JP2000248156A - Epoxy resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor-sealing epoxy resin composition excellent in high temperature storage properties and moisture-proof reliability as well as in the balance thereof with flame retardancy. SOLUTION: This resin composition comprises, as essential components, an epoxy resin, a phenol resin, 0.1-5 wt.%, based on the total resin composition, of a red phosphorus-based flame-retardant obtained by coating the surface of red phosphorus with aluminum hydroxide and subsequently coating the surface thereof further with a phenol resin, 0.1-5 wt.%, based on the total resin composition, of a hydrotalcite of the formula: MgxAly(OH)2x+3y-2z(CO3)z.mHz0 (wherein O<y/x<=1; 0<=z/y<1.5; and (m) is a positive number), an inorganic filler and a curing accelerator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition which is excellent in high-temperature storage characteristics and moisture resistance reliability, and is excellent in balance with flame retardancy, and a semiconductor device using the same.

[0002]

2. Description of the Related Art In recent years, a low-pressure encapsulation method using an epoxy resin composition has been generally used for sealing semiconductor elements such as ICs and LSIs. This resin composition is required to have flame retardancy, and usually contains a bromine compound and antimony oxide for imparting flame retardancy. However, when a semiconductor device sealed with this resin composition is stored at a high temperature, it is known that brominated products thermally decomposed from these flame retardant components are liberated, which impairs the reliability of the junction of the semiconductor element. ing. The term “reliability” as used herein refers to a bonding portion (bonding pad portion) of a semiconductor element after a semiconductor device sealed with this resin composition is left at a high temperature (for example, 200 ° C. or the like).
(Hereinafter referred to as high-temperature storage characteristics).
As a method for improving the high-temperature storage characteristics, a method using diantimony pentoxide (JP-A-55-146950) or a method of combining antimony oxide with an organic phosphine (JP-A-61-53321). However, it has not yet reached the required level of high-temperature storage characteristics for recent semiconductor devices. Recent reports have shown that the method using a red phosphorus-based flame retardant is very effective. However, semiconductor devices using devices without a protective film on the chip, glass transition, etc. When applied to a field where the moisture resistance is extremely weak, such as an epoxy resin composition having a temperature lower than the test temperature, the requirements are not completely satisfied, and further improvement is required. That is, there is a demand for an epoxy resin composition which is excellent in high-temperature storage characteristics, humidity resistance and flame retardancy without using a bromine compound and antimony oxide as a flame retardant.

[0003]

SUMMARY OF THE INVENTION The present invention is to provide an epoxy resin composition which is excellent in high-temperature storage characteristics and moisture resistance reliability and is excellent in balance with flame retardancy, and a semiconductor device using the same. is there.

[0004]

According to the present invention, the surfaces of (A) an epoxy resin, (B) a phenol resin, and (C) red phosphorus are coated with aluminum hydroxide, and then the surfaces are further coated with a phenol resin. 0.1 to 5% by weight of the red phosphorus-based flame retardant in the total resin composition, (D) 0.1 to 5% by weight of the hydrotalcites of the general formula (1) in the total epoxy resin composition, E) an inorganic filler, and (F) a curing accelerator as essential components. In particular, the average particle size of the red phosphorus-based flame retardant is 1 to 70 μm, the maximum particle size is 150 μm or less, and red in the red phosphorus-based flame retardant is used. An epoxy resin composition having a phosphorus content of 60 to 95% by weight, and a semiconductor device in which a semiconductor element is sealed using the epoxy resin composition. Mg _X Al _Y (OH) _{2X + 3Y-2Z} (CO ₃ ) _Z · mH ₂ O (1) (where 0 <y / x ≦ 1, 0 ≦ z / y <1.5, m is a positive number )

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin used in the present invention is:
There is no particular limitation as long as the monomer, oligomer, or polymer has two or more epoxy groups in the molecule.
Orthocresol novolak epoxy resin, phenol novolak epoxy resin, triphenolmethane epoxy resin, bisphenol epoxy resin, biphenyl epoxy resin, stilbene epoxy resin, dicyclopentadiene modified phenol epoxy resin, naphthalene epoxy resin, etc. These may be used alone or as a mixture. For the curability of the resin composition, the epoxy equivalent is desirably 150 to 300.

[0006] The phenolic resin used in the present invention includes a monomer, an oligomer having a phenolic hydroxyl group in the molecule,
The polymer is not particularly limited as long as it is a polymer, and examples thereof include a phenol novolak resin, a phenol aralkyl resin, a terpene-modified phenol resin, and a triphenolmethane resin, and these may be used alone or as a mixture.
For the curability of the resin composition, the hydroxyl equivalent is 80-2.
50 is desirable.

The red phosphorus flame retardant used in the present invention is obtained by coating the surface of red phosphorus with aluminum hydroxide and then coating the surface with a phenol resin. The aluminum hydroxide and the phenol resin used for coating are not particularly limited as long as they are commonly used. The coating method is not particularly limited, but from the viewpoint of coating uniformity, red phosphorus is reduced by reducing aluminum sulfate, aluminum nitrate, etc. to aluminum hydroxide in a liquid phase. Most preferred is a method of coating, further using an acid in a resole resin solution, coating with a formed phenol resin, and drying. The content of red phosphorus in the red phosphorus flame retardant is preferably from 60 to 95% by weight.
If the content of red phosphorus is less than 60% by weight, a large amount of a red phosphorus-based flame retardant must be incorporated into the resin composition to obtain flame retardancy. It may decrease. The compounding amount of the red phosphorus-based flame retardant used in the present invention is preferably 0.1 to 5% by weight in the whole resin composition.
If the amount is less than 0.1% by weight, the flame retardancy indispensable as a sealing material characteristic is not satisfied. If the amount exceeds 5% by weight, red phosphorus conversely assists the combustion of the resin component and sufficient flame retardancy is obtained. I can't. The red phosphorus flame retardant used in the present invention is manufactured by Rin Kagaku Kogyo Co., Ltd.
It is commercially available from.

The hydrotalcites used in the present invention include:
By capturing the ionic impurities, the ionic impurities contained in the resin component and the like are reduced. It is known that these ionic impurities corrode aluminum wirings and pads. However, by using hydrotalcite, ionic impurities can be captured and aluminum corrosion can be prevented. The compounding amount is preferably from 0.1 to 5% by weight, and more preferably from 0.1 to 5% by weight in the whole resin composition.
If the amount is less than the above, ionic impurities in the resin composition are not sufficiently captured, and satisfactory moisture resistance reliability cannot be obtained. If the amount exceeds 5% by weight, the curability is reduced and sufficient hot hardness cannot be obtained. The present invention maintains the high-temperature storage characteristics by using a red phosphorus-based flame retardant instead of a bromine compound and antimony oxide that adversely affect the high-temperature storage characteristics, and by using hydrotalcites as an ion scavenger, It traps phosphate ions released from the red phosphorus-based flame retardant and adversely affects the moisture resistance reliability and suppresses corrosion of the joint. That is, it aims at achieving both high-temperature storage characteristics and humidity resistance reliability, which could not be achieved by blending only a red phosphorus-based flame retardant.

The type of the inorganic filler used in the present invention is not particularly limited, and those generally used for a sealing material can be used. For example, fused silica powder, fused spherical silica powder, crystalline silica powder, alumina, titanium white, aluminum hydroxide, talc, clay, glass fiber and the like can be mentioned. The curing accelerator used in the present invention,
There is no particular limitation as long as the reaction between the epoxy resin and the phenol resin can be promoted. For example, amine compounds such as 1,8-diazabicyclo (5,4,0) undecene-7, tributylamine, triphenylphosphine, tetraphenyl Organic phosphorus compounds such as phosphonium / tetraphenyl borate salts; 2-methylimidazole; and the like, which may be used alone or in combination.

[0010] The resin composition of the present invention comprises, in addition to the components (A) to (F), if necessary, a flame retardant other than a bromine compound, a silane coupling agent, a coloring agent, a mold release of a natural wax or a synthetic wax. Various additives such as low-stress components such as silicone oil and silicone oil may be appropriately added and used. The resin composition of the present invention is obtained by mixing the components (A) to (F) and other additives at room temperature using a mixer, kneading the mixture with a kneader such as a roll or an extruder, cooling, and pulverizing the mixture. Can be In order to manufacture a semiconductor device by encapsulating an electronic component such as a semiconductor element using the resin composition of the present invention, it is sufficient to cure and mold by a molding method such as a transfer mold, a compression mold, and an injection mold.

[0011]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples. The mixing ratio is by weight. First, raw materials used in Examples and Comparative Examples will be described. Epoxy resin 1 (ESCN-1 manufactured by Sumitomo Chemical Co., Ltd.)
95 LA, softening point 65 ° C., epoxy equivalent 200) Epoxy resin 2 (YX- manufactured by Yuka Shell Epoxy Co., Ltd.)
4000, melting point 105 ° C., epoxy equivalent 195) phenol resin (phenol novolak resin, softening point 9)
0 ° C., hydroxyl equivalent: 104) Red phosphorus flame retardant (manufactured by Rin Kagaku Kogyo Co., Ltd., Nova Excel ST140, red phosphorus content: 93% by weight, average particle size: 30 μm)
m, maximum particle size 110 μm) Hydrotalcite (Kyowa Chemical Industry Co., Ltd., DHT)
-4) Inorganic filler (fused spherical silica, average particle size 30 μm, specific surface area 1.4 m ² / g) Curing accelerator (1,8-diazabicyclo (5,4,0) undecene-7, hereinafter referred to as DBU) Silane Coupling agent carbon black carnauba wax

Example 1 Epoxy resin 1 100 parts by weight Phenol novolak resin 60 parts by weight Fused spherical silica 700 parts by weight DBU 2 parts by weight Red phosphorus-based flame retardant 10 parts by weight Hydrotalcites 10 parts by weight Silane coupling agent 5 parts by weight 3 parts by weight of carbon black and 5 parts by weight of carnauba wax were mixed by a mixer, kneaded at 100 ° C. using a biaxial roll, cooled and mixed, and then pulverized to obtain a resin composition. The obtained resin composition was evaluated by the following method. Table 1 shows the results.

Evaluation method Spiral flow: Spiral flow was measured using a mold for measuring spiral flow according to EMMI-I-66 at a mold temperature of 175 ° C., an injection pressure of 70 kg / cm ² , and a curing time of 2 minutes. Flame retardancy: conforms to UL-94, test piece thickness 1 / 8i
It was measured by nch. High-temperature storage characteristics: Using a low-pressure transfer molding machine, a 16 pDIP (package width 300 mils) was molded at a mold temperature of 175 ° C., a pressure of 70 kg / cm ² , and a curing time of 2 minutes, and was post-cured at 175 ° C. for 8 hours. Ten packages were obtained. The obtained package was stored at 200 ° C., and the electrical resistance of the wiring of the package was examined at room temperature.
Tests were performed for up to 500 hours, and those showing a resistance value of 1.2 times or more the initial resistance value were determined to be defective. When the number of defective packages was n, it was indicated as n / 10. Moisture resistance reliability: Samples were prepared under the same conditions as the high-temperature storage characteristics, and ten packages were obtained. The obtained package was stored under a condition of 125 ° C./100% for 1000 hours, and an electric current test was performed to measure a leakage defect. When the number of defective packages was n, it was indicated as n / 10. Bacoal hardness: measured at the time of preparing 16pDIP for measuring high-temperature storage characteristics. The measurement was performed 10 seconds after the mold was opened. Those having a Bacoal hardness of 60 or more were judged to be good.

Examples 2 to 6 According to Table 1, a resin composition was obtained in the same manner as in Example 1, and evaluated in the same manner as in Example 1. Table 1 shows the results. Comparative Examples 1 to 6 According to Table 2, a resin composition was obtained in the same manner as in Example 1, and evaluated in the same manner as in Example 1. Table 2 shows the results.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

According to the present invention, it is possible to obtain a semiconductor device which is excellent in high-temperature storage characteristics and humidity resistance reliability, and which is extremely excellent in balance with flame retardancy.

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Claims (3)

[Claims] 1. A resin composition comprising: (A) an epoxy resin, (B) a phenolic resin, and (C) a red phosphorus flame retardant whose surface is coated with aluminum hydroxide and then further coated with a phenol resin. 0.1 to 5% by weight in the composition, (D) 0.1 to 5% by weight of the hydrotalcites of the general formula (1) in the total resin composition, (E) an inorganic filler, and (F) An epoxy resin composition comprising a curing accelerator as an essential component. Mg _X Al _Y (OH) _{2X + 3Y-2Z} (CO ₃ ) _Z · mH ₂ O (1) (where 0 <y / x ≦ 1, 0 ≦ z / y <1.5, m is a positive number ) 2. The red phosphorus-based flame retardant has an average particle size of 1 to 70 μm,
The epoxy resin composition according to claim 1, wherein the maximum particle size is 150 µm or less, and the content of red phosphorus in the red phosphorus-based flame retardant is 60 to 95% by weight. 3. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition according to claim 1, 2 or 3.