JP2006089670A - Epoxy resin composition and semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy resin composition for use in semiconductor encapsulation which does not contain such a large-sized aggregate of an electrically-conductive matter of carbon black and the like as to cause an electrical fault such as the short circuit or leak in the wiring for a semiconductor chip. <P>SOLUTION: The epoxy resin composition is characterized by containing the essential ingredients of (A) an epoxy resin, (B) a phenol resin, (C) an inorganic filler, (D) a cure accelerator, (E) a coloring material and (F) an allyl ether copolymer; and this epoxy resin composition contains the above allyl ether copolymer of preferably 0.1-1% by weight relative to the whole epoxy resin composition; and also the semiconductor device is formed by encapsulating a semiconductor element by using these. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an epoxy resin composition and a semiconductor device, and in particular, there are no coarse aggregates of a conductive material such as carbon black that causes electrical failure such as short circuit of a semiconductor chip wiring or leakage failure, and has electrical characteristics. The present invention relates to a highly reliable epoxy resin composition for semiconductor encapsulation and a semiconductor device.

  Conventionally, an epoxy resin composition used for semiconductor encapsulation generally contains carbon black having conductivity as a colorant in the composition. This is because the semiconductor element is shielded, and when marking the product name, lot number, or the like on the semiconductor device, a clearer print can be obtained if the background is black. Recently, an increasing number of electronic component manufacturers adopt YAG laser marking, which is easy to handle, and carbon black that absorbs the wavelength of YAG laser is an essential component of epoxy resin for semiconductor encapsulation.

However, due to the recent trend toward finer pitches in semiconductor devices, when carbon black, which is a conductive colorant, is present as coarse aggregates between inner leads and between wires, electrical characteristics such as wiring short-circuit defects and leakage defects are poor. Will occur. Further, when coarse aggregates such as carbon black are sandwiched between the narrowed wires, the wires are subjected to stress, which also causes electrical characteristics defects. Development of an epoxy resin composition that is free of coarse aggregates such as carbon black and that enables clear YAG laser marking is desired.
It has been reported that carbon black with a controlled particle size is effective as a countermeasure against poor electrical characteristics (for example, see Patent Document 1). In addition, a method of dispersing carbon black aggregates has also been reported (see, for example, Patent Document 2), but it is not sufficient for further fine pitching in recent years, and shorting of wiring and leakage failure are not sufficient. There is a problem. Development of an epoxy resin composition using carbon black without coarse aggregates is strongly desired.
JP 2001-19833 (pages 2 to 4) JP 2000-169676 A (pages 2 to 5)

  The present invention has been made to solve the problems of the conventional background art, and its purpose is to conduct electrical conductivity such as carbon black which causes electrical defects such as short-circuiting of a semiconductor chip and leakage defects. An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation that does not have coarse aggregates of the product, and a semiconductor device using the same.

The present invention
[1] Characteristically comprising (A) an epoxy resin, (B) a phenol resin, (C) an inorganic filler, (D) a curing accelerator, (E) a colorant, and (F) an allyl ether copolymer. Epoxy resin composition,
[2] The epoxy resin composition according to item [1], wherein the allyl ether copolymer is contained in an amount of 0.1 to 1% by weight based on the total epoxy resin composition.
[3] A semiconductor device comprising a semiconductor element sealed using the epoxy resin composition according to the item [1] or [2],
It is.

  According to the present invention, there is no coarse aggregate of conductive material such as carbon black which causes electrical failure such as short circuit of a semiconductor chip wiring and leakage failure that could not be obtained by the prior art, and excellent electrical property reliability. An epoxy resin composition and a semiconductor device can be obtained.

In the present invention, an epoxy resin, a phenol resin, an inorganic filler, a curing accelerator, a colorant, and an allyl ether copolymer are essential components. Preferably, the allyl ether copolymer is 0.1 to 1 weight based on the total epoxy resin composition. By blending, the electrical characteristics such as carbon black, which cause electrical failures such as short circuiting of semiconductor chips and leakage failures, which cannot be obtained with the prior art, are eliminated, and the electrical characteristics are highly reliable. An epoxy resin composition and a semiconductor device can be obtained.
Hereinafter, the present invention will be described in detail.

  The epoxy resin used in the present invention is a monomer, oligomer or polymer in general having two or more epoxy groups in the molecule, and its molecular weight and molecular structure are not particularly limited. For example, bisphenol A type epoxy resin, ortho Cresol novolac type epoxy resin, naphthol novolak type epoxy resin, phenol aralkyl type epoxy resin having phenylene skeleton, biphenylene skeleton, dicyclopentadiene modified phenol type epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, etc. Can be used alone or in combination. In consideration of moisture resistance reliability as an epoxy resin composition for semiconductor encapsulation, it is preferable that Na ions and Cl ions as ionic impurities are as small as possible, and an epoxy equivalent is preferably 100 to 500 g / eq from the viewpoint of curability. .

  The phenol resin used in the present invention includes monomers, oligomers, and polymers in general having two or more phenolic hydroxyl groups in the molecule, and the molecular weight and molecular structure are not particularly limited. For example, phenol novolak resin, phenylene skeleton , A phenol aralkyl resin having a biphenylene skeleton, a terpene-modified phenol resin, a dicyclopentadiene-modified phenol resin, and the like. These can be used alone or in combination. From the viewpoint of curability, the hydroxyl equivalent is preferably 90 to 250 g / eq.

  Examples of the inorganic filler used in the present invention include fused silica, spherical silica, crystalline silica, alumina, silicon nitride, and aluminum nitride that are generally used for sealing materials. The particle size of the inorganic filler is desirably 150 μm or less in consideration of the filling property to the mold. Further, the filling amount of the inorganic filler is preferably 80 to 94% by weight with respect to the entire epoxy resin composition. The cracking property may be inferior, and if the upper limit is exceeded, the fluidity is impaired, which may cause a problem in moldability, which is not preferable.

  The curing accelerator used in the present invention is not particularly limited as long as it accelerates the reaction between an epoxy group and a phenolic hydroxyl group, and those generally used for sealing materials can be used. For example, diazabicycloalkenes such as 1,8-diazabicyclo (5,4,0) undecene-7 and derivatives thereof, organic phosphines such as triphenylphosphine, amine compounds such as benzyldimethylamine, 2-methylimidazole, etc. There are imidazole compounds and the like, and these may be used alone or in combination.

  As the colorant used in the present invention, those generally used for sealing materials can be used. For example, carbon black, iron oxide, organic dye, etc. are mentioned. These may be used alone or in combination.

In the present invention, an allyl ether copolymer is essential. The allyl ether copolymer acts on a conductive material such as carbon black and has an effect of preventing generation of coarse aggregates by improving its dispersibility. Although it does not specifically limit as an allyl ether copolymer used for this invention, The thing whose saponification value is 50-300 is desirable. If the lower limit of the saponification value is not reached, the dispersibility of the allyl ether copolymer itself may be lowered. If the upper limit is exceeded, the dispersibility of a conductive material such as carbon black may be lowered.
The amount of the allyl ether copolymer used in the present invention is not particularly limited, but it is preferably 0.1 to 1% by weight in the total epoxy resin composition. If the lower limit is not reached, sufficient dispersibility of the conductive material such as carbon black is not imparted, so there is a risk that the reduction of coarse agglomerates may not be observed, and if the upper limit is exceeded, the flowability of the epoxy resin composition is low. This is not preferable because it may be hindered.

The epoxy resin composition of the present invention has components (A) to (F) as essential components, but in addition to these, a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, an aluminum / zirconium cup Coupling agents such as ring agents, natural waxes such as carnauba wax, synthetic waxes such as polyethylene wax, mold release agents such as higher fatty acids such as stearic acid and zinc stearate and their metal salts or paraffin, silicone oil, silicone rubber, etc. Such additives as low-stress additives and inorganic ion exchangers such as bismuth oxide hydrate may be appropriately blended.
The epoxy resin composition of the present invention is obtained by uniformly mixing the components (A) to (F) and other additives at room temperature using a mixer or the like, and then melt-kneading with a heating roll or kneader, an extruder, etc. It can be manufactured by grinding after cooling.
In order to seal a semiconductor element and manufacture a semiconductor device using the epoxy resin composition of the present invention, it may be molded and cured by a molding method such as transfer molding, compression molding, or injection molding.

  The most important point of the present invention is that the inclusion of the allyl ether copolymer increases the dispersibility of the conductive material such as carbon black contained in the epoxy resin composition and does not generate coarse aggregates.

EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these. The blending ratio is parts by weight.
Example 1
Biphenyl type epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd., YX4000H, melting point 105 ° C., epoxy equivalent 195 g / eq) 8.1 parts by weight phenol novolak resin (softening point 65 ° C., hydroxyl group equivalent 104 g / eq)
4.0 parts by weight Spherical fused silica (average particle size 30 μm) 86.5 parts by weight Triphenylphosphine 0.2 parts by weight Carbon black (particle diameter 18 nm, specific surface area 140 m ² / g) 0.5 parts by weight Allyl ether copolymer A ( Made by Nippon Oil & Fats Co., Ltd., Marialim AKM-0531, saponification value 130) 0.5 part by weight Carnauba wax 0.2 part by weight is mixed at room temperature with a mixer, melt-kneaded with a heating roll at 80 to 100 ° C., cooled and pulverized An epoxy resin composition was obtained. The obtained epoxy resin composition was evaluated by the following methods. The results are shown in Table 1.

Spiral flow: Using a mold according to EMMI-1-66, measurement was performed at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and a pressure holding time of 120 seconds. The unit is cm. The criteria for determining the spiral flow were less than 110 cm as unacceptable and 110 cm or more as acceptable.
High-temperature leakage characteristics: 100 pieces of 144pTQFP with a die of 175 ° C, injection pressure of 7.8MPa, holding pressure of 90 seconds and a 60µm pitch test chip with a 30µm diameter metal wire using a low pressure transfer molding machine Sealed and molded. Next, leakage current was measured using a microammeter 8240A manufactured by ADVANTEST. The criterion was a failure when the leakage current at 175 ° C. was two orders of magnitude higher than the initial median value. When the number of defective products was n, it was displayed as n / 100.
Evaluation of agglomerates: Using a low-pressure transfer molding machine, a 100 mmφ disk was molded with a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and a holding time of 120 seconds. The surface of this disk was polished, and the polished surface was observed with a fluorescence microscope (Olympus Co., Ltd., BX51M-53MF). The number of aggregates of 80 μm or more was measured. A case where one or more aggregates of 80 μm or more were present was regarded as defective.

Examples 2-5, Comparative Example 1
An epoxy resin composition was produced in the same manner as in Example 1 and evaluated in the same manner. The evaluation results are shown in Table 1.
Allyl ether copolymer B in Table 1 (manufactured by NOF Corporation, Marialim AAB-0851) has a saponification number of 160.

  The epoxy resin composition for semiconductor encapsulation of the present invention has excellent dispersibility, and a semiconductor device using the epoxy resin composition does not cause short circuit of a wiring of a semiconductor chip, leakage failure, etc., and has excellent electrical property reliability. Therefore, it can be suitably used for electrical appliances, automobiles and the like.

Claims (3)

An epoxy resin comprising (A) an epoxy resin, (B) a phenol resin, (C) an inorganic filler, (D) a curing accelerator, (E) a colorant, and (F) an allyl ether copolymer. Composition. The epoxy resin composition according to claim 1, wherein the allyl ether copolymer is contained in an amount of 0.1 to 1% by weight based on the total epoxy resin composition. A semiconductor device comprising a semiconductor element sealed with the epoxy resin composition according to claim 1.