JPH10287795A - Epoxy resin composition for semiconductor sealing and semiconductor device sealed therewith - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition excellent in moldability, reliability and flame retardancy by using an epoxy resin, a phenolic curing agent, a cure accelerator, a red phosphorus flame retardant and an inorganic filler as the essential components and specifying the amounts of the inorganic filler and the red phosphorus flame retardant. SOLUTION: The inorganic filler is used in an amount of 80-95 wt.%, and the red phosphorus flame retardant is sued in an amount of 0.1-0.5 wt.%. The epoxy resin is particularly desirably a biphenyl-derived one. The curing agent is particularly desirably of an aralkyl type. The cure accelerator is especially desirably an adduct of triphenylphosphine with benzoquinone. The inorganic filler is particularly desirably spherical fused silica. The red phosphor desirably used is one surface-coated to enhance its stability. The coating resin is desirably one having a high affinity for the epoxy resin, and the thickness of the coating film is desirably at least 1% of the mean particle diameter of the red phosphorus. This composition is freed from a bromine-containing flame retardant and an antimony compound, so that it is friendly to the environment and can be desirably used for sealing transistors ICs, LSIs, etc.

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, which has been pointed out as a potential carcinogen, has been increasingly required. 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 a large amount in order to exhibit sufficient flame retardancy, which causes deterioration of the curability, strength, etc. of the resin composition. . Various products have also been proposed for phosphate ester-based flame retardants (including those used in combination with nitrogen).
The reality is that there is no one that can meet the demands of semiconductor sealing applications in terms of reliability.

[0003]

SUMMARY OF THE INVENTION The present invention relates to an epoxy resin composition for semiconductor encapsulation which does not contain a bromine-based flame retardant or antimony, is excellent in moldability, reliability and flame retardancy, and a semiconductor device using the same. The purpose is to provide.

[0004]

That is, the present invention is characterized in that in a sealing material mainly composed of an epoxy resin, a phenol curing agent and an inorganic filler, red phosphorus is blended as an essential component as a flame retardant. The present invention relates to an epoxy resin composition for semiconductor encapsulation and a semiconductor device using the same.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION 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. Is preferred. The curing agent is not particularly limited, and a phenol novolak type, an aralkyl type, a terpene type or the like can be used alone or in combination, and an aralkyl type is particularly preferable. Although there is no particular limitation on the curing accelerator, tetraphenylphosphonium-tetraphenylborate,
Triphenylphosphine, an adduct of triphenylphosphine and benzoquinone, 1,8-diaza-bicyclo (5,
(4,0) -undecene-7,2-phenyl-4methyl-
Imidazole, triphenylphosphonium-triphenylborane and the like can be used alone or in combination,
Particularly, an adduct of triphenylphosphine and benzoquinone is preferable. As the coupling agent, epoxysilane, alkylsilane and mercaptosilane are used as essential components. The release agent is not particularly limited, but a higher fatty acid such as carnauba wax and a polyethylene wax can be used alone or in combination, but the combination is particularly preferred. The inorganic filler is blended in an amount of 80 to 95% by weight and the shape of the filler is not particularly limited as long as it is 50% or more spherical, but fused silica, crystalline silica, alumina, and the like can be used alone or in combination. Particularly, spherical fused silica is preferred. When the amount of the filler is less than 80% by weight, the flame retardancy is lowered, and when the amount is more than 95% by weight, a problem tends to occur in the fluidity.

Red phosphorus is used as a flame retardant. In particular, those obtained by coating the surface of red phosphorus with a resin to enhance the stability are preferably used. The type of the resin and the thickness of the coating are not particularly limited, but a resin having a high affinity with the epoxy resin as the base resin is preferable. The thickness of the coating is preferably 1% or more of the average particle diameter of red phosphorus. When the thickness is less than 1%, a problem tends to occur in stability. The content of red phosphorus in the resin composition is preferably from 0.1 to 0.5%. 0.1
When the amount is less than 0.5%, the flame retardancy is insufficient. When the amount is more than 0.5%, a problem is likely to occur in the moisture resistance reliability. As other additives, a colorant (eg, carbon black) and a modifier (eg, silicone, silicone rubber) 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, etc., cooled, and pulverized. By doing so, a molding material can be obtained.

[0007] As a method for sealing electronic parts using the epoxy resin composition obtained by the present invention, a low pressure transfer molding method is the most common, but it is performed by a method such as injection molding, compression molding and casting. Is also possible. The epoxy resin composition manufactured using the above-described means is environmentally friendly because it does not contain a brominated flame retardant or an antimony compound, and has excellent moldability and reliability, and is suitable for sealing of transistors, ICs, LSIs, and the like. Can be 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 Comparative Examples 1 to 5 First, using various materials shown in Table 1, in Examples 1 and 2 and Comparative Examples 1 to 5, the respective materials were premixed (dry blending).
After that, 10 rolls with a biaxial roll (roll surface temperature about 80 ° C)
The mixture was kneaded for 5 minutes, cooled and pulverized to produce the product.

[0009]

[Table 1] * Rin Chemical Co., Ltd.

[0010]

[Table 2]

Using this sealing material and a transfer molding machine, a mold temperature of 180 ° C. and a molding pressure of 70 kgf / cm.
^2. Each test was conducted under the condition of 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 the moisture resistance is an SOP-28 pin, which is 85 ° C./85 RH% 72.
Time moisture absorption + 215 ° C / 90 seconds (VPS)
It was left at CT (121 ° C./2 atm) to evaluate the presence or absence of wiring on the chip. The semiconductor device used for solder heat resistance is Q
FP80 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. 85 ° C / 85% after baking at 125 ° C / 24h
After absorbing moisture for a predetermined period of time at RH, the crack occurrence 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.

[0012]

[Table 3] * 1 Heat resistance: Time until the disconnection failure reaches 50%. * 2 Solder heat resistance: Moisture absorption time until appearance cracks occur.

[0013]

EFFECT OF THE INVENTION In an epoxy resin composition for encapsulating a semiconductor element containing an epoxy resin, a phenol curing agent and an inorganic filler as main components, by blending red phosphorus as a flame retardant as an essential component, excellent reliability is obtained. In addition, it is possible to obtain a molding material having an extremely small effect on the environment. Also,
By sealing a semiconductor element using this molding material, a semiconductor device having excellent reliability and flame retardancy can be obtained.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI C08K 3/02 C08K 3/02 H01L 23/29 H01L 23/30 R 23/31 (72) Inventor Yuji Yamamoto Yuki-shi, Ibaraki Pref. 1772-1 Shikabo, Shimodate Plant, Hitachi Chemical Industry Co., Ltd. (72) Inventor, Yoshinori Endo, 172-1 Shikadate, Oki, Yuki City, Ibaraki Prefecture, Shimodate Plant, Hitachi Chemical Co., Ltd.

Claims (4)

[Claims] 1. An epoxy resin (B) a curing agent (C) a curing accelerator (D) a red phosphorus flame retardant (E) an inorganic filler as an essential component, and an inorganic filler (E). 80-95
% By weight, and the content of the (D) component red phosphorus-based flame retardant is
An epoxy resin composition for semiconductor encapsulation, which is 0.1 to 0.5% by weight. 2. The epoxy resin composition according to claim 1, wherein the epoxy resin (A) is a biphenyl type epoxy compound. 3. The epoxy resin composition for semiconductor encapsulation according to claim 1, wherein the curing agent (B) is a paraxylylene-modified phenol resin. 4. A resin-encapsulated semiconductor device wherein a semiconductor element is encapsulated with the epoxy resin composition for encapsulating a semiconductor according to claim 1, 2 or 3.