JPH0525364A - Epoxy resin composition for sealing semiconductor - Google Patents

Abstract

PURPOSE:To obtain the subject composition, containing an epoxy resin, a curing agent, a filter, a hydrotalcite-based compound, a bromine compound, an antimony compound and an inorganic ion exchanger in a specific proportion, and excellent in flame retardancy, reliability at high temperatures and moldability. CONSTITUTION:The objective composition containing (A) an epoxy resin, (B) a curing agent, (C) 60-95wt.% filler, (D) 0.01-10wt.% hydrotalcite-based compound, (E) a bromine compound, (F) an antimony compound and (G) 0.01-10wt.% inorganic ion exchanger expressed by the formula MxOy(NO3)z(OH)w.nH2O (M is tri- to pentavalent transition metal; (x) is 1-5; (y) is 1-7; (z) and (w) are 0.2-3; (n) is 0-2).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor encapsulating epoxy composition which is excellent in flame retardancy, high temperature reliability and moldability.

[0002]

2. Description of the Related Art Epoxy resins are excellent in heat resistance, moisture resistance, electrical properties, adhesiveness, etc. and can be given various properties by compounding formulation, so they are used as industrial materials such as paints, adhesives and electrical insulating materials. Has been done.

For example, as a method of sealing electronic circuit parts such as semiconductor devices, hermetic seals made of metal or ceramics and phenol resin, silicone resin,
Resin encapsulation with an epoxy resin or the like has been proposed. However, resin sealing with an epoxy resin is mainly used from the viewpoint of the balance of economic efficiency, productivity, and physical properties.

Then, in order to improve the moisture resistance of the encapsulating resin, a hydrotalcite compound is added (JP-A-61-161).
(19625 gazette) is proposed.

On the other hand, the electronic components such as semiconductors are obliged to be provided with flame retardancy by the UL standard. Therefore, the encapsulating resin usually contains a bromine compound and a flame retardant such as antimony trioxide. There is.

Further, in order to improve the moisture resistance of the encapsulating resin, an inorganic ion exchanger is added (Japanese Patent Laid-Open No. 62-21242).
No. 2) is proposed.

[0007]

[Problems to be Solved by the Invention] High temperature reliability is 150-
This guarantees the functions of semiconductors in a high temperature environment of 200 ° C, and is an essential performance for semiconductors that generate a large amount of heat or are used around automobile engines.

It has been known that the high temperature reliability is lowered mainly due to the decomposition of flame retardants such as bromine compounds and antimony compounds added for imparting flame retardancy. Therefore, an epoxy compound for semiconductor encapsulation excellent in both flame retardancy and high temperature reliability has not been obtained.

On the other hand, the method of adding a hydrotalcite compound in order to improve the moisture resistance of the encapsulating resin (Japanese Patent Laid-Open No. 61-19625) is effective in improving the high temperature reliability. Since mold stains occur during molding, it was necessary to increase the frequency of mold cleaning.

A method of adding an inorganic ion exchanger to improve the moisture resistance of the encapsulating resin (JP-A-62-2).
No. 12422), the effect of improving high temperature reliability was small. The object of the present invention is to reduce the decrease in reliability at high temperatures due to the addition of a flame retardant, and to reduce mold stains due to the addition of hydrotalcite-based compounds, that is, both flame retardancy, high temperature reliability and moldability are excellent. An object is to provide an epoxy composition for semiconductor encapsulation.

[0011]

Means for Solving the Problems The present inventors have achieved the above-mentioned problems by adding a hydrotalcite-based compound and an inorganic ion exchanger, so that an epoxy composition for semiconductor encapsulation which meets the purpose can be obtained. They have found that they can be obtained and have reached the present invention.

That is, according to the present invention, the epoxy resin (A), the curing agent (B), the filler (C), the hydrotalcite compound (D), the bromine compound (E), the antimony compound (F) and the following formula (I): _{M x O y (NO 3)} z (OH) w · nH 2 O ‥‥‥ (I) (M is one kind or two or more of 3-5-valent transition metal, x
= 1 to 5, y = 1 to 7, z = 0.2 to 3, w = 0.2 to
3, n = 0 to 2 is shown. ), The composition containing the inorganic ion exchanger (G), wherein the proportion of the filler (C) is 60 to 95% by weight of the whole, and the hydrotalcite compound (D). ) Is 0.0
The epoxy composition for semiconductor encapsulation has a content of 1 to 10% by weight and a proportion of the inorganic ion exchanger (G) of 0.01 to 10% by weight based on the whole.

The structure of the present invention will be described in detail below.

The epoxy resin (A) in the present invention is 1
It is not particularly limited as long as it has two or more epoxy groups in the molecule, and specific examples thereof include, for example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, bisphenol. A type epoxy resin,
Examples include various novolac type epoxy resins synthesized from bisphenol A and resorcin, linear aliphatic type epoxy resins, alicyclic epoxy resins, heterocyclic epoxy resins, spiro ring containing epoxy resins and brominated epoxy resins. Be done.

Of these, a biphenyl type epoxy resin and a naphthalene type epoxy resin are preferably used in view of solder heat resistance during mounting in the surface mounting method.

Preferred specific examples of the biphenyl type epoxy resin are 4,4'-bis (2,3-epoxypropoxy) biphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetramethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3 ', 5,5'-tetramethyl-2-chlorobiphenyl, 4,4'-bis (2 , 3-Epoxypropoxy) -3,3 ', 5,5'-tetramethyl-2-bromobiphenyl, 4,4'-bis (2,3-epoxypropoxy) -3,3', 5,5'- Tetraethylbiphenyl, 4,4'-bis (2,3-epoxypropoxy)-
3,3 ', 5,5'-tetrabutylbiphenyl and the like can be mentioned.

Preferred specific examples of the naphthalene type epoxy resin include 1,5-diglycidyl naphthalene and 1,5.
-Diglycidyl-7-methylnaphthalene, 1,6-diglycidylnaphthalene, 1,6-diglycidyl-2-methylnaphthalene, 1,6-diglycidyl-8-methylnaphthalene, 1,6-diglycidyl-4,8-dimethylnaphthalene , 2-bromo-1,6-diglycidylnaphthalene, 8-bromo-1,6-diglycidylnaphthalene, and the like.

In the present invention, the compounding amount of the epoxy resin (A) is usually 3 to 25% by weight, preferably 6 to 18% by weight based on the whole amount.
% By weight.

The curing agent (B) in the present invention is not particularly limited as long as it reacts with the epoxy resin (A) and is cured, and specific examples thereof include, for example, phenol novolac resin, cresol novolac resin, and the following. A novolak resin represented by the general formula (II),

[0020]

[Chemical 1]

(However, n represents an integer of 0 or more.) Various novolac resins synthesized from bisphenol A and resorcin, various polyvalent phenol compounds such as tris (hydroxyphenyl) methane, dihydroxybiphenyl, and maleic anhydride. Examples thereof include acids, acid anhydrides such as phthalic anhydride and pyromellitic anhydride, and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone. For semiconductor encapsulation,
From the viewpoint of heat resistance, moisture resistance and storage stability, a phenol-based curing agent is preferably used, and two or more curing agents may be used in combination depending on the application.

In the present invention, the content of the curing agent (B) is usually 2 to 15% by weight, preferably 3 to 10% by weight. Further, the compounding ratio of the epoxy resin (A) and the curing agent (B) is such that the chemical equivalent ratio of (B) to (A) is 0.7 to 1.3, particularly 0 from the viewpoint of mechanical properties and moisture resistance. .8-
It is preferably in the range of 1.2.

Further, in the present invention, the epoxy resin (A)
A curing catalyst may be used to accelerate the curing reaction of the curing agent (B). The curing catalyst is not particularly limited as long as it accelerates the curing reaction, and for example, 2-methylimidazole,
2,4-Dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-imidazole compounds such as 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyl Tertiary amine compounds such as dimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo (5,4,0) undecene-7, zirconium tetra Organometallic compounds such as methoxide, zirconium tetrapropoxide, tetrakis (acetylacetonato) zirconium, tri (acetylacetonato) aluminum and triphenylphosphine, trimethylphosphine,
Examples thereof include organic phosphine compounds such as triethylphosphine, tributylphosphine, tri (p-methylphenyl) phosphine, and tri (nonylphenyl) phosphine. Among them, organic phosphine compounds are preferable, and triphenylphosphine is particularly preferably used, from the viewpoint of moisture resistance. Two or more kinds of these curing catalysts may be used in combination depending on the use, and the addition amount thereof is the epoxy resin (A).
A range of 0.5 to 5 parts by weight is preferable with respect to 100 parts by weight.

As the filler (C) in the present invention, amorphous silica, crystalline silica, silicon nitride, silicon carbide,
Calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, asbestos, glass fiber and the like can be added. Among them, amorphous silica is preferably used from the viewpoint of low stress.

In the present invention, the proportion of the filler (C) is
From the viewpoint of formability and low stress, 60 to 95% by weight of the whole
Is. When amorphous silica is used as the filler (C), its proportion is preferably 60 to 90% by weight, and
0 to 88% by weight is particularly preferred.

The hydrotalcite compound (D) in the present invention is a composite metal compound represented by the following formula (III) or (IV).

Mg _x Al _y (OH) _{2x + 3y-nz} A _z · mH ₂ O (III) Mg _x Al _y O _{(2x + 3y) / 2} (IV) (where A is A functional group capable of generating an n-valent anion A ^n- , n is an integer of 1 to 3, and x, y and z are 0 <y / x ≦.
1, 0 or a positive number in the relationship of 0 ≦ z / y <1.5,
m represents 0 or a positive number. ).

In the above formula (III), preferred specific examples of the n-valent anion A ^n- which can be generated from the functional group A are F ⁻ , Cl ⁻ , Br ⁻ , I ⁻ , OH ⁻ and HC.
_{^{O 3 -, CH 3 COO -}} , HCOO -, CO 3 2-, SO
_{^{4 2-, (COO -) 2}} , tartrate [CH (OH) C
OO ^-] _2, citrate ion [C (OH) COO ^-]
(CH ₂ COO ⁻ ) ₂ , salicylate ion C ₆ H ₄ (O
H) COO- ^{and the} like. Of these, CO ₃ ^2- is particularly preferable.

The hydrotalcite-based compound (D) represented by the above formula (IV) is, for example, 400 to 90% of the hydrotalcite-based compound (D) represented by the above formula (III).
It is manufactured by baking at 0 ° C.

A preferred specific example of the hydrotalcite compound (D) is Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ .multidot.
3.5H ₂ O, Mg _4.5 Al ₂ (OH) ₁₃ CO ₃ , Mg
₅ Al _1.5 (OH) ₁₃ CO ₃ · 3.5H ₂ O, Mg ₅ A
l _1.5 (OH) ₁₃ CO ₃ , Mg ₆ Al ₂ (OH) ₁₆ CO
_{3 · 4H 2 O, Mg 6} Al 2 (OH) 16 CO 3, Mg
_0.65 Al _0.35 O _1.175 , Mg _0.7 Al _0.3 O _1.15 , Mg
_Examples include _0.75 Al _0.25 O _1.125 and Mg _0.8 Al _0.2 O _1.1 .

In the present invention, the amount of the hydrotalcite compound (D) added is 0.01 to 10% by weight, preferably 0.02 to 5% by weight, and particularly preferably 0.05 to
It is 2% by weight. If the addition amount is less than 0.01% by weight, the effect of improving the high temperature reliability is insufficient, and if it exceeds 10% by weight, the moldability such as mold stain is deteriorated.

The bromine compound (E) in the present invention is usually
It is added as a flame retardant to the epoxy compound for semiconductor encapsulation and is not particularly limited, and known compounds can be used.

Preferred specific examples of the bromine compound (E) include brominated epoxy resins such as brominated bisphenol A type epoxy resin and brominated phenol novolac type epoxy resin, brominated polycarbonate resin, brominated polystyrene resin, brominated polyphenylene. Examples thereof include oxide resins, tetrabromobisphenol A, decabromodiphenyl ether, and the like. Among them, brominated epoxy resins such as brominated bisphenol A type epoxy resin and brominated phenol novolac type epoxy resin are particularly preferably used from the viewpoint of moldability. Be done.

The amount of the bromine compound (E) added is preferably 0.1 to 5% by weight based on the total amount of bromine atoms in terms of flame retardancy and high temperature reliability. It is particularly preferably 0.2 to 2% by weight.

Antimony compound (F) in the present invention
When used in combination with a bromine compound (E) as a flame retardant,
It is added to improve flame retardancy. Specific preferred examples of the antimony compound (F) include antimony trioxide and antimony tetraoxide. The object of the present invention can be achieved by using antimony trioxide or antimony tetraoxide alone or in combination as the antimony compound (F), but from the viewpoint of high temperature reliability, regardless of whether antimony trioxide is added or not. It is preferable to add antimony tetroxide.

The amount of the antimony compound (F) added is 0.01 to 10% by weight, preferably 0.1 to 4% by weight, based on the flame retardancy and high temperature reliability.

Inorganic ion exchanger (G) in the present invention
Is represented by the following formula _{(I) M x O y (} NO 3) z (OH) w · nH 2 O ‥‥‥ (I) (M is one kind or two or more of 3-5-valent transition metal, x
= 1 to 5, y = 1 to 7, z = 0.2 to 3, w = 0.2 to
3, n = 0 to 2 is shown. ) In the above formula (I), 3 to
Specific preferred examples of the pentavalent transition metal M include phosphorus, arsenic, antimony, bismuth, aluminum, gallium,
Indium and the like can be mentioned, and among them, a combination of antimony and bismuth is particularly preferably used from the viewpoint of high temperature reliability.

The amount of the inorganic ion exchanger (G) added is 0.01 to 10% by weight, preferably 0.1 to 4% by weight, based on the moldability.

It is not clear why the mold stain is reduced by adding the inorganic ion exchanger (G), but it is presumed that it may react with some component that adheres to the mold during molding and causes mold stain. It

In the present invention, the surface treatment of the filler (C) with a coupling agent such as a silane coupling agent or a titanate coupling agent is preferable in terms of reliability. As the coupling agent, silane coupling agents such as epoxysilane, aminosilane, mercaptosilane and the like are preferably used.

The epoxy compound for semiconductor encapsulation of the present invention includes carbon black, coloring agents such as iron oxide, silicone rubber, modified nitrile rubber, modified polybutadiene rubber, elastomer such as styrene block copolymer, and heat such as polyethylene. A plastic resin, a long-chain fatty acid, a metal salt of a long-chain fatty acid, an ester of a long-chain fatty acid, an amide of a long-chain fatty acid, a releasing agent such as paraffin wax and a cross-linking agent such as an organic peroxide can be optionally added. ..

The epoxy compound for semiconductor encapsulation of the present invention is preferably melt-kneaded, for example, using a known kneading method such as a Banbury mixer, a kneader, a roll, a single-screw or twin-screw extruder and a co-kneader. It is manufactured by

[0043]

EXAMPLES The present invention will be specifically described below with reference to examples.

Examples 1 to 6 and Comparative Examples 1 to 4 The raw materials were dry blended with a mixer according to the formulation shown in Table 1 and Table 2. This, barrel setting temperature 90 ℃
After melt-kneading with the twin-screw extruder, the mixture was cooled and pulverized to produce an epoxy composition for semiconductor encapsulation.

[0045]

[Table 1]

[0046]

[Table 2]

This composition was molded by a low pressure transfer molding method under the conditions of 175 ° C. × 2 minutes and 180 ° C. ×
Post cure was carried out under the condition of 5 hours, and the physical properties and moldability of each composition were measured by the following physical property measuring methods.

High temperature reliability: 16 pi equipped with simulated element
Using nDIP, the high temperature reliability was evaluated at 220 ° C., and the time at which the cumulative failure rate was 50% was determined and defined as the high temperature life.

Flame retardance: A 5 ″ × 1/2 ″ × 1/16 ″ combustion test piece was molded and post-cured, and the flame retardancy was evaluated according to UL94 standard.

Moldability: 16 pin DIP for 20 consecutive
After shot molding, the mold was washed and molded with a melamine resin, and stains on the mold transferred to the melamine resin were visually determined.

The results are shown together in Table 2.

As shown in Table 2, the epoxy compounds for semiconductor encapsulation of the present invention (Examples 1 to 6) are excellent in flame retardancy, high temperature reliability and moldability. Among them, Example 6 in which antimony tetroxide was added as the antimony compound (F)
Is particularly excellent in high temperature reliability.

On the other hand, Comparative Example 1 containing no hydrotalcite compound (D) is inferior in high temperature reliability. Further, Comparative Example 2 containing no inorganic ion exchanger (G) is inferior in moldability. Furthermore, Comparative Example 3 containing no bromine compound (E) and Comparative Example 4 containing no antimony compound (F) are inferior in flame retardancy.

[0054]

Industrial Applicability The epoxy compound for semiconductor encapsulation of the present invention is difficult because it is mixed with an epoxy resin, a curing agent, a filler, a hydrotalcite compound, a bromine compound, an antimony compound and a specific inorganic ion exchanger. Excellent in flammability, high temperature reliability and moldability.

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Claims (1)

Claims: 1. An epoxy resin (A), a curing agent (B), a filler (C), a hydrotalcite compound (D), a bromine compound (E), an antimony compound (F) and formula _{(I) M x O y (} NO 3) z (OH) w · nH 2 O ‥‥‥ (I) (M is one kind or two or more of 3-5-valent transition metal, x
= 1 to 5, y = 1 to 7, z = 0.2 to 3, w = 0.2 to
3, n = 0 to 2 is shown. ), The composition containing the inorganic ion exchanger (G), wherein the proportion of the filler (C) is 60 to 95% by weight of the whole, and the hydrotalcite compound (D). ) Is 0.0
The epoxy composition for semiconductor encapsulation is 1 to 10% by weight, and the proportion of the inorganic ion exchanger (G) is 0.01 to 10% by weight based on the whole.