JPH1112436A - Epoxy resin composition for sealing semiconductor and semiconductor device made by using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which contains neither a brominated flame retardant nor an antimony compound and is excellent in moldability, reliability and flame retardancy by blending an epoxy resin, a curing agent, a specified amount of an inorganic filler, and a flame retardant comprising a specified amount of zinc molybdate as the essential constituents. SOLUTION: An epoxy resin, a curing agent, zinc molybdate, and an inorganic filler are used as the essential constituents, wherein the content of an inorganic filler is 70-95 wt.% based on the total composition. A biphenyl type epoxy resin is preferably used in particular as the epoxy resin, although an o-cresol novolak type, a biphenyl type, a dicyclo type, etc., can be used alone or together, without limitation particularly. The curing agent used preferably comprises a paraxylylene-modified phenolic resin in particular. The content of zinc molybdate is preferably 0.05-10.0 wt.% based on the total composition. The inorganic filler used preferably comprises a spherical fused silica in particular.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to flame retardancy, moldability,
The present invention relates to a sealing material excellent in reliability and a semiconductor device using the same.

[0002]

2. Description of the Related Art Resin encapsulation is mainly used for encapsulating semiconductor devices in terms of productivity and cost. As this sealing resin, an epoxy resin composition excellent in electrical characteristics, cost, workability and the like is mainly used. However, since epoxy resins have insufficient flame retardancy, brominated epoxy resins are usually added to improve flame retardancy. In addition, antimony compounds that have a synergistic effect with brominated flame retardants (antimony trioxide,
Antimony pentoxide). In recent years, from the viewpoint of environmental protection, the use of brominated flame retardants suspected of producing dioxins during combustion and antimony compounds, which have been pointed out as having carcinogenic potential, have been increasingly demanded.
To meet this demand, various alternative flame retardants have been studied.
For example, metal hydrates such as aluminum hydroxide and magnesium hydroxide must be added in large amounts in order to exhibit sufficient flame retardancy, resulting in deterioration of the curability, strength, etc. of the resin composition. I will. Various products have also been proposed for a phosphoric ester-based flame retardant (including the combined use with nitrogen), but none of them can meet the demands for semiconductor encapsulation in terms of moldability and reliability.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides a moldable, reliable, non-containing brominated flame retardant and antimony compound.
An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation excellent in flame retardancy and a semiconductor device using the same.

[0004]

That is, the present invention relates to a sealing material containing an epoxy resin, a phenol curing agent and an inorganic filler as main components, wherein zinc molybdate is blended as a flame retardant as an essential component, and a bromine-based compound is used. The present invention relates to an epoxy resin composition for semiconductor encapsulation containing no flame retardant or antimony compound, and a semiconductor device using the same. Heretofore, zinc molybdate has been known as a smoke suppressant such as vinyl chloride. However, these are auxiliary agents for other flame retardants (especially brominated flame retardants) or as smoke suppressants, and there is no report that zinc molybdate alone achieves UL94 V-0. The present inventors have made intensive studies and surprisingly found that the epoxy resin composition produced with the above composition achieves UL94 V-0 only by adding a small amount of zinc molybdate as a flame retardant. And completed the present invention. Hereinafter, the details will be described.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin used in the present invention is not particularly limited, and orthocresol novolak type, biphenyl type, dicyclo type and the like can be used alone or in combination. It is suitable. The curing agent is not particularly limited, and a phenol novolak type, an aralkyl type (paraxylylene-modified phenolic resin), a terpene type, or the like can be used alone or in combination, and an aralkyl type is particularly preferable. The curing accelerator is not particularly limited, but may be tetraphenylphosphonium-tetraphenylborate, triphenylphosphine, an adduct of triphenylphosphine and benzoquinone, 1,8-diaza-bicyclo (5,4,0) -undecene. -7,2-phenyl-4methyl-imidazole,
Triphenylphosphonium-triphenylborane or the like can be used alone or in combination, but an adduct of triphenylphosphine and benzoquinone is particularly preferred. The coupling agent is not particularly limited, but epoxy silane is preferably used. The release agent is not particularly limited, but a higher fatty acid such as carnauba wax or the like and a polyethylene wax can be used alone or in combination, and the combination is particularly preferable. The inorganic filler is blended in an amount of 70 to 95% by weight, and the shape of the filler is spherical or crushed, and fused silica, crystalline silica, alumina or the like can be used alone or in combination. In particular, spherical fused silica is preferred. When the amount of the filler is 70% by weight or less, the flame retardancy decreases, and
If the content is 5% by weight or more, a problem tends to occur in fluidity. Especially 85-
A range of 95% by weight is preferred.

[0006] As the flame retardant, zinc molybdate is used. Preferably, a core of magnesium oxide, silicon oxide, or the like coated with zinc molybdate is used. The content of zinc molybdate in the resin composition is 0.05 to 1
0.0% by weight is preferred. If it is less than 0.05%, the flame retardancy is insufficient, and if it is more than 10.0%, there is a problem in formability. In particular, the range of 0.1 to 5.0% is suitably used. Examples of the flame retardant obtained by coating talc with zinc molybdate include KE of SHERWIN-WILLAMS.
MGARD911 and the like are readily available.

As other additives, colorants (such as carbon black), modifiers (such as silicone and silicone rubber), and ion trappers (such as hydrotalcite and antimony-bismuth) can be used. As a general method for producing a molding material using the above-described raw materials, a raw material mixture having a predetermined compounding amount is sufficiently mixed by a mixer or the like, and then kneaded by a hot roll, an extruder, and the like, cooled, and pulverized. By doing so, a molding material can be obtained. As a method for sealing an electronic component using the epoxy resin composition obtained in the present invention, a low-pressure transfer molding method is the most common, but injection molding, compression molding, casting, and other methods are also possible. is there. The epoxy resin composition manufactured using the above-mentioned means is environmentally friendly because it does not contain a brominated flame retardant or an antimony compound, and is excellent in moldability and reliability, and is suitable for sealing of transistors, ICs, LSIs and the like. It can be suitably used.

[0008]

The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples. Examples 1 to 3 and Comparative Examples 1 to 3 First, the various materials shown in Table 1 were used. (Roll surface temperature of about 80 ° C.) for 10 minutes, followed by cooling and pulverization.

[0009]

[Table 1]

[0010]

[Table 2] Using the sealing material, each test was performed using a transfer molding machine under the conditions of a mold temperature of 180 ° C., a molding pressure of 70 kgf / cm 2, and a curing time of 90 seconds. Spiral flow was measured by EMMI1-66. Hot hardness was measured by a Shore hardness tester. Further, using this sealing material, a semiconductor element was molded by a transfer molding machine under the same conditions, and after post-curing (175 ° C./5 h), the moisture resistance and the solder heat resistance were evaluated. The semiconductor device used for moisture resistance is SOP-
28 pins, moisture absorption at 85 ° C / 85RH% for 72 hours +2
After pretreatment at 15 ° C./90 seconds (VPS), PCT (121
(° C./2 atm) to evaluate the presence or absence of a cross section of the wiring on the chip. The semiconductor device used for solder heat resistance is QFP8
0-pin resin-encapsulated semiconductor device (external dimensions 20 × 14 ×
2.0 mm), and the lead frame is made of 42 alloy material (no processing) and has a chip size of 8 × 10 mm. The solder heat resistance of the resin-encapsulated semiconductor device thus obtained was measured by the following method.
After baking at 125 ° C./24 h, moisture absorption was performed at 85 ° C./85% RH for a predetermined time, and a crack generation rate of the resin-encapsulated semiconductor device when a process at 240 ° C./10 sec was performed was determined. Table 3 summarizes the above test results.

[0011]

[Table 3]

[0012]

According to the epoxy resin composition for semiconductor encapsulation containing an epoxy resin, a phenol curing agent and an inorganic filler as main components, a brominated flame retardant can be obtained by blending zinc molybdate as an essential component as a flame retardant. A molding material that satisfies the flame retardant UL94 V-0 without containing an antimony compound, is excellent in reliability and moldability, and has an extremely small influence on the environment can be obtained. By sealing a semiconductor element using this molding material, a semiconductor device having excellent reliability and flame retardancy can be obtained.

Claims (6)

[Claims] 1. An epoxy resin (B) curing agent (C) zinc molybdate (D) inorganic filler as an essential component,
(D) The epoxy resin composition for semiconductor encapsulation, wherein the content of the inorganic filler as the component is 70 to 95% by weight based on the whole resin composition. 2. The content of the zinc molybdate of the component (C) is 0.05 to 10.0% by weight based on the whole resin composition.
The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein 3. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the epoxy resin as the component (A) is a biphenyl type epoxy resin. 4. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the curing agent (B) is a paraxylylene-modified phenol resin. 5. The content of the inorganic filler of component (D) is 85.
2. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the amount is from about 95% by weight. 6. A resin-sealed semiconductor device in which a semiconductor element is sealed by using the epoxy resin composition for semiconductor sealing according to claim 1.