JPS63299151A - Semiconductor device - Google Patents

Abstract

PURPOSE:To improve the moisture resistance, reliability and thermal conductivity of a semiconductor device without deterioration of other various characteristics by sealing a semiconductor element with an epoxy resin composition containing epoxy resin, novolac phenol resin, silicone compound, hydrotalcite compound antimony pentoxide, and alumina component. CONSTITUTION:Epoxy resin (component A), novolac phenol resin (component B), silicone compound (component C), hydrotalcite compound (component D), antimony pentoxide (component E) and alumina (component F) are used, and the mixture is normally powderlike or tablet state obtained by tableting it. A semiconductor element is sealed with the epoxy resin composition. Excellent moisture resistance and reliability are obtained and a plastic package having high thermal conductivity is attained by using the components D, E and F, and a high reliability semiconductor device is obtained by using it.

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 in ceramic packages, plastic packages, or the like to form semiconductor devices. In the ceramic package, the constituent material itself has heat resistance, low moisture permeability, and is a hollow package, so it can be sealed with excellent heat resistance and moisture resistance. but,
The disadvantages are that the constituent materials are relatively expensive and that mass production is poor. Therefore, recently, from the viewpoint of cost and mass production, resin sealing using plastic packages has become mainstream. Epoxy resins have conventionally been used for this type of resin sealing, and have achieved good results. However, due to technological innovation in the semiconductor field, the degree of integration has increased, element sizes have become larger, and interconnects have become finer, and packages are also becoming smaller and thinner. There is a demand for further improvement in reliability. In particular, the internal stress caused by shrinkage of the epoxy resin composition due to cooling from the curing temperature to room temperature reduces the reliability of the epoxy resin composition, so reducing the internal stress is important. In response to such demands, efforts have been made to reduce the internal stress of semiconductor devices by adding silicone-based organic flexibility compounds to epoxy resin compositions.

[Problem that the invention seeks to solve]

In addition, when semiconductor elements for calculations used in microcomputers and the like are sealed with resin, the heat generated by driving the elements needs to be quickly radiated outside the package, so there is a higher demand than ever for high thermal conductivity. is now being done.

In response to the demand for reducing the internal stress of semiconductor devices, as described above, silicone-based organic flexibility compounds are added to epoxy resin compositions. However, when doing so, a problem arises in that the sealing resin composition is softened, resulting in a decrease in moisture resistance due to ionic impurities. One method for solving such problems is to use an ion trapping agent. The above-mentioned ion trapping agents include those that trap cations and those that trap anions. The cation trap agent has the effect of suppressing corrosion by trapping cations that cause corrosion on the cathode side of the aluminum wiring of the semiconductor device, and the anion trap agent has the effect of suppressing corrosion on the anode side. However, when using the above ion trapping agents to improve moisture resistance reliability, it is necessary to use both anion and cation trapping agents; One of the ions remains without being captured, and the remaining ions cause corrosion of the cathode side or the anode side of the aluminum wiring, and as a result, the effect of improving moisture resistance reliability cannot be obtained. However, the reality is that no material has been found that can trap both anions and cations and does not cause any adverse effects when used. Furthermore, technology has been developed that satisfies the requirement for high thermal conductivity for the sealing resin.

The present invention was made in view of the above circumstances, and an object of the present invention is to significantly improve the moisture resistance reliability and thermal conductivity of a semiconductor device without impairing other characteristics.

[Means for solving problems]

In order to achieve the above object, the semiconductor device of the present invention includes:
A configuration is adopted in which a semiconductor element is sealed using an epoxy resin composition containing the following components (A) to (F).

(A) Epoxy resin.

(B) Novolac type phenolic resin.

(C) Silicone compound.

(D) Hydrotalcite compound.

(E) Antimony pentoxide.

(F) Alumina.

That is, the present inventors have conducted a series of studies in search of a trapping agent that does not cause any adverse effects when used and can exhibit good trapping performance for anions and cations, respectively. As a result, we found that ``a hydrotalcite compound was used as an anion trapping agent, and antimony pentoxide (anhydrous or hydrated) was used as a cation trapping agent.
When these two are used in combination, good results are obtained, and when a silicone compound and alumina are further combined, it is possible to obtain the effect of reducing internal stress and high thermal conductivity, which led to this invention. .

This invention consists of an epoxy resin (component A), a novolac type phenolic resin (component B), and a silicone compound (component C).
It is obtained using a hydrotalcinic compound (D component), antimony pentoxide (E component), and alumina (F component), and is usually prepared in powder form or in the form of tablets made by compressing it. It has become.

Such an epoxy resin composition has extremely excellent moisture resistance reliability, especially by using the above-mentioned components E and F.
Moreover, it can be made into a plastic package with high thermal conductivity, and by using it, a semiconductor device with high reliability can be obtained.

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 an average of two or more epoxy groups in one molecule. In other words, there are novolac type epoxy resins, which are the mainstream of conventional encapsulation resins for semiconductor devices, as well as other epibis type epoxy resins, which are diglycidyl ether of bisphenol A and its polymers, bisphenol F type epoxy resins, and alicyclic epoxy resins. Available for use. Among these, the preferred phenol novolac type epoxy resin usually has an epoxy equivalent of 180 to 230. Those having a softening point of 50 to 130°C are used, and in particular, the Talesol novolac type epoxy resin has an epoxy equivalent of 190 to 210. Softening point 60~
A temperature of 110°C is generally used.

The novolac-type phenolic resin as component B used together with the epoxy resin as component A acts as a curing agent for the epoxy resin, and includes phenol novolac, talesol novolac, and other alkylated phenol novolacs with an alkyl group added to the phenol resin. etc. are preferably used. Among these, those with a softening point of 100 to 1
It is preferable to use one having a temperature of 30°C and a hydroxyl equivalent of 80 to 180.

The blending ratio of the epoxy resin as component A and the novolac type phenol resin as component B is such that the hydroxyl group in the phenol resin is 0.8 to 1 equivalent of the epoxy group in the epoxy resin.
It is preferable that the amount is 1.2 equivalents.

The silicone compound of component C used together with the above components A and B acts to reduce the internal stress of the sealing resin, and is usually expressed by the following general formula (% formula %). The silicone compound represented by the above formula (1) is preferable, and a random copolymer is particularly preferable. There is no problem.

The content of the silicone compound as component C is preferably set to 1 to 50% by weight (hereinafter abbreviated as "%") of the total amount of the epoxy resin as component A and the novolac type phenol resin as component B. A more preferable range is 5 to 30%.

That is, if the amount of the C component added is less than 1%, a sufficient stress reduction effect will not be observed, whereas if it exceeds 50%, a decrease in resin strength will be observed.

Furthermore, the hydrotalcite compound as component D used together with each of the above components is a component that effectively traps anions such as chlorine ions or bromide ions that are present as impurity ions in the epoxy resin composition. The above hydrotalcite compound is represented by the following formula, for example.

MgJj! y (OH) zx*, y-is (CO
s) s ・5HzO As an example, KW-2000 (Mgo, y^f O, 301, I5 manufactured by Kyowa Chemical Industry Co., Ltd.
) can be given.

Furthermore, antimony pentoxide, component E, used together with each of the above components, is S b! It is expressed by the OS,
sb, o, 411.0 for hydrated and 5 for anhydrous
bzOs, used alone or in combination. This antimony pentoxide is a component that effectively traps cations such as sodium ions present in the epoxy resin composition. As an example of this, for example, Toagosei Co., Ltd.
AK-300 (SbzOs・4H,0), AHK-6
00 (antimony-bismuth-based oxide).

It is preferable that the content of the above-mentioned components (1-hydrotalcin) I [compound] be set at 1 to 10% of the total amount of the epoxy resin as the A component and the novolak type phenol resin as the B component. A more preferable range is 1 to 7%. In other words, if the amount of the above-mentioned components added is less than 1%, the ion trapping effect will hardly be observed, whereas if it exceeds 10%, there will be a tendency to adversely affect the moisture resistance reliability and electrical characteristics. . Similarly, the amount of antimony pentoxide as component E is preferably set to 1 to 10% of the total amount of the epoxy resin as component A and the novolac type phenol resin as component B. A more preferable range is 1 to 7%. In addition, the total amount of the hydrotalcyanide (D component) I [compound and the antimony pentoxide of the E component is
It is preferable to set the amount to 15% or less of the total amount of novolac type phenolic resin as a component, especially 10%.
% or less brings about good results. That is, if the total amount exceeds 15%, there is a tendency for an adverse effect to appear on the properties other than the moisture resistance reliability of the sealing resin.

The F component alumina used together with each of the above components is A
It is represented by 1*Os, and there are anhydrides and hydrates. These anhydrides and hydrates may be used alone or in combination. Usually, the alumina used has an average particle diameter of 5 to 200 uII+. Particularly suitable is one with a diameter of 10 to 100 #@. Further, it is preferable that the amount of alumina added as the F component is set to 30% or more of the total weight of the filler mentioned below. Particularly preferred is 50% or more. That is, if the amount of alumina added is less than 30%, the effect of improving the thermal conductivity of the sealing resin tends to be insufficient.

Further, in this invention, in addition to the above-mentioned components, a curing accelerator, a filler other than alumina (component F), 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-methylimidazole, 2-methylimidazole,
,4.6-)su(dimethyl7minomethyl)phenol,
Examples include 1,8-diazobicyclo(5,4,O)undecene and triphenylphosphine.

A filler other than alumina is quartz glass powder.

You can give talcum powder etc. In addition, as mold release agents, 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, waxes such as carnauba wax and montan wax, etc. can give.

The epoxy resin composition used in this invention can be produced, for example, as follows. That is, epoxy resin (component A), novolac type phenolic resin (component B), silicone compound (component C), hydrotalcite compound (component D), antimony pentoxide (component E), alumina (component F), and the necessary components. Add curing accelerators, mold release agents, and other agents according to the requirements. This can be manufactured by mixing and kneading this by appropriately adopting a tri-blend method or a melt-blending method according to a conventional method. In this case, prior to the above blending, the epoxy resin (component A) or It is preferable to preheat and mix the novolac type phenol resin (component B) and the silicone compound (component C) because the compatibility of the silicone compound (component C) with the resin improves.

In addition, in the above manufacturing process, a hydrotalcite compound (D component), antimony pentoxide (E component), and alumina (F component) are included in the epoxy resin (A component) or novolac type phenol resin (B component) in advance. It is also possible to manufacture by melt-mixing the filler, pulverizing it, blending it with other raw materials in the same manner as above, and performing tri-blending or melt-blending.

The epoxy resin composition obtained in this way contains the above-mentioned components and component C as an ion trapping agent, and therefore, the cured product contains extremely few anions and cations. Moreover, those containing the C component and the F component can also provide an internal stress reduction effect and high thermal conductivity.

Semiconductor encapsulation using such an epoxy resin composition is not particularly limited, and can be performed, for example, by a known molding method such as transfer molding.

The semiconductor device thus obtained has extremely high reliability.

〔Effect of the invention〕

As described above, the semiconductor device of the present invention is made of a special epoxy resin composition containing a silicone compound, a hydrotalcite compound as an anion trapping agent, antimony pentoxide as a cation trapping agent, and further containing alumina. Since it is sealed, it has high moisture resistance reliability, low internal stress, and the sealing resin has high thermal conductivity. Therefore, it has extremely high reliability. In particular, encapsulation using the special epoxy resin composition mentioned above can be used to encapsulate very large scale integrated circuits (VLSIs), and allows special semiconductor devices with Affi wiring on the element of 2μ or less to be exposed to severe conditions of high temperature and humidity. This is a major feature, since high reliability can also be obtained. Furthermore, by using alumina as a filler, the thermal conductivity of the sealing resin is improved, and the heat generated from the semiconductor element is quickly dissipated outside the package. It becomes fully compatible with sealing.

Next, examples will be described together with comparative examples.

[Examples 1 to 9. Comparative Examples 1 to 5] Each raw material was blended according to Table '41 below, melted and kneaded for 10 minutes with a mixing roll machine (roll temperature 100°C), cooled and solidified, and then pulverized to obtain the desired fine powder. An epoxy resin composition was obtained.

In addition, silicone compound a used in Examples and Comparative Examples
-f is as shown in Table 2.

(Left below) Using the finely powdered epoxy resin compositions obtained in the above Examples and Comparative Examples, the temperature was 175°C and the pressure was 50°C.
A semiconductor device was obtained by transfer molding the semiconductor element under the conditions of kg/cd and molding time of 120 seconds. Regarding the semiconductor device obtained in this way,
Bending test at room temperature, glass transition temperature Tg, -50°C 15
Temperature cycle test (hereinafter referred to as "TCT test") of 1,000 times from 150℃ to 150℃ for 15 minutes, using piezoresistance and resistance.
A pressure puller bias test (hereinafter abbreviated as rPCBT test) was conducted under the conditions of internal stress of 121° C. and 2 atmospheres, and a bias of 10 volts was applied. The results are shown in Table 3.

(Margin below)

Claims (1)

[Claims] (1) A semiconductor device in which a semiconductor element is sealed using an epoxy resin composition containing the following components (A) to (F). (A) Epoxy resin. (B) Novolac type phenolic resin. (C) Silicone compound. (D) Hydrotalcite compound. (E) Antimony pentoxide. (F) Alumina.