JPH0665353A - Epoxy resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in humidity and soldering- heat resistances by mixing a specified epoxy resin with 1,6-dihydroxynaphthalene and a specified amount of an inorganic filler as the essential components. CONSTITUTION:The objective resin composition essentially consists of an epoxy resin of the formula (wherein R<1> is CjH2j+1; R<2> is CkH2k+1; R<3> is ClH2l+1; R<4> is CmH2m+1; and (j), (k), (l), (m) and (n) are each 0 or greater), 1,6- dihydroxynaphthalene and 25-90wt.%, based on the whole composition, inorganic filler (e.g. silica powder).

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 and solder heat 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 a flat package type semiconductor device is attached to a circuit board, soldering is conventionally 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 resin composition comprising an epoxy resin such as a novolac type epoxy resin, a novolac type phenolic resin and silica powder has a moisture resistance when the entire device is immersed in a solder bath. There was a drawback that the property deteriorated. Especially when a semiconductor device that has absorbed moisture is immersed, peeling between the encapsulating resin and the semiconductor chip, or between the encapsulating resin and the lead frame, and internal resin cracks cause significant deterioration in moisture resistance, which may cause wire breakage or moisture due to electrode corrosion. Leakage current, resulting in
The semiconductor device has a drawback in that it cannot guarantee long-term reliability.

The present invention has been made in order to solve the above-mentioned drawbacks, has little influence of moisture absorption, and is particularly excellent in moisture resistance and solder heat resistance after being immersed in a solder bath. Epoxy resin composition and semiconductor encapsulation device capable of ensuring long-term reliability without peeling of resin and lead frame or generation of internal resin cracks, disconnection due to electrode corrosion or leakage current due to moisture It is what

[0005]

Means for Solving the Problems As a result of intensive studies to achieve the above-mentioned object, the present inventors have found that by using a specific epoxy resin and a specific phenol as a curing agent, moisture resistance, solder The present invention has been completed by finding that a resin composition having excellent heat resistance can be obtained.

That is, the present invention provides (A) an epoxy resin represented by the following general formula:

[0007]

[Chemical 3] (However, in the formula, R ¹ is a C _j H _{2j + 1} group, and R ² is C _k H _{2k + 1.}
R ³ represents a C ₁ H _{2l + 1} group, R ⁴ represents a C _m H _{2m + 1} group, and j, k, l and m and n in each group are
0 or an integer of 1 or more) (B) 1,6-dihydroxynaphthalene and (C) an inorganic filler as essential components, and the resin composition contains the inorganic filler of (C) in an amount of 25 to 90% by weight. The epoxy resin composition is characterized in that it is contained at a ratio of. A semiconductor encapsulation device is obtained by encapsulating a semiconductor device 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, the one represented by the above-mentioned general formula 3 is used, and it can be used without being restricted by its molecular weight and the like. As a specific compound, 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) and the like, and these can be used alone or in combination. In addition, a novolac-based epoxy resin, an epibis-based epoxy resin, and other generally known epoxy resins can be used in combination with this epoxy resin.

As the phenolic curing agent used in the present invention, (B) 1,6-dihydroxynaphthalene represented by the following formula is used.

[0013]

[Chemical 6] The (B) 1,6-dihydroxynaphthalene may be used in combination with a novolac type phenol resin obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde and modified resins thereof.

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.

The epoxy resin composition of the present invention contains the above-mentioned specific (A) epoxy resin, specific curing agent (B) 1,6-dihydroxynaphthalene and (C) inorganic filler as essential components. To the extent that it does not violate the purpose of the invention,
If necessary, for example, natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides, esters,
A release agent such as paraffin, a flame retardant such as antimony trioxide, a colorant such as carbon black, a silane coupling agent, various curing accelerators, a rubber-based or silicone-based low stress imparting agent, etc. are appropriately added and blended. be able to.

The general method for preparing the epoxy resin composition of the present invention as a molding material is as follows: the specific (A) epoxy resin, the specific curing agent (B) 1,6-dihydroxynaphthalene, and (C). After mixing inorganic filler and other components and mixing them sufficiently evenly with a mixer, etc., melt mixing with a hot roll or mixing with a kneader etc., then cooling and solidifying and crushing to an appropriate size and molding It can be a material. If the molding material thus obtained is applied to sealing, coating, insulation, etc. of electronic parts or electric parts including semiconductor devices,
It is possible to impart excellent characteristics and reliability.

The semiconductor encapsulation device of the present invention can be easily manufactured by encapsulating a semiconductor chip using the above molding material. As a semiconductor device for sealing,
For example, an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, etc. are not particularly limited.
The most general 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 molding material, heat and cure,
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.

[0018]

The epoxy resin composition and the semiconductor encapsulation device of the present invention include the above-mentioned specific epoxy resin, specific curing agent 1,
By using 6-dihydroxynaphthalene, the glass transition temperature of the resin composition rises, the thermomechanical properties and low stress properties are improved, the occurrence of resin cracks after solder immersion and solder reflow is eliminated, and moisture resistance deterioration It will be less.

[0019]

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 Epoxy resin 10% represented by the following chemical formula 7,

[0021]

[Chemical 7] 90% to 95% of 1,6-dihydroxynaphthalene 4%, silica powder 85%, curing accelerator 0.3%, ester waxes 0.3% and silane coupling agent 0.4% are mixed at room temperature.
After kneading and cooling at 0 ° C., it was pulverized to produce a molding material (A).

Example 2 Epoxy resin of the same chemical formula 7 used in Example 1 10%, 1,6-
2.1% dihydroxynaphthalene, 2.1% novolak type phenolic resin, 84.8% silica powder, 0.3% curing accelerator,
0.3% of ester waxes and silane coupling agent
After mixing 0.4% at room temperature and kneading at 90-95 ℃,
The material was crushed to produce a molding material (B).

Comparative Example 1 o-Cresol novolac type epoxy resin 17%, novolac type phenol resin 8%, silica powder 74%, curing accelerator
0.3%, ester waxes 0.3%, and silane coupling agent 0.4% were mixed at room temperature, further kneaded and cooled at 90 to 95 ° C., and then pulverized to produce a molding material (C).

Comparative Example 2 20% of epibis type epoxy resin (epoxy equivalent 450),
Novolak type phenolic resin 5%, silica powder 74%, hardening accelerator 0.3%, ester waxes 0.3% and silane coupling agent 0.4% are mixed at room temperature and then 90-95%.
After kneading and cooling at 0 ° C., it was pulverized to produce a molding material (D).

Molding materials (A) to (D) thus produced
Transfer injection was carried out into a mold heated to 170 ° C. by using, and cured to seal a semiconductor chip to manufacture a semiconductor sealing device. Various tests were performed 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 moisture resistance and solder heat resistance, It was possible to confirm the remarkable effect of the present invention.

[0026]

[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: Using a molding material, attach a silicon chip with two or more aluminum wires to a normal 42 alloy frame and transfer mold at 175 ° C for 2 minutes.
Post-curing was performed at 175 ° C for 8 hours. The molded product thus obtained is subjected to moisture absorption treatment in advance at 40 ° C., 95% RH for 100 hours, and then
It was immersed in a solder bath at 250 ° C for 10 seconds. After that, 127 ℃,
PCT was performed in saturated steam of 2.5 atm and 50% disconnection due to corrosion of aluminum was evaluated as defective. * 5: A dummy chip of 8 x 8 mm is used for QFP (14 x 14 x 1.4 m
m) The product was placed in a package, transfer molded at 175 ° C for 2 minutes using the molding material, and then post-cured at 175 ° C for 8 hours. The semiconductor encapsulation device obtained in this way is 85 ℃, 85%,
After absorbing moisture for 24 hours, it was immersed in a solder bath at 240 ° C for 1 minute. Then, the package surface was observed with a stereoscopic microscope to evaluate the presence or absence of external resin cracks.

[0027]

As is clear from the above description and Table 1, the epoxy resin composition and the semiconductor encapsulation device of the present invention have excellent moisture resistance and solder heat resistance, are less affected by moisture absorption, and are not affected by electrode corrosion. It is possible to remarkably reduce the generation of leakage current due to disconnection and moisture, and it is possible to guarantee the reliability for a long period of time.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 23/31 // B29K 63:00

Claims (2)

[Claims] 1. An epoxy resin represented by the following general formula (A): (However, in the formula, R ¹ is a C _j H _{2j + 1} group, and R ² is C _k H _{2k + 1.}
R ³ represents a C ₁ H _{2l + 1} group, R ⁴ represents a C _m H _{2m + 1} group, and j, k, l and m and n in each group are
0 or an integer of 1 or more) (B) 1,6-dihydroxynaphthalene and (C) an inorganic filler as essential components, and the resin composition contains the inorganic filler of (C) in an amount of 25 to 90% by weight. An epoxy resin composition, characterized in that it is contained at a ratio of. 2. An epoxy resin represented by the following general formula (A): (However, in the formula, R ¹ is a C _j H _{2j + 1} group, and R ² is C _k H _{2k + 1.}
R ³ represents a C ₁ H _{2l + 1} group, R ⁴ represents a C _m H _{2m + 1} group, and j, k, l and m and n in each group are
0 or an integer of 1 or more) (B) 1,6-dihydroxynaphthalene and (C) an inorganic filler as essential components, and 25 to 90% by weight of the (C) inorganic filler with respect to the resin composition. A semiconductor encapsulation device, which is obtained by encapsulating a semiconductor chip with a cured product of an epoxy resin composition contained at a ratio of.