JPH0790048A - Epoxy resin composition and device for sealing semiconductor - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in moisture resistance and soldering heat resistance, little in the affection with absorbed moisture, not generating the breakage of wires due to the corrosion of electrodes, and suitable for sealing semiconductor chips, etc., by modifying a specific epoxy resin and a phenol resin as a curing agent with a specified polyimide resin. CONSTITUTION:This composition comprises (A) an epoxy resin of formula I [R<1> is CjH2j+1; R<2> is CkH2k+1; R<3> is ClH21+1; R<4> is CmH2m+1 (j), (k), (l), (m), (n) is 0 or an integer of >=1)], (B) a phenol resin, (C) a polyimide resin of formula II (R<5> is ClH21+1; R<6> is CmH2m+1) and (D) an inorganic filler as essential components, the content of the component D being 25-95wt.% based on the resin 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 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 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 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, is particularly excellent in moisture resistance and solder heat resistance after immersion in a solder bath, and has a sealing resin and a semiconductor chip or sealing. 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 aimed at achieving the above object, the present inventors have found that a specific epoxy resin and a phenol resin are used as a curing agent and modified with a specific polyimide resin. It was found that a resin composition having excellent moisture resistance and solder heat resistance can be obtained by the above, and the present invention has been completed.

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

[0007]

[Chemical 5] (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, m and n in each group are 0.
Or represents an integer of 1 or more) (B) phenol resin, (C) polyimide resin represented by the following general formula, and

[0008]

[Chemical 6] (However, in the formula, R ⁵ is a C ₁ H _{2l + 1} group, and R ⁶ is a C _m H _{2m + 1 group.}
Each represents a group, and l and m in each group represent 0 or an integer of 1 or more) (D) The inorganic filler is an essential component, and the inorganic filler of (D) is added to the resin composition in an amount of 25 to 90. The epoxy resin composition is characterized in that it is contained in a weight percentage. 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, the one represented by the above general formula 5 is used, and it can be used without being limited by its molecular weight and the like. Specific compounds include, for example:

[0011]

[Chemical 7] (However, in the formula, n represents 0 or an integer of 1 or more)

[0012]

[Chemical 8] (However, in the formula, n represents 0 or an integer of 1 or more)

[0013]

[Chemical 9] (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.

The (B) phenolic resin used in the present invention is not particularly limited, and a novolak type phenolic resin obtained by reacting phenols such as fail and alkylphenol with formaldehyde or paraformaldehyde, and their modification. Resin, or other generally known phenol resin can be used.

As the (C) polyimide resin used in the present invention, the one represented by the above general formula 6 can be used. Specific compounds include, for example:

[0016]

[Chemical 10] Etc. can be mentioned.

As the inorganic filler (D) used in the present invention, those generally used for molding materials are widely used. Among them, the impurity concentration is low and the average particle size is 30.
Silica powder having a size of less than μm is preferably used. Average particle size 3
If it exceeds 0 μm, the moisture resistance and the moldability are deteriorated, which is not preferable. The blending ratio of the inorganic filler is preferably 25 to 90% by weight based on the total resin composition. 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 epoxy resin, phenolic resin, specific polyimide resin and inorganic filler as essential components, but it is also necessary as long as it does not violate the object of the present invention. Accordingly, for example, natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, release agents 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, and the like can be appropriately added and blended.

The general method for preparing the epoxy resin composition of the present invention as a molding material is to blend the above-mentioned specific epoxy resin, phenol resin, specific polyimide resin, inorganic filler and other components, and blend with a mixer. And the like, followed by melt-mixing treatment with a hot roll or mixing treatment with a kneader, and then cooling and solidifying to pulverize to an appropriate size to obtain a molding material. The molding material thus obtained is used for sealing and covering electronic components such as semiconductor devices or electrical components.
If applied to insulation or the like, excellent characteristics 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. The curing by heating is preferably performed by heating to 150 ° C.

[0021]

The epoxy resin composition and the semiconductor encapsulation device of the present invention have the glass transition temperature of the resin composition increased by using a specific epoxy resin, a phenol resin, and a specific polyimide resin, and have a thermomechanical property. The low-stress property is improved, the generation of resin cracks after solder immersion and solder reflow is eliminated, and the deterioration of moisture resistance is reduced.

[0022]

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 9.0% of the epoxy resin of the above chemical formula 7, 4.0% of the phenol resin represented by the following chemical formula 11,

[0024]

[Chemical 11] (However, in the formula, n represents 0 or an integer of 1 or more.) 5% of the polyimide resin of Chemical formula 10 described above and silica powder 81
%, Curing accelerator 0.3%, ester waxes 0.3% and silane coupling agent 0.4% are mixed at room temperature, and
After kneading and cooling at 90 to 95 ° C., the mixture was pulverized to produce a molding material (A).

Example 2 6.0% of the epoxy resin of Chemical formula 7 used in Example 1, Example 1
2.0% of the phenol resin of Chemical formula 11 used in Example 1, 10% of the polyimide resin of Chemical formula 10 used in Example 1, 81% of silica powder, 0.3% of curing accelerator, 0.3% of ester waxes and 0.4% of silane coupling agent at room temperature. And mix for 90-95
After kneading and cooling at 0 ° C., it was pulverized to produce a molding material (B).

Comparative Example 1 o-Cresol novolak 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 Epibis type epoxy resin (epoxy equivalent 450) 20%, novolac type phenol resin 5%, silica powder 74%, curing accelerator 0.3%, ester waxes 0.3% and silane coupling agent 0.4% were used at room temperature. And mix at 90-95 ℃
After kneading and cooling with, the mixture was 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 are excellent in moisture resistance and solder heat resistance. The remarkable effect of the invention could be confirmed.

[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: Using a molding material, a silicon chip with two or more aluminum wires is bonded to a normal 42 alloy frame and transfer molded 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 at 40 ° C., 90% RH for 100 hours in advance, 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: QFP (14 × 14 × 1.4m) with 8 × 8mm dummy chip
m) The package was placed, transfer molding was performed for 2 minutes at 175 ° C using the molding material, and post-curing was performed at 175 ° C for 8 hours. The semiconductor encapsulation device obtained in this way was used at 85 ℃, 85%, 24
After absorbing moisture for a period of time, 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.

[0030]

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. ⁶ Identification code Internal reference number FI technical display location H01L 23/31

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, m and n in each group are 0.
Or represents an integer of 1 or more) (B) Phenolic resin, (C) Polyimide resin represented by the following general formula, and (However, in the formula, R ⁵ is a C ₁ H _{2l + 1} group, and R ⁶ is a C _m H _{2m + 1 group.}
Each represents a group, and l and m in each group represent 0 or an integer of 1 or more) (D) The inorganic filler is an essential component, and the inorganic filler of (D) is added to the resin composition in an amount of 25 to 90. An epoxy resin composition, characterized in that it is contained in a weight percentage. 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, m and n in each group are 0.
Or represents an integer of 1 or more) (B) a phenol resin, (C) a polyimide resin represented by the following general formula, and (However, in the formula, R ⁵ is a C ₁ H _{2l + 1} group, and R ⁶ is a C _m H _{2m + 1 group.}
Each represents a group, and l and m in each group represent 0 or an integer of 1 or more) (D) The inorganic filler is an essential component, and the inorganic filler of (D) is added to the resin composition in an amount of 25 to 90. A semiconductor encapsulation device, which is obtained by encapsulating a semiconductor chip with a cured product of an epoxy resin composition contained in a weight percentage.