JPH06228282A - Epoxy resin composition and sealed semiconductor device - Google Patents

Abstract

PURPOSE:To obtain the subject composition, improved in wettability of the interface between a resin and an inorganic filler, excellent in moisture resistance, moldability and fluidity and having high reliability by using a resin containing the inorganic filler uniformly dispersed in an epoxy resin. CONSTITUTION:The objective composition comprises a resin prepared by uniformly dispersing and mixing (B) a part or all of an inorganic filler to be blended (preferably silica powder or alumina) in (A) an epoxy resin and (C) a phenolic resin as essential components. This composition comprises 30-95wt.% resin prepared by dispersing and mixing the component (B) in the component (A) and 25-90wt.% component (B) based on the whole resin composition. In order to prepare the composition as a molding material, the component (A) is usually heated above the melting point and completely melted with an extruder, etc., and the part of the component (B) is subsequently added to stir the resultant mixture at >=100 deg.C for 20min. The resin and the component (C) are pulverized and the residual component (B) and other components are then uniformly mixed therewith. The obtained mixture is thermally kneaded and further cooled, solidified and subsequently pulverized.

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 which is excellent in moisture resistance, moldability and the like and is suitable for sealing electronic or electric parts, a method for producing the same, and a semiconductor sealing device.

[0002]

2. Description of the Related Art Conventionally, thermosetting resins have been used for sealing electronic parts such as diodes, transistors and integrated circuits. This sealing method is made of glass,
Since it is economically advantageous as compared with the hermetic seal method using metal or ceramic, it is widely used. Among thermosetting resins, epoxy resins are most commonly used as the sealing resin from the viewpoints of reliability and price. Hardeners such as acid anhydrides, aromatic amines, and novolac-type phenolic resins are used as epoxy resins. Among these, epoxy resins using novolac-type phenolic resins as hardeners are those that use other curing agents. Compared with, it is widely used as a resin for semiconductor encapsulation because it is excellent in moldability and moisture resistance, has no toxicity, and is inexpensive.
As the filler, fused silica powder or crystalline silica powder is generally used together with the above-mentioned curing agent.

In recent years, the surface area of fillers has increased due to the frequent use of fine inorganic fillers and the high filling of inorganic fillers. As a result, the wetting of the filler interface is insufficient, and it is easy to form agglomerates of the filler due to the heavy use of fine fillers, and it is not possible to uniformly disperse the agglomerates in the encapsulation resin, causing fluidization. However, there are drawbacks such as poor moldability, high hygroscopicity, and poor moldability due to burrs and the like.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks by improving the wettability of the interface between the resin and the inorganic filler and uniformly dispersing the inorganic filler. Hygroscopicity is reduced, moisture resistance, moldability,
It is intended to provide a highly reliable epoxy resin composition having excellent fluidity and a semiconductor sealing 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 the use of a resin in which an inorganic filler is uniformly dispersed in an epoxy resin makes it possible to achieve the above object. The present invention has been completed by discovering that the above can be achieved.

That is, according to the present invention, resins ((a) + (b)) and ((A) (a) epoxy resin (b) in which a part or all of the inorganic filler to be blended are uniformly mixed and mixed. B) Phenolic resin is an essential component, and [(a) + (b)] of the above (A) resin is added to the whole resin composition by 30%.
To 95% by weight and (b) an inorganic filler in a proportion of 25 to 90% by weight, and an epoxy resin composition and a method for producing the same. 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.

The resin (A) used in the present invention includes (a)
) A resin obtained by uniformly dispersing and mixing a part or all of the inorganic filler to be blended with (b) in the epoxy resin. As the (a) epoxy resin used here, as long as it is a compound having at least two epoxy groups in the molecule, it is not limited by molecular structure, molecular weight, etc., and widely used ones can be widely used. You can Examples thereof include resins such as bisphenol type aromatic resins, cyclohexan derivatives and other alicyclic resins, and epoxy novolac resins represented by the following general formula.

[0009]

[Chemical 1] (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. You can

As the inorganic filler (b) used in (A), generally used ones are widely used.
Examples of these inorganic fillers include silica powder,
Alumina, antimony trioxide, talc, calcium carbonate, white titanium, clay, red iron oxide, glass fiber,
Examples thereof include carbon fiber, and silica powder and alumina are particularly 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 resin composition will be inferior in moisture resistance, heat resistance, mechanical properties and moldability, and if it exceeds 90% by weight, the fluidity will be extremely deteriorated and moldability will be inferior.

The resin (A) is obtained by heating (a) the epoxy resin to its melting point or higher to completely melt it, then adding (b) the inorganic filler and stirring the mixture for 20 minutes or more to homogenize the inorganic filler. It is made by dispersing and mixing. In this case, the inorganic filler may be the whole or a part thereof.

[0012] It is desirable that the proportion of this resin is 30 to 95% by weight based on the total resin composition. If the amount is less than 30% by weight, the resin composition has high hygroscopicity and poor moisture resistance, and if the amount is more than 95% by weight, fluidity is poor and moldability is poor, which is not preferable.

Examples of the (B) phenol resin used in the present invention include novolak type phenol resins obtained by reacting phenols such as phenol and alkylphenol with formaldehyde or paraformaldehyde, and modified resins thereof, for example, epoxidized or butylated. Novolak type phenolic resins are mentioned, and these can be used alone or in combination. The mixing ratio of the phenol resin is such that the molar ratio [(x) / (y)] of the epoxy group (x) of the epoxy resin in the resin (A) and the phenolic hydroxyl group (y) of the phenol resin of (B) is 0.1 ~ 10
It is desirable to be within the range. If the molar ratio is less than 0.1 or more than 10, the moisture resistance, the molding workability and the electrical properties of the cured product deteriorate, which is not preferable in any case.

The epoxy resin composition of the present invention comprises (A)
The resin [(a) + (b) is prepared by uniformly dispersing and mixing a part or all of the inorganic filler to be blended with the epoxy resin (a) (b).
)] And (B) as the essential components, but to the extent that the objects of the present invention are not impaired, and if necessary, for example, natural wax, synthetic wax, metal salts of straight chain fatty acids, acid amides, Release additives such as esters and paraffins, flame retardants such as chlorinated paraffin, bromtoluene, hexabromobenzene, antimony trioxide, colorants such as carbon black and red iron oxide, various curing agents, etc. are appropriately added and blended. be able to.

In the method for producing the epoxy resin composition of the present invention as a molding material, a resin in which an inorganic filler is heat-mixed in an epoxy resin and uniformly dispersed and mixed may be used, and the other steps are particularly limited. It is not something that will be done.
However, it is usually manufactured as follows. Use a device (container) that can heat to a temperature above the melting point of the epoxy resin, such as a strong kneader, a heating reaction kettle, an extruder, a heating roll, etc. After being melted, a part of the inorganic filler is added to the epoxy resin in an amount of 25 to 90% by weight, and the mixture is stirred preferably at 100 ° C. or higher for 20 minutes to prepare a resin uniformly dispersed and mixed. The resin and the phenol resin are pulverized, and the remaining inorganic filler and other components are mixed sufficiently uniformly with a raw material composition selected in a predetermined composition ratio by a mixer or the like, and then a hot roll, an extruder, or a kneader. The mixture is heated and kneaded by a method such as the above, waits for it to cool and solidify, and then it is pulverized to an appropriate size to produce a molding material. Here, the method of dispersing and mixing the inorganic filler in the epoxy resin and then blending the phenol resin with other components was explained, but a resin in which the inorganic filler is uniformly dispersed and mixed is prepared in the epoxy resin manufacturing process. If necessary, it may be mixed and kneaded with the required amount and other components. What is important as a manufacturing method is to have a step of uniformly dispersing and mixing an inorganic filler in an epoxy resin to obtain a resin, and a step of blending and kneading the resin with a phenol resin and other components. 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 a semiconductor chip using the epoxy resin composition described above. As the semiconductor chip to be sealed, for example, an integrated circuit, a large-scale integrated circuit,
It is not particularly limited to transistors, thyristors, diodes and the like. The most common method of sealing is
Although there is a low-pressure transfer molding method, sealing by injection molding, compression molding, casting, etc. is also possible. The epoxy resin composition is heated and cured during encapsulation, and finally a semiconductor encapsulation device encapsulated with this composition is obtained. For curing by heating, it is desirable to heat and cure at 150 ° C or higher.

[0017]

In the epoxy resin composition of the present invention, the inorganic filler is uniformly dispersed and mixed in the epoxy resin to reduce the formation of aggregates, and to improve the wettability and fluidity of the interface between the inorganic filler and the resin. It was possible to improve the moldability, improve the moldability, and reduce the amount of moisture absorption.

[0018]

EXAMPLES The present invention will now 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"
Means

[Production of resin] 30% of cresol novolac epoxy resin (epoxy equivalent 215) was put in an extruder.
Heat to 20 ° C. After the cresol novolac epoxy resin was completely melted, 70% of the inorganic filler was added and the mixture was heated and kneaded for 20 minutes to obtain a resin (E-
We made F resin).

Example 1 67% of EF resin and 10% of novolak type phenolic resin (phenol equivalent 107) were pulverized to about 2 mm in diameter, 18% of fused silica powder and 5% of other components were mixed at room temperature, and further,
A molding material was manufactured by kneading and cooling at 90 to 100 ° C.

Example 2 50% of EF resin and 10% of novolac type phenolic resin (phenol equivalent 107) were pulverized to about 2 mm in diameter, 35% of fused silica powder and 5% of other components were mixed at room temperature, and further,
The mixture was kneaded and cooled at 90 to 100 ° C. and then pulverized to produce a molding material.

Comparative Example 1 Cresol novolac epoxy resin (epoxy equivalent 21
5) 20%, novolak type phenolic resin (phenol equivalent 107) 10%, fused silica powder 65% and other components 5% are mixed at room temperature, and further kneaded and cooled at 90 to 100 ° C to produce a molding material. did.

Comparative Example 2 Cresol novolac epoxy resin (epoxy equivalent 21
5) Mix 15% with 10% novolac type phenolic resin (phenol equivalent 107), 70% fused silica powder and 5% other components at room temperature, knead and cool at 90-100 ° C, and then crush and mold. Was manufactured.

Using the molding materials produced in Examples 1 and 2 and Comparative Examples 1 and 2, transfer molding is performed in a mold heated to 175 ° C. to seal the semiconductor chip, and the semiconductor chip is cured by heating to mold the semiconductor sealing device. Was manufactured. Various tests were conducted on the molding material and the semiconductor encapsulation device, and the results are shown in Table 1. The epoxy resin composition and semiconductor encapsulation device of the present invention have excellent moisture resistance and moldability, and the effects of the present invention could be confirmed.

[0025]

[Table 1] * 1: A molded product with a diameter of 50 mm and a thickness of 3 mm was made by transfer molding, left to stand in saturated steam at 127 ° C and 2.5 atm for 24 hours, and measured by the increased weight. * 2: At 175 ° C, make a molded product similar to that of water absorption
After 8 hours of curing, a test piece having an appropriate size was prepared and measured using a thermomechanical analyzer. * 3: Measured according to JIS-K-6911. * 4: A semiconductor chip with two aluminum wirings is bonded to a normal 42 alloy frame using a molding material, transfer molded at 170 ° C for 3 minutes, and then aged at 180 ° C for 8 hours. It was 100 pieces of the molded articles thus obtained were subjected to PCT in high-pressure steam at 120 ° C., and the time at which 50% disconnection (defect occurrence) due to aluminum corrosion occurred was evaluated. * 5: A 25 x 25 x 3 mm copper plate was embedded in the bottom of a 30 x 25 x 5 mm molded product, placed in a constant temperature bath at -40 ° C and + 200 ° C for 30 minutes each, repeated 15 cycles, and then examined for resin cracks. .

[0026]

As is clear from the above description and Table 1, according to the method for producing an epoxy resin composition of the present invention,
Improving the wettability of the interface between the resin and the inorganic filler, reducing the hygroscopicity by uniformly dispersing the inorganic filler, moisture resistance, moldability, an epoxy resin composition having excellent fluidity is obtained. A highly reliable semiconductor encapsulation device could be manufactured by using the composition.

Claims (3)

[Claims] 1. A resin [(a) + (b)] and (B) a phenol resin in which a part or all of an inorganic filler to be compounded with (b) an epoxy resin (a) is uniformly mixed. In an amount of 30 to 95% by weight of (A) resin [(a) + (b)] and 25 to 90% by weight of (b) inorganic filler, based on the total resin composition. An epoxy resin composition comprising: 2. A resin [(a) + (b)] and (B) a phenol resin in which a part or all of the inorganic filler to be blended with (a) (a) an epoxy resin (b) is uniformly dispersed and mixed. In an amount of 30 to 95% by weight of (A) resin [(a) + (b)] and 25 to 90% by weight of (b) inorganic filler, based on the total resin composition. A semiconductor encapsulation device, which is obtained by encapsulating a semiconductor chip with a cured product of the epoxy resin composition contained in 1. 3. A process of (a) melting an epoxy resin, (b) adding a part or all of an inorganic filler to be blended and uniformly dispersing and mixing the resin [(a) + (b)], and A method for producing an epoxy resin composition, comprising the step of mixing and kneading the resin [(a) + (b)] and the phenol resin (B).