JP2000309680A - Epoxy resin composition and semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition for semiconductor sealing use with excellent high-temperature storability and superior in its balance with flame retardancy. SOLUTION: This epoxy resin composition essentially comprises an epoxy resin, a phenolic resin, 0.1-5 wt.% of active carbon, inorganic filler, curing promoter, 0.1-5 wt.% of bismuth oxide hydrate, and brominated epoxy resin.

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 having excellent high-temperature storage characteristics and a good balance between high-temperature storage characteristics and flame retardancy, and a resin obtained by sealing a semiconductor element using the same. The present invention relates to a sealed semiconductor device.

[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 pyrolyzed bromine ions are liberated from these flame retardant components, thereby impairing the reliability of the junction of the semiconductor elements. ing. The term “reliability” as used herein refers to the reliability of a bonding portion (bonding pad portion) of a semiconductor element after the semiconductor device sealed with the resin composition is left at a high temperature (for example, 185 ° C.). (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-55-1469) is used.
No. 50) and a method of combining antimony oxide and organic phosphine (Japanese Patent Application Laid-Open No. 61-53321) have been studied, but have not yet reached the required level of high-temperature storage characteristics for recent semiconductor devices. is the current situation.

[0003]

SUMMARY OF THE INVENTION The present invention relates to an epoxy resin composition having excellent high-temperature storage characteristics and an excellent balance between high-temperature storage characteristics and flame retardancy, and a method for encapsulating a semiconductor element using the same. A semiconductor device is provided.

[0004]

The present invention provides (A) an epoxy resin, (B) a phenolic resin, (C) 0.1 to 5% by weight of activated carbon in the total epoxy resin composition, and (D) an inorganic filler. Material, (E) a hardening accelerator, (F) 0.1 to 5% by weight of bismuth oxide hydrate in the total epoxy resin composition, and (G) a brominated epoxy resin as essential components. The diameter is 10 to 100 μm, the specific surface area by BET method is 800
An epoxy resin composition of about 3500 m ² / g and a semiconductor device obtained by sealing a semiconductor element using the same.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The epoxy resin used in the present invention is:
There is no particular limitation as long as it has an epoxy group in the molecule, for example, orthocresol novolak type epoxy resin, phenol novolak type epoxy resin, triphenolmethane type epoxy resin, bisphenol type epoxy resin, biphenyl type epoxy resin, stilbene type An epoxy resin, a dicyclopentadiene-modified phenol type epoxy resin, a naphthalene type epoxy resin and the like can be mentioned, and these may be used alone or in combination. For the curability of the resin composition, the epoxy equivalent is desirably 150 to 300.

The phenolic resin used in the present invention is not particularly limited as long as it has a phenolic hydroxyl group in the molecule. Examples thereof include phenol novolak resin, phenol aralkyl resin, triphenolmethane type resin, and modified resins thereof. And these may be used alone or as a mixture. For the curability of the resin composition, the hydroxyl equivalent is preferably from 80 to 250.

[0007] The activated carbon used in the present invention is not particularly limited as long as it is used as an adsorbent, and examples thereof include vegetable, petroleum-based, and coal-based. The average particle size is 10 to 100 μm, the specific surface area is 800 to
Those having 3500 m ² / g are preferred. Average particle size is 10μ
If it is less than m, the fluidity may be reduced, and if it exceeds 100 μm, the mold gate may be blocked at the time of molding, and unfilling failure may occur. Also, less adsorption effect required high-temperature storage characteristics specific surface area and less than 800m ² / g, 3500m ² /
If it exceeds g, the fluidity may be reduced. The content of the activated carbon is 0.1 to 5% by weight in the whole resin composition.
Is preferred. If it is less than 0.1% by weight, the effect on high-temperature storage characteristics is small, and if it exceeds 5% by weight, flame retardancy, which is indispensable as a sealing material characteristic, is not satisfied, and fluidity is undesirably reduced.

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 is not particularly limited as long as it can promote the reaction between the epoxy resin and the phenol resin. For example, 1,8-diazabicyclo (5,4,0) undecene-7, Amine compounds such as butylamine, triphenylphosphine, organic phosphorus compounds such as tetraphenylphosphonium / tetraphenylborate, imidazole compounds such as 2-methylimidazole, and the like. Good.

The bismuth oxide hydrate used in the present invention is a hydronitrate nitrate, for example, BiO _x (OH) _y (N
_{O 3) z, SbBi w O} x (OH) y (NO 3) z · nH 2 O,
SbSi _v Bi _w O _x (OH) _y (NO ₃ ) _z · nH ₂ O,
(V, w, x, y, and z are positive numbers, and n is a positive integer), and these may be used alone or in combination. By using these in combination with the activated carbon of the present invention, bromine ions released from the brominated epoxy resin can be captured and reduced in weight, so that high-temperature storage characteristics and flame retardancy can be easily balanced, and high-temperature storage characteristics are also improved. improves. By using the activated carbon of the present invention and bismuth oxide hydrate in combination, it is not clear why, but bromine ions can be trapped more effectively than when each is used alone. The compounding amount of the bismuth oxide hydrate of 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 effect as a bromine ion scavenger cannot be exerted, so that the high-temperature storage characteristics are not satisfied.

The brominated epoxy resin used in the present invention includes, for example, a brominated phenol novolak type epoxy resin and a brominated bisphenol A type epoxy resin, and these may be used alone or as a mixture. The compounding amount of the brominated epoxy resin is desirably 0.1 to 3% by weight of the total amount of bromine in the resin composition. Epoxy equivalent is 200
~ 450 is desirable.

The resin composition of the present invention comprises, in addition to the components (A) to (G), a mold release agent such as a flame retardant other than a bromine compound, a silane coupling agent, a coloring agent, a natural wax or a synthetic wax, if necessary. 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 components (A) to (G) and other additives at room temperature using a mixer, kneading with a kneading machine such as a roll or an extruder, cooling, and pulverizing. 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.

[0013]

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 A (ESCN-1 manufactured by Sumitomo Chemical Co., Ltd.)
95 LA, softening point 65 ° C., epoxy equivalent 200) Epoxy resin B (YX- manufactured by Yuka Shell Epoxy Co., Ltd.)
4000, melting point 105 ° C., epoxy equivalent 195) phenol resin (phenol novolak resin, softening point 9)
Activated carbon (coconut shell activated carbon manufactured by Kansai Thermochemical Co., Ltd., average particle diameter: 60 μm, specific surface area: 1200 m ² / g) Inorganic filler (fused spherical silica, average particle diameter: 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) Bismuth oxide hydrate (IXE-50 manufactured by Toagosei Co., Ltd.)
0S) Brominated epoxy resin (Epiclon 153 manufactured by Dainippon Ink and Chemicals, Inc., softening point 70 ° C., epoxy equivalent 40)
0, bromine content 48% by weight) Silane coupling agent carbon black carnauba wax

Example 1 Epoxy resin A 90 parts by weight Phenol novolak resin 50 parts by weight coconut shell activated carbon 10 parts by weight Fused spherical silica 800 parts by weight DBU 3 parts by weight Bismuth oxide hydrate 30 parts by weight Brominated epoxy resin 10 parts by weight Silane 6 parts by weight of a coupling agent, 4 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: Measurement was performed 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. Curability: Using a low-pressure transfer molding machine, a test piece prepared at a mold temperature of 175 ° C. and a pressure of 70 kg / cm ² was read with a Shore D hardness tester for a hardness of 10 seconds after the mold was opened, and a hardness of less than 80 was used. Those were judged to be defective. 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 185 ° C., and the electrical resistance of the package wiring 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.

Examples 2 to 7 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 5 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.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

According to the present invention, excellent high-temperature storage characteristics are obtained.
In addition, a semiconductor device having an extremely excellent balance between high-temperature storage characteristics and flame retardancy can be obtained.

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Claims (3)

[Claims] 1. An epoxy resin, (B) a phenolic resin, (C) 0.1 to 5% by weight of activated carbon in the total epoxy resin composition, (D) an inorganic filler, and (E) a curing accelerator. ,
(F) An epoxy resin composition comprising, as essential components, 0.1 to 5% by weight of bismuth oxide hydrate in the total epoxy resin composition and (G) a brominated epoxy resin. 2. The activated carbon has an average particle size of 10 to 100 μm,
The epoxy resin composition according to claim 1, wherein by the BET method is a specific surface area 800~3500m ² / g. 3. A semiconductor device comprising a semiconductor element encapsulated with the epoxy resin composition according to claim 1.