JPH07242738A - Epoxy resin composition and sealed semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin composition giving a cured sealing resin which is excellent in moisture resistance and adherence, suffers neither from debonding from a semiconductor chip or a lead frame nor internal cracking, has excellent anti-reflowing property, and is capable of ensuring long-term reliability. CONSTITUTION:This composition comprises as essential components an epoxy resin, a phenolic resin represented by the formula (wherein R is H or an alkyl and n is 0 or 1), an inorganic filler, and a curing accelerator, the amount of the filler being 25-90wt.% based on the whole composition. This device comprises a semiconductor chip sealed with a cured resin obtained from this composition.

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 moisture resistance, adhesiveness and reflow resistance, and a semiconductor encapsulation device.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductor integrated circuits,
At the same time as technology development for high integration and high reliability, automation of the mounting process of semiconductor devices is being promoted. For example, when mounting a flat package type semiconductor device on a circuit board, conventionally, soldering is performed for each lead pin, but recently, a solder dipping method or a solder reflow method has been adopted.

[0003]

A semiconductor device sealed with a conventional epoxy resin such as a novolac type epoxy resin, a dicyclopentadiene type phenolic resin and a resin composition composed of silica powder includes a sealing resin and a semiconductor chip, Alternatively, there is a drawback that peeling between the sealing resin and the lead frame and internal resin cracks occur, and in particular, the crack resistance during mounting is extremely poor.

The present invention has been made to solve the above-mentioned drawbacks and is excellent in moisture resistance and adhesiveness, and peeling between the sealing resin and the semiconductor chip or the sealing resin and the lead frame and the occurrence of internal resin cracks. And has excellent reflow resistance,
It is intended to provide an epoxy resin composition and a semiconductor encapsulation device capable of guaranteeing long-term reliability.

[0005]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above-mentioned object, the present inventor has found that the use of a specific phenol resin has excellent moisture resistance, adhesiveness, reflow resistance and the like. It was found that a resin composition can be obtained, and the present invention has been completed.

That is, the present invention relates to (A) epoxy resin,
(B) a phenolic resin represented by the following general formula,

[0007]

[Chemical 3] (Wherein R is a hydrogen atom or an alkyl group, and n is 0
Or (representing an integer of 1 or more) (C) an inorganic filler and (D) a curing accelerator as essential components, and the proportion of the inorganic filler (C) is 25 to 90% by weight with respect to the entire resin composition. It is an epoxy resin composition characterized by containing. A semiconductor encapsulation device is obtained by encapsulating a semiconductor chip with a cured product of this epoxy resin composition.

The present invention will be described in detail below.

As the epoxy resin (A) used in the present invention, those generally used for sealing can be widely used and are not particularly limited. As a specific compound, in addition to the epibis type epoxy resin, for example,

[0010]

[Chemical 4] (However, in the formula, n represents 0 or an integer of 1 or more)

[0011]

[Chemical 5] (Wherein n represents 0 or an integer of 1 or more) As the (B) phenol resin used in the present invention, a phenol resin obtained by a reaction of cyclohexanedione and phenols, that is, the above-mentioned general formula 3 The one shown in is used. As a specific compound, for example,

[0012]

[Chemical 6]

[0013]

[Chemical 7] Etc. In addition to this phenol resin, a novolac type phenol resin obtained by reacting phenols such as fail and alkylphenol with formaldehyde or paraformaldehyde and modified resins thereof can be used in combination.

As the inorganic filler (C) used in the present invention, generally used ones are widely used. Among them, silica powder having a low impurity concentration and an average particle diameter of 30 μm or less is preferably used. . If the average particle size exceeds 30 μm, the moisture resistance and moldability are poor, which is not preferable. The blending ratio of the inorganic filler is 25 to 90 with respect to the entire resin composition.
It is preferable to mix them so as to contain them by weight. When the proportion is less than 25% by weight, the hygroscopicity of the resin composition is high and the moisture resistance after solder immersion is poor, and when it exceeds 90% by weight, the fluidity is extremely deteriorated and the moldability is poor, which is not preferable.

As the curing accelerator (D) used in the present invention, a phosphorus curing accelerator, an imidazole curing accelerator, D
BU-based curing accelerators and other curing accelerators can be widely used. These can be used alone or in combination of two or more kinds. It is desirable that the curing accelerator is blended in an amount of 0.01 to 5% by weight based on the total resin composition. If the proportion is less than 0.01% by weight, the gel time of the resin composition will be long and the curing characteristics will be poor, and if it exceeds 5% by weight, the fluidity will be extremely poor and the moldability will be poor, and the electrical characteristics will also be poor and the moisture resistance will be poor. It is inferior in sex and is not preferable.

The epoxy resin composition of the present invention contains an epoxy resin, a specific phenolic resin, an inorganic filler and a curing accelerator as essential components, but within the range not deviating from the object of the present invention, and if necessary, for example, , Natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides,
A releasing agent such as esters or paraffin, a flame retardant such as antimony trioxide, a coloring agent such as carbon black, a silane coupling agent, a rubber-based or silicone-based low stress imparting agent, and the like can be appropriately added and blended.

A general method for preparing the epoxy resin composition of the present invention as a molding material is to add the above-mentioned epoxy resin, a specific phenol resin, an inorganic filler, a curing accelerator and other components to a mixer, etc. The mixture can be sufficiently uniformly mixed by means of the above method, and further subjected to melt mixing treatment with a hot roll or mixing treatment with a kneader or the like, and then cooled and solidified to be pulverized to an appropriate size to obtain a molding material.
When the molding material thus obtained is applied to sealing, coating, insulation, etc. of electronic parts or electric parts such as semiconductor devices, excellent properties and reliability can be imparted.

The semiconductor encapsulation device of the present invention can be easily manufactured by encapsulating a semiconductor chip using the above molding material. The semiconductor chip to be sealed is not particularly limited to, for example, an integrated circuit, a large scale integrated circuit, a transistor, a thyristor, a diode and the like. The most common method of sealing is a low-pressure transfer molding method, but sealing by injection molding, compression molding, casting or the like is also possible. After sealing with a molding material, it is heated and cured, and finally a semiconductor sealing device sealed with this cured product is obtained. For curing by heating, it is desirable to heat and cure at 150 ° C or higher.

[0019]

In the epoxy resin composition and the semiconductor encapsulation device of the present invention, the glass transition temperature of the resin composition is increased by using the epoxy resin and the specific phenol resin.
The thermo-mechanical properties, low stress and adhesiveness are improved, and the occurrence of resin cracks after solder immersion and solder reflow is eliminated.

[0020]

EXAMPLES Next, the present invention will be described with reference to examples, but the present invention is not limited to these examples. In the following examples and comparative examples, “%” means “% by weight”.

Example 1 10% of an epoxy resin represented by the following formula,

[0022]

[Chemical 8] 7.5% of phenolic resin represented by the following formula,

[0023]

[Chemical 9] 81% of silica powder, 0.2% of hardening accelerator, 0.3% of ester waxes and 1% of silane coupling agent are mixed at room temperature, further kneaded and cooled at 90 to 95 ° C, and then crushed to produce molding material (A). did.

Example 2 10% of the epoxy resin of Chemical formula 8 used in Example 1, 3.5% of the phenolic resin of Chemical formula 9 used in Example 1, 4% of novolac type phenolic resin, 81% of silica powder, 0.2% of curing accelerator %,
0.3% of ester waxes and silane coupling agent
1% was mixed at room temperature, further kneaded and cooled at 90 to 95 ° C., and then pulverized to produce a molding material (B).

Comparative Example 1 10% of the epoxy resin of Chemical formula 8 used in Example 1, 7.5% of dicyclopentadiene type phenolic resin represented by the following formula,

[0026]

[Chemical 10] 81% of silica powder, 0.2% of hardening accelerator, 0.3% of ester wax and 1% of silane coupling agent are mixed at room temperature, further kneaded and cooled at 90 to 95 ° C, and then crushed to produce molding material (C). did.

Comparative Example 2 10% of the epoxy resin of Chemical formula 8 used in Comparative Example 1, 5.5% of the phenolic resin of Chemical formula 10 used in Comparative Example 1, 2% of novolac type phenolic resin, 81% of silica powder, curing accelerator 0.2
%, Ester waxes 0.3% and silane coupling agent 1% were mixed at room temperature, further kneaded and cooled at 90 to 95 ° C., and then pulverized to produce a molding material (D).

Molding materials (A) to (D) thus produced
Was used to transfer transfer into a mold heated to 170 ° C., and the semiconductor chip was sealed and cured to manufacture a semiconductor sealing device. Various tests were conducted on these semiconductor encapsulation devices, and the results are shown in Table 1. The epoxy resin composition and the semiconductor encapsulation device of the present invention have excellent properties, and It was possible to confirm the remarkable effect of.

[0029]

[Table 1] * 1: Diameter 50 mm, thickness 3 mm by transfer molding
The molded product of No. 1 was prepared, and it was left in saturated steam at 127 ° C. and 2.5 atm for 24 hours and measured by the increased weight. * 2: Make a molded product similar to the case of water absorption, 175 ℃, 8
After post-curing for a certain time, a test piece of an appropriate size was prepared and measured using a thermomechanical analyzer. * 3: Tested according to JIS-K-6911. * 4 :: A 15x15mm dummy chip is replaced by a QFP (36x36x3.6
(mm) Packaged, transfer molded using the molding material for 2 minutes at 175 ° C, and then post-cured at 175 ° C for 8 hours. The semiconductor encapsulation device obtained in this way was used at 85 ℃, 85%, 16
After absorbing moisture for 8 hours, it was immersed in a solder bath at 240 ° C for 1 minute. After that, observe the package surface with a stereomicroscope,
The occurrence of external resin cracks was evaluated.

[0030]

As is clear from the above description and Table 1, the epoxy resin composition and the semiconductor encapsulating device of the present invention have excellent moisture resistance and adhesiveness, and are superior in encapsulating resin and semiconductor chip or encapsulating resin. There is no peeling from the lead frame or internal resin cracks, excellent reflow resistance, and long-term reliability can be guaranteed.

Claims (2)

[Claims] 1. An epoxy resin (A), a phenol resin represented by the following general formula (B), and (Wherein R is a hydrogen atom or an alkyl group, and n is 0
Or (representing an integer of 1 or more) (C) an inorganic filler and (D) a curing accelerator as essential components, and the proportion of the inorganic filler (C) in the whole resin composition is 25 to 90% by weight. An epoxy resin composition comprising: 2. An epoxy resin (A), a phenol resin represented by the following general formula (B), and (However, in the formula, R represents a hydrogen atom, an alkyl group, and n represents an integer of 0 or 1 or more.) (C) An inorganic filler and (D) a curing accelerator are essential components, and the entire resin composition is used. On the other hand, a semiconductor encapsulation device in which a semiconductor chip is encapsulated by a cured product of an epoxy resin composition containing the inorganic filler (C) in a proportion of 25 to 90% by weight.