JPH01101658A - Semiconductor device - Google Patents

Abstract

PURPOSE:To obtain high reliability under high temperature and to improve the mechanical strength of a sealing resin by forming a semiconductor element by means of sealing using an epoxy resin formed substance containing certain elements. CONSTITUTION:A semiconductor element is sealed using an epoxy resin formed substance containing an epoxy resin which is other than a novolak type epoxy resin and which consists of at least 3 epoxy radicals in a molecule, a phenol resin which is other than the novolak type phenol resin and which consists of at least 3 phenyl radicals in a molecule, a brominated epoxy resin, and at least one compound selected from among a group of epoxy resins consisting of a Bi hydroxide, a Bi oxide, an Al hydroxide, and an Al oxide. Accordingly, such semiconductor element presents high reliability when left in a high temperature ambient for a long time, as well as its mechanical properties in the high temperature ambient are less subject to deterioration.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a semiconductor device that maintains reliability, particularly excellent reliability even in a high temperature atmosphere.

[Conventional technology]

Semiconductor elements such as transistors, ICs, and LSIs are generally sealed using epoxy resin compositions to form semiconductor devices. The above epoxy resin is characterized by its electrical properties, moisture resistance,
Because it has good adhesive properties, it is used for sealing semiconductor devices and has achieved good results. however,
In recent years, as semiconductor devices have been used in large quantities in outdoor equipment such as automobiles, many devices have become more heat resistant than ever before, especially storage reliability at high temperatures, which was not a problem in the past. It has come to be required for semiconductor devices.

[Problem that the invention seeks to solve]

Conventionally, such heat resistance has been improved by increasing the flame retardance of the epoxy resin used for sealing. That is, by blending a combination of a brominated epoxy resin and antimony oxide into an epoxy resin composition, the flame retardance of the cured epoxy resin composition is increased,
This aims to improve the heat resistance of the sealing resin. The combination of the above-mentioned brominated epoxy resin and antimony oxide shows good results in terms of flame retardancy. However, a problem arises in terms of storage stability at high temperatures. That is,
Under high temperature conditions, hydrogen bromide is generated by the thermal decomposition of the brominated epoxy resin, and this hydrogen bromide reacts with the joint between the gold wire and aluminum pad of the semiconductor element, promoting the formation of an alloy, which generates electricity. This leads to an increase in resistance value, resulting in poor continuity.

In addition, semiconductor devices are increasingly being used at high temperatures, and the entire package is sometimes exposed to solder temperatures of 215 to 260°C during mounting, so excellent mechanical properties under high temperature conditions are also required. It has become so.

This invention was made in view of these circumstances, and provides a semiconductor device that exhibits excellent reliability even when left in a high-temperature atmosphere for a long time, and at the same time exhibits less deterioration of mechanical properties in a high-temperature atmosphere. Its purpose is to provide.

[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 (D).

(A) An epoxy resin other than a novolac type epoxy resin, which has at least three epoxy groups in one molecule.

(B) A phenol resin other than a novolac type phenol resin, which has at least three phenyl groups in one molecule.

(C) Brominated epoxy resin.

(D) At least one compound selected from the group consisting of Bi hydroxide, Bi oxide, /l hydroxide, and A2 oxide.

That is, in order to achieve the above object, the present inventors
As a result of a series of research, we have discovered that the halogen compound gas generated during the thermal decomposition of brominated epoxy resin as a flame retardant,
Bi, Aj! It was found that the hydroxides and oxides of these materials are captured and trapped, effectively maintaining reliability under high-temperature atmospheres.

In addition, regarding mechanical properties in a high temperature atmosphere, by using the above-mentioned specific epoxy resin and phenol resin, it is possible to obtain a cured epoxy resin composition with excellent mechanical properties in a high temperature atmosphere. We discovered this and arrived at this invention.

The epoxy resin composition used in the semiconductor device of the present invention includes a specific epoxy resin (component A), a specific phenol resin (component B), a brominated epoxy resin (component C), Bt,
It is obtained using a compound (D component) consisting of Al hydroxide and oxide, and is usually in the form of a powder or a tablet formed by compressing it.

The epoxy resin serving as component A of the epoxy resin composition is an epoxy resin other than a novolac type epoxy resin, and is an epoxy resin having at least three epoxy groups in one molecule. In other words, as a result of a series of studies conducted by the present inventors on improving the mechanical properties of sealing resins in high-temperature atmospheres, we found that the components of binuclear or lower contained in epoxy resins and phenolic resins It was found that the mechanical properties at high temperatures deteriorate. Epoxy resins and phenol resins that contain such components of binuclear or less are novolak type, and epoxy resins other than novolac type epoxy resins have 3 epoxy groups in one molecule. It has been found that if the epoxy resin has more than two nuclear atoms, it will hardly contain any components having less than two nuclear atoms.

Examples of such epoxy resins include those shown in the following (1) to (2). Such epoxy resins may be used alone or in combination.

(Hereinafter in the margin) (Hereinafter in the margin) Also, the phenolic resin of the B component is a phenol resin other than a novolak type phenol resin, similar to the epoxy resin, and is a phenol resin having at least three phenyl groups in one molecule. . Like the epoxy resin described above, this phenol resin is also a phenol resin containing almost no components of binuclear bodies or less. This phenol resin acts as a curing agent for the epoxy resin of component A above.

Typical examples of such phenolic resins include the following ■
Examples include those listed in ~■. Such phenolic resins may be used alone or in combination.

The brominated epoxy resin of component C has an epoxy equivalent of 4.
It is desirable to use 20 or more, preferably 420 to 550. Particularly good results are obtained by using a brominated bisphenol type epoxy resin. This is because when the epoxy equivalent is less than 420, not only does the resin tend to have poor heat resistance, but also hydrogen halide gas is likely to be generated.

In this way, the amount of brominated epoxy resin used is 1 to 10% of the resin components (A+B+C components) of the epoxy resin composition.
It is preferable to set it within the range of weight % (hereinafter abbreviated as "%"). That is, the amount of brominated epoxy resin used is 1
If it is less than 10%, the effect of improving heat retardance will be insufficient;
%, hydrogen halide gas tends to be generated in large quantities, which tends to have an adverse effect on semiconductor devices.

The mutual usage ratio of the above-mentioned phenol resin and epoxy resin is selected appropriately from the relationship with the epoxy equivalent of the epoxy resin, but the equivalent ratio of the phenolic hydroxyl group to the epoxy group is within the range of 0.5 to 1.5. It is preferable to set it so that This is because if the equivalent ratio is out of the above range, the heat resistance of the resulting cured epoxy resin composition tends to decrease.

It is preferable to use one or both of the above epoxy resins and phenol resins that have reacted with an organosiloxane represented by the following general formula (1). By using such an epoxy resin, crack resistance and temperature cycle resistance are improved. However, it is disadvantageous in terms of heat resistance. However, D used in the present invention
Components Bi, A1. By using compounds consisting of hydroxides and oxides, the phenomenon of decrease in heat resistance is eliminated,
Good heat resistance can be obtained.

The above components are a hydroxide of Bl, an oxide of Bi, a hydroxide of A2, and an oxide of AN. A typical example of such a compound is bismuth hydroxide.

Examples include aluminum hydroxide, dibismuth trioxide, and nialium dioxide. The above-mentioned compounds may be used alone or in combination without any problem. It is preferable to set the ratio to %. That is, the content is 1
If it is less than 10%, the effect of improving high-temperature storage properties will not be sufficient, and if it exceeds 10%, a phenomenon of deterioration of moisture resistance will be observed. The compound having such a component is preferably fine particles having an average particle size of 0.5 to 30 μm and a maximum particle size of 74 μm or less. This is because if the particle size is larger than this, the dispersibility is markedly reduced and it tends to be difficult to obtain a sufficient improvement effect on high temperature storage characteristics.

The epoxy resin composition used in this invention includes the above A
In addition to component -D, other conventionally used additives may be included as necessary.

In particular, antimony oxide powder is included when improving flame retardancy as well as reliability when left at high temperatures.

In addition, examples of the above-mentioned other additives include a curing accelerator, a mold release agent, a coloring agent, and a silane coupling agent.

Examples of the curing accelerator include tertiary amines, quaternary ammonium salts, imidazoles, organic phosphorus compounds, and boron compounds, which can be used alone or in combination.

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 are used. be able to.

The epoxy resin composition used in this invention can be produced, for example, as follows. That is, the above A-
Ingredient D and the other additives mentioned above are appropriately blended, this mixture is melt-mixed in a heated state by applying a kneading machine such as a mixing roll machine, and after cooling it to room temperature, it is pulverized by a known means, and as necessary. It can be obtained through a series of steps of tabletting.

The encapsulation of a semiconductor element using such an epoxy resin composition is not particularly limited, and can be performed by a known molding method such as ordinary transfer molding.

The semiconductor device thus obtained maintains sufficient reliability when left at high temperatures, and shows no deterioration in mechanical properties at high temperatures.

〔Effect of the invention〕

As described above, the semiconductor device of the present invention includes the specific epoxy resin (component A), the specific phenol resin (component B), the brominated epoxy resin (component C), Bi, Af
! It is sealed using a special epoxy resin composition containing compounds such as hydroxides and oxides (component D), and the halogen compounds generated when left in a high temperature atmosphere for a long time are Because it is captured, excellent reliability can be maintained even when left at high temperatures. Moreover, due to the above-mentioned specific epoxy resin (component A) and phenol resin (component B), the mechanical strength of the sealing resin decreases little (
The semiconductor element is sufficiently protected at high temperatures, and together with the above-mentioned halogen compound trapping effect, reliability at high temperatures is excellent.

Next, examples will be described together with comparative examples.

[Examples 1 to 9, Comparative Examples 1 to 5] (Margin below) Raw materials as shown in Table 1 below were prepared.

Next, these raw materials were blended in the proportions shown in Table 2 below, kneaded with a mixing roll machine, cooled, and pulverized to obtain the desired powdered epoxy resin composition.

(The following is a blank space) A semiconductor element was sealed using the powdered epoxy resin composition obtained as described above, and the characteristics of the obtained semiconductor device were investigated and shown in Table 3 below.

(The following is a blank space) In Table 3 above, the bending strength was measured using a Tensilon universal testing machine (manufactured by Toyo Baldwin Co., Ltd.). Element failure in high temperature conditions was measured by assembling a semiconductor device by sealing the semiconductor element with resin, exposing all 120 FFs to high temperature, and determining the number of FFs exhibiting conductivity failure.

From the results in Table 3, it can be seen that the actual height measurement is superior to the comparative height measurement in terms of the number of defective elements and high-temperature strength, and is highly reliable at high temperatures.

Patent applicant: Nitto Electric Industry Co., Ltd. Agent: Patent attorney Yukihiko Nishifuji

Claims (2)

[Claims] (1) A semiconductor device in which a semiconductor element is sealed using an epoxy resin composition containing the following components (A) to (D). (A) An epoxy resin other than a novolac type epoxy resin, which has at least three epoxy groups in one molecule. (B) A phenol resin other than a novolac type phenol resin, which has at least three phenyl groups in one molecule. (C) Brominated epoxy resin. (D) At least one compound selected from the group consisting of Bi hydroxide, Bi oxide, Al hydroxide, and Al oxide. (2) At least one of the above (A) component epoxy resin and B component phenol resin has the following general formula (1) ▲ Numerical formula, chemical formula, table, etc. ▼ (1) [In formula (1), R are monovalent organic groups, and may be the same or different in the phase. However, in one molecule, at least two of the above R are an amino-substituted organic group, an epoxy-substituted organic group, a hydroxyl-substituted organic group, a vinyl-substituted organic group, a mercapto-substituted organic group, and a carboxyl-substituted organic group. m is an integer from 0 to 500. ] The semiconductor device according to claim 1, which is reacted with an organopolysiloxane represented by: