JPS60207353A - Resin sealed type semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the breaking or the poor contact of a bonding wire by forming a sealing resin material with epoxy resin, an epoxy resin hardener and/ or an acid anhydride hardener and a carbon fiber and/or a silicon carbide fiber. CONSTITUTION:In a resin sealed type semiconductor device, a sealing resin material is made of epoxy resin, an epoxy resin hardener having at least two phenol hydroxyl group in one molecule and/or an acid anhydride hardener and a carbon fiber and/or a silicon carbide fiber. The above-mentioned epoxy resin is novolak type epoxy resin of epoxy equivalent 170-300. For the epoxy resin hardener, novolak type phenol resin and polyoxystyrene are most preferable. The above-mentioned carbon fiber is desirable to have a fiber of 1mm. or less length and to be contained 0.01-10wt% in the sealing resin material. The silicon carbide fiber is also desirable to have a fiber of 1mm. or less length and to be contained 0.01-20wt% in the sealing resin material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a resin-sealed semiconductor device, and more particularly to a resin-sealed semiconductor device in which a resin-sealed body for sealing a semiconductor element is improved.

[Technical background of the invention and its problems]

For example, hermetic seals using metal-containing ceramics, etc., are used to unseal semiconductor elements such as ICs, LSIs, and h-transistors.

However, such hermetic seals have economical problems such as a large number of parts and complicated processes. For this reason, recently, resin-sealed semiconductor devices, in which a semiconductor element is sealed with a resin molding body made of a thermosetting resin or the like, as shown in the drawings, have become mainstream. That is, 1 in the figure is a semiconductor element, and this semiconductor element 1 is mounted on a bed 2. A plurality of bonding wires 3 are connected to the electrode portion (pad portion) of the semiconductor element 1, and the other ends of these wires 3 are connected to a lead bin 4. Then, the semiconductor element 1. Bed 2. A portion of the wire 3 and the dowel 4 are sealed with a resin sealing body 5.

However, resin-sealed semiconductor devices have the following drawbacks. That is, the bonding wire 3 connecting the semiconductor element 1 and the lead bin 4 is embedded in the resin molding body 5, and the bonding wire 3 is subjected to mechanical stress by the resin molding body 5.

Since the thermal expansion coefficients of the resin molded body 5 and the embedded components are different, if the resin molded semiconductor device is repeatedly exposed to high and low temperatures, it will no longer be able to withstand the stress due to the difference in the thermal expansion coefficients, and the bonding wire 3 had the disadvantage that it was easy to cause disconnection or poor contact.

[Purpose of the invention]

The present invention has been made in view of the above circumstances and aims to provide a highly reliable resin-sealed semiconductor device.

[Summary of the invention]

The inventors of the present invention have conducted extensive research to achieve the above object, and have discovered that the following resin-sealed semiconductor device has superior characteristics compared to conventional devices.

That is, the present invention provides a resin-sealed semiconductor device comprising a semiconductor element and a resin-sealed body for sealing the semiconductor element, wherein the resin-sealed body contains an epoxy resin and at least two phenols in one molecule. An epoxy resin curing agent and/or an acid anhydride curing agent having a hydroxyl group, and carbon! fiber and/
or silicon carbide fiber.

The above-mentioned epoxy resin is commonly known and is not particularly limited. For example, bisphenol A type epoxy resin, phenol novolak type epoxy resin, glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, linear aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic type epoxy resin, Examples include epoxy resins having two or more epoxy groups in one molecule, such as halogenated epoxy resins. However, these epoxy resins may be used alone or in a mixed system of two or more. More preferred epoxy resins are novolak-type epoxy resins having an epoxy equivalent of 170 to 300, such as phenol novolac-type epoxy resins, cresol novolac-type epoxy resins, and halogenated phenol novolak-type epoxy resins. These epoxy resins preferably have a chlorine ion content of 10 ppm or less and a hydrolyzable chlorine content of 0.1% by weight or less. The reason for this is that if chlorine ions exceeding 10 ppph or hydrolyzable chlorine exceeding 0.1% by weight are 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, which is one of the curing agents mentioned above, includes phenol resins, polyoxystyrene, and polyhydric phenol compounds. Novolac type phenolic resins such as novolac resin, cresol novolac resin, tert-butylphenol novolac resin, nonylphenol novolak resin, resol type phenolic resin, polyoxystyrene such as polybalaoxystyrene, bisphenol A, etc., and halogens of these compounds. It's a monster. Among these, novolac type phenolic resin and polyoxystyrene are most preferred.

Further, these curing agents can be used alone or in a mixed system of two or more.

As the acid anhydride which is the other curing agent, any aliphatic, alicyclic or aromatic carboxylic anhydride or a substituted carboxylic anhydride thereof can be used. Examples of such acid anhydrides include maleic anhydride,
Succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimellitic anhydride,
Pyromellitic anhydride, nadic anhydride [9 (3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride), methyl nadic anhydride, 3.3", 4.4=-
Examples include benzophenone tetracarboxylic anhydride, tetrabromophthalic anhydride, chlorendic anhydride, etc.
One or more types selected from the group consisting of these are used.

Each of the above curing agents may be used alone, or both may be used in an appropriate combination. The blending amount of the curing agent is 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 0.5 to 1.
It is preferable to mix it so that it is within the range of 5. The reason for this is that outside the above range, the moisture resistance of the resulting epoxy resin composition tends to deteriorate. In addition, when using silicon carbide m-fibers, it is effective to use an epoxy resin curing agent having a phenolic hydroxyl group as a curing agent from the viewpoint of improving the moisture resistance of the resin molded body.

The above-mentioned carbon fibers preferably have a mH diameter of 1 to 0 μm and a fiber length of 1 M. Carbon a! The fiber is 0.0% in the resin molded body.
It is desirable to contain 1 to 10% by weight. The reason is,
If it is less than 0.01% by weight, no effect of addition is observed, and 10
This is because if the weight exceeds 1%, the electrical properties of the resin molded body are likely to deteriorate. Carbon an is classified into rayon type, polyacrylonyl type, pitch type and others depending on the type of raw material used, and any of them can be used in the present invention.

The above silicon carbide fiber has a fiber diameter of 30 μm or less and a fiber length of 1
m or less is preferable. As a typical silicon carbide III fiber, 1 t of Ia fiber diameter 10 to 50 μm continuous fiber is used.
Cut into lengths of nm or less, or IIH diameter 0.05
There are silicon carbide whiskers with fiber lengths of 10 to 40 μm. It is desirable that the silicon carbide Ili fibers be contained in the resin sealing body in an amount of 0.01 to 20% by weight. The reason for this is that if the amount is 0.01 to 20% by weight or less, the effect of addition is not recognized, and if it exceeds 20% by weight, the electrical properties of the resin molded body are likely to deteriorate. The characteristics of the epoxy resin composition can be further improved by treating carbon van or silicon carbide mis with a surface treatment agent such as a silane coupling agent, similar to the inorganic filler described below.

Various additives such as the above-mentioned inorganic filler and curing accelerator can be added to the resin molded body constituting the semiconductor of the present invention.

19 = Fused silica powder and/or crystalline silica powder is used as the inorganic filler. 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 melting crystalline silica into an amorphous form. Fused silica and crystalline silica are preferable because they have high purity and low thermal expansion.

Other fillers, such as glass l1iIf, talc.

Alumina, calcium silicate, calcium carbonate.

Barium sulfate, magnesia, etc. can be used in combination with fused silica or crystalline silica.

The amount of the inorganic filler blended is preferably about 1.5 to 4 times the total weight of the epoxy resin and curing agent. Curing accelerators are useful for shortening curing time and improving the properties of cured products. Although generally known curing accelerators can be used in the present invention, it is desirable to use an organic phosphine compound in order to obtain a highly reliable epoxy resin for sealing and a resin-encapsulated semiconductor device. The organic phosphine compound has the general formula 1 I2-P3 [However, a tertiary phosphine compound in which R1-R3 are all organic groups, a secondary phosphine compound in which only R3 is hydrogen,
represents a first phosphine compound in which R2 and R3 are both hydrogen. Specifically, triphenyphosphine, tributylphosphine, tricyclohexylphosphine, methyldiphenylphosphine, and butylphenylphosphine.

These include diphenylphosphine, phenylphosphine, and octylphosphine. Furthermore, R1 in the general formula 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, particularly triphenylphosphine and 1,2-bis(diphenylphosphino)ethane.

Most preferred are bis(diphenylphosphino)methane and the like. 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 components (epoxy resin and curing agent) in the resin sealant.
It may be within the range of 001 to 20% by weight, but especially 0.01 to 20% by weight.
It is preferably within the range of 5% by weight.

The resin encapsulation constituting the semiconductor device of the present invention may further contain other additives, such as natural waxes, synthetic waxes, and metal salts of straight fatty acids, if necessary.

Mold release agents such as acid amides, esters or paraffins, chlorinated paraffins, bromotoluene.

Flame retardants such as hexabromobenzene and antimony trioxide, colorants such as carbon black, silane coupling agents, and the like may be appropriately added and blended. The general method for preparing the epoxy resin composition, which is the raw material for the resin encapsulation described above, as a molding material is to thoroughly mix the raw material components selected to a predetermined composition ratio, for example, with a mixer, and then further with a hot roll. An epoxy resin molding material can be easily obtained by melt mixing treatment or 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 an epoxy resin composition that is a raw material for the resin-sealed body. 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 is cured by heating during sealing, and a resin-sealed semiconductor device can finally be obtained by encapsulating the cured product of this composition. It is particularly desirable to heat to 150° C. or higher during curing.

The semiconductor elements constituting the resin-sealed semiconductor according to the present invention include integrated circuits, transistors, thyristors, diodes, etc., and are not particularly limited.

[Embodiments of the invention]

Examples 1 to 6 Cresol novolak type epoxy resin (epoxy resin A) with an epoxy equivalent weight of 220, brominated epoxy novolac tree 13 with an epoxy equivalent weight of 290
- Fat (epoxy resin B), phenol novolac resin curing agent with molecules up to 800, tetrahydrophthalic anhydride curing agent, carbon 11$1A (fiber diameter 9 μm, fiber length 500 μm
) Carbon fiber IB (III diameter 8 μm, IH 100.
cz m) Carbon fiber C (1 mm diameter 6 m, fiber 30
μm) Glass fiber (fiber diameter 9μm, @ braid length 500μm)
Fused silica powder, triphenylphosphine curing accelerator,
A 2-methylimidazole curing accelerator, antimony trioxide, carnauba wax, carbon black, and a silane coupling agent (γ-glycidoxyprobyltrimethoxysilane) were selected in the compositions (parts by weight) shown in Table 1, and each composition was Ten types of transfer molding materials, including comparative examples, were prepared by mixing the materials with a mixer and mixing with a heating roll.

Using the molding material thus obtained, an MO8 type integrated circuit was resin-sealed by transfer molding.

For sealing, molding material heated to 90℃ with a high-frequency preheater is heated to 17℃.
This was carried out by molding at 0°C for 2 minutes and then post-curing at 180°C for 4 hours.

Therefore, two thermostats at +200°C and -65°C were prepared, and 100 resin-sealed semiconductor device stands of Examples 1 to 6 and Comparative Examples 1 to 4 were placed in the oven at +200°C for 30 minutes. Leave it for a minute. Then take it out and leave it at room temperature for 5 minutes.
Next, it was left 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. In addition, each resin-sealed semiconductor device was heated to 120°C.
Moisture resistance test (bias PC
T) was conducted and the results are shown in Table 3.

Table 2 Table 3 [Examples of the invention] Examples 7 to 12 Cresol novolac type epoxy resin (epoxy resin A) with epoxy equivalent of 220, phenol novolak type epoxy resin (epoxy resin B) with epoxy equivalent of 190, epoxy equivalent 290 Brominated Epoxy Novolak Resin (
Epoxy resin C), 7 enol novolak resin curing agent with molecular weight 800, silicon carbide sea<fiber diameter 10 μm, fiber length o, aam)
Silicon carbide whisker<ta fiber diameter 01 μm, fiber length 2
0 μm) Glass fiber (fiber diameter 10 μm, fiber length 0.8 m*) Fused silica powder, triphenylphosphine curing accelerator, 2-
Methylimidazole curing accelerator, antimony trioxide, carnauba wax, carbon black, silane coupling agent (γ-glycidoxyprobyltrimethoxysilane)
The compositions (parts by weight) shown in Table 4 were selected, and each composition was mixed with a mixer and mixed with a heating roll to prepare 10 types of transfer molding materials, including Comparative Example 19-1.

Using the molding material thus obtained, an MO8 type integrated circuit was resin-sealed by transfer molding.

The molding material was heated to 90°C using a high-frequency preheater and then molded at 170°C for 2 minutes, followed by after-curing at 180°C for 4 hours.

As in Example 1, thermal cycle tests and bias PCT tests were conducted on the resin-sealed semiconductor devices of Examples 7 to 12 and Comparative Examples 5 to 8. The results are shown in Tables 5 and 6 below.

20 - Table 5 - 22 - Table 6 23 - Examples 13 to 15 Cresol novolac type epoxy resin (epoxy resin A) with epoxy equivalent of 220, brominated epoxy novolac resin with epoxy equivalent of 290 (
Epoxy resin B), 7 enol novolak resin curing agent with a molecular weight of 800, silicon carbide fiber (Ili minor diameter 10 μm, 8N length 0.8 m+)
Silicon carbide whiskers (fiber diameter 0.1 μm, saw length 2
0 μm) Carbon fiber C (fiber diameter 6 μm, 4111 length 30 μm) fused silica powder, triphenylphosphine curing accelerator, antimony trioxide, carnauba wax, carbon black,
The silane coupling agent (γ-glycidoxypropyltrimethoxysilane) was selected to have the composition (parts by weight) shown in Table 7, and each composition was mixed with a mixer and mixed with a heated roll to create three types of A transfer molding material was prepared.

Using the molding material thus obtained, an MO8 type integrated circuit was resin-sealed by transfer molding.

For sealing, molding material heated to 90℃ with a high-frequency preheater is heated to 17℃.
This was carried out by molding at 0°C for 2 minutes and then after-curing at 180°C for 4 hours.

As in Example 1, the resin-sealed semiconductor devices of Examples 13 to 15 were subjected to a thermal cycle test and a bias PCT test. The results are summarized in Table 8.

Table 7 26 - Table 8 27 - (Effects of the Invention) As detailed above, according to the present invention, a highly reliable resin-sealed semiconductor which prevents bonding wires from being cut due to stress or corrosion equipment can be provided.

[Brief explanation of the drawing]

The drawing is a cross-sectional view of a resin-sealed semiconductor device. 1... Semiconductor element, 3... Bonding wire, 4
...Lead bin, 5...Resin sealing body. Applicant's agent Patent attorney Takehiko Suzue 28-

Claims (1)

[Scope of Claims] (1) In a resin-sealed semiconductor device comprising a semiconductor element and a resin-sealed body for sealing the semiconductor element, the resin-sealed body contains an epoxy resin and at least one molecule of the resin-sealed body. A resin-encapsulated semiconductor device comprising an epoxy resin curing agent and/or acid anhydride curing agent having two phenolic hydroxyl groups, and carbon fiber and/or silicon carbide fiber. (2) The resin-sealed semiconductor device according to claim 1, wherein the epoxy resin is a novolac type epoxy resin having an epoxy equivalent of 170 to 300. (3) The resin-sealed semiconductor device according to claim 1, wherein the epoxy resin curing agent is a novolac type phenolic resin. (4) Claim 1, characterized in that carbon fiber is contained in the resin sealing body in an amount of 0.01 to 20% by weight.
The resin-sealed semiconductor device described in Section 1. (5) The resin-sealed semiconductor device according to claim 1, wherein the resin-sealed body contains 0.01 to 20% by weight of carbon llI fibers or silicon carbide fibers. (6) The resin-sealed semiconductor device according to claim 1, wherein the m-line length of the silicon carbide fiber is 1H or less. (7) The resin-sealed semiconductor device according to claim 1, wherein the silicon carbide fibers are silicon carbide whiskers. (8) The resin-sealed semiconductor device according to claim 1, wherein the resin-sealed body contains an inorganic filler. (10) The resin-sealed semiconductor device according to claim 9, wherein the inorganic filler is either fused silica powder or crystalline silica powder. (11) The resin-sealed semiconductor device according to claim 1, wherein an organic phosphine compound is blended in the resin-sealed body.