JPH0733860A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition containing an epoxy resin, a phenol resin curing agent, an inorganic filler, a curing promoter and a specified amount of a specified benzimidazole-based compound, excellent in adhesion to copper, resistance to solder cracking and moisture resistance and useful for surface mounting sealing, etc. CONSTITUTION:The objective resin composition contains (A) an epoxy resin, (B) a phenol resin curing agent, (C) a benzimidazole-based compound of the formula (R1 is CH, N or CSH), (D) an inorganic filler and (E) a curing promoter as the essential components. The content of the component (C) is 0.05 to 2.0wt.% based on the whole resin composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a resin composition having excellent adhesion to copper.

[0002]

2. Description of the Related Art Conventionally, electronic parts such as diodes, transistors and integrated circuits have been sealed with a thermosetting resin. Especially in integrated circuits, O-cresol novolac epoxy resin which is excellent in heat resistance and moisture resistance is used as a novolac resin. An epoxy resin composition cured with a type phenolic resin is used. In recent years, semiconductor packages have tended to have a large number of pins and to be small and thin. Along with this, the degree of integration has been improved and the speed has been increased by narrowing the pitch of the design rule, and the power consumption tends to increase. With respect to the high power consumption of this element, each semiconductor manufacturer applies a copper alloy lead frame to a conventional 42 alloy lead frame. Alternatively, a copper heat spreader is used. Also,
Due to the miniaturization and thinning of packages, the semiconductor mounting method has changed from the conventional insertion type to the surface mounting type (VPS reflow type, I type).
R reflow type, solder dipping method, etc.). Due to the surface mounting type mounting method, a phenomenon in which the interface between the copper alloy lead frame and the sealing material or the interface between the heat spreader and the sealing material is separated when the package is rapidly exposed to a high temperature of 200 ° C. or higher in the solder dipping process However, there is a problem that moisture resistance is deteriorated and reliability is lowered. Therefore, there is an urgent need to develop a resin composition having excellent adhesion to copper.

[0003]

SUMMARY OF THE INVENTION The present invention provides a resin composition having excellent adhesion to copper against such problems.

[0004]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve these problems and found a resin composition having the following composition. That is, the present invention provides: (A) epoxy resin (B) phenolic resin curing agent (C) benzimidazole compound represented by formula (1)

[0005]

[Chemical 2]

(D) An inorganic filler and (E) a curing accelerator are essential components, and the benzimidazole compound is contained in an amount of 0.05 to 2.0% by weight in the total resin composition. It is a stopping resin composition.

The present invention will be described in detail below. Formula (1)
The imidazole structure of the benzimidazole-based compound shown in Fig. 3 forms a complex with a metal, while the benzene ring has an affinity with the resin component. Become. R ₁ of the substituent of the benzimidazole compound used in the present invention is CH,
Either N or CSH compound is effective. You may mix and use these compounds. The amount of the benzimidazole-based compound added is from 0.05 to 0.05 in the total resin composition.
It is preferably 2.0% by weight. If it is less than 0.05% by weight, the effect of adhesion to copper is weak, and if it exceeds 2.0% by weight, the fluidity is insufficient, which is not suitable.

The epoxy resin used in the present invention is a general polymer having an epoxy group. For example, bisphenol type epoxy resin, cresol novolak type epoxy resin, biphenyl type epoxy resin, phenol novolac type epoxy resin and triphenol methane type epoxy resin, trifunctional epoxy resin such as alkyl modified triphenol methane type epoxy resin, triazine nucleus-containing epoxy resin Etc. The phenol novolac resin curing agent used in the present invention refers to all polymers having a phenolic hydroxyl group. For example, phenol novolac resin, cresol novolac resin, dicyclopentadiene modified phenol resin, co-condensation product of dicyclopentadiene modified phenol resin and phenol novolac or cresol novolac resin, paraxylylene modified phenol resin and the like can be used. The ratio of the epoxy group equivalent of the epoxy resin and the hydroxyl group equivalent of the phenol resin is preferably 0.8 to 1.2.

As the inorganic filler used in the present invention, fused silica powder, spherical silica powder, crystalline silica powder, secondary agglomerated silica powder, porous silica powder, secondary agglomerated silica powder or silica obtained by pulverizing porous silica powder is used. Examples thereof include powder and alumino, and fused silica powder is particularly preferable. The amount of the inorganic filler in the entire composition is preferably 70 to 90% by weight.
The curing accelerator used in the present invention may be any one as long as it accelerates the reaction between the epoxy resin and the phenolic hydroxyl group, and those generally used for the encapsulating material can be widely used, for example, diazabicyclo. Undecen (DB
U), triphenylphosphine (TPP), tetraferulphosphonium tetraphenorborate (TPP-
K), dimethylbenzylamine (2MZ) and the like are used alone or in combination of two or more.

The encapsulating epoxy resin composition of the present invention contains an epoxy resin, a phenol resin curing agent, a benzimidazole compound, an inorganic filler and a curing accelerator as essential components. Ring agents, brominated epoxy resins, flame retardants such as antimony trioxide and hexabromobenzene, colorants such as carbon black and red iron oxide, release agents such as natural wax and synthetic wax, and low stress additives such as silicone oil and rubber. Various additives such as the above may be appropriately blended. Further, in order to produce the encapsulating epoxy resin composition of the present invention as a molding material, the epoxy resin, the curing agent, the benzimidazole compound, the curing accelerator, the filler, and other additives are sufficiently homogenized with a mixer or the like. After mixing, the mixture can be further melt-mixed with a hot roll or a kneader, cooled and pulverized to obtain a molding material. These molding materials can be applied to sealing, coating, insulating, etc. of electronic parts or electric parts.

The present invention will be shown below with reference to examples. The mixing ratio is parts by weight. Examples 1 to 4, Comparative Examples 1 to 4 Benzimidazole compound represented by formula (2)

[0012]

[Chemical 3]

Epoxy resin (3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenylglycidyl ether) Orthocresol novolac epoxy resin (epoxy equivalent 200, softening point 55 ° C) Formula (3 ) Phenolic resin curing agent (hydroxyl equivalent 170, softening point 70 ° C.) (n = 1: 20% by weight, n = 2: 60% by weight, n = 3: 20% by weight)

[0014]

[Chemical 4]

Phenol novolac resin (hydroxyl group equivalent 104, softening point 95 ° C.) Brominated bisphenol type epoxy resin (epoxy equivalent 273, softening point 65 ° C.) triphenylphosphine, fused silica powder, antimony trioxide, epoxy silane Carbon black and carnauba wax are mixed in the respective proportions shown in Table 1 at room temperature with a mixer, kneaded with a biaxial roll at 70 to 100 ° C., cooled and pulverized to obtain a molding material, which is tableted into a semiconductor encapsulation. An epoxy resin composition for use was obtained. A low-pressure transfer molding machine (molding conditions: 175 ° C., 70 kg / c)
m ² for 120 seconds), and the resulting molded product is 1
It was post-cured at 75 ° C. for 8 hours and evaluated. The evaluation results are shown in Table 1.

Evaluation method * 1 Spiral flow Using a mold for spiral flow measurement according to EMMI-I-66, a sample was molded at 15 g, a molding temperature of 175 ° C., a molding pressure of 70 kg / cm ² , and a molding time of 2 minutes. Molded product length * 2 Solder cracking property test 80 pQFP package (chip size 81 mm ² , package thickness 2.0 mm, copper frame) 20 pieces 8
After treatment for 72 hours under steam at 5 ° C / 85% RH, 260
The number of molded products in which a crack was generated after immersion in a solder bath at ℃ for 10 seconds is shown. * 3 Solder moisture resistance test Test element (16pSOP) at 85 ℃, 85% RH
72Hr treatment in the environment of, and then immersed in a solder bath at 260 ° C for 10 seconds, and then subjected to a pressure cooker test (125
C., 100% RH) and the number of open defects in the circuit was measured. * 4 Presence or absence of peeling between the lead frame and the sealing resin of the QFP molded product After the solder cracking test evaluation package is molded, the lead frame is sealed with the lead frame sealing resin by an ultrasonic flaw detector. The adhesion of the resin was examined. * 5 Lead adhesion strength Using the tensile shearing jig 1 shown in Fig. 1, the sealing resin part 2
The adhesion force between the and the flat plate 3 of the lead frame material was examined by measuring the tensile shear strength. (Adhesive area:
1.0cm ² , shape: circle)

[0017]

[Table 1]

[0018]

EFFECT OF THE INVENTION The resin composition according to the present invention is highly reliable as a surface mounting encapsulating resin composition because it has excellent adhesion to copper and extremely excellent solder crack resistance and moisture resistance. It is a thing.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a test piece is fixed to a tensile shearing jig.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C08K 5/3445 H01L 23/29 23/31

Claims (1)

[Claims] 1. (A) Epoxy resin (B) Phenolic resin curing agent (C) Benzimidazole compound represented by formula (1) (D) Inorganic filler and (E) Curing accelerator as essential components, and the benzimidazole compound is contained in the total resin composition in an amount of 0.05 to 2.0% by weight. Composition.