JP2001189333A - Semiconductor device and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor device of superior solidifying characteristics, bending, packing characteristics, and appearance through injection-molding with a molding material which is satisfactory in long-term conservation characteristics at normal temperature. SOLUTION: A semiconductor element is sealed with a injection molding device comprising an injection unit of screw in-line method, using an epoxy resin molding material comprising, as essential component, epoxy resin, phenol resin, hardening accelerator, and inorganic filler where an A component with the epoxy resin and inorganic filler being mixed, melted under heat, kneaded, and crushed, and a B component where the phenol resin, solidification accelerator, and remaining inorganic filler are mixed, molten under heat, kneaded, and crushed, are mixed together before molding under heat.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor device sealed by injection molding and a method for manufacturing the same.

[0002]

2. Description of the Related Art Semiconductor devices such as ICs, LSIs, and discretes are encapsulated mainly by transfer molding using an epoxy resin molding material, and are conventionally used as a method suitable for low cost, high reliability and productivity. Used from. In transfer molding, the majority of the epoxy resin molding material shaped into a tablet is put into a pot in a mold, and heated and melted, and pressed with a plunger.
In general, the resin is transferred into a mold cavity, cured, and molded.

This epoxy resin molding material contains an epoxy resin, a phenol resin, a curing accelerator, and an inorganic filler as essential components, weighs and mixes each component in a predetermined amount, heat-melts and kneads with a kneading machine, and after cooling, After being crushed and shaped into tablets, it is stored in a cool, dark place. When used, it is generally taken out of a cool and dark place and then left at room temperature until the molding material returns to room temperature. However, if it takes a long time to shape the epoxy resin molding material that has been heated, melted, kneaded, cooled, and pulverized with a kneader into tablets,
Alternatively, after forming into tablets, etc., store in a cool dark place at about 10 ° C to -20 ° C so as not to impair the quality of the molding material. To shape. There is no problem if the entire amount is used at the time of molding, but if the molding material remains, it must be stored again in a cool and dark place. If not stored in a cool and dark place, the quality will deteriorate significantly depending on the storage period, and if used without normal temperature restoration, condensation will occur due to differences in temperature environment and water will be absorbed, resulting in significant deterioration of quality. There are problems in handling such as these, cost reduction, mass productivity,
There is a limit to labor saving.

On the other hand, an epoxy resin and an inorganic filler are mixed, heated and melted, kneaded and crushed, and a phenol resin, a curing accelerator and an inorganic filler are mixed, heated and melted, kneaded and crushed, and the material is remixed. When transfer molding is performed by shaping into a tablet shape, molding of the molded product is possible, but there is a problem that the curing reaction between the epoxy resin and the phenol resin does not occur and the molded product cracks, blisters, etc. It was difficult to obtain a moldable and curable epoxy resin molding material.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a semiconductor device in which a semiconductor element is sealed with an injection molding machine having a screw-in-line type injection unit using a material which can be stored at room temperature for a long time, and a method of manufacturing the same. To provide.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an epoxy resin molding material comprising an epoxy resin, a phenol resin, a curing accelerator, and an inorganic filler as essential components, wherein the epoxy resin and the inorganic filler are mixed and heated and melted. A, kneaded and crushed
The component, a phenolic resin, a curing accelerator and the remaining inorganic filler are mixed, heated and melted, kneaded, and the crushed B component,
A semiconductor device in which a semiconductor element is sealed by an injection molding machine having a screw-in-line type injection unit using a molding material mixed before heat molding, and a method of manufacturing the semiconductor device.

Hereinafter, the present invention will be described. The epoxy resin molding material used in the present invention is not one in which all components are mixed, heated and melted, kneaded, but mixed with an epoxy resin and an inorganic filler, heated and melted, kneaded, crushed, and a phenol resin. And a hardening accelerator and the remaining inorganic filler are mixed, heated and melted, kneaded, and crushed to separately produce a B component. The A component and the B component are mixed before heat molding and used as a molding material. The shape of the molding material used in the present invention does not need to be in the form of a tablet used in transfer molding, and both component A and component B may be in the form of powder or granules, and the particle size is preferably 5 mesh or less. . It is desirable that the molding material in which the component A and the component B are mixed has excellent thermal stability in the cylinder of the injection unit, excellent fluidity in the cavity of the mold, and is quickly cured. The component A and the component B used in the present invention can be produced using the same production apparatus as the epoxy resin molding material generally used in transfer molding.

The component A of the present invention is prepared by weighing a predetermined amount of an epoxy resin and an inorganic filler, mixing them with, for example, a mixer, and then heating and melting and kneading them with a heating kneader, a twin-screw kneader or a hot roll. It is manufactured by cooling and crushing. The B component is produced in the same manner by weighing a predetermined amount of a phenol resin, a curing accelerator, and a residual inorganic filler. From the viewpoint of uniform dispersion of both the component A and the component B, it is preferable to use a meshing type co-rotating twin-screw kneader. The A component and the B component do not require the epoxy resin and the phenol resin as a curing agent to be mixed and heated and kneaded together, so that it does not need to be kept in a cool and dark place to prevent acceleration of the curing reaction, and uses a mixer before molding. Thus, the molding material can be prepared only by uniformly mixing the component A and the component B, so that there is no need to perform a process of returning the temperature from a low temperature to a normal temperature before use as used in the material for transfer molding.

The injection unit used in the present invention is preferably a screw-in-line type from the viewpoint of uniformity of heat melting / kneading and easy temperature control. Since the shape of the material used in the injection unit method is powder or granule, it is not necessary to shape it into a tablet as in the case of transfer molding. A used in the present invention
The epoxy resin, the phenol resin, the curing accelerator, and the inorganic filler in the component and the component B are the same as the raw materials used for the epoxy molding material used for sealing the semiconductor element with the transfer molding machine, and are particularly limited. Not something. The epoxy resin refers to a monomer, oligomer, or polymer having two or more epoxy groups in one molecule. A phenol resin refers to a monomer, oligomer, or polymer having two or more phenolic hydroxyl groups in one molecule. The curing accelerator promotes the reaction between the epoxy group and the phenolic hydroxyl group, and includes amine compounds such as 1,8-diazabicyclo (5,4,0) undecene-7, triphenylphosphine, tetraphenylphosphonium tetra Phosphorus compounds such as phenylborate salts, 2-
Examples include an imidazole compound of methyl imidazole. As the inorganic filler, fused silica, crystalline silica,
Examples include alumina, silicon nitride, and aluminum nitride. The molding material used in the present invention contains an epoxy resin, a phenol resin, a hardening accelerator, and an inorganic filler as essential components. If necessary, a brominated epoxy resin, antimony oxide, and ion trapping material used in a transfer molding material are used. A component, a carbon black, a release agent, a low stress agent, a silane coupling agent, and the like may be appropriately contained in the component A or the component B.

[0010]

The present invention will be described below with reference to examples. The parts by weight indicate parts by weight. Example 1 Component A Orthocresol novolak type epoxy resin (epoxy equivalent 200) 150 parts Fused silica (average particle size 23 μm) 480 parts γ-glycidoxypropyltrimethoxysilane 3 parts Release agent 4 parts Colorant, low stress, etc. 29 parts of the above additive were heated and melted, kneaded and pulverized with an interlocking coaxial biaxial kneader to obtain an A component. Component B Phenol novolak resin (hydroxyl equivalent 104) 73 parts Fused silica (average particle size 23 μm) 240 parts Tetraphenylphosphonium / tetraphenylborate 2 parts γ-glycidoxypropyltrimethoxysilane 2 parts Release agent 3 parts Coloring And 14 parts of additives such as low stress, etc. The above materials were heated and melted, kneaded and pulverized by an intermeshing type biaxial kneader to obtain a B component. The components A and B were mixed before molding to form a molding material, and the room temperature storage property was measured. Further, they were mixed to form a molding material, and were heated and melted and kneaded in an injection unit having a screw in-line system to evaluate physical properties such as fluidity, curability and bending strength. 64pQFP 2
In a fully automatic injection molding system having a screw in-line system with a frame forming die, the A component and the B component immediately after production were mixed and subjected to actual molding to evaluate moldability. Table 1 shows the results of these evaluations.

Evaluation method Room temperature storage: Spiral when a molding material obtained by mixing component A and component B is injected into a mold at a temperature of 175 ° C. with a plunger at a pressure of 70 kgf / cm ² and cured for 2 minutes. The initial value of the flow was used as the denominator, and the value of the spiral flow of the molding material stored at 25 ° C. after the number of days elapsed was expressed as a percentage using the numerator as the numerator. In Example 1, the A component and the B component were separately stored, mixed and evaluated before measurement. Curability: 6 g of the mixed molding material is shaped into a tablet having a diameter of 35 mm, and using the tablet, the mold temperature is set to 175 with a Curastometer VPS manufactured by Orientec Co., Ltd.
C. and the curability was measured at the rise of the torque. Flexural strength: A test piece was prepared from a molding material in accordance with JIS K 6911 and measured in a 25 ° C. atmosphere using a Tensilon material testing machine manufactured by Orientec. Moldability: The filling property and the appearance of the molded article were visually observed. Comparative Examples 1 and 2 Comparative Example 1 was manufactured in the same manner as in the molding material for transfer molding according to the composition shown in Table 1, and evaluated in the same manner as in Example 1. The room temperature storage property was evaluated by standing at room temperature. The material immediately after production was transfer molded. In Comparative Example 2, a mixture of the component A and the component B was allowed to stand at room temperature, and the room temperature storage property was evaluated. A mixture of the component A and the component B immediately after production was subjected to transfer molding. Table 1 shows the evaluation results.

[0012]

[Table 1]

[0013]

According to the present invention, a semiconductor device having excellent curability, bending strength, filling property and appearance can be obtained by performing an injection molding machine using a molding material excellent in long-term room temperature storage stability. it can.

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Claims (2)

[Claims] An epoxy resin molding material comprising an epoxy resin, a phenol resin, a curing accelerator, and an inorganic filler as essential components, wherein the epoxy resin and the inorganic filler are mixed, heated and melted, kneaded, and crushed. Using a molding material obtained by mixing a phenolic resin, a curing accelerator and the remaining inorganic filler, heating and melting, kneading, and crushed B components before heat molding, a screw-in-line injection unit for a semiconductor element is formed. A semiconductor device characterized by being sealed by an injection molding machine. 2. An epoxy resin molding material comprising an epoxy resin, a phenolic resin, a curing accelerator, and an inorganic filler as essential components, wherein the epoxy resin and the inorganic filler are mixed, heated and melted, kneaded, and crushed. Using a molding material obtained by mixing a phenolic resin, a curing accelerator and the remaining inorganic filler, heating and melting, kneading, and crushed B components before heat molding, a screw-in-line injection unit for a semiconductor element is formed. A method for manufacturing a semiconductor device, wherein the semiconductor device is sealed by an injection molding machine.