 2009, JEITA Japan Electronics and Information Technology Industries Association Semiconductor Technology Roadmap Specialist Association, [Search May 30, 2012], Internet <URL http://strj-jeita.elisasp.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

Maleimide resin has high hardness and high water absorption rate, and is very poor in reactivity. Even if it is cured at 100 to 200 ° C. like epoxy resin, it cannot be reacted, resulting in poor properties. There is a problem that it is stable and very difficult to handle. Specifically, when a polybismaleimide resin is laminated, treatment at a high temperature of 220 ° C. or higher and a long time is required.
Moreover, the technique of modifying maleimide resin with an amine and using it results in high viscosity, and an inorganic filler cannot be introduced. Even if the reactivity can be improved, a lot of amino groups are introduced into the network, so the viscosity is greatly increased as a problem in the chemical resistance characteristics and water absorption rate of the cured product, especially at the composition stage. There is a problem of doing it.
Therefore, the present invention is an epoxy resin mixture excellent in fluidity, workability, curability when made into a blend, and further excellent in flame retardancy and thermal decomposition characteristics contrary to the heat resistance of the cured product, and the cured product thereof. I will provide a.

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
(1) An epoxy resin mixture containing a bifunctional or higher functional epoxy resin (A) and a bifunctional or higher functional maleimide resin (B), wherein the content of the epoxy resin (A) is 10 to 90 with respect to the total amount of the resin. % By weight, maleimide resin content of 10 to 90% by weight, ICI melt viscosity at 150 ° C. (cone plate method) of 0.01 to 0.9 Pa · s, softening point in ring and ball method of 50 to 160 Epoxy resin mixture, which is
(2) The bifunctional or higher functional epoxy resin (A) is an orthocresol novolak type epoxy resin, a phenol novolak type epoxy resin, a dicyclopentadiene-phenol type epoxy resin, a naphthol-cresol novolak type epoxy resin, a phenol aralkyl type epoxy resin. And at least one selected from biphenylene type phenol aralkyl type epoxy resins, and the bifunctional or higher maleimide resin (B) is bis (maleimidophenyl) methane, bis (tetraalkyl-substituted maleimidophenyl) methane, phenol novolac type maleimide Resin, at least one selected from isopropylidenebis (phenoxyphenylmaleimide) phenylmaleimide aralkyl resin and biphenylene type phenylmaleimide aralkyl resin. The epoxy resin mixture as described in (1) above,
(3) The epoxy resin mixture according to item (1) or (2), wherein the total chlorine content is 500 ppm or less,
(4) An epoxy resin composition comprising the epoxy resin mixture according to any one of claims 1 to 3 and an inorganic filler, the amount of which is contained in a ratio of 5:95 to 35:65,
(5) The epoxy resin composition according to item (4), wherein the inorganic filler contains at least one selected from silica gel and alumina, and the gel time at 175 ° C. in the composition is 15 seconds to 10 minutes,
(6) The epoxy resin composition according to the above item (4) or (5), which contains a phenol resin type curing agent,
(7) A cured product obtained by curing the epoxy resin composition according to any one of (5) to (6) above,
(8) A method for producing an epoxy resin mixture in which a bifunctional or higher functional epoxy resin (A) and a bifunctional or higher functional maleimide resin (B) are heated and mixed in a temperature range of 50 to 160 ° C.
(9) The epoxy resin mixture according to (8) above, wherein the bifunctional or higher functional epoxy resin (A) and the bifunctional or higher functional maleimide resin (B) are mixed using at least one of a kneader and a roll kneader. Production method,
(10) A bifunctional or higher functional epoxy resin (A) and a bifunctional or higher functional maleimide resin (B) in at least one solvent selected from acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, toluene, and xylene After mixing, the method for producing an epoxy resin mixture according to (8) or (9) above, wherein the solvent is distilled off under reduced pressure by heating in a temperature range of 50 to 160 ° C.,
About.

  The epoxy resin mixture of the present invention is excellent in fluidity, and contributes to curability when formed into a blend, and further to heat resistance, flame retardancy, and thermal decomposition characteristics of the cured product. Useful for cured products.

The epoxy resin mixture of the present invention is a mixture of a bifunctional or higher functional epoxy resin (A) and a bifunctional or higher functional maleimide resin (B), and the content of the epoxy resin (A) is 10 to 10% of the total resin amount. 90 wt%, maleimide resin content is 10 to 90 wt%, ICI melt viscosity (cone plate method) at 150 ° C. is 0.01 to 0.9 Pa · s, softening point in ring and ball method is 50 to 50 It is characterized by being 160 ° C.

The maleimide resin is powdery by itself and has a very high melting point, which is difficult not only to make a composition but also difficult to dissolve homogeneously, so that it is difficult to make a molded product neatly. In addition, since the curing temperature is very high in the first place, a beautiful molded product cannot be produced unless a curing temperature in the vicinity of 200 to 220 ° C. is applied for a long time.
On the other hand, a technique of improving the melting characteristics by modifying a part of the maleimide resin with a modifying agent such as amine is also mentioned. However, since amine deteriorates the properties of the cured product, it is not preferable.
In the epoxy resin mixture of the present invention, it has been clarified that by mixing a maleimide resin with an epoxy resin in advance, it can be stably handled as a resin having a softening point and fluidity can be secured. Furthermore, by mixing with an epoxy resin, not only fluidity but also a composition that can be cured in a temperature range similar to that of a general epoxy resin and exhibit excellent curing characteristics.

Examples of the bifunctional or higher functional epoxy resin (A) that can be used in the present invention include novolac type epoxy resins, bisphenol type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, and phenol aralkyl type epoxy resins.
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-hydroxyacetophenone, -Hydroxyacetophenone, dicyclopentadiene, furfural, 4,4'-bis (chloromethyl) -1,1'-biphenyl, 4,4'-bis (methoxymethyl) -1,1'-biphenyl, 1,4-bis Polycondensates with (chloromethyl) benzene or 1,4-bis (methoxymethyl) benzene and their modified products, halogenated bisphenols such as tetrabromobisphenol A, and glycidyl ethers derived from alcohols, fats Cyclic epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin, silsesquioxane epoxy resin (chain, cyclic, ladder, or a mixed structure of at least two of these glycidyl groups and siloxane structures) Epoxy tree having epoxy cyclohexane structure Examples thereof include, but are not limited to, solid or liquid epoxy resins such as (fat).

In the present invention, since it is preferable to handle as a solid resin, a solid epoxy resin, an epoxy resin having a softening point of 50 to 100 ° C. is particularly preferable, and an ortho-cresol novolak type epoxy resin or a phenol novolak type is more preferable. It is preferable to contain at least one selected from epoxy resins, dicyclopentadiene-phenol type epoxy resins, naphthol-cresol novolac type epoxy resins, phenol aralkyl type epoxy resins, and biphenylene type phenol aralkyl type epoxy resins.
In particular, a phenol aralkyl type epoxy resin, a biphenylene type phenol aralkyl type epoxy resin, and a dicyclopentadiene-phenol type epoxy resin are preferable from the viewpoints of flame retardancy, thermal decomposition characteristics, dielectric characteristics, and water absorption characteristics when cured.

As a characteristic of the epoxy resin (A) used in the present invention, the melt viscosity at 150 ° C. (ICI cone plate method) is preferably 0.4 Pa · s or less, particularly 0.3 Pa · s or less. It is preferable from the viewpoint of handleability. In particular, it is preferable to use an epoxy resin that is solid at room temperature, and preferably 0.005 to 0.3 Pa · s.

The softening point of the epoxy resin (A) used in the present invention is preferably 50 to 100 ° C., and particularly preferably 52 to 95 ° C. in terms of handling (workability). In the case of an epoxy resin having a melting point, it cannot be neatly mixed and it may be difficult to achieve the object of the present invention.

The total chlorine content (hydrolysis method) of the epoxy resin (A) used in the present invention is preferably 1000 ppm or less, particularly preferably 900 ppm or less. When the amount of chlorine exceeds 1000 ppm, the maleimide compound tends to be affected by the water absorption characteristics, so that the electrical reliability may be lowered.

The bifunctional or higher functional maleimide resin (B) that can be used in the present invention is not particularly limited as long as it is a maleimide resin having two or more maleimide groups in the molecule.
Examples of the maleimide resin (B) that can be used in the present invention include bis (maleimidophenyl) methane, bis (tetraalkyl-substituted maleimidophenyl) methane, phenol novolac-type maleimide resin, isopropylidenebis (phenoxyphenylmaleimide) phenylmaleimide aralkyl resin, Biphenylene type phenylmaleimide aralkyl resins are preferred.

As the maleimide resin (B) that can be used in the present invention, those having a melting point and a softening point can be used. In particular, when it has a melting point, it is preferably 200 ° C. or lower, and when it has a softening point, it is preferably 150 ° C. or lower.
An excessively high melting point or softening point is not preferable because the possibility of gelation increases during subsequent mixing with the epoxy resin.

  The epoxy resin mixture of the present invention is obtained by mixing a bifunctional or higher functional epoxy resin (A) and a bifunctional or higher functional maleimide resin (B).

As a mixing method of the epoxy resin mixture, there are a melt blending method and a dry blending method.
In the method of dry blending two types of resin mixtures, it is difficult to mix uniformly, so it is difficult to create a homogeneous cured product. Therefore, in the present invention, it is preferable to produce while melting and / or dissolving.

When one or both of the bifunctional or higher epoxy resin (A) and the bifunctional or higher maleimide resin (B) have a softening point, mixing at a temperature equal to or higher than the softening point is preferable. As mixing temperature, 50-160 degreeC is preferable, Most preferably, it is 50-150 degreeC. This is because the heat mixing in the temperature range of 50 to 160 ° C. is settled with a reaction that does not cause a large characteristic change. On the other hand, clean (homogeneous) mixing is not possible at a low temperature of 50 ° C. or lower, and when the temperature exceeds 160 ° C., the curing reaction proceeds when the mixture of the epoxy resin and the maleimide resin is melted, resulting in gelation. May progress. Specifically, gelation may start in about 10 minutes at 175 ° C. This phenomenon is likely to occur when the epoxy resin and the maleimide resin are mixed to some extent homogeneously. For example, when the epoxy resin is a simple substance, it does not gel even when heated at 175 ° C. for 20 hours.

In order to produce the epoxy resin mixture of the present invention, the bifunctional or higher functional epoxy resin (A) and the bifunctional or higher functional maleimide resin (B) are melt blended, and at least one side of the resin has fluidity as described above. It knead | mixes with an extruder, a kneader, a roll, a planetary mixer etc. on conditions. The processing time is 5 minutes to 3 hours.

In the case of a melt blend, after dissolving or diffusing in one or more solvents selected from acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, toluene, xylene, etc., heating under reduced pressure in a temperature range of 50 to 160 ° C It can be produced by a method of distilling off the solvent under the above.
Excessive heating exceeding 160 ° C. causes gelation of the epoxy resin mixture. If the temperature is low, the resin does not sufficiently flow, and it may be difficult to obtain a homogeneous epoxy resin mixture.

In the epoxy resin mixture of the present invention, the mixing ratio of the bifunctional or higher functional epoxy resin (A) and the bifunctional or higher functional maleimide resin (B) is such that the content of (A) is 10 to 90% by weight. The case where the content of the maleimide resin (B) is 10 to 90% by weight is preferable, the content of (A) is 10 to 60% by weight, and the content of (B) is 40 to 90% by weight. % Is preferable from the balance of heat resistance and toughness.
When there are too many epoxy resins (A), heat resistance will fall, and when there are too many maleimide resins (B), toughness will fall, and also the water absorption rate is high, and as a semiconductor sealing use from the surface of the reliability, It becomes difficult to use.

In addition, regarding these compounding amounts, priority is given to satisfying the following characteristics, and it is preferable to change the formulation as appropriate.

In the epoxy resin mixture of the present invention, the ICI melt viscosity (cone plate method) at 150 ° C. is preferably 1.0 Pa · s or less, particularly preferably 0.01 to 0.9 Pa · s.
Depending on the thickness of the wiring and its structure, if the viscosity exceeds 1.0 Pa · s, there will be a problem with the moldability of a simple semiconductor structure, and unfilled parts will be created. Because it comes.

The epoxy resin mixture of the present invention preferably has a softening point of 160 ° C. or less in the ring and ball method.
Moreover, when using it as a sealing material as a tablet, it is preferably 50 to 160 ° C., more preferably 55 to 160 ° C., particularly preferably because it is difficult to use without a softening point of 50 ° C. or higher. Is 55-150 ° C.

In the epoxy resin mixture of the present invention, the total chlorine amount (based on ISO 21627-3) is preferably 500 ppm or less, particularly preferably 250 ppm or less in view of the recent transition of semiconductors from gold wires to copper wires. 150 ppm or less is preferable.
When the total chlorine amount exceeds 500 ppm, although the resin structure is somewhat affected, the amount of ions extracted when a semiconductor encapsulating material is generally increased is not preferable. Specifically, when the epoxy resin composition is made into a cured product, the amount of ions that are thermally extracted and eluted is preferably 20 ppm or less, particularly preferably 10 ppm or less, which is an order of magnitude.

The epoxy resin mixture of the present invention thus obtained can be handled in the form of a flake or powder by taking it out as a plate, making it into a flake with a flaker, etc., pulverizing it into a powder, etc. preferable.
In particular, in the case of powder, it is preferable to apply a pressure of 1.0 MPa or more to form a granular, string-like, or tablet-like state due to problems such as powdering in the next step, suction, and contamination of peripheral devices. .

Next, the epoxy resin composition of the present invention will be described.
The epoxy resin composition of the present invention preferably contains an inorganic filler in addition to the epoxy resin mixture of the present invention. Moreover, it is preferable to contain another epoxy resin, a hardening | curing agent, and a hardening accelerator as an arbitrary component.

The epoxy resin composition of the present invention may contain an epoxy resin in addition to the epoxy resin contained in the epoxy resin mixture of the present invention. The proportion of the total amount of the epoxy resin in the epoxy resin mixture of the present invention in all the epoxy resins is preferably 20% by weight or more, more preferably 30% by weight or more, and particularly preferably 40% by weight or more.
Examples of the epoxy resin that can be used in combination include novolak type epoxy resin, bisphenol type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, and phenol aralkyl type epoxy resin.
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-hydroxyacetophenone, -Hydroxyacetophenone, dicyclopentadiene, furfural, 4,4'-bis (chloromethyl) -1,1'-biphenyl, 4,4'-bis (methoxymethyl) -1,1'-biphenyl, 1,4-bis Polycondensates with (chloromethyl) benzene or 1,4-bis (methoxymethyl) benzene and their modified products, halogenated bisphenols such as tetrabromobisphenol A, and glycidyl ethers derived from alcohols, fats Cyclic epoxy resin, glycidylamine epoxy resin, glycidyl ester epoxy resin, silsesquioxane epoxy resin (chain, cyclic, ladder, or a mixed structure of at least two of these glycidyl groups and siloxane structures) Epoxy tree having epoxy cyclohexane structure Examples thereof include, but are not limited to, solid or liquid epoxy resins such as (fat).

In particular, since it is important to handle as a solid resin in the present invention, an epoxy resin that is solid at room temperature is particularly preferable, an epoxy resin having a softening point of 50 to 100 ° C. is more preferable, and an orthocresol novolak is more preferable. Type epoxy resin, phenol novolac type epoxy resin, dicyclopentadiene-phenol type epoxy resin, naphthol-cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, at least one selected from biphenylene type phenol aralkyl type epoxy resin Among them, phenol aralkyl type epoxy resins, biphenylene type phenol aralkyl type epoxy resins, dicyclopentadiene-phenone are preferred because of flame retardancy, thermal decomposition properties, dielectric properties, and water absorption properties. A ruby epoxy resin is preferred.

Specific examples of the curing catalyst that can be used in the epoxy resin composition of the present invention include amine compounds such as triethylamine, tripropylamine, and tributylamine, pyridine, dimethylaminopyridine, and 1,8-diazabicyclo [5.4.0]. Undec-7-ene, imidazole, triazole, tetrazole 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6 (2′-methylimid) Dazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-undecylimidazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-ethyl, 4-methylimidazole (1 ′)) ethyl-s-triazine, 2,4-diamino-6 (2′-methylimidazole (1 ′)) ethyl-s-triazine isocyanuric acid adduct, 2-methylimidazole isocyanuric acid 2: 3 adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl- Various heterocyclic compounds such as 3,5-dicyanoethoxymethylimidazole and the like, phthalic acid, Salts with polyvalent carboxylic acids such as phthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, maleic acid and succinic acid, amides such as dicyandiamide, 1,8-diaza-bicyclo (5.4. 0) Diaza compounds such as undecene-7 and salts thereof such as tetraphenylborate and phenol novolak, salts with the above polycarboxylic acids or phosphinic acids, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxy , Tetrabutylammonium hydroxide, trimethylethylammonium hydroxide, trimethylpropylammonium hydroxide, trimethylbutylammonium hydroxide, trimethylcetylammonium hydroxide, trimethyl Ammonium salts such as octylmethylammonium hydroxide, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetramethylammonium acetate, trioctylmethylammonium acetate, triphenylphosphine, tri (tolyl) phosphine, tetraphenylphosphonium Phosphines and phosphonium compounds such as bromide and tetraphenylphosphonium tetraphenylborate, phenols such as 2,4,6-trisaminomethylphenol, amine adducts, metal carboxylates (2-ethylhexanoic acid, stearic acid, behenic acid) , Zinc salts such as myristyl acid, tin salts, zirconium salts) and phosphate metal (octyl phosphate, stearyl phosphate, etc.) ), Alkoxy metal salt (tributyl aluminum, tetrapropyl zirconium, etc.), acetylacetonates (acetylacetone zirconium chelate, a metal compound such as acetylacetone titanium chelate) and the like, can be mentioned. In the present invention, phosphonium salts, ammonium salts, and metal compounds are particularly preferable in terms of coloring at the time of curing and changes thereof. Further, when a quaternary salt is used, a salt with a halogen leaves the cured product with a halogen, which is not preferable from the viewpoint of electrical reliability and prefectural border problems.
In the present invention, a phosphorus catalyst, or a nitrogen-containing catalyst such as an imidazole or amine catalyst is particularly preferable. In particular, when no phenol resin or the like as a curing agent for an epoxy resin is added, an imidazole or amine catalyst is used. Such nitrogen-containing catalysts are particularly preferred.
The curing accelerator is used in an amount of 0.01 to 5.0 parts by weight based on the epoxy resin mixture 100 as necessary.

The epoxy resin composition of the present invention preferably contains a curing agent. Examples thereof include amine compounds, acid anhydride compounds, amide compounds, phenol resins, carboxylic acid compounds, and the like. Specific examples of the curing agent that can be used in the present invention include nitrogen-containing compounds such as diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, and a dimer of linolenic acid and a polyamide resin synthesized from ethylenediamine. Compound (amine, amide compound): phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, nadic anhydride, hexahydrophthalic anhydride , Methylhexahydrophthalic anhydride, butanetetracarboxylic anhydride, bicyclo [2,2,1] heptane-2,3-dicarboxylic anhydride, methylbicyclo [2,2,1] heptane-2,3-dicarboxylic acid acid Acid anhydrides such as water, cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride; carboxylic acids obtained by addition reaction of various alcohols, carbinol-modified silicones and the above-mentioned acid anhydrides Resins; 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, phenols (phenol, Alkyl-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, Hydroxynaphthalene etc.) and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, p-hydroxyacetophenone, o-hydroxyacetophenone, dicyclopentadiene, furfural, 4,4′-bis (chloromethyl) -1, Heavy weight with 1′-biphenyl, 4,4′-bis (methoxymethyl) -1,1′-biphenyl, 1,4′-bis (chloromethyl) benzene, 1,4′-bis (methoxymethyl) benzene or the like Phenol resins such as condensates and modified products thereof, halogenated bisphenols such as tetrabromobisphenol A, terpene and phenol condensates; imidazole, trifluoroborane-amine complexes, guanidine derivative compounds, etc. these It is not limited to. These may be used alone or in combination of two or more.
In the present invention, the above-mentioned phenol resin is preferable from the viewpoint of water absorption, chemical resistance, insulation reliability, electrical properties, etc. of the cured product, especially for use in semiconductor sealing applications, particularly phenol novolac, cresol novolac, phenol aralkyl. Resin (Xylok type, biphenylene type) is preferable.
Amine-based curing agents and acid anhydride curing agents are not preferred because of their chemical resistance, electrical reliability, and water absorption rate. Especially in the case of acid anhydride systems, the generation of acid due to hydrolysis reaction due to moisture absorption and water absorption causes Since it becomes weak against corrosion of the connecting portion with the pad portion on the chip, particularly when the connecting portion is used, it is preferable to use it as an additive without being mainly used.

As for the usage-amount of the hardening | curing agent in the epoxy resin composition of this invention, 1.2 equivalent or less is preferable with respect to 1 equivalent of epoxy groups of the epoxy resin contained in the whole epoxy resin composition of this invention. When it exceeds 1.2 equivalents with respect to 1 equivalent of epoxy groups, curing may be incomplete and good cured properties may not be obtained.
In addition, when using a phosphorus catalyst etc. as said hardening accelerator, it is preferable that the usage-amount of the hardening | curing agent shall be 0.7 equivalent or more. This is to prevent poor curing due to the remaining epoxy resin itself.

In addition, cyanate ester compounds can be used. The cyanate ester compound can be made into a highly heat-resistant cured product having a higher crosslinking density by a reaction with an epoxy resin in addition to a curing reaction alone. Specific examples of the cyanate ester resin include 2,2-bis (4-cyanatephenyl) propane, bis (3,5-dimethyl-4-cyanatephenyl) methane, and 2,2-bis (4-cyanatephenyl) ethane. And derivatives thereof, aromatic cyanate ester compounds, and the like.
Further, for example, as described in the above-mentioned curing agent, synthesis can be performed by reaction of various phenol resins with hydrocyanic acid or salts thereof. In the present invention, those having a structure having no methylene structure at the benzyl position in the molecule, such as 2,2-bis (4-cyanatephenyl) propane and derivatives thereof (partially polymerized products, etc.) are particularly preferred. You may use independently and may use 2 or more types together.

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 100 parts by weight in total of the epoxy resin and the curing agent, 0.05 to 20 parts by weight is used as necessary.

It is preferable to add an inorganic filler (inorganic filler) to the epoxy resin composition of the present invention. 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. However, the present invention is not limited to these. These fillers may be used alone or in combination of two or more.
In the epoxy resin composition of the present invention, the content of these inorganic fillers is generally in an amount of 0 to 95% by weight, although depending on the use, 5 to particularly when used for semiconductor encapsulant use. It is preferable to use a proper amount in the range of 50 to 95% by weight, particularly preferably 65 to 95% by weight depending on the shape of the package and the required linear expansion coefficient.
Specifically, it is preferably 65 to 85% by weight for FC type thin type, particularly MUF type, and 80 to 95% by weight for wire type and those that seal the top or side of FC, especially lead frame type lead. When the exclusive area of the frame is large, 81 to 93% by weight is preferably used. Thus, it will be selected after taking into account the molding method, linear expansion coefficient and fluidity of each member.
Moreover, as a particle size to be used, the average particle size is preferably 0.1 μm to 30 μm. If it is larger than 30 μm, there is a problem such as being caught by a wire in the package, and if it is smaller than 0.1 μm, there is a problem that the fluidity is extremely lowered, which is not preferable.

Furthermore, the epoxy resin composition of the present invention includes an antioxidant, a light stabilizer, a silane coupling agent, carnauba wax, a release agent such as stearic acid, palmitic acid, zinc stearate, calcium stearate, pigment, carbon black, Various compounding agents such as dyes and various thermosetting resins can be added. It is preferable that halogen and sulfuric acid traces remaining in these are as small as possible. Especially about a coupling agent, addition of the coupling agent which has an epoxy group is preferable.

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.
Specifically, the materials necessary for the epoxy resin composition of the present invention are pulverized and mixed with mixers as necessary, and then kneaded in an extruder, kneader, roll, planetary mixer, etc. as necessary. An epoxy resin composition is obtained by thoroughly mixing until uniform using an apparatus. At this time, the temperature of a kneader such as a kneader or a roll is preferably 150 ° C. or lower. As described above, when a maleimide resin is mixed, the risk of gelation increases, so it is preferable not to apply a temperature higher than 150 ° C. Further, the kneading temperature is preferably 40 ° C. or higher, particularly 50 ° C. or higher, in relation to the softening point of each resin.
In addition, since it can mix homogeneously, it is preferable to use a kneader of two or more types (the same type may be used).

The obtained epoxy resin composition of the present invention is pulverized into powder or flakes and then molded by applying pressure to granules (small particles) or plates or tablets (columns). A molded body of the resin composition is obtained.
The molded product of the epoxy resin composition of the present invention thus obtained can be stored between -40 to 40 ° C, and in particular, at -40 to 25 ° C in order to delay the progress of the reaction in this molded product. Is preferable. In general, maleimide resin is said to react slowly, but in the epoxy resin composition of the present invention, the reaction is faster than usual, so temperature management is important.

The obtained epoxy resin composition of the present invention has a reaction start temperature in DSC of 50 to 150 ° C, and particularly preferably in the range of 70 to 140 ° C. Moreover, it is preferable that the temperature of the reaction peak top is between 130-180 degreeC, and it is preferable that the peak end temperature is 160-220 degreeC. If the reaction start temperature is too early, sufficient fluidity is not easily produced at the time of molding, so that molding defects are likely to occur and problems such as deformation of the wire at the end of the mold arise. Also, if the peak end temperature is too high, the cured product will not harden sufficiently and become uncured, so the characteristics will change gradually during re-reaction and driving during the process, and the performance will be sufficient It is not preferable because there is a problem that it cannot be released.

The gel time of the epoxy resin composition of the present invention (referring to the time taken for the resin to start to solidify) is preferably 15 seconds to 10 minutes at 175 ° C., although depending on the molding technique, 20 seconds to 5 minutes. Is more preferable, and 20 seconds to 3 minutes is particularly preferable. When using a molding method such as compression molding, it is preferably adjusted to 50 to 10 minutes. However, the gel time is preferably 200 seconds or less from the viewpoint of productivity.
In the present invention, when the IR chart of the molded product is compared within the above gel time, the double bond peak of the maleimide resin has disappeared / or reduced to a level at which it appears to have almost disappeared). Can be confirmed.

The method for producing a cured product of the epoxy resin composition of the present invention will be described below. Although not limited to the following, it is an example of a preferred method.
The epoxy resin composition of the present invention is generally cured in two stages. The two-stage process is a first-stage process in which gelation is performed in a mold, or a process in which a second-stage reaction is performed by post-curing after demolding.
Prepare a lead frame with an IC chip mounted on the mold or a package substrate, etc., and generally perform the first-stage curing in the mold using a transfer molding / compression molding method, and then remove it. After molding, it is post-cured in the second stage.
Specifically, initial curing is performed between 80 to 150 ° C., and in the case of a silicon chip, post-curing is performed between 100 to 200 ° C., particularly preferably 150 to 180 ° C., and particularly preferably 160 to 175 ° C. A silicon chip is not preferable if an excessively high temperature is applied, because the chip itself is overloaded and adversely affected. It is particularly preferable to handle at a temperature up to around 175 ° C. In the case of a chip such as silicon carbide or gallium nitride, the temperature is 170 to 250 ° C. The curing time is 1 to 10 hours. At this time, it is preferable to take a gas countermeasure so that a gas or the like is vented by a vent or the like so as not to form a void or a vacuum or a gas such as air is not involved. In this way, a semiconductor device can be obtained.

  The applicable semiconductor device is not limited as long as it is a package such as a capacitor, a transistor, a diode, an IC, and an LSI. For example, sealing when IC packages such as QFP, BGA, and CSP are mounted (including a reinforcing underfill) ) Is effective.

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.
The various analysis methods used in the examples are described below.
Epoxy equivalent: Conforms to JIS K 7236 (ISO 3001)
ICI melt viscosity: compliant with JIS K 7117-2 (ISO 3219) Softening point: compliant with JIS K 7234 Total chlorine: compliant with JIS K 7243-3 (ISO 21672-3) Chlorine ion: JIS K 7243-1 (ISO 21672) -1) GPC:
Column (Shodex KF-603, KF-602x2, 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)
Glass transition point (Tg):
TMA thermomechanical measuring device: TA Instruments TQ400EM
Temperature increase rate: 2 ° C./min.
-Water absorption rate Weight increase rate (%) after boiling a disk-shaped test piece having a diameter of 5 cm and a thickness of 4 mm in water at 100 ° C for 24 hours
・ Hygroscopic rate Weight increase rate (%) after boiling a disk-shaped test piece of diameter 5cm × thickness 4mm under conditions of 85 ℃ -85%, 121 ℃ -100% for 24 hours
<Flame retardance test>
・ Flame retardancy: Conforms to UL94. The sample size was 12.5 mm wide × 150 mm long, and the thickness was 0.8 mm.
・ Afterflame time: Total afterflame time after 10 times contact with 5 samples

Example 1
Place 3 parts of NC-3000L (Nippon Kayaku phenol aralkyl type epoxy resin softening point 52 ° C) in an aluminum cup placed on a 150 ° C hot plate and preheated, and melt it into bis (maleimidophenyl) methane. 7 parts (mixed with diaminodiphenylmethane and maleic anhydride. Melting point: 168 ° C.) were added while mixing little by little. After the addition, the mixture was stirred for 180 seconds and then prepared in advance. It poured on the plate and the epoxy resin mixture (EPX-1) of this invention was obtained. The obtained resin mixture (EPX-1) was pulverized into powder.
When the obtained resin mixture (EPX-1) was dissolved in tetrahydrofuran at a concentration of 1%, it was uniformly dissolved without any problem and became a pale yellow liquid.
Moreover, when confirmed by GPC, it was in the state in which each was mixed, and the polymer was 1% or less. The softening point was 128 ° C. (ring and ball method), and the melt viscosity at 150 ° C. by the ICI cone plate method was 0.12 Pa · s. Moreover, the epoxy equivalent of the obtained resin mixture (EPX-1) is 902 g / eq. Met.

Reference example 1
Place an aluminum cup on a hot plate at 180 ° C and heat it in advance, and then add 3 parts of NC-3000L (Nippon Kayaku phenol aralkyl type epoxy resin softening point 52 ° C) to melt it, and then bis (maleimidophenyl) 7 parts of methane (obtained by maleimidation with diaminodiphenylmethane and maleic anhydride. Melting point: 168 ° C.) was added while mixing little by little. After addition, the mixture was stirred for 180 seconds. I confirmed that I would go. When the obtained epoxy resin mixture for reference (EPX-2) was dissolved in tetrahydrofuran at a concentration of 1%, it was a reddish-brown solution that was partially undissolved and clouded, producing a gelled product. I was able to confirm.

Example 2
Using two rolls heated to 50 ° C and 80 ° C, NC-3000L (manufactured by Nippon Kayaku, phenol aralkyl type epoxy resin, softening point 52 ° C) 150 parts, bis (maleimidophenyl) methane (diaminodiphenylmethane and maleic anhydride 350 parts of a melting point of 168 ° C. were kneaded for 60 seconds and taken out as a plate-like mixture (EPX-2).
When the obtained resin mixture (EPX-2) was dissolved in tetrahydrofuran at a concentration of 1%, it was uniformly dissolved without any problem and became a pale yellow liquid.
Moreover, when confirmed by GPC, it was in the state in which each was mixed, and the polymer was 1% or less. The softening point was 131 ° C. (ring and ball method), and the melt viscosity at 150 ° C. by the ICI cone plate method was 0.11 Pa · s.
The obtained epoxy resin mixture was made into flakes by grinding.

Example 3, Comparative Examples 1-3
Epoxy resin mixture (EPX-1) obtained in Example 1 or comparative epoxy resin (EP1: Trisphenolmethane type epoxy resin Nippon Kayaku EPPN-502H, EP2: biphenyl-phenol aralkyl type epoxy resin Nippon Kayaku NC-3000), a curing agent (P-1: phenol novolac, Meiwa Kasei Kogyo H-1) (P-2: trisphenol methane type phenolic resin, KAYAHARD KTG-105) (P-3: Biphenyl-phenol aralkyl type Nippon Kayaku KAYAHARD GPH-65), curing catalyst (curing accelerator), inorganic filler, coupling agent, release agent are blended in the proportions (equivalents) shown in Table 1, and mixing rolls are used. Were uniformly mixed and kneaded to obtain an epoxy resin composition. 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 test results are shown in Table 1.

(Table 1)

From Table 1, it can be confirmed that the cured product using the epoxy resin mixture of the present invention maintains the electrical characteristics and improves the flame retardancy, although the heat resistance is improved as compared with the comparative example. .

Claims (10)

An epoxy resin mixture containing a bifunctional or higher functional epoxy resin (A) and a bifunctional or higher functional maleimide resin (B), wherein the content of the epoxy resin (A) is 10 to 90% by weight based on the total amount of the resin. Yes, the maleimide resin content is 10 to 90% by weight, the ICI melt viscosity at 150 ° C. (cone plate method) is 0.01 to 0.9 Pa · s, and the softening point in the ring and ball method is 50 to 160 ° C. Epoxy resin mixture. The bifunctional or higher epoxy resin (A) is an orthocresol novolak type epoxy resin, a phenol novolak type epoxy resin, a dicyclopentadiene-phenol type epoxy resin, a naphthol-cresol novolac type epoxy resin, a phenol aralkyl type epoxy resin, a biphenylene type. It contains at least one selected from phenol aralkyl type epoxy resins, and the bifunctional or higher maleimide resin (B) is bis (maleimidophenyl) methane, bis (tetraalkyl-substituted maleimidophenyl) methane, phenol novolac type maleimide resin, isopropyl Contains at least one selected from redenbis (phenoxyphenylmaleimide) phenylmaleimide aralkyl resin and biphenylene type phenylmaleimide aralkyl resin The epoxy resin mixture according to claim 1. The epoxy resin mixture according to claim 1 or 2, wherein the total chlorine amount is 500 ppm or less. An epoxy resin composition comprising the epoxy resin mixture according to any one of claims 1 to 3 and an inorganic filler, the blending amount of which is 5:95 to 35:65. The epoxy resin composition according to claim 4, wherein the inorganic filler contains at least one selected from silica gel and alumina, and the composition has a gel time at 175 ° C of 15 seconds to 10 minutes. The epoxy resin composition of Claim 4 or Claim 5 containing a phenol resin type hardening | curing agent. Hardened | cured material which hardened | cured the epoxy resin composition as described in any one of Claim 5 or Claim 6. A method for producing an epoxy resin mixture, in which a bifunctional or higher functional epoxy resin (A) and a bifunctional or higher functional maleimide resin (B) are heated and mixed in a temperature range of 50 to 160 ° C. The method for producing an epoxy resin mixture according to claim 8, wherein the bifunctional or higher functional epoxy resin (A) and the bifunctional or higher functional maleimide resin (B) are mixed using at least one of a kneader and a roll kneader. After mixing bifunctional or higher epoxy resin (A) and bifunctional or higher maleimide resin (B) in at least one solvent selected from acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, toluene, and xylene. The method for producing an epoxy resin mixture according to claim 8 or 9, wherein the solvent is distilled off under reduced pressure by heating in a temperature range of 50 to 160 ° C.