JPH09216937A - Epoxy resin composition and sealed electronic part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin compsn. improved in moldability and resistances to moisture and soldering heat by compounding an epoxy resin, a novolak phenol resin, an inorg. filler, a cure accelerator, and a specific polysiloxane. SOLUTION: This compsn. is prepd. by compounding an epoxy resin having at least two epoxy groups in the molecule, a novolak phenol resin in a molar ratio of its phenolic hydroxyl group to the epoxy group of the epoxy resin of 0.1-10, 25-95wt.% inorg. filler, 0.01-5wt.% phosphorus- or imidazol-based cure accelerator, and 0.01-2.0wt.% polysiloxane represented by the formula [wherein R<1> and R<2> are each (CH2 )x ; (x) is 1 or higher, and (n) is 50-300].

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 solder heat resistance and moldability, and an electronic component sealing device sealed by the epoxy resin composition.

[0002]

2. Description of the Related Art In recent years, in the field of semiconductor integrated circuits,
At the same time as the development of high integration and high reliability technologies, automation of the mounting process of semiconductor devices has been 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 device is dipped in a solder bath heated to 250 ° C and soldered at once. The method has been adopted.

[0003]

The conventional epoxy resin,
A semiconductor device sealed with a resin composition consisting of a novolac type phenolic resin and an inorganic filler has a drawback that the moisture resistance is lowered when the entire device is immersed in a solder bath. In particular, when a semiconductor device that has absorbed moisture is immersed, peeling between the sealing resin and the semiconductor chip, or between the sealing resin and the lead frame, and internal resin cracks occur, causing significant deterioration of moisture resistance. Leakage current occurs, and as a result, the semiconductor device has a disadvantage that long-term reliability cannot be guaranteed.

The present invention has been made in order to solve the above-mentioned drawbacks, has little influence of moisture absorption, is particularly excellent in solder heat resistance, moisture resistance and moldability after immersion in a solder bath, and has a sealing resin and a semiconductor chip. Alternatively, there is no peeling of the encapsulating resin and the lead frame or internal resin cracking, and there is no disconnection due to electrode corrosion or leak current due to moisture, and epoxy resin composition and electronic component encapsulation that can guarantee long-term reliability. It is intended to provide a device.

[0005]

Means for Solving the Problems As a result of intensive studies aimed at achieving the above object, the present inventors have found that by blending a specific polysiloxane, the solder heat resistance and the moldability are excellent and the solder bath is excellent. It was found that the moisture resistance after immersion is improved, and the present invention has been completed.

That is, the present invention provides (A) an epoxy resin,
(B) novolac type phenol resin, (C) inorganic filler, (D) curing accelerator, and (E) polysiloxane represented by the following general formula

[0007]

Embedded image (However, in the formula, R ¹ and R ² are a-(CH ₂ ) _x- group,
Represents an integer of 1 or more, and n represents an integer of 50 to 300) as an essential component, and contains the inorganic filler (C) in a proportion of 25 to 95% by weight with respect to the entire resin composition. It is an epoxy resin composition characterized by the following. An electronic component sealing device is characterized in that an electronic component is sealed with a cured product of the epoxy resin composition.

Hereinafter, the present invention will be described in detail.

The epoxy resin (A) used in the present invention is not particularly limited in its molecular structure, molecular weight, etc., 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 is possible to broadly include what has been done. As a concrete example, for example,
Examples thereof include bisphenol type aromatic type, aliphatic type such as cyclohexane derivative, biphenyl type epoxy resin, and epoxy novolac type resin represented by the following general formula.

[0010]

Embedded image (In the formula, R ¹ is a hydrogen atom, a halogen atom or an alkyl group, R ² is a hydrogen atom or an alkyl group, and n is
Each of these represents an integer of 1 or more) These epoxy resins can be used alone or in combination.

The novolak type phenolic resin (B) used in the present invention is a novolak 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 to the phenolic hydroxyl group (b) of the (B) novolak type phenol resin is within the range of 0.1 to 10. When the molar ratio is less than 0.1 or exceeds 10, the heat resistance, moisture resistance, molding workability and electrical properties of the cured product deteriorate, and in either case, it is not preferable.

Examples of the inorganic filler (C) used in the present invention include silica powder, alumina, antimony trioxide, talc, calcium carbonate, titanium white, clay, mica, red iron oxide, glass fiber and the like, which may be used alone or Two or more kinds can be mixed and used. Among these, silica powder and alumina powder are particularly preferably used. It is preferable to mix the inorganic filler so that the inorganic filler is contained in an amount of 25 to 95% by weight based on the entire resin composition. If the proportion is less than 25% by weight, heat resistance, moisture resistance,
Solder heat resistance is poor, mechanical properties and moldability are poor, and if it exceeds 95% by weight, dryness becomes large and moldability is poor, which is not preferable.

The (D) curing accelerator used in the present invention includes a phosphorus-based curing accelerator, an imidazole-based curing accelerator,
BU-based curing accelerators and other curing accelerators can be widely used. These can be used alone or as a mixture. 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. Moisture resistance is inferior and not preferable.

As the (E) polysiloxane used in the present invention, those having at least two amino groups in the molecule and represented by the above general formula are used. As a specific compound of the polysiloxane, for example,

[0015]

Embedded image (However, n represents an integer of 50 to 300) and the like, and these can be used alone or in combination. Furthermore, other polysiloxanes having an epoxy group, an amino group or a mercapto group can be used in combination. The compounding ratio of polysiloxane is 0.01 to 2.0 with respect to the resin composition.
It is desirable to formulate so as to contain the composition in a weight percentage. If the proportion is less than 0.01% by weight, the moldability is not effective, and if it exceeds 2.0% by weight, the solder heat resistance and the moldability, especially the resin burr are adversely affected, which is not suitable for practical use.

The epoxy resin composition of the present invention contains the above-mentioned epoxy resin, novolac type phenol resin, inorganic filler, curing accelerator and specific polysiloxane as essential components, but within the range not deviating from the object of the present invention. Also, 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, carbon black, red iron oxide, etc. The colorant, the silane coupling agent, the 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 as follows: epoxy resin, novolac type phenol resin, inorganic filler, curing accelerator,
A specific polysiloxane and other ingredients are mixed and mixed sufficiently well with a mixer, etc., and further subjected to melt mixing treatment with a heat roll or mixing treatment with a kneader etc., followed by cooling and solidifying and pulverizing to an appropriate size to form a molding material. Can be When the molding material thus obtained is applied to sealing, coating, insulation, etc. of electronic parts such as semiconductor devices, excellent properties and reliability can be imparted.
It can also be applied to sealing, covering, insulating, etc. of electric parts.

The electronic component sealing device of the present invention can be easily manufactured by sealing the electronic component using the above-mentioned molding material. Examples of electronic components for sealing include integrated circuits, large-scale integrated circuits, transistors,
The thyristor and the diode are not particularly limited. The most common sealing method 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 the cured product is obtained. The curing by heating is desirably performed by heating to 150 ° C. or more.

The present invention uses an epoxy resin, a novolac type phenol resin, an inorganic filler, a curing accelerator and a specific polysiloxane to prevent deterioration of the resin composition due to moisture absorption and improve moldability. A resin composition and an electronic component device can be manufactured.

[0020]

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 Biphenyl type epoxy resin (epoxy equivalent 193) 8.5
%, Tetrabromobisphenol A type epoxy resin (epoxy equivalent 400) 1.5%, novolac type phenol resin (hydroxyl equivalent 104) 5.0%, polysiloxane of Chemical formula 5 (average molecular weight 5000) 0.5% 5%, fused silica powder 81.2% , 0.3% of hardening accelerator, 0.3% of ester waxes, 0.3% of carbon black, 2.0% of antimony trioxide and 0.4% of γ-glycidoxypropyltrimethoxysilane at room temperature and further kneaded at 90 to 95 ° C. After cooling, it was crushed to an appropriate size to produce a molding material (A).

Example 2 Biphenyl type epoxy resin (epoxy equivalent 193) 8.5
%, Tetrabromobisphenol A type epoxy resin (epoxy equivalent 400) 1.5%, novolac type phenol resin (hydroxyl equivalent 104) 5.0%, polysiloxane of Chemical formula 5 (average molecular weight 8000) 0.5%, fused silica powder 81.2%, curing acceleration After mixing 0.3% of agent, 0.3% of ester wax, 0.3% of carbon black, 2.0% of antimony trioxide and 0.4% of γ-glycidoxypropyltrimethoxysilane at room temperature, further kneading at 90 to 95 ° C and cooling. A molding material (B) was manufactured by crushing into a suitable size.

Example 3 Biphenyl type epoxy resin (epoxy equivalent 193) 8.5
%, Tetralomobisphenol A type epoxy resin (epoxy equivalent 400) 1.5%, novolac type phenol resin (hydroxyl equivalent 104) 5.0%, polysiloxane of Chemical formula 5 (average molecular weight 8000) 0.5%, fused silica powder 81.2%, curing acceleration Agent 0.3%, ester waxes 0.3%, carbon black 0.3%, antimony trioxide 2.0% and γ-mercaptopropyltrimethoxysilane 0.4% are mixed at room temperature, and after further kneading at 90 to 95 ° C. and cooling, A molding material (C) was manufactured by crushing to an appropriate size.

Comparative Example Biphenyl type epoxy resin (epoxy equivalent 193) 8.5
%, Tetralomobisphenol A type epoxy resin (epoxy equivalent 400) 1.5%, novolac type phenol resin (hydroxyl equivalent 104) 5.0%, epoxy polyether modified polysiloxane (average molecular weight 3000) 0.5%, fused silica powder 72%, 0.3% curing accelerator, ester wax
0.3%, carbon black 0.3%, antimony trioxide 2.
0% and 0.4% of γ-glycidoxypropyltrimethoxysilane were mixed at room temperature, further kneaded at 90 to 95 ° C, cooled, and then pulverized to an appropriate size to produce a molding material (D).

The molding materials (A) to (D) thus produced
Transfer injection was carried out into a mold heated to 170 ° C by using, and a photocoupler was sealed and cured to manufacture an electronic component sealing device. Various tests were conducted on these electronic component sealing devices, and the results are shown in Table 1. The epoxy resin composition and the electronic component sealing device of the present invention are excellent in various characteristics, and the remarkable features of the present invention. I was able to confirm the effect.

[0026]

[Table 1] * 1: A transfer molded product with a diameter of 50 mm and a thickness of 3 mm was made, left in saturated steam at 127 ° C and 2 atm for 24 hours, and calculated by the increased weight. * 2: The same molded product as in the water absorption test was made and measured using a thermal instrument analyzer. * 3: A silicon chip (test element) with two or more aluminum wirings is bonded to a normal 42 alloy frame using the molding material, and transfer molding is performed at 175 ° C for 2 minutes to obtain 5 × 10 A flat package type semiconductor device with a size of × 1.5 mm was fabricated and then post-cured at 175 ° C for 8 hours. 30 semiconductor encapsulation devices were preliminarily subjected to moisture absorption treatment at 40 ° C, 90% RH for 100 hours and then immersed in a solder bath at 250 ° C for 10 seconds. Then, PCT was performed in saturated steam at 127 ° C. and 2.5 atm, and 50% disconnection due to corrosion of aluminum was evaluated as defective.

[0027]

As is clear from the above description and Table 1, the epoxy resin composition and the electronic component sealing device of the present invention have excellent moisture resistance even after immersion in a solder bath, and as a result, breakage due to electrode corrosion It is possible to remarkably reduce the generation of leak current due to water and moisture, and to ensure the reliability for a long time. It also showed excellent solder heat resistance despite immersion in a solder bath at 250 ° C.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location H01L 23/31

Claims (2)

[Claims] 1. An epoxy resin (A), a novolac type phenolic resin (B), an inorganic filler (C), a curing accelerator (E) and a polysiloxane represented by the following general formula: (However, in the formula, R ¹ and R ² are a-(CH ₂ ) _x- group,
Represents an integer of 1 or more, and n represents an integer of 50 to 300) as an essential component, and contains the inorganic filler (C) in a proportion of 25 to 95% by weight with respect to the entire resin composition. An epoxy resin composition comprising: 2. An epoxy resin (A), a novolac type phenolic resin (B), an inorganic filler (C), a curing accelerator (E), and a polysiloxane represented by the following general formula: (However, in the formula, R ¹ and R ² are a-(CH ₂ ) _x- group,
Is an integer of 1 or more, and n is an integer of 50 to 300) as an essential component, and the inorganic filler of (C) is contained in a proportion of 25 to 95% by weight with respect to the entire resin composition. An electronic component encapsulation device, wherein an electronic component is encapsulated with a cured product of an epoxy resin composition.