JPH0665357A - Epoxy resin composition and semiconductor device - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in heat, humidity and soldering-heat resistances by using an epoxy resin, a novolac phenolic resin, a specified alkoxysilane, a specified silane coupling agent and a specified filler as the essential components and specifying the amounts of the latter three components used. CONSTITUTION:The objective resin composition essentially consists of an epoxy resin (e.g. cresol novolac epoxy resin), a novolac phenolic resin, 0.01-5.0wt.% silane having alkoxyl at each terminal and represented by formula I or II (wherein R<1> is alkoxyl; R<2> and R<3> are each alkyl or phenyl; and (m) is 1 or greater), 0.01-5.0wt.% silane coupling agent of formula III (wherein R is alkyl) and 25-90wt.% 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 good moldability, 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 to a circuit board, conventionally, each lead pin was soldered, but recently, the entire semiconductor device is dipped in a solder bath heated to 250 ° C and soldered at once. The way to do is done.

[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. In particular, when a semiconductor device that has absorbed moisture is immersed, peeling occurs between the encapsulating resin and the semiconductor chip, or the encapsulating resin and the lead frame, causing significant moisture resistance deterioration, causing wire breakage due to electrode corrosion and leakage current due to moisture, As a result, the semiconductor device has a drawback that it cannot guarantee long-term reliability.

The present invention has been made to solve the above-mentioned drawbacks, and has high heat resistance, particularly excellent moisture resistance and solder heat resistance after immersion in a solder bath, and a sealing resin and a semiconductor chip or a sealing resin. To provide an epoxy resin composition and a semiconductor encapsulation device which can ensure long-term reliability without peeling off from a lead frame and a lead frame, without causing wire breakage due to corrosion of electrodes or generation of leakage current due to moisture, and ensuring long-term reliability. Is.

[0005]

Means for Solving the Problems As a result of earnest studies to achieve the above object, the present inventor has improved moisture resistance and solder heat resistance by using a specific alkoxysilane or silane coupling agent. It was found that a resin composition having excellent properties can be obtained, and the present invention has been completed.

That is, the present invention relates to (A) epoxy resin,
(B) novolac type phenolic resin, (C) both-end alkoxysilane represented by the following general formula,

[0007]

[Chemical 5] (In the formula, R ¹ represents an alkoxyl group, R ² and R ³ represent an alkyl group or a phenyl group, and m represents an integer of 1 or more.) (D) A silane coupling agent represented by the following formula and

[0008]

[Chemical 6] (Wherein R represents an alkyl group) (E) An inorganic filler is an essential component, and 0.01 to 5.0 of the both-end alkoxysilane of the above (C) is added to the resin composition.
% By weight of the silane coupling agent (D) above 0.01-
5.0% by weight and 25 to 90% by weight of the inorganic filler (E)
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.

The (A) epoxy resin used in the present invention is not particularly limited in molecular structure and molecular weight as long as it is a compound having at least two epoxy groups in its molecule, and it is generally used as a sealing material. It can be broadly included. Examples thereof include bisphenol type aromatic resins, aliphatic compounds such as cyclohexane derivatives, and epoxy novolac resins represented by the following general formula.

[0011]

[Chemical 7] (In the formula, R ¹ represents a hydrogen atom, a halogen atom or an alkyl group, R ² represents a hydrogen atom or an alkyl group, and n represents an integer of 1 or more.) These epoxy resins may be used alone or in combination. be able to.

The novolak type phenolic resin (B) used in the present invention is a novolac type phenolic resin obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and modified resins thereof, such as epoxidized or Butylated novolac type phenolic resin and the like can be used, and these can be used alone or in combination.
The compounding ratio of the novolac type phenol resin is the same as the above (A).
It is desirable that the molar ratio [(a) / (b)] of the epoxy group (a) of the epoxy resin of (1) and the phenolic hydroxyl group (b) of the novolak type phenolic resin of (B) be within the range of 0.1 to 10. . When the molar ratio is less than 0.1 or more than 10, the heat resistance, moisture resistance, molding workability and electrical properties of the cured product deteriorate, which is not preferable.

The (C) both-terminal alkoxysilane used in the present invention is represented by the above general formula 5, and specific compounds include, for example,

[0014]

[Chemical 8] Etc., and these can be used alone or in combination. The mixing ratio of the alkoxysilanes at both ends is
It is desirable to add 0.01 to 5.0% by weight to the whole resin composition. If this ratio is less than 0.01% by weight, the moisture resistance is not effective, and if it exceeds 5.0% by weight, the deterioration of the resin strength under heat and the moldability are adversely affected.
Not suitable for practical use.

As the silane coupling agent (D) used in the present invention, those represented by the following formula are used.

[0016]

[Chemical 9] (However, in the formula, R represents an alkyl group) The compounding ratio of this silane coupling agent is 0.0 with respect to the entire resin composition.
It is desirable that the content be 1 to 5.0% by weight. If the proportion is less than 0.01% by weight, the moisture resistance is not effective, and if it exceeds 5.0% by weight, the moldability and the like are adversely affected, which is not suitable for practical use and is not preferable.

As the inorganic filler (E) used in the present invention, generally used ones are widely used. Specific examples thereof include silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, mica, red iron oxide, and glass fiber, and these can be used alone or in combination. Among these, silica powder and alumina are preferably used. The blending ratio of the inorganic filler is preferably 25 to 90% by weight based on the total resin composition. If the proportion is less than 25% by weight, the heat resistance, moisture resistance, solder heat resistance, mechanical properties and moldability will be poor, and if it exceeds 90% by weight, the dryness will be extremely large and the fluidity will be extremely poor, resulting in poor moldability. Not preferable.

The epoxy resin composition of the present invention contains an epoxy resin, a novolac type phenolic resin, alkoxysilanes having both ends, a specific silane coupling agent and an inorganic filler as essential components, but the content does not contradict the purpose of the present invention. In addition, and if necessary, for example, natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides, esters, release agents such as paraffin, flame retardants such as antimony trioxide, coloring of carbon black and the like. Agents, various curing accelerators 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 use the above-mentioned epoxy resin, novolac type phenol resin, both-end alkoxysilane, specific silane coupling agent, inorganic filler and After blending other ingredients and mixing sufficiently evenly with a mixer, etc., further perform melt mixing treatment with hot rolls or mixing treatment with a kneader etc., then cool and solidify and pulverize to an appropriate size to obtain a molding material You can 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 the semiconductor device using the molding material described above. The semiconductor device 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.

[0020]

The epoxy resin composition and the semiconductor encapsulation device of the present invention have improved moisture resistance of the resin composition by using alkoxysilanes at both ends and a specific silane coupling agent, and even when immersed in a solder bath. It was possible to reduce the humidity resistance deterioration.

[0021]

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 Cresol novolac epoxy resin (epoxy equivalent 21
5) 18%, novolac type phenolic resin (phenol equivalent 107) 9%, both ends alkoxysilane shown in Chemical formula 10
0.15%,

[0023]

[Chemical 10] And 0.4% of the silane coupling agent shown in Chemical formula 11,

[0024]

[Chemical 11] 72% of fused silica powder and 0.3% of ester waxes were mixed at room temperature, further kneaded and cooled at 90 to 95 ° C., and then pulverized to produce a molding material (A).

Example 2 Cresol novolac epoxy resin (epoxy equivalent 21
5) 19%, novolac type phenolic resin (phenol equivalent 107) 9%, both ends alkoxysilane shown in Chemical formula 11
0.15%

[0026]

[Chemical 12] And 0.4% of the silane coupling agent shown in Chemical formula 11, 72% of fused silica powder, and 0.3% of ester waxes at room temperature, further kneaded and cooled at 90 to 95 ° C, and then pulverized to obtain a molding material (B). Manufactured.

Comparative Example Cresol novolac type epoxy resin (epoxy equivalent 2
15) 19%, novolac type phenol resin (phenol equivalent 107) 9%, silica powder 71%, curing accelerator 0.3%, ester waxes 0.3% and silane coupling agent
0.4% was mixed at room temperature, further kneaded and cooled at 90 to 95 ° C., and then pulverized to produce a molding material (C).

Molding materials (A) to (C) thus produced
A semiconductor encapsulation device was manufactured by injecting transfer into a mold heated to 170 ° C., encapsulating the semiconductor device and curing it. Various tests were conducted on these semiconductor encapsulation devices, and the results are shown in Table 1. The resin composition and the semiconductor encapsulation device of the present invention are excellent in moisture resistance, solder heat resistance and the like. 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 was prepared and left in saturated steam at 127 ° C. and 2.0 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: Using the molding material, attach a silicon chip with two or more aluminum wirings to a normal 42 alloy frame and transfer molding at 175 ° C for 2 minutes to obtain 5 ×.
A 10 × 1.5 mm flat package type semiconductor device was made and then post-cured at 175 ° C for 8 hours. The molded product thus obtained was subjected to moisture absorption treatment at 40 ° C., 90% RH for 100 hours in advance, and then immersed in a solder bath at 250 ° C. for 10 seconds. Then, perform PCT in saturated steam at 127 ° C and 2.5 atm,
50% disconnection due to aluminum corrosion was evaluated as defective.

[0030]

As is clear from the above description and Table 1, the epoxy resin composition and the semiconductor encapsulation device of the present invention are excellent in heat resistance, moisture resistance, solder heat resistance, less affected by moisture absorption, It is possible to remarkably reduce the disconnection due to corrosion and the generation of leak current due to moisture, and the moldability is good, and the reliability can be guaranteed for a long period of time.

Claims (2)

[Claims] 1. An (A) epoxy resin, (B) a novolac type phenol resin, (C) an alkoxysilane having both terminals at the both ends represented by the following general formula: (In the formula, R ¹ represents an alkoxyl group, R ² and R ³ represent an alkyl group or a phenyl group, and m represents an integer of 1 or more.) (D) A silane coupling agent represented by the following formula: Chemical 2] (Wherein R represents an alkyl group) (E) An inorganic filler is an essential component, and 0.01 to 5.0 of the both-end alkoxysilane of the above (C) is added to the resin composition.
% By weight of the silane coupling agent (D) above 0.01-
5.0% by weight and 25 to 90% by weight of the inorganic filler (E)
An epoxy resin composition, characterized in that it is contained at a ratio of. 2. (A) an epoxy resin, (B) a novolac type phenol resin, (C) an alkoxysilane having both terminals at the both ends represented by the following general formula: (Wherein R ¹ represents an alkoxyl group, R ² and R ³ represent an alkyl group or a phenyl group, and m represents an integer of 1 or more.) (D) A silane coupling agent represented by the following formula: Chemical 4] (Wherein R represents an alkyl group) (E) An inorganic filler is an essential component, and 0.01 to 5.0 of the both-end alkoxysilane of the above (C) is added to the resin composition.
% By weight of the silane coupling agent (D) above 0.01-
5.0% by weight and 25 to 90% by weight of the inorganic filler (E)
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.