JPS63148663A - Semiconductor device - Google Patents

Abstract

PURPOSE:To decrease internal stress and to improve reliability of heat-resisting performance and reliability of damp-proof performance under severe service conditions, by using specific epoxy resin components so as to seal a semiconductor element. CONSTITUTION:Epoxy resin, novolak type phenol resin, and an epoxy resin composition containing products formed from reaction of silicone compound and polyepoxy compound and primary monoamine compound are used to seal a semiconductor element. Since the primary monoamine compound in stead of polyamine compound is used, the reaction products obtained become excellent in dissolubility to the epoxy resin, and resultingly sealing resin with the reaction products uniformly dispersed can be formed. Hence, low stress performance, heat-resisting performance, and damp-proof performance satisfied under further severe conditions for use are obtained to improve reliability.

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 sealed with ceramic packages, plastic packages, or the like to form semiconductor devices. The above-mentioned ceramic package has heat resistance in the constituent material itself,
It also has excellent moisture resistance, so it is resistant to temperature and humidity.
Moreover, since it is a hollow package, it has high mechanical strength and can be sealed with high reliability. However, recently, resin sealing using a plastic package has become mainstream because the constituent materials are relatively expensive and the mass productivity is poor. Epoxy resin compositions have conventionally been used for this type of resin sealing, and have achieved good results.

The above-mentioned epoxy resin composition includes, in particular, an epoxy resin, a phenol resin as a curing agent, 2-methylimidazole as a curing accelerator, and a butadiene-terminated carboxylic acid-acrylonitrile copolymer as a combination resin for elastic reinforcement. Those composed of a composition system such as fused silica as an inorganic filler are praised for their excellent sealing workability (especially workability during transfer molding).

However, technological innovation in the semiconductor field is remarkable, and recently, along with improvements in the degree of integration, element sizes have become larger and
While interconnects are becoming finer, packages are becoming smaller and thinner, and along with this, encapsulation materials for semiconductor devices are also becoming more resistant to stress, heat, and moisture than ever before. Sexuality is now in demand. Conventional epoxy resin compositions for encapsulation are excellent as encapsulating materials for semiconductor devices such as ICs and LSIs, but are not fully satisfactory as encapsulating materials for semiconductor devices such as VLSIs. do not have.

[Problem that the invention seeks to solve]

Therefore, in order to provide a semiconductor device that is fully compatible with the encapsulation of VLSI etc. and has excellent low stress, heat resistance, and moisture resistance, the present inventors particularly developed a silicone compound having an epoxy group and a polyepoxy resin. When a reaction product of a compound and a polyamine is included in an epoxy resin composition, the action of the reaction product results in resin sealing with low stress, excellent heat resistance, and moisture resistance, and a high degree of reliability. He discovered the potential to provide semiconductor devices and has already applied for a patent (January 1985).
Filed on October 28th, patent application No. 6O-242464). However, in the course of subsequent research, it was found that the above reaction product was not uniformly dispersed in the sealing resin because the compatibility of the above reaction product with the epoxy resin was rather poor, and therefore, the number of cycles of the thermal shock test It became clear that increasing the amount further would cause package cracks, and it became necessary to improve the low stress properties.

The present invention aims to improve the previous application (Japanese Patent Application No. 6O-242464), and aims to provide a semiconductor device with further improved low stress properties and higher reliability.

[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) Novolac type phenolic resin.

(C) A reaction product of a silicone compound having an epoxy group, a polyepoxy compound, and a monoamine compound.

The epoxy resin composition used in this invention comprises an epoxy resin (component A) and a novolac type phenol resin (component B).
It is obtained using a reaction product (component C) of a silicone compound having an epoxy group, a polyepoxy compound, and a monoamine compound (component C), and is usually in the form of a powder or a tablet formed by compressing it. There is.

Since such an epoxy resin composition uses a monoamine compound instead of the polyamine of the earlier application, especially in component C, the resulting reaction product has good compatibility with the epoxy resin, and as a result, A sealing resin in which the reaction product is uniformly dispersed can be formed. Therefore, it is possible to realize a semiconductor device that has satisfactory moisture resistance even under severe usage conditions and has further improved reliability.

The epoxy resin serving as component A of the epoxy resin composition is not particularly limited as long as it is an epoxy compound having two or more epoxy groups in one molecule. That is, various epoxy resins conventionally used as encapsulating resins for semiconductor devices are suitable, and in addition, diglycidyl ether of bisphenol A, Ebibis type epoxy resin which is a polymer thereof, bisphenol F type epoxy resin, resorcinol. Type epoxy resins, cycloaliphatic epoxy resins, and the like can also be used as suitable epoxy resins.

The novolac type epoxy resin usually has an epoxy equivalent of 160 to 210. Those with a softening point of 50 to 130°C are used, and as Talesol novolac type epoxy resins,
Epoxy equivalent: 180-210. Those having a softening point of 60 to 110°C are generally used.

The novolak type phenol resin as component B used together with the above epoxy resin acts as a curing agent for the above epoxy resin, and among them, the novolac type phenol resin has a softening point of 50 to 13.
0°C, preferably 70-90°C, hydroxyl equivalent 100-90°C
It is preferable to use one with a diameter of 130.

The blending ratio of the epoxy resin as component A and the novolac type phenol resin as component B in the epoxy resin composition is such that the equivalent ratio of the epoxy group in the epoxy resin to the hydroxyl group in the phenol resin is 0.8 to 1. It is preferable to mix it so that it becomes 1.2. The closer this equivalence ratio is to 1, the better the results.

In addition, component C used together with the above epoxy resin and novolak type phenol resin is a reaction product obtained from a silicone compound having an epoxy group, a polyepoxy compound, and a primary monoamine compound, and is particularly resistant to thermal shock. Improved properties 5: Excellent internal stress reduction effect, as a result, the occurrence of minute cracks and peeling (which becomes a path for moisture intrusion) due to thermal shock and thermal stress of the sealing resin is prevented,
It has an excellent effect on improving moisture resistance reliability under harsh usage conditions such as repeated exposure to large thermal shocks.

Here, the silicone compound having an epoxy group (hereinafter referred to as "silicone compound") has an epoxy equivalent of 100 to 50,000. Si content is 1 to 35% by weight
(hereinafter abbreviated as "%") and has 1 to 10 epoxy groups at at least one of the terminal or side chain. Particularly preferred among these are those having 1 to 6 epoxy groups in the side chain or terminal and having an epoxy equivalent of 100 to 12,000. The St content is 3 to 33%.

In addition, as the above polyepoxy compound, a bisphenol A type epoxy resin having an epoxy equivalent of 100 to 1500 is usually used, but it is not limited thereto, and bisphenol F type epoxy resin or other polyfunctional epoxy resins are used. A wide variety of resins can be used.

Further, as the -class monoamine compound, it is preferable to use one having one primary amino group in the molecule and having a molecular weight of 40 to 300. In particular, the above-mentioned -grade amino group has high reactivity with epoxy groups, and therefore it is preferable to use one that has high compatibility with other resin component raw materials. A typical example of the -class monoamine compound is ethanolamine (β-aminoethyl alcohol).

The content of the C component which is the reaction product is the above A, B,
It is suitable to set it to 50% or less, preferably 5 to 30% of the total amount of C component. This is because when the content of the C component exceeds 50%, the resin strength of the sealing resin tends to decrease significantly.

In addition, the above C of the epoxy resin composition used in this invention
The component is contained in any state, such as in a reacted state with the novolac type phenol resin that is component B, in an independent state, or in a state in which these are mixed.

Further, in this invention, in addition to the above-mentioned components A, B, and C, a curing accelerator, a filler, 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-)li(dimethylaminomethyl)phenol, 2-methylimidazole, etc. I can do it. As a filler, use quartz glass powder.

Silica powder, talc, etc. can be used. As the mold release agent, conventionally known long-chain carboxylic acids such as stearic acid and palmitic 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, first, the novolac type phenol resin, which is the B component, is modified with the reaction product of the silicone compound, the polyepoxy compound, and the primary monoamine compound, which is the C component. and,
The obtained modified product and epoxy resin (component A) are essential components, and a curing accelerator, l! It can be produced by suitably blending an i-type agent and a filler and mixing and kneading them using a tri-blend method or a melt-blend method according to a conventional method. As a method for modifying the novolak type phenolic resin, (1) First, a silicone compound, a polyepoxy compound, and a monoamine compound are mixed at 170°C with a temperature of 0.
A method of preparing a reaction product by heating, stirring and mixing for 5 to 5 hours, and stirring and mixing this with a molten novolac type phenol resin at 170°C for 0.5 to 5 hours;
■A silicone compound, a polyepoxy compound, and a monoamine compound are added to the novolac type phenol resin.
Any method of stirring or mixing at 170° C. for 0.5 to 5 hours may be used.

Moreover, the epoxy resin composition used in this invention can also be manufactured as follows. That is, instead of producing a consistently modified phenolic resin from components C and B and then mixing and kneading it with other components, as in the production method described above, the reaction product, which is component C, is added to the epoxy resin from the beginning. (A component) Novolac type phenol resin (B component)
It can also be produced by mixing and kneading in the same manner as described above, along with a curing accelerator, a mold release agent, and a filler, which are blended as necessary.

The presence of the C component in the epoxy resin composition can be confirmed by analysis using infrared absorption spectroscopy (IR).

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 has excellent low stress properties, heat resistance, and moisture resistance, and has significantly improved package crack resistance in thermal shock tests.

〔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 (component C) of a silicone compound, a polyepoxy compound, and a monoamine compound. Because the plastic package is different from conventional epoxy resin compositions, it has low internal stress and high heat resistance, and in particular, has higher moisture resistance under harsh usage conditions than the previous application. ing. The sealing with the above-mentioned special epoxy resin composition is sufficient for sealing VLSI etc., and the device size is 16f12 or more, and the width of AJ wiring on the device is 2.
This is a major feature of a special semiconductor device of micrometers or smaller, in which high reliability as described above can be obtained.

Next, examples will be described.

First, a silicone compound and a polyepoxy compound were prepared as raw materials for component C. Their structures and epoxy equivalents are shown in Table 1.

(Left below) Next, add 500% of each component raw material in the proportions shown in Table 2 below.
ml round bottom flask and stirred at 175°C for 1 to 5 hours to form a reaction product (component C) t1~ of the silicone compound, polypoxy compound, and mm monoamine compound.
I got a 7. Reaction products obtained in this way 1 to 7
were added to the phenol resin at 175°C in the formulation shown in Table 3 below, and stirred for about 2 hours to prepare fish 1 to 8 and fish 1.
In addition to producing a modified phenolic resin of No. 0, the phenol resin, polyepoxy compound, silicone compound, and ethanolamine were heated at 175°C as shown in Figure 9.
A modified phenol resin was obtained by stirring for 1 to 5 hours.

(Hereinafter in the margin) (Hereinafter in the margin) [Examples 1 to 10] The reaction product of component C and the modified phenol resin obtained in this way and other raw materials were blended according to Table 4,
The mixture was melt-kneaded for 10 minutes using a mixing roll machine (roll temperature: 100°C), cooled and solidified, and then pulverized to obtain the desired powdered epoxy resin composition.

(The following is a blank space) [Comparative Examples 1 to 3] Using the raw materials shown in Table 5 below, these raw materials were kneaded for 10 minutes with a mixing roll machine (roll temperature 100 ° C.), and the obtained sheet composition was used. A powdered epoxy resin composition was obtained in the same manner as in Examples 1 to 10.

*, 5: Turning to the third layer Using the powdered epoxy resin compositions obtained in the above Examples and Comparative Examples, a semiconductor device was obtained by molding a semiconductor element by transfer molding. Regarding the semiconductor device obtained in this way, the bending elastic modulus,
Glass transition temperature, 1000 hour test using a pressure cooker under voltage application (hereinafter referred to as rPCBT test) and -50°C/30 minutes to 150°C/30 minutes
A temperature cycle test (hereinafter abbreviated as "rTCT test") of 200 minutes was conducted. The results are shown in Table 6 below.

(Margins below) From the results in Table 6, it can be seen that the results of the PCBT test or TCT test of the tested products are significantly superior to those of Comparative Example 1.2 products. In particular, as the silicone compound having an epoxy group, a hydrophobic silicone compound (for example, silicone compounds a, b, and d in Table 1 above) is used, and before roll kneading, the silicone compound, the polyepoxy compound, and the monoamine compound are mixed together. When a novolac type phenol resin is modified in advance with a reaction product (component C) (
In Examples 3 to 9), the failure rate in the PCBT test was 0. An extremely excellent result with a defective rate of O in the TCT test was obtained. In addition, Comparative Example 3 is related to the earlier application of the present application, and the results of the flexural modulus, glass transition temperature, and PCR test are as good as those of the other product, but under the harsh conditions of 300 TCT tests. In this case, cracks were generated, and it can be seen that there is a difference from the actual product in this respect.

Claims (3)

[Claims] (1) A semiconductor device in which a semiconductor element is sealed using an epoxy resin composition containing the following components (A) to (C). (A) Epoxy resin. (B) Novolac type phenolic resin. (C) A reaction product of a silicone compound having an epoxy group, a polyepoxy compound, and a primary monoamine compound. (2) The mutual content ratio of the epoxy resin as the component (A) and the novolak type phenol resin as the component (B) is such that the equivalent ratio of the hydroxyl group in the novolak type phenol resin to 1 equivalent of epoxy group in the epoxy resin is 0. 2. The semiconductor device according to claim 1, wherein the semiconductor device is set to have a value of .8 to 1.2. (3) The content ratio of the above (C) component is the above (A), (B)
), (C) The semiconductor device according to claim 1 or 2, wherein the amount is set to 50% by weight or less of the total weight of components (C).