JPH04248830A - Sealing resin composition and sealed semiconductor device - Google Patents

Abstract

PURPOSE:To obtain the subject composition, consisting essentially of an epoxy resin, a novolak type phenolic resin, a specific amount of a silane coupling agent having the imidazole skeleton and a specified amount of an inorganic filler and useful as sealed semiconductor devices improved in moisture resistance, moldability, etc. CONSTITUTION:The objective composition is obtained by using (A) an epoxy resin (e.g. an epoxy novolak-based resin) having >=2 epoxy groups in the molecule, (B) a novolak type phenolic resin, (C) a (1-imidazolyl)alkyl-based silane coupling agent {e.g. 4,5-dihydro-1-[3-(triethoxysilyl)propyl]imidazole} in an amount of 0.1-5wt.% (based on the resin composition) and (D) 25-90wt.% inorganic filler (preferably silica powder, etc.) as essential components. The equiv. ratio of the epoxy groups in the aforementioned component (A)/phenolic hydroxyl groups in the component (B) is preferably 0.1-10.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention provides moisture resistance, soldering heat resistance,
The present invention relates to a sealing resin composition with excellent moldability and a semiconductor sealing device.

0002

2. Description of the Related Art In recent years, along with the development of technologies for higher integration and higher reliability in the field of semiconductors and integrated circuits, automation of semiconductor device mounting processes has been promoted. For example, when attaching a flat packaged semiconductor device to a circuit board, conventionally each lead pin was soldered individually, but recently the entire semiconductor device is immersed in a solder bath heated to 250°C and soldered all at once. A method of doing this has been adopted.

[0003] A semiconductor device sealed with a conventional resin composition comprising an epoxy resin, a novolak type phenolic resin, and an inorganic filler has a drawback that moisture resistance is reduced when the entire device is immersed in a solder bath. In particular, if a semiconductor device that has absorbed moisture is immersed in a solder bath, peeling will occur between the encapsulating resin and the semiconductor chip, or between the encapsulating resin and the frame, resulting in significant deterioration of moisture resistance, resulting in disconnection due to electrode corrosion, and breakage due to moisture. It has the drawback that it generates leakage current and cannot guarantee long-term reliability. For this reason, there has been a strong demand for the development of a sealing resin with good moldability that has less influence on moisture resistance and exhibits less deterioration in moisture resistance even when the entire semiconductor device is immersed in a solder bath.

0004

[Problems to be Solved by the Invention] The present invention has been made in order to solve the above-mentioned drawbacks and meet the demands. The present invention aims to provide a sealing resin composition with good moldability and a semiconductor sealing device.

[0005]

[Means for Solving the Problems] As a result of intensive research to achieve the above object, the present inventors have found that by incorporating an imidazole-based silane coupling agent, the present inventors have achieved heat resistance and moisture resistance after immersion in a solder bath. The properties and soldering heat resistance are improved.
They also found that the moldability was improved, and completed the present invention. That is, the present invention includes (A) an epoxy resin, (B) a novolac type phenol resin, (C) a (1-imidazolyl)alkyl silane coupling agent, and (D) an inorganic filler as essential components, and a resin composition containing On the other hand, (1) of (C) above
-imidazolyl)alkyl-based silane coupling agent
A sealing resin composition characterized by containing 0.1 to 5% by weight and 25 to 90% by weight of the inorganic filler (D). Further, the present invention is a semiconductor sealing device characterized in that a semiconductor pellet is sealed with a cured product of this sealing resin composition.

The present invention will be explained in detail below.

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

[0008]

[Formula 1] (In the formula, R1 represents a hydrogen atom, a halogen atom, or an alkyl group, R2 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 of two types. The above mixture is used.

The novolak type phenolic resin (B) used in the present invention includes novolac type phenol resins obtained by reacting phenols such as phenol and alkylphenols with aldehydes such as formaldehyde and paraformaldehyde, and modified resins thereof. Examples include epoxidized or butylated novolac type phenolic resins, and these resins may be used alone or in combination of two or more. The blending ratio of the novolac type phenolic resin is the epoxy group (a) of the epoxy resin described above and the phenolic hydroxyl group (b) of the novolac type phenol resin.
) with an equivalent ratio [(a)/(b)] of 0.1 to 1
It is desirable that it be within the range of 0. If the equivalent ratio is less than 0.1 or more than 10, heat resistance, moisture resistance, molding workability, and electrical properties of the cured product will deteriorate, and either case is unfavorable. Therefore, it is better to limit it within the above range.

As the (C)(1-imidazolyl)alkyl-based silane coupling agent used in the present invention, for example, 4,5-dihydro-1-[3-(
triethoxysilyl)propyl]imidazole and 2-
Phenyl-4-dihydro-5-methyl-1-[3
-(triethoxysilyl)propyl]imidazole and the like.

[0011]

embedded image These can be used alone or in combination of two or more. Further, other coupling agents such as silane type, titanium type, zirconium type, etc. can also be used in combination. The blending ratio of the imidazole-based silane coupling agent is preferably 0.1 to 5% by weight based on the entire resin composition. If this proportion is less than 0.1% by weight, it has no effect on soldering heat resistance, and if it exceeds 5% by weight, the resin viscosity increases, which adversely affects moldability, making it unsuitable for practical use.

Inorganic fillers (D) used in the present invention include silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, mica,
Examples include red iron oxide and glass fiber, which may be used alone or in combination of two or more. Among these, silica powder and alumina powder are particularly preferred and often used. The blending ratio of the inorganic filler is 25 to 90% by weight based on the entire resin composition. If the proportion is less than 25% by weight, the heat resistance, moisture resistance, soldering heat resistance, mechanical properties and moldability will be poor, and if it exceeds 90% by weight, the bulk will be large and the moldability will be poor, making it unsuitable for practical use.

The sealing resin composition of the present invention contains an epoxy resin, a novolac type phenolic resin, an imidazole-based silane coupling agent, and an inorganic filler as essential components, but as long as the object of the present invention is not impaired, If necessary, release agents such as natural waxes, synthetic waxes, metal salts of linear fatty acids, acid amides, esters, paraffins, chlorinated paraffins, brominated toluene, hexabromobenzene, antimony trioxide, etc. Flame retardants, colorants such as carbon black and red iron oxide, and various curing accelerators can be appropriately added and blended.

[0014] A general method for producing the encapsulating resin composition of the present invention as a molding material is to prepare an epoxy resin, a novolac type phenolic resin, an imidazole silane coupling agent, an inorganic filler, and other raw materials. After selecting a predetermined composition ratio and mixing it sufficiently uniformly using a mixer, etc., it is further melted and mixed using hot rolls, and mixed using a kneader, etc., then cooled and solidified, and pulverized to an appropriate size to form a molding material. shall be. This molding material can be applied to seal semiconductor pellets, electronic components, or electrical components, and to coat, insulate, etc., and provide excellent characteristics and reliability.

The semiconductor encapsulation device of the present invention can be easily manufactured by encapsulating semiconductor pellets using the encapsulation resin composition obtained as described above. The most common method for sealing is low-pressure transfer molding, but sealing by injection molding, compression molding, casting, etc. is also possible. The sealing resin composition is heated and cured during sealing, and a semiconductor sealing device sealed with the cured product of this composition is finally obtained. Curing by heating
It is desirable to heat and harden at a temperature of 150° C. or higher. Examples of semiconductor pellets for sealing include integrated circuits,
It is not particularly limited to large-scale integrated circuits, transistors, thyristors, diodes, etc.

[0016]

[Function] In the present invention, the desired properties can be obtained by using a specific imidazole-based silane coupling agent. The silane coupling agent having an imidazole skeleton can improve the heat resistance of the resin composition and prevent deterioration of moisture resistance even when immersed in a solder bath.

[0017]

[Examples] Next, the present invention will be specifically explained using examples, but the present invention is not limited to the following examples. In the following Examples and Comparative Examples, "%" means "% by weight".

Example 1 Cresol novolac epoxy resin (epoxy equivalent weight 2
15) 18%, novolac type phenol resin (phenol equivalent: 107) 9%, 4,5-dihydro-1-[3-(triethoxylyl)propyl]imidazole shown in the following formula 0.4%,

[0019]

[Chemical formula 3] Fused silica powder 71% and ester wax 0
．． 3%, mixed at room temperature, kneaded and cooled at 90 to 95°C, and then pulverized to produce a molding material. This molding material was transfer-injected into a mold heated to 170° C. and cured to produce a molded product (sealed product). This molded product was tested for characteristics such as moisture resistance, and the results are shown in Table 1.
It was shown to. In particular, the remarkable effects of the present invention on moisture resistance were observed.

Example 2 Cresol novolac epoxy resin (epoxy equivalent weight 2
15) 19%, novolac type phenol resin (phenol equivalent: 107) 9%, 2-phenyl-4-dihydro-5-methyl-1-[3-(triethoxysilyl)propyl]imidazole shown in the following formula 0. 4%,

[0021]

[Chemical formula 4] Silica powder 71% and ester wax 0.3
% was mixed, kneaded, and crushed in the same manner as in Example 1 to produce a molding material. In addition, a molded article was made in the same manner as in Example 1, and property tests such as moisture resistance were conducted. The results are shown in Table 1. The remarkable effect of the present invention on moisture resistance was observed.

Example 3 Cresol novolak epoxy resin (epoxy equivalent weight 2
15) 19%, novolac type phenolic resin (phenol equivalent 107) 9%, 2-phenyl-4-dihydro-5-methyl-1-[3-(triethoxysilyl)propyl]imidazole 0.2%, γ- A molding material was prepared by mixing, kneading, and pulverizing 0.2% glycidoxypropyltrimethoxysilane, 71% silica powder, and 0.3% ester wax in the same manner as in Example 1. In addition, a molded article was made in the same manner as in Example 1, and property tests such as moisture resistance were conducted. The results are shown in Table 1. The remarkable effect of the present invention on moisture resistance was confirmed.

Comparative Example Cresol novolac epoxy resin (epoxy equivalent: 2
15) 19%, 9% novolac type phenol resin (phenol equivalent: 107), 71% silica powder, 0.3% curing accelerator, 0.3% ester wax, and 0.4% silane coupling agent. Example 1
A molding material was produced in the same manner. This molding material was used to make a molded article, and the various properties of the molded article were tested in the same manner as in Example 1. The results are shown in Table 1.

[0024]

[Table 1] *1: A molded product with a diameter of 50 mm and a thickness of 3 mm was made by transfer molding, and this was heated to 127°C, 2
Determined by weight increase after being left in saturated steam at atmospheric pressure for 24 hours *2: The same molded product as in the water absorption test was made, and this was post-cured at 175°C for 8 hours, and a test piece of an appropriate size was prepared. *3: Silicon chip (test element) with two or more aluminum wirings using molding material.
was adhered to a 42 alloy frame and transfer molded at 175℃ for 2 minutes to create a flat package molded product measuring 5 x 10 x 1.5mm, and then transferred to 175℃.
Post-curing was carried out for 8 hours. This molded product is heated at 40℃ in advance.
, 90% RH, after 100 hours of moisture absorption treatment, 2
It was immersed in a 50°C solder bath for 10 seconds. Then 127℃
, PCT was performed in saturated steam at 2.5 atmospheres, and wire breaks due to corrosion of aluminum were evaluated as defects.

[0025]

Effects of the Invention As is clear from the above explanation and Table 1, the encapsulating resin composition and semiconductor encapsulating device of the present invention have
It has excellent heat resistance, moldability, and moisture resistance even after being immersed in a solder bath, and as a result, it can significantly reduce the occurrence of disconnections due to electrode corrosion and leakage current due to moisture, and it also guarantees long-term reliability. can do. Also,
It showed excellent soldering heat resistance despite being immersed in a 250°C solder bath.

Claims (2)

[Claims] Claim 1: A resin composition containing (A) an epoxy resin, (B) a novolac type phenol resin, (C) a (1-imidazolyl)alkyl silane coupling agent, and (D) an inorganic filler as essential components. and (1) of (C) above.
-imidazolyl)alkyl-based silane coupling agent
A sealing resin composition comprising 0.1 to 5% by weight and 25 to 90% by weight of the inorganic filler (D). 2. A resin composition containing (A) an epoxy resin, (B) a novolac type phenol resin, (C) a (1-imidazolyl)alkyl silane coupling agent, and (D) an inorganic filler as essential components. and (1) of (C) above.
-imidazolyl)alkyl-based silane coupling agent
A semiconductor characterized in that a semiconductor pellet is sealed with a cured product of a sealing resin composition containing 0.1 to 5% by weight and 25 to 90% by weight of the inorganic filler (D). Sealing device.