JPS60127748A - Resin-sealed semiconductor device - Google Patents

Abstract

PURPOSE:To enhance the reliability by using a cured material of epoxy resin composition which contains specific resin curing agent, a titanate fiber, silica powder for an epoxy resin sealer. CONSTITUTION:An epoxy resin sealer uses an epoxy resin composition which contains an epoxy resin, an epoxy resin curing agent having at least two phenol hydroxyl group in one molecule and/or acid anhydride curing agent, titanate fiber and/or titanic acid fiber, molten silica powder and/or crystalline silica powder. As the titanate fiber potassium salt is particularly useful, and the fiber having 10-20mum of mean fiber length and 0.2-0.5mum of fiber diameter is particularly preferably. Titania fiber or titania aqueous hydride fiber is used as the titanic acid fiber, and can be obtained by treating, for example, potassium titanate fiber. Thus, a semiconductor device which has high reliability can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention relates to a resin-sealed semiconductor device, and particularly to a highly reliable resin-sealed semiconductor device.

[Technical background of the invention and its problems] Resin-sealed semiconductor devices include, for example, integrated circuits (ICs),
In order to protect semiconductor devices such as large-scale integrated circuits (LSI), Rungis, etc. from external atmosphere and mechanical shock,
It is sealed using a thermosetting resin or the like.

Conventionally, hermetic sealing using metals, ceramics, etc. was used as a sealing technology for semiconductor devices.
Recently, resin encapsulation has become popular because it is advantageous in terms of cost.However, resin encapsulation type semiconductor devices have the following drawbacks.

FIG. 1 shows a cross-sectional view of a semiconductor device sealed using ceramics. Semiconductor element 1 is in lead bin 2
are electrically connected to each other by a thin bonding wire 3, but the bonding wire 3 exists within the space 4 and
Not subject to mechanical stress.

On the other hand, in the resin-sealed semiconductor device, as shown in the cross-sectional view in FIG.
The masturbation is embedded in the greasy l], and the bonding wire is 10
It is subjected to mechanical stress due to the sealing resin. Because the coefficient of thermal expansion of the sealing resin and the embedded parts are different,
Resin sealing! However, if a semiconductor device is repeatedly exposed to high and low temperatures, it will not be able to withstand the stress due to the difference in thermal expansion coefficients, and the bonding wire 10 has the disadvantage of being prone to breakage or poor contact.

[Object of the Invention] An object of the present invention is to improve the drawbacks of the conventional resin-sealed semiconductor device, and to provide a highly reliable resin-sealed semiconductor device.

[Summary of the Invention] In order to achieve the above object, the inventors of the present invention have conducted intensive research and have discovered that the following resin-encapsulated semiconductor device has superior characteristics compared to conventional ones. Ta.

That is, the present invention relates to a resin-sealed semiconductor device comprising a semiconductor element and an epoxy resin sealing body for plugging the semiconductor element.

The epoxy resin encapsulant includes: a) an epoxy resin curing agent and/or an acid anhydride curing agent containing at least two 7-enol hydroxyl groups in one molecule; C) a titanate fiber and/or an acid anhydride curing agent; If, bamboo titanate fiber, and d) fused silica powder and/or crystalline silica powder is a cured product of an epoxy resin composition.

The epoxy resin used in the present invention is commonly known and is not particularly limited. For example, bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, linear aliphatic epoxy hydrated gH'ij, blade quality. Cyclic epoxy tree B'
Examples include 4% heterocyclic epoxy resins, halogenated epoxy resins, and other epoxy 4-cap resins having two or more epoxy groups in one molecule. These epoxy resins may be used alone or in a mixed system of two or more types. A more preferable epoxy resin used in the present invention is a novolac type epoxy resin having an epoxy equivalent of 170 to 300, such as a phenol novolak. These include epoxy resins such as cresol novolak epoxy resins, halogenated phenol novolac epoxy resins, etc. This f'L epoxy resin has a chlorine ion content of 10 ppm or less,
It is desirable that the hydrolyzable chlorine content is 0.1 ML tic % or less. The reason for this is that if more than 10 ppm of chlorine ions or more than 0.1% by weight of hydrolyzable chlorine is contained, the aluminum electrodes of the sealed semiconductor element are likely to be corroded.

The epoxy resin curing agent having two or more phenolic hydroxyl groups in one molecule used in the present invention includes phenolic resins, polyoxystyrene, and polyhydric phenol compounds. resin, novolak type phenolic resin such as cresol novolak resin, tert-butylphenol novolac resin, nonylphenol novolac resin; resol type phenolic resin; polyoxystyrene such as polyparaoxystyrene; It is a monster, etc. Among these, novolac type phenolic resin and polyoxystyrene are most preferred. Further, these curing agents can be used alone or in a mixed system in which two or more of them are appropriately combined.

The acid anhydride used in the present invention may be any aliphatic, alicyclic or aromatic carboxylic anhydride, or any substituted carboxylic anhydride. Examples of such acid anhydrides include maleic anhydride,
Succinic anhydride, 7-talic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride,
Pyromellitic anhydride, nadic anhydride (3,6-endomethylene phthalic anhydride 3,6-tetrahydrophthalic anhydride), methyl nadic anhydride, 3.3', 4.4'-benzophenonetetracarboxylic anhydride, anhydride Examples include tetrabromophthalic acid, chlorendic anhydride, and one or more selected from the group consisting of these.

These curing agents may be used alone or in an appropriate combination.

The amount of the curing agent to be blended is preferably such that the ratio of the total number of phenolic hydroxyl groups and/or anhydrous carboxyl groups to the number of epoxy groups in the epoxy resin is in the range of 0.5 to 1.5. The reason for this is that outside the above range, the moisture resistance of the resulting epoxy resin composition tends to deteriorate.

The titanate fibers used in the present invention include:
Particularly useful are potassium salts. Potassium titanate fiber is a compound represented by the general formula %, and so far n=1.2,4゜6.8
things are well known. Among these, chemically stable fibers with n=6.8 are preferred. Additionally, hydrates of potassium titanate fibers can be used similarly.

Particularly preferred potassium titanate fiber (K2O・(iTi
oz) has an average fiber length of 10 to 20 μm and a Q fiber diameter of 0.
It is 2 to 0.5 μm.

Titanium fibers include titania fibers (TiO2 fibers),
There are titania hydrate fibers (TiO2.nH2,0 fibers), which can be made, for example, by treating potassium titanate fibers. Titanate fibers and titanate fibers may each be used alone. However, both may be appropriately blended.

The blending fit of these fibers is 0 for the epoxy resin composition.
．． It is preferable to mix it within the range of 1 to 2 otM%.

The fibers of Koit et al., as well as the inorganic bulking agent described below,
By treating with a silane coupling agent, modified silicone oil, or other optical surface treating agent, the properties of the epoxy resin composition can be significantly improved.

In the present invention, bath-fused silica powder and/or crystalline silica powder are used as the inorganic bulking agent. Crystalline silica powder is obtained by crushing quartz, cristobalite, and silica stone into a powder form, and fused silica powder is a powder obtained by bath-melting crystalline silica to make it amorphous. Fused silica and crystalline silica are preferable because they have high purity and low thermal expansion.

Other fillers, such as glass fiber, Merck, alumina, calcium silicate, calcium carbonate, barium sulfate, magnesia, etc., can be used in combination with bath-fused silica or crystalline silica.

The blending amount of the inorganic filler is preferably about 1.5 to 4 times the total 1 m-ti of the epoxy resin and curing agent.

The epoxy resin composition according to the present invention may include, as necessary,
Additives can be added in moderation. Among these, curing accelerators are particularly useful for shortening the curing time and improving the properties of the cured product. Although generally known curing accelerators can be used in the present invention, in order to obtain a highly reliable resin-sealed semiconductor device, it is desirable to use an organic phosphine compound.

In the present invention, organic phosphine compounds preferably used as curing accelerators include formulas;
Tertiary phosphine compound in which all R8 are organic groups, Jz
A second bosphine compound in which only 8 is hydrogen, R2, R8
4, there is a pA1 phosphine compound that is hydrogen.

Specific examples include triphenylphosphine, tributylphosphine, tricyclohexylphosphine, methyldiphenylphosphine, butylphenylphosphine, diphenylphosphine, phenylphosphine, and octylphosphine. Further, R1 may be an organic group containing an organic phosphine. Examples include 1,2-bis(diphenylphosphino)ethane and bis(diphenylphosphino)methane. Among these, arylphosphine compounds are preferred, and triphenylphosphine, 1,2-bis(diphenylphosphino)ethane, bis(diphenylphosphino)methane and the like are particularly preferred. Further, these organic phosphine compounds may be used alone or in a mixed system of two or more. However, the composition ratio of the organic phosphine compound is generally 0.0% of the resin content (epoxy resin and curing agent).
It may be within the range of 0.01 to 20% by weight, but particularly preferred properties are obtained within the range of 0.01 to 5% by weight.

Furthermore, the epoxy resin composition according to the present invention may contain, if necessary,
For example, natural waxes, synthetic waxes, metal salts of straight chain fatty acids, acid amides, mold release agents such as esters or paraffins, flame retardants such as chlorinated paraffins, bromotoluene, hexabromobenzene, antimony trioxide,
There is no problem in adding and blending a coloring agent such as Carpump Thick, a silane coupling agent, etc. as appropriate.

A general method for preparing the epoxy resin composition according to the present invention as a molding material is to thoroughly mix the raw material components selected to have a predetermined composition using, for example, a mixer, and then melt-mix them using a hot roller A. Alternatively, an epoxy resin molding material can be easily obtained by adding a mixing treatment using a kneader or the like.

The resin-sealed semiconductor device of the present invention can be easily manufactured by sealing the semiconductor device using the epoxy resin composition or molding material.

The most common method for sealing is low-pressure transfer molding, but sealing by injection molding, compression molding, casting, etc. is also possible.

The epoxy resin composition or molding material is heated and cured during sealing, and finally a resin-sealed semiconductor device can be obtained which is sealed with the cured product of this composition or molding material. During curing, it is particularly desirable to heat to -150°C or higher.

The semiconductor device in the present invention includes an integrated circuit, a large-scale integrated circuit, a transistor, a silice, a diode, etc., and is not particularly limited.

[Examples of the invention Examples 1 to 6 Cresol novolac type epoxy resin (epoxy resin A) with an epoxy equivalent weight of 220, -AX with an epoxy equivalent weight of 290
epoxy novolac resin (epoxy resin B), phenol novolac resin curing agent with a molecular weight of 800, tetrahydrophthalic anhydride, potassium titanate (Kzo・5Ti0
z) Fiber, potassium titanate hydrate (Kzo・5Ti0
2., R20) Fiber, titania (Ti02) fiber, glass fiber, fused silica powder, triphenylphosphine, 2
- Methylimidazole, antimony trioxide, carnauba wax, carbon black, silane coupling agent (γ
-glycidoxyglobyltrimethoxysilane) in the composition (parts by weight) shown in Table 1, and by mixing each composition with a mixer and kneading with a heated roll, 10 kinds of transfer molding materials including comparative examples were prepared. was prepared.

The MO8 type integrated circuit was resin-sealed by transfer molding using the molding material thus obtained. For sealing, molding material heated to 90℃ using a high-frequency preheater is heated to 175℃.
It was molded at 180°C for 2 minutes and after-cured at 180°C for 4 hours.

Table 1 Evaluation Test 1 Two constant temperature baths at +200°C and -65°C were prepared, and 100 of each of the resin-sealed semiconductor devices were placed in the constant temperature baths at +200°C and left for 30 minutes. Then take it out and leave it at room temperature for 5 minutes.
It was left to stand for 30 minutes, and then placed in a constant temperature bath at -65°C for 30 minutes. Thereafter, it was taken out and left at room temperature again for 5 minutes. The above operation was considered as one cycle, and a thermal cycle test was conducted continuously. The cycle was interrupted at any time as the thermal cycle test progressed, and the characteristics of the resin-sealed semiconductor device were measured using a tester to investigate the occurrence of defects. The results are shown in Table 2.

The cause of the failure was a disconnection or poor contact in the bonding wire.

Below margin

Claims (1)

[Scope of Claims] (1) A resin-encapsulated semiconductor device comprising a semiconductor element and an epoxy resin encapsulant covering the semiconductor element, wherein the epoxy resin encapsulant comprises: (a) an epoxy resin encapsulant; resin, (b) an epoxy resin curing agent and/or acid anhydride curing agent having at least two phenolic hydroxyl groups in one molecule, (C) titanate fibers and/or titanate fibers, and (d) Resin restraint guard conductor device characterized in that it is a cured product of an epoxy resin composition containing fused silica powder and/or crystalline silica powder (2) The epoxy resin has an epoxy equivalent of 170 to 300
The resin-sealed semiconductor device (13+) according to claim 1, in which the novolac-type epoxy 4☆ (resin) is a novolac-type phenol resin; Resin-encapsulated semiconductor device (4) The resin-encapsulated semiconductor device according to claim 1, wherein the titanate fiber is potassium titanate fiber (5) The potassium titanate fiber is potassium hexatitanate fiber. (K2Ti6O13) The resin-encapsulated semiconductor device according to claim 4 (6) The resin-encapsulated semiconductor device according to claim 1, wherein the epoxy resin composition contains an organic phosphine compound