JPH02209949A - Epoxy resin composition and cured product for semiconductor encapsulation - Google Patents

Abstract

PURPOSE:To obtain epoxy resin composition for sealing of semiconductor having excellent fluidity and processability and giving cured material having low expansion coefficient containing epoxy resin, hardener and spherical silica having specific character. CONSTITUTION:(A) An epoxy resin (e.g. epoxidized cresol-novolak resin) is mixed with (B) a hardener (preferably phenol-novolak type hardener) and (C) a filler containing preferably >=50wt.% spherical silica having 5-35mum, preferably 8-32mum averaged particle diameter and <=1.4m<2>/g, preferably <=1m<2>/g specific surface area and containing particles having >=75mum diameter in an amount of <=1wt.%, preferably <=0.5wt.% of the whole filler. 250-700 pts.wt., preferably 350-500 pts.wt. of the component C, and hardening accelerator and silicone-based polymer, etc., as necessary, are mixed with total 100 pts.wt. of the component A and the component B to afford the aimed epoxy resin composition.

Description

[Detailed Description of the Invention] 1 Presentation Summer ■ and Minute Sample The present invention provides a semiconductor that provides a cured product with a low expansion coefficient, has high fluidity, and has excellent moldability with few molding defects such as unfilling and wire flow. The present invention relates to an epoxy resin composition for sealing and a cured product thereof.

Conventionally, epoxy resin compositions used for semiconductor encapsulation have generally been made by blending epoxy resin with phenol resin or the like as a hardening agent and silica or the like as an inorganic filler. Such epoxy resin compositions have low viscosity when melted and high fluidity compared to other thermosetting resin compositions such as phenolic resin compositions, so they are suitable for LS.
It is effective in suppressing damage to fine patterns and wires of I, IC, transistors, etc. and improving moisture resistance, and is therefore suitably used for semiconductor encapsulation.

In addition, as recent trends have shown that silicon chips have become larger and wiring widths have become finer, there has been a demand for semiconductor encapsulants to have an expansion coefficient closer to that of silicon chips. The expansion coefficient of the cured product is lowered by increasing the amount of the agent blended.

However, on the other hand, as packages are becoming larger and the number of bottles is increasing, it is desired that the sealing material has higher fluidity, but generally speaking, the greater the amount of filler, the higher the fluidity of the epoxy resin composition. There were problems in that the molding properties were poor, unfilling and wire flow were likely to occur during molding, moldability was reduced, and the moisture resistance of the obtained cured product was poor. Therefore, it has been desired to develop an epoxy resin composition for semiconductor encapsulation that provides a cured product with a low coefficient of expansion, has high fluidity, and has excellent moldability.

The present invention was developed in view of the above circumstances, and provides a cured product with a low expansion coefficient and high fluidity.

An object of the present invention is to provide an epoxy resin composition for semiconductor encapsulation that has excellent moldability and hardly causes molding defects such as unfilling or wire flow during molding, and a cured product thereof.

In order to achieve the above object, the inventor of the present invention has made extensive studies and found that, in an epoxy resin composition containing an epoxy resin, a curing agent, and a filler, the average particle size is The diameter is 5-35M and the specific surface area is 1.4rr? /g or less is preferably blended so that the content of such spherical silica is 50% by weight or more of the total filler, and the content of particles with a particle size of 754 or more is 1% by weight of the total filler. When the following fillers are used, the fluidity of the composition does not decrease even if the filler content is increased to lower the expansion coefficient of the cured product, and molding defects such as unfilled and wire flow occur during molding. An epoxy resin for semiconductor encapsulation that hardly generates moisture and can provide a cured product with good moisture resistance.Therefore, it provides a cured product with a low expansion coefficient, has high fluidity, and has excellent moldability. It was discovered that a composition can be obtained, and the present invention was completed.

Accordingly, the present invention provides an epoxy resin composition containing an epoxy resin, a curing agent, and a filler, in which the filler has an average particle size of 5 to 35 mm and a specific surface area of 1.4 rr. /g
An epoxy resin composition for semiconductor encapsulation characterized in that it contains the following spherical silica and uses a filler in which the content of particles with a particle size of 75P or more is 1% by weight or less of the entire filler, and the same: A cured product obtained by curing is provided.

The present invention will be explained in more detail below.

As described above, the epoxy resin composition of the present invention contains an epoxy resin, a curing agent, and a filler as main components.

Here, as the epoxy resin, various conventionally known ones can be used, such as epoxidized orthocresol novolak resin.

Examples include epoxidized phenol novolac resins, alicyclic epoxy scavenging resins, epoxidized bisphenol resins, @-substituted or unsubstituted triphenol alkane type epoxy resins, and epoxy resins in which halogen atoms are introduced therein. Note that these epoxy resins are not necessarily limited to the use of only one type, and two or more types may be mixed and blended.

Further, the curing agent is not particularly limited and can be appropriately selected depending on the epoxy resin used. Examples include amine curing agents, acid anhydride curing agents, phenol novolak type curing agents, etc. Among these, phenol novolak type curing agents are more desirable in terms of moldability and moisture resistance of the composition, and can be suitably used. Note that specific examples of the phenol novolac type curing agent include phenol novolak resin, cresol novolak resin, and the like.

The amount of curing agent blended can be the amount normally used,
When a phenol novolac type curing agent is used, it is preferably blended so that the molar ratio of epoxy groups in the epoxy resin to OH groups in the curing agent is 1:0.5 to 1:1.5.

In the present invention, it is desirable to use various curing accelerators, such as imidazoles, tertiary amines, phosphine compounds, and cycloamidine compounds, in order to accelerate the reaction between the epoxy resin and the curing agent.

Furthermore, in the present invention, a silicone polymer may be blended into the composition for the purpose of reducing stress in the cured product. By adding a silicone polymer, it is possible to significantly reduce the occurrence of package scrubbing in a thermal shock test of a cured product.

Examples of silicone-based polymers include silicone oils having epoxy groups, amino groups, carboxyl groups, hydroxyl groups, hydrosilyl groups, vinyl groups, and the like.

Examples include silicone resins, silicone rubbers, and copolymers of these silicone polymers and organic polymers 1, such as substituted or unsubstituted phenol novolak resins, epoxidized phenol novolak resins, and the like.

The amount of silicone polymer added is not particularly limited, but usually the total amount of epoxy resin and curing agent used is 100
The amount is preferably 1 to 50 parts (parts by weight, hereinafter the same).

Next, as the filler used in the present invention, the particle size of the entire filler is 75. The content of the above particles is 1% (weight %, same hereinafter) or less, preferably 0.5% or less, and contains a specific spherical silica.

Here, as for the spherical silica, particles having a particle size of 75 Im or more account for 2% or less, preferably 1% or less of the total spherical silica, and the average particle size is 5-35. , preferably 8 to 32 units, and a specific surface area of 1.4 po/g or less, preferably 1r
Use one with rf/g or less.

It should be noted that if more than 1% of coarse particles with a particle size of 75 pm or more are present in the filler, the damage to the chip surface of the cured product will be increased and the moisture resistance will be impaired.

Furthermore, if the average particle size of the spherical silica is smaller than 5-5, the crack resistance of the cured product during heat cycling will be poor. On the other hand, if the average particle size exceeds 35 mm, wire flow occurs during molding, and furthermore, if spherical silica with a specific surface area larger than 1.4 m/g is used.

The fluidity of the composition is significantly reduced.

The spherical silica can be obtained by various methods, such as by melting natural quartz, by hydrolyzing or thermally melting purified chlorosilane or alkoxysilane, or by a sol-gel method.

In addition, in the present invention, only the above-mentioned specific spherical silica may be blended alone as a filler, but crushed fused silica may be used together with the above-mentioned spherical silica to the extent that the low expansion coefficient and high fluidity of the target composition are not impaired. , other inorganic fillers such as spherical silica and fumed silica having a specific surface area of more than 1 rrr/g can be used in combination. In this case, it is preferable that the blending ratio of the spherical silica is 50% or more of the total filler amount; if the blending amount is less than 50%, the fluidity of the composition will decrease and the moldability will be poor. It may happen.

Note that if the inorganic filler is used after being subjected to surface treatment with a silane coupling agent before use, a composition that provides a cured product with even higher moisture resistance can be obtained.

Furthermore, the blending amount of the filler is 250 to 700 parts, particularly 350 to 700 parts, based on 100 parts of the total amount of the epoxy resin and curing agent.
Preferably, the amount is 500 parts.

Various additives can be further added to the composition of the present invention, if necessary. Carnauba wax is preferably used from the viewpoint of moldability).

Flexibility imparting agents such as organic rubber, carbon black.

Pigments such as cobalt blue and red iron, antimony oxide,
Flame retardants such as halogen compounds 2 Surface treatment agents (Y-glycidoxyprobyltrimethoxysilane, etc.), coupling agents such as epoxysilane, vinyl silane, boromine compounds, alkyl titanates, anti-aging agents, etc. Additive 1
A species or two or more species can be blended.

In addition, 1. When producing the epoxy resin composition of the present invention, predetermined amounts of the above-mentioned components are uniformly stirred and mixed, and the epoxy resin composition is prepared in advance for 7
It can be obtained by heating it to 0 to 95°C, mixing it with a kneader, roll, extruder, etc., cooling it, and pulverizing it, but a melt mixing method using a mixing roll or extruder is particularly preferred. Adopted. Here, there is no particular restriction on the order of blending the components.

As mentioned above, the epoxy resin composition of the present invention includes IC,
It is used for sealing semiconductor devices such as LSIs, transistors, thyristors, and diodes, and can also be effectively used for manufacturing printed circuit boards.

Here, when sealing the semiconductor device, a conventional molding method such as transfer molding, injection molding, casting method, etc. can be used. In this case, the molding temperature of the epoxy resin composition is 15
0 to 180℃, post cure at 150 to 180℃
It can be carried out for ~16 hours.

11 people are ashamed The epoxy resin composition for semiconductor encapsulation of the present invention is as follows.

It has high fluidity and excellent moldability with almost no unfilling or wire flow during molding, and provides a cured product with a low coefficient of expansion and good moisture resistance. Therefore,
It can be effectively used as a sealing material for semiconductors such as ICs, LSIs, and transistors to prevent damage to fine patterns and wires and improve moisture resistance.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

In addition, in the following examples, all parts indicate parts by weight.

[Examples 1 to 4. Comparative Examples 1 to 5] Epoxy equivalent: 200. 58 parts of epoxidized cresol novolak resin with a softening point of 65°C, 6 parts of brominated epoxidized phenol novolak resin with an epoxy equivalent of 280, 36 parts of a phenol novolak resin with a phenol equivalent of 11o and a softening point of 80°C, 0.7 part of triphenylphosphine, A base containing 10 parts of antimony trioxide, 1.5 parts of carnauba wax, 1.6 parts of γ-glycidoxypropyltrimethoxysilane, and 1 part of carbon is mixed with 0.6 parts of γ-glycidoxypropyltrimethoxysilane. % surface-treated silica shown in Table 1 was blended in the amount shown in Table 2, melted and mixed on a mixing roll at 80°C for 5 minutes, taken out in the form of a sheet, cooled and pulverized to form a composition. Obtained.

The following tests were conducted on the obtained composition.

The results are also listed in Table 2.

(b) Spiral flow 175℃ using a mold that complies with EMMI standards.

Measurement was performed under the condition of 70 kgf/ffl.

(b) Expansion coefficient: Measured using a 5X5X5 test piece formed at 175℃ for 2 minutes and post-cured at 180℃ for 4 hours, using Agne (manufactured by Shinku Riko Co., Ltd.) at a heating rate of 5℃/1n. did.

(c) Using a DIP frame with 64 PINs and 600 ■ ill filling, 1
The composition was molded at 75°C, 70kgf/cj, and a preheat temperature of 85°C, and the fillability of the composition was measured. In this case, 0.5
Items with more than 100% unfilled were considered defective.

(d) Wire flow: 14 x 20 x 2.7 (Thickness) Using a frame of Peng's 100 PIN flat package, 175°C.

The flow of the gold wire during molding at 70 kgf/d and a preheat temperature of 85° C. was measured using soft X-rays, and the state of the flow of the gold wire was observed. As a result, when the flow is good, it is 0, and when it is slightly bad, it is Δ
, if it was bad, it was judged as ×.

(e) Moisture resistance Evaluation was performed using a 14-PIN DIP type semiconductor device using a test chip with a minimum line width of 1.5 parts m and a chip size of 45 mm. Molded at 175°C for 2 minutes, post-cured at 180°C for 4 hours, immersed in a 260°C solder bath for 10 seconds,
Next, the disconnection defect rate of the aluminum wiring was measured after being left in a pressure gunker at 130''C for 1000 hours.

From the results in Table 2, the epoxy resin compositions (Examples 1 to 4) containing spherical silica according to the present invention as a filler are as follows:
It was confirmed that the cured product has a small expansion coefficient, almost no filling defects or wire flow during molding, and provides a cured product with excellent moldability and good moisture resistance. On the other hand, the particle size is 75. Compositions containing silica whose particle content, average particle diameter, and specific surface area are outside the range of the present invention (Comparative Examples 1 to 5) cause poor filling and wire flow during molding, and the moisture resistance of the cured product also deteriorates. It was bad.

[Examples 5 to 11] Epoxy equivalent weight 198. 100 parts of an epoxidized cresol novolak resin with a softening point of 60'C, 6 parts of a brominated epoxidized phenol novolac resin with an epoxy equivalent weight of 280, and a phenol equivalent weight of 110. 33 parts of a phenol novolak resin with a softening point of 90°C, 25 parts of a reaction product of 60 parts of a compound of the following formula and 40 parts of a compound of the following formula, 0.65 part of triphenylphosphine, 10 parts of antimony trioxide, 1. A composition was obtained in the same manner as in Example 1 by adding silica of the type and amount shown in Table 3 to a base containing 2 parts of γ-glycidoxypropyltrimethoxysilane and 1 part of carbon. Ta.

The test results for the composition are also listed in Table 3.

Zero Silica 10: Average particle size 20yrx, particle size 75. More than 0
．． 1% by weight, 44-7571117% by weight, 12-10% by weight or less, specific surface area 0.8 I/g Spherical silica Wooden silica 11; Average particle size 0.5- Spherical silica Based on the results in Table 3, 1 The spherical silica according to the present invention is
Compositions containing 0% or more have a low expansion coefficient, and even if the amount of filler added is increased, there is almost no filling failure or wire flow during molding, and the composition has excellent moldability, and the cured product has excellent moisture resistance. The properties were also found to be good.

Applicant: Shin-Etsu Chemical Co., Ltd. Agent, Patent Attorney: Takashi Kojima Dougaku Itosale Amendment (voluntary) 6. Contents of the amendment (1) 1 on page 18, line 2 of the specification, 1. Indication of the case 1999 patent application No. 30813 2, Title of the invention: Epoxy resin composition and cured product for semiconductor encapsulation 3, Name of person making the amendment Address related to the case

Claims (1)

[Claims] 1. In an epoxy resin composition containing an epoxy resin, a curing agent, and a filler, the filler has an average particle size of 5 to 35 μm and a specific surface area of 1.4 m^2/g. An epoxy resin composition for semiconductor encapsulation, characterized in that it contains the following spherical silica and uses a filler in which the content of particles with a particle size of 75 μm or more is 1% by weight or less based on the total filler. 2. A cured product obtained by curing the epoxy resin composition for semiconductor encapsulation according to claim 1.