JPH115888A - Resin composition for sealing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition used for sealing semiconductors, enabling transportation and storage at the ordinary temperature and not requiring a conventional refrigerator and the leaving of the composition at the ordinary temperature to avoid the absorption of moisture. SOLUTION: This resin composition contains an epoxy resin, a phenolic resin curing agent, a curing accelerator and an inorganic filler as essential components. Therein, (E) a powdery material obtained by melting and kneading the epoxy resin with a part or all of the inorganic filler and having the maximum particle diameter of <=3 mm, and (F) a powdery material obtained by malting and kneading the phenolic resin curing agent and the curing accelerator with the remainder of the inorganic filler and having the maximum particle diameter of <=1.5 mm are separately packed, and subsequently mixed with each other before molded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for semiconductor encapsulation which does not require low-temperature transportation, low-temperature storage, and standing at room temperature before use.

[0002]

2. Description of the Related Art Conventionally, electronic components such as diodes, transistors, and integrated circuits are sealed with a thermosetting resin. In particular, an integrated circuit is obtained by curing an epoxy resin having excellent moisture resistance and electric characteristics with a phenol resin. An epoxy resin composition (hereinafter, referred to as a resin composition) is used. However, these resin compositions have a curing accelerator uniformly mixed therein, and the reaction proceeds slowly at room temperature, and the fluidity is impaired with the passage of time. In order to avoid moisture absorption at the time of opening, it is necessary to leave at room temperature for 8 to 24 hours before use. Furthermore, the shelf life after standing at room temperature is often within one week, and when the shelf life is not enough within one week after standing at room temperature, it is not uncommon to discard it without necessity. For these reasons, there is a strong demand for the development of a resin composition for semiconductor encapsulation that does not require low-temperature transport, low-temperature storage, or standing at room temperature before use. No examples have been reported yet.

[0003]

SUMMARY OF THE INVENTION The present invention provides a resin composition for semiconductor encapsulation which does not require low-temperature transportation, low-temperature storage, and standing at room temperature before use.

[0004]

The present invention provides a resin composition comprising (A) an epoxy resin, (B) a phenolic resin curing agent, (C) a curing accelerator, and (D) an inorganic filler as essential components. (A) and powder (E) having a maximum particle size of 3 mm or less obtained by melting and kneading a part or all of (D);
Powders (F) having a maximum particle size of 1.5 mm or less obtained by melting and kneading the remainder of (B), (C), and (D) are separately packaged, and before molding, (F) and (E) are mixed. A resin composition for encapsulating a semiconductor, characterized in that (F) is mixed and used, and this resin composition does not impair various properties even when transported or stored at room temperature.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The resin composition of the present invention is characterized in that an epoxy resin, a phenol resin curing agent and a curing accelerator are separately packaged. By separately packing the phenolic hydroxyl group and the curing accelerator so that they do not come into contact with each other, transport and storage at room temperature are possible. Therefore, the types and properties of the respective raw materials are not particularly limited, but the components (A) and (B), or the components (A) and (C) are melt-kneaded or mixed in the same package. Must not be saved. When both are brought into contact with each other, the reaction between the epoxy group and the phenolic hydroxyl group proceeds slowly even at room temperature, and it becomes impossible to maintain proper fluidity. Therefore, refrigerated storage is required. Moreover, even if the inorganic filler is melt-kneaded with either the powder (E) or the powder (F),
It is possible to melt and knead both parts separately, but it is preferable to knead both parts separately in order to avoid segregation and classification of powder (E) and powder (F) during mixing before molding. As the particle size of these powders, the maximum particle size of the powder (E) is 3 mm.
Hereinafter, the maximum particle size of the powder (F) is preferably 1.5 mm or less. When the maximum particle size of the powder (E) exceeds 3 mm, when the powder mixed using a small molding machine is used little by little,
One component is undesirably segregated, and a uniform curing reaction does not occur, leading to poor mold release and reduced reliability. If the maximum particle size of the powder (F) exceeds 1.5 mm, the amount of the curing accelerator locally increases, so that uniform flow and curing behavior in the mold cannot be obtained, poor filling, and mold release. Poor sex,
This is not preferable because it leads to poor reliability and the like.

The particle shapes of the powder (E) and the powder (F) are not particularly limited. However, in consideration of segregation and classification at the time of mixing, it is preferable that both have similar particle shapes. The packaging form is not particularly limited as long as the resin composition is not exposed to moisture or light, but as the packaging material, an aluminum bag or the like is preferable because of excellent handling efficiency.

Hereinafter, each component will be described. The epoxy resin, phenolic resin curing agent, curing accelerator and inorganic filler used in the present invention may be the same as those usually used in epoxy resin compositions for semiconductor encapsulation. The epoxy resin used in the present invention is not particularly limited as long as it has two or more epoxy groups in one molecule and is a solid at room temperature. For example, a bisphenol type epoxy compound, a biphenyl type epoxy compound Phenol novolak type epoxy resin, cresol novolak type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, and the like, and these may be used alone or in combination.

The phenolic resin curing agent used in the present invention is not particularly limited as long as it is solid at room temperature. Resins, terpene-modified phenolic resins and the like, which may be used alone or as a mixture.

The amount of the phenol resin curing agent in the mixture of the powder (E) and the powder (F) is such that the ratio of the number of epoxy groups of the epoxy resin to the number of phenolic hydroxyl groups of the phenol resin is 0.8. It is preferable to set it to 1.3.

The inorganic filler used in the present invention includes, for example, fused silica powder, crystalline silica powder, alumina, silicon nitride and the like, and these may be used alone or as a mixture. The amount of the inorganic filler in the mixture of the powder (E) and the powder (F) is determined based on the balance between moldability and reliability.
60 to 90% by weight of the total resin composition is preferred.

The curing accelerator used in the present invention may be any one which promotes the curing reaction between the epoxy group of the epoxy resin and the phenolic hydroxyl group of the phenol resin. Can be used. For example, 1,8-diazabicyclo (5,4,
0) Undecene-7, triphenylphosphine, 2-methylimidazole, etc., and these may be used alone or in combination.

The resin composition of the present invention contains the components (A) to (D) as essential components. In addition, if necessary, a silane coupling agent, a coloring agent such as carbon black, a carnauba wax or the like. Various additives such as a release agent, a low-stress agent such as silicone oil, and a flame retardant such as antimony trioxide may be appropriately compounded. Among the resin composition of the present invention,
As the powder (E), for example, epoxy resin, part or all of an inorganic filler, and part or all of various additives, as the powder (F), for example, a phenol resin curing agent, a curing accelerator, The remainder of the inorganic filler, and the rest of the various additives, after each is mixed sufficiently uniformly using a mixer, etc., further melt-kneaded with a heating roll, or a kneader, etc., cooled and then pulverized. , Then powder (E), powder (F)
Packing separately. The powder (E) and the powder (F) may be stored at room temperature, mixed with each other by a predetermined amount immediately before sealing the semiconductor, and used as a tablet or may be used in a mixed state. . The method for producing each powder is not particularly limited. Hereinafter, the present invention will be described specifically with reference to Examples. The present invention is characterized in that an epoxy resin, a phenol resin curing agent and a curing accelerator are packed in a non-contact state, but the present invention is not limited to the following examples.

Embodiment 1 1. Formulation A (powder A) Orthocresol novolak type epoxy resin (softening point 55 ° C., epoxy equivalent 205) (hereinafter referred to as epoxy resin) 12.0 parts by weight Fused silica powder (average particle size 13 μm) 40.0 parts by weight Carbon black 0.1 parts by weight Carnauba wax 0.3 parts by weight 2. Formulation B (powder B) Phenol novolak resin (softening point 65 ° C., hydroxyl equivalent 104) 6.0 parts by weight 1,8-diazabicyclo (5,4,0) undecene-7 (hereinafter referred to as DBU) 0.2 part by weight Parts Fused silica powder (average particle size 13 μm) 40.0 parts by weight Carbon black 0.1 part by weight Silicone oil 0.3 part by weight Antimony trioxide 1.0 part by weight Each of compounding A and compounding B was mixed using a mixer The mixture was mixed at room temperature, melt-kneaded with a heating roll at 80 to 100 ° C., cooled and pulverized to obtain powder A and powder B. The particle size of the powder A is
9 mesh on is 4% by weight, 9 mesh pass to 32 mesh on is 54% by weight, 32 mesh pass is 42% by weight, maximum particle size is 2.7mm, and particle size of powder B is 16 mesh on is 3% by weight. , 16 mesh pass to 32 mesh on were 61% by weight, 32 mesh pass was 36% by weight, and the maximum particle size was 1.2 mm. The maximum particle diameter was determined by measuring the largest one of the powder remaining on the sieve with a caliper.

Evaluation method Spiral flow: 500 g each of powder A and powder B
After weighing, mix well in plastic bag, EMMI-I
Using a mold conforming to -66, using a low-pressure transfer molding machine, 175 ° C, injection pressure 70 kgf / cm ² ,
Molding was performed under the conditions of a dwelling time of 120 seconds, and the spiral flow was measured immediately after production and after 30 days (unit: cm). 30
The spiral flow after the day was measured by storing powder A and powder B separately at room temperature (25 ° C.). Spiral flow residual ratio: Spiral flow after storage for 30 days at room temperature is 90% of spiral flow immediately after production
The above samples were judged as acceptable (○), and those with less than 90% were judged as unacceptable (X). Releasability: When the spiral flow was measured, the cured product that was released only by blowing air was judged as acceptable (O), and the one that did not release without peeling using a jig was judged as unacceptable (X).

Examples 2 to 6 and Comparative Examples 1 to 6 Powders were produced in the same manner as in Example 1 and evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2. In Comparative Example 2, the resin composition was mixed at once without dividing the mixture into powder A and powder B.

[Table 1]

[0016]

[Table 2]

[0017]

According to the present invention, a resin composition for semiconductor encapsulation which can be transported at normal temperature and stored at normal temperature, does not require conventional refrigeration equipment, and does not need to be left at normal temperature to avoid moisture absorption, and has excellent workability. can get.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 23/29 H01L 23/30 R 23/31

Claims (1)

[Claims] 1. A resin composition comprising (A) an epoxy resin, (B) a phenolic resin curing agent, (C) a curing accelerator, and (D) an inorganic filler as essential components, wherein (A) and (D) The maximum particle size obtained by melting and kneading part or all of
The following powder (E) and the powder (F) having a maximum particle size of 1.5 mm or less obtained by melting and kneading the rest of (B), (C) and (D) are separately packaged. A resin composition for encapsulating a semiconductor, wherein (E) and (F) are mixed and used before molding.