JPH05243426A - Epoxy resin composition for semiconductor sealing - Google Patents

Abstract

PURPOSE:To obtain a resin composition for semiconductor sealing use, which is superior in soldering temperature resistance, nonflammability and high- temperature reliability, by a method wherein an epoxy resin having a biphenyl skeleton is used as the essential component of the resin composition and at the same time, an inorganic ion-exchanger containing a trivalent to pentavalent transition metal is used. CONSTITUTION:A resin composition for semiconductor sealing use consists of an epoxy resin containing an epoxy resin having a skeleton, which is shown by Formula I (Provided that, R<1> to R<8> show hydrogen atoms, the lower alkyl groups of C1 to C4 or halogen atoms.), as its essential component, a hardening agent, a filler and an inorganic ion-exchanger, which is shown by Formula II (M shows one kind or more than one kinds of trivalent to pentavalent transition metals and (x), (y), (z), (w) and (n) respectively show 1 to 5, 1 to 10, 0.2 to 4, 0.2 to 4 and 0 to 5.), and a resin containing 0.02 to 30wt.% of an inorganic ion-exchanger is used as a resin for semiconductor sealing use. In such a way, the resin composition using the epoxy resin having the biphenyl skeleton and the inorganic ion-exchanger is improved its soldering temperature resistance and its nonflammability and high-temperature reliability are ensured.

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 resin composition having excellent solder heat resistance, flame retardancy and high temperature reliability.

[0002]

2. Description of the Related Art A semiconductor element is sealed with various sealing materials in order to protect it from an external environment or mechanical shock, or to electrically insulate it.

As the sealing material and sealing method, a hermetic seal made of metal or ceramics and a resin seal made of phenol resin, silicone resin, epoxy resin, etc. have been proposed. Above all, resin sealing with an epoxy resin is mainly used from the viewpoint of the balance of economic efficiency, productivity and physical properties.

In recent years, electronic parts have become smaller and thinner,
As a semiconductor mounting method, a surface mounting method has become popular in place of the conventional pin insertion method. In this case, the semiconductor is processed at a high temperature such as being immersed in a solder bath during mounting, but under such high temperature conditions, problems such as cracking of the sealing resin and deterioration of moisture resistance have been pointed out. .. Therefore, it has been desired to realize a resin composition having more excellent solder heat resistance than the conventional sealing resin.

Various improvements in solder heat resistance have been studied by improving the sealing resin itself. For example, a method of blending an epoxy resin having a biphenyl skeleton (Japanese Patent Laid-Open No. 63-251).
No. 419) has been proposed.

On the other hand, the flame retardancy of electronic parts is due to Underwriters Laboratorie founded by the American fire insurance industry.
Mandatory by the standard (UL standard) set by s Inc. As the semiconductor encapsulating resin, a combination system of a brominated epoxy resin and an antimony oxide such as antimony trioxide (Sb ₂ O ₃ ) is generally used. Non-halogen flame retardants such as phosphorus flame retardants have been studied, but they have not been put into practical use due to problems such as poor moisture resistance and moldability.

Further, in applications requiring heat resistance such as under hoods of automobiles, for example, they are exposed to a high temperature of 150 ° C. or higher. At this time, the brominated epoxy resin used as the flame retardant decomposes to generate HBr,
This finally causes a conduction failure of the element, resulting in deterioration of reliability. Since such a problem has been pointed out, further high temperature reliability is required.

As described above, the brominated epoxy resin is indispensable at the present stage in order to satisfy the flame retardancy, but it has a bad effect of deteriorating the high temperature reliability. Development is strongly desired.

Therefore, improvement of reliability by additives has been investigated, and for example, improvement of moisture resistance by blending an inorganic ion exchanger (Japanese Patent Laid-Open No. 62-212422) has been proposed.

[0010]

However, when an epoxy resin having a biphenyl skeleton is used, there is a problem that the high temperature reliability is inferior to the conventionally used orthocresol novolac type epoxy resin.

Further, the method of adding the inorganic ion exchanger has a problem that the heat resistance of the solder is deteriorated in the conventional epoxy resin system.

Therefore, an object of the present invention is to solve the problems of the above-mentioned epoxy resin composition, to improve the solder heat resistance,
An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation which is excellent in flame retardancy and high temperature reliability.

[0013]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that an epoxy resin having a biphenyl skeleton is used as an essential component, and
The inventors have found that an epoxy resin composition that meets the above purpose can be obtained by using an inorganic ion exchanger containing a trivalent to pentavalent transition metal, and have reached the present invention.

That is, the present invention provides the following general formula (I)

[Chemical 2] (However, R ^{1 to} R ⁸ represent a hydrogen atom, a C _{1 to} C ₄ lower alkyl group or a halogen atom.) An epoxy resin (A) containing an epoxy resin (a) having a skeleton represented by , Curing agent (B), filler (C) and the following general formula (II) MzOy (NO ₃ ) x (OH) w · nH ₂ O (II) (M is one or more than 3 Pentavalent transition metal, x
= 1-5, y = 1-10, z = 0.2-4, w = 0.2
4 and n = 0 to 5 are shown. ) The inorganic ion exchanger (D) represented by
The present invention provides an epoxy resin composition for semiconductor encapsulation containing 0% by weight.

The epoxy resin (A) in the present invention contains the epoxy resin (a) represented by the above formula (I) as an essential component. If the epoxy resin (a) is not contained, the effect of preventing the occurrence of cracks during the soldering process is insufficient.

In the above formula (I), preferred examples of R ^{1 to} R ⁸ are hydrogen atom, methyl group, ethyl group,
Propyl group, i-propyl group, n-butyl group, sec-
Examples thereof include a butyl group, a tert-butyl group, a chlorine atom and a bromine atom.

Preferred specific examples of the epoxy resin (a) in the present invention include 4,4'-bis (2,3-epoxypropoxy) biphenyl and 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 and 4,4'-bis (2,3-epoxypropoxy) -3,3' , 5,5'-tetrabutylbiphenyl and the like.

The epoxy resin (A) in the present invention may contain the above epoxy resin (a) together with an epoxy resin other than the epoxy resin (a).
Other epoxy resins that can be used in combination are not particularly limited as long as they have two or more epoxy groups in one molecule,
For example, cresol novolac type epoxy resin, phenol novolac type epoxy resin, various novolac type epoxy resins synthesized from bisphenol A and resorcin, bisphenol A type epoxy resin, linear aliphatic epoxy resin, heterocyclic epoxy resin, alicyclic Formula epoxy resins and halogenated epoxy resins and the like can be mentioned.

The ratio of the epoxy resin (a) contained in the epoxy resin (A) is not particularly limited, and the effect of the present invention can be exhibited if the epoxy resin (a) is contained as an essential component. Epoxy resin (a) is usually contained in epoxy resin (A) in an amount of 30% by weight in order to exert a sufficient effect.
As described above, it is necessary to contain 50% by weight or more.

In addition to the epoxy resin (a), two or more kinds of epoxy resins may be used in combination depending on the application, but a cresol novolac type epoxy resin is used for sealing a semiconductor device from the viewpoint of heat resistance and moisture resistance. preferable.

In the present invention, the compounding amount of the epoxy resin (A) is preferably in the range of 5 to 25% by weight.

The curing agent (B) in the present invention is not particularly limited as long as it cures by reacting with the epoxy resin (A), and specific examples thereof include novolac type compounds such as phenol novolac and cresol novolac. Phenolic resins, bisphenol compounds such as bisphenol A, bisphenol F and bisphenol AD, acid anhydrides such as maleic anhydride, phthalic anhydride and pyromellitic anhydride, and aromatic amines such as metaphenylenediamine, diaminodiphenylmethane and diaminodiphenylsulfone. Is mentioned. For semiconductor device encapsulation,
From the viewpoint of heat resistance, moisture resistance and storage stability, novolac type phenolic resins such as phenol novolac and cresol novolac are preferably used, and two or more curing agents may be used together depending on the application.

In the present invention, the compounding amount of the curing agent (B) is usually 2 to 15% by weight. Furthermore, epoxy resin (A)
The mixing ratio of the curing agent (B) and the curing agent (B) is such that the chemical equivalent ratio of (B) to (A) is 0.6 to 1.5 from the viewpoint of mechanical properties and heat resistance.
In particular, it is preferably in the range of 0.8 to 1.3.

In the present invention, a curing catalyst may be used to accelerate the curing reaction between the epoxy resin (A) and 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-
Imidazole compounds such as 4-methylimidazole and 2-heptadecylimidazole, triethylamine, benzyldimethylamine, α-methylbenzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,
4,6-tris (dimethylaminomethyl) phenol,
1,8-diazabicyclo (5,4,0) undecene-7
Such as tertiary amine compounds, zirconium tetramethoxide, zirconium tetrapropoxide, tetrakis (acetylacetonato) zirconium, tris (acetylacetonato) aluminum and other organometallic compounds, and triphenylphosphine, trimethylphosphine, triethylphosphine, tributylphosphine , Organic phosphine compounds such as tri (p-methylphenyl) phosphine and tri (nonylphenyl) phosphine. Among them, organic phosphine compounds are preferable, and triphenylphosphine is particularly preferable, from the viewpoints of reliability and moldability.

Two or more kinds of these curing catalysts may be used in combination depending on the use, and the amount of the curing catalyst is the epoxy resin (A).
The range of 0.1 to 10 parts by weight is preferable with respect to 100 parts by weight.

Examples of the filler (C) in the present invention include amorphous silica, crystalline silica, calcium carbonate, magnesium carbonate, alumina, magnesia, clay, talc, calcium silicate, titanium oxide, asbestos and glass fiber. Be done. Among them, amorphous silica has a large effect of lowering the coefficient of linear expansion and is effective in lowering stress, and thus is preferably used.

The amount of these fillers (C) added is 70% of the total.
˜90 wt% is preferable in terms of moldability and low stress.

The inorganic ion exchanger (D) in the present invention is
It is represented by the following formula (II).

MxOy (NO ₃ ) z (OH) w · nH ₂ O (II) Here, in the formula (II), M is a trivalent to pentavalent transition metal,
They may be used alone or in combination of two or more.
In the formula (II), x is 1 to 5, y is 1 to 10, and z is 0.
2 to 4, w is 0.2 to 4, and n is 0 to 5. Here, examples of the transition metal include phosphorus, arsenic, antimony, bismuth, aluminum, gallium, indium, and the like, and particularly preferable is a combination of antimony and bismuth.

Preferred examples of the inorganic ion exchanger (D) used in the present invention include Sb ₂ Bi _1.4 O _6.4 (NO
₃ ) _0.4 (OH) _0.95・ 0.5H ₂ O, Sb ₂ Bi _{1.2
O 6. 2 (NO 3) 0.4} (OH) 0.8 · 2H 2 O, Sb 2
Bi _0.4 O ₆ (NO ₃ ) _0.4 (OH) _0.8 / 2H ₂ O,
Sb ₂ Bi _3.0 O ₆ (NO ₃ ) _0.4 (OH) _0.8 / 2H
₂ O, Sb ₂ Bi _1.2 O ₁₀ (NO ₃ ) _0.4 (OH) _0.8
・ 2H ₂ O, Sb ₂ Bi _1.2 O ₆ (NO ₃ ) _0.4 (O
H) _4.0・ 2H ₂ O, Sb ₂ Bi _1.2 O ₆ (NO ₃ )
_4.0 (OH) _0.8 / 2H ₂ O, Sb ₂ Bi _1.2 O ₆ (N
O ₃ ) _0.8 (OH) _0.8 · 4H ₂ O and the like can be mentioned.

The compounding amount of this inorganic ion exchanger is 0.02.
The range is preferably from 30 to 30% by weight, more preferably 0.
It is in the range of 05 to 5% by weight.

If the content of the inorganic ion exchanger is less than 0.02% by weight, the high temperature reliability is lowered, while if it exceeds 30% by weight, the solder heat resistance is adversely affected, which is not preferable. Further, in order to enhance the ion exchange capacity, the inorganic ion exchanger may be kneaded with the epoxy resin in advance, that is, 80 to 160 ° C., preferably 120 to 1
The inorganic ion exchanger is added to the epoxy resin which has been melted in advance at 50 ° C., and the mixture is kneaded for about 0.5 to 3 hours, then taken out, cooled, solidified and pulverized. The particle size of the ground product is preferably 200 μm or less.

In addition, a releasing agent, a coupling agent, a flame retardant and a coloring agent can be used in the epoxy resin composition of the present invention. As the release agent, natural waxes, synthetic waxes, metal salts of long-chain fatty acids and the like can be used.

The epoxy resin composition of the present invention is preferably melt-kneaded, for example by melt-kneading using a known kneading method such as a Banbury mixer, a kneader, a roll, a single or twin screw extruder and a cokneader. Manufactured.

[0035]

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

Examples 1 to 4 and Comparative Examples 1 to 5 After mixing the raw materials in the composition ratios shown in Table 1 at room temperature, 90 to
The mixture was kneaded at 95 ° C., cooled and pulverized to obtain an epoxy resin composition.

This resin composition was molded by a low pressure transfer molding method under the conditions of 175 ° C. × 4 minutes, and
A 16-pin DIP equipped with 4-pin QFP and TEG and a flame-retardant test piece (5 ″ × 1/2 ″ × 1/16 ″) were obtained, and then post-cured at 175 ° C. for 5 hours.

After post-curing, the physical properties of each composition were measured by the following measuring methods.

Solder heat resistance: 32 pieces of 44 pin QFP
215 after leaving it in a humidifier at 85 ° C / 85% RH for 72 hours
9 in VPS (vapor phase soldering) at ℃
It was heated for 0 seconds or for 10 seconds in a solder bath at 260 ° C., and the ratio of the number of QFPs in which cracks did not occur was determined.

High temperature reliability: using 16 pin DIP, 2
A test was carried out at a high temperature of 10 ° C., a resistance value exceeding 1 Ω was treated as a failure, and the time at which the cumulative failure rate became 50% was determined.

Flame retardance: 10 flame retardant test pieces were used and UL
It was measured according to the -94 standard.

The results are shown in Table 2.

[0043]

[Table 1]

[Table 2] As is clear from Table 2, the resin compositions (Examples 1 to 4) using the epoxy resin having a biphenyl skeleton of the present invention and the inorganic ion exchanger are excellent in solder heat resistance, flame retardancy and high temperature reliability. There is.

[0044]

The epoxy resin composition for semiconductor encapsulation of the present invention can provide a semiconductor device excellent in solder heat resistance, flame retardancy and high temperature reliability.

Claims (1)

[Claims] 1. The following general formula (I): (However, R ^{1 to} R ⁸ represent a hydrogen atom, a C _{1 to} C ₄ lower alkyl group or a halogen atom.) An epoxy resin (A) having an skeleton represented by (A) as an essential component. ), A curing agent (B), a filler (C) and the following general formula (II) MxOy (NO ₃ ) z (OH) w · nH ₂ O (II) (M is one or more than 3 ~ Pentavalent transition metal, x
= 1-5, y = 1-10, z = 0.2-4, w = 0.2
4 and n = 0 to 5 are shown. ) The inorganic ion exchanger (D) represented by
An epoxy resin composition for semiconductor encapsulation containing 0% by weight.