JPS62101055A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve an adhesive state, to interrupt the intrusion path of water and to enhance damp-proofing by constituting a sealing plastic package by using an epoxy resin composition as a special reaction product. CONSTITUTION:A sealing package is organized by employing an epoxy resin, a reaction product from a silane compound having at least one of a methoxy group and an ethoxy group in a molecule and a phenol resin, and inorganic fillers. The epoxy resin has two or more of epoxy groups in one molecule. THe reaction product from the silane compound having at least one of the methoxy group or the ethoxy group in the molecule and the phenol resin functions as a curing agent for the epoxy resin, and is acquired by arbitrarily combining the phenol resin and the silane compound and reacting them. Quartz glass powder and crystalline silica powder are proper as the inorganic fillers.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a highly reliable semiconductor device.

[Conventional technology]

Semiconductor elements such as transistors, ICs, and LSIs are usually packaged in ceramic packages or plastic packages. It has been turned into a semiconductor device. The above-mentioned ceramic package is resistant to temperature and humidity because the constituent material itself has heat resistance and is excellent in 5fFA resistance.Moreover, since it is a hollow package, it has high mechanical strength and is highly reliable. is possible. However, since the constituent materials are relatively expensive and the mass productivity is poor, resin sealing using the above-mentioned plastic package has recently become mainstream. As such resins for semiconductor encapsulation, epoxy resin compositions containing epoxy resin, novolac type phenolic resin, and inorganic filler as main components, and further containing a curing accelerator, a coloring agent, and a mold release agent have been praised. .

[Problem that the invention seeks to solve]

However, semiconductor devices encapsulated with such epoxy resin compositions are easier to operate and more economical than semiconductor devices obtained by conventional hermetic encapsulation methods using metal or ceramic materials. Although it has the advantage of being superior, it has the disadvantage that the aluminum wiring or aluminum electrodes of the sealed semiconductor device corrode due to moisture absorption, and this corrosion causes the aluminum wiring to break, resulting in defects. This is because water enters the semiconductor device from the interface between the encapsulating resin and the lead frame or from the surface of the encapsulating resin, and when the infiltrated water permeates through the encapsulating resin, ionic impurities in the encapsulating resin are generated. It is thought that these ionic impurities act as carriers and cause corrosion of aluminum wiring or aluminum electrodes.

Therefore, research is progressing on the development of semiconductor devices with excellent moisture resistance that prevents water from penetrating into the semiconductor devices, and research is underway to develop semiconductor devices that contain silane coupling agents in resin compositions and surface treatment of inorganic fillers. It has been proposed that
However, the reality is that sufficient effects have not been obtained.

This invention was made in view of these circumstances,
The purpose is to provide a semiconductor device which has excellent moisture resistance and corrosion resistance, and whose plastic package itself has excellent mechanical properties.

[Means for solving problems]

In order to achieve the above object, the semiconductor device of the present invention includes:
The structure is such that a semiconductor element is sealed using an epoxy resin composition containing the following components (A) to (C).

(A) Epoxy resin.

(B) A reaction product of a silane compound having at least one of a methoxy group and an ethoxy group in the molecule and a phenol resin.

(C) Inorganic filler.

That is, with the aim of obtaining a semiconductor device with excellent moisture resistance and even corrosion resistance, the present inventors carefully considered the main route of water infiltration into a semiconductor device, and found that an inorganic filler dispersed in the sealing resin. Confirm that this is the void at the interface between the filler particle and the surrounding resin, and the interface between the lead frame and the resin, and check the adhesion of the sealing resin to the inorganic filler particle and the lead frame in order to block the above-mentioned path. A series of studies were conducted to improve this. As a result, they discovered that the desired purpose could be achieved by using a reaction product of a silane compound having at least one of a methoxy group and an ethoxy group in the molecule and a phenolic novolac as a curing agent for epoxy resin. The invention has been achieved.

As mentioned above, the epoxy resin composition used in this invention is a reaction product of an epoxy resin (component A), a silane compound having at least one of a methoxy group and an ethoxy group in the molecule, and a phenol resin (component B). and an inorganic filler (component C), and is usually in the form of a powder or a tablet formed by compressing it.

The epoxy resin serving as the above-mentioned A component is not particularly limited as long as it has two or more epoxy groups in one molecule. Various epoxy resins are used as sealing resins. Among these resins, it is preferable to use one that has a melting point above room temperature and is in the form of a solid or highly viscous solution at room temperature. As a novolac type epoxy resin, usually epoxy grade 160-25
0. A cresol novolak type epoxy resin with a softening point of 50 to 130°C is used, and an epoxy equivalent of 1
80-210. Those having a softening point of 60 to 110°C are generally used.

The reaction product of a phenolic resin and a silane compound having at least one of a methoxy group and an ethoxy group in the molecule, which is used together with the epoxy resin, acts as a curing agent for the epoxy resin, It is obtained by reacting any combination of the following phenol resin and silane compound.

Here, as the phenol resin, phenol novolak, O-talesol novolak, m-talesol novolak, p-talesol novolak, 0-ethylphenol novolak, m-ethylphenol novolak, p-
Ethylphenol novolak etc. can be used, while silane compounds include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-eboxycyclohexyl)ethyl 1 -rimethoxysilane, 3-glycidoxypropylmethylmethoxydiethoxysilane, 3-glycidoxypropyltriethoxydisilane, etc. can be used.

The reaction between the phenol resin and the silane compound can be shown as follows, for example, when the silane compound is 3-glycidoxyprobyltrimethoxysilane.

The reaction rate of such phenolic resin and silane compound is
It is preferably 85% or more, particularly preferably 95% or more. In addition, the blending ratio of the silane compound to the phenol resin is 0.1 to 10% by weight (hereinafter "%").
”) is preferable.

As the inorganic filler for component C, commonly used quartz glass powder, talc, crystalline silica powder, alumina powder, clay, calcium oxide, zirconium oxide, zirconium silicate, beryllium oxide, glass fiber, etc. can be used as appropriate. In particular, quartz glass powder and crystalline silica powder are suitable.

Moreover, in this invention, in addition to the above-mentioned components A, B, and C, a curing accelerator, a mold release agent, etc. can be used as necessary. As the curing accelerator, any catalyst for the curing reaction of the phenol-cured epoxy resin can be used, such as 2,4,6-tri(dimethylaminomethyl)phenol, 2-methylimidazole, etc. can. As the mold release agent, conventionally known long-chain carboxylic acids such as stearic acid and barmitic acid, metal salts of long-chain carboxylic acids such as zinc stearate and calcium stearate, and waxes such as carnauba wax and montan wax may be used. I can do it.

The epoxy resin composition used in this invention can be produced, for example, as follows. That is, the above-mentioned components and other additives such as pigments and coupling agents are appropriately blended, and the mixture is kneaded in a heated state using a kneading machine such as a mixing roll machine to melt and mix, and the mixture is cooled to room temperature. Then, the desired epoxy resin composition can be obtained through a series of steps of pulverizing by known means and, if necessary, tableting.

Sealing of a semiconductor element using such an epoxy resin composition is not particularly limited, and can be performed by a conventional method, for example, a known molding method such as transfer molding.

The semiconductor device thus obtained is sealed using an epoxy resin composition containing a reaction product of a phenol resin and a silane compound having at least one of a methoxy group and an ethoxy group in the molecule as a curing agent for the epoxy resin. The adhesion of the resin is improved at the interface between the inorganic filler particles and the resin and the interface between the lead frame and the resin, blocking the path of water ingress, resulting in moisture resistance (IIliJ corrosion resistance). significantly superior to Also,
The sealed plastic package itself also has excellent mechanical strength.

〔Effect of the invention〕

As described above, the semiconductor device of the present invention is encapsulated using a special epoxy resin composition containing a reaction product of a phenol resin and a silane compound having at least one of a methoxy group and an ethoxy group in the molecule. Since the sealed plastic package is different from those made from conventional epoxy resin compositions, the adhesion between the resin component and inorganic filler such as silane powder and the adhesion between the resin component and the lead frame are good. Water infiltration routes are blocked, making it highly moisture resistant. Therefore, corrosion of aluminum wiring, aluminum electrodes, etc. does not occur, and reliability is greatly improved. In addition, the above-mentioned sealed plastic package has excellent mechanical properties, and can be used not only for semiconductor devices such as transistor elements and integrated circuits, but also for VL devices such as memories, microcombiners, and single-unit devices.
It can be widely used up to SI (ultra high density integrated circuit).

Next, examples will be described.

[Examples 1 to 8] First, a phenol resin and a silane compound were reacted to obtain a curing agent (component B). Next, the above curing agent and other raw materials are mixed and processed using a mixing roll machine (roll temperature 80 to 90).
The mixture was melt-kneaded for 10 minutes at a temperature of 100° C.), cooled and solidified, and then pulverized to obtain the desired powdered epoxy resin composition. The composition of each raw material was as shown in Table 1 below.

(The following is a blank space) [Comparative Examples 1 and 2] A simple phenol novolac resin was used instead of the reaction product of a phenol novolac resin and a silane compound.

Other than that, a powdered epoxy resin composition (Comparative Example 1) was obtained in the same manner as in Examples 1 to 8.

Further, instead of the reaction product of the phenol novolac resin and the silane compound, 90 parts by weight of the phenol novolac resin and 2 parts by weight of 3-glycidoxylopropyltrimethoxysilane were used as they were without reacting them. A powdered epoxy resin composition (Comparative Example 2) was obtained in the same manner as in Examples 1 to 8 except for the above.

A semiconductor device was obtained by molding a semiconductor element by transfer molding (170° C., 2 minutes) using the powdered epoxy resin composition obtained in the above Examples and Comparative Examples. Regarding the semiconductor device thus obtained, boiling ρV characteristic 1 flexural modulus, water absorption, corrosion resistance, etc. were measured. The above bending elastic modulus is JIS-K-691
According to 1, the water absorption rate is 40℃/95%R11, 60℃/95%R1 after molding the epoxy resin composition used for the actual height measurement and comparative height measurement into a disk with a diameter of 50 fins and a thickness of 1 crane.
The weight change was determined by standing for 50 hours under the following conditions: 1.degree. 80.degree. C./95% R1+. The above-mentioned corrosion resistance was evaluated by measuring the disconnection time due to corrosion of the aluminum wiring or electrodes in an atmosphere of 145° C., 95% RH, and 4,000 ml of atm.

The results of these measurements are shown in Table 2 below.

(Left below) From the results in Table 2, it can be seen that the plastic package of the actual height measurement has a lower water absorption rate, better corrosion resistance, and better mechanical properties than the comparative product. .

In addition, in the epoxy resin composition that was measured,
It is clear from the reaction mechanism of the curing reaction that the silane compound reacts with the phenol resin and is incorporated as a reaction product.

Claims (1)

[Claims] (1) A semiconductor device in which a semiconductor element is encapsulated using an epoxy resin composition containing the following components (A) to (C). (A) Epoxy resin. (B) A reaction product of a silane compound having at least one of a methoxy group and an ethoxy group in the molecule and a phenol resin. (C) Inorganic filler.