JPS60202118A - Sealing epoxy resin composition and semiconductor device sealed therewith - Google Patents

Abstract

PURPOSE:The titled composition excellent in thermal cycling property and capable of providing a flame-retarding resin-sealed semiconductor device, prepared by mixing an epoxy resin with a specified curing agent, an organic phosphine compound and a halogen compound. CONSTITUTION:The titled composition prepared by mixing (A) an epoxy resin (e.g., novolak epoxy resin of an equivalent weight of 170-300 with (B) a curing agent having at least two phenolic hydroxyl groups in the molecule (e.g., elastomer component-grafted novolak phenolic resin), (C) an organic phosphine compound (e.g., triphenylphosphine), and (D) a halogen compound (e.g., brominated novolak epoxy resin). In resin A containing compound C, its thermal cycling property can be markedly improved when its flame retardation is performed by using compound D alone without Sb2O3. By the co-use of curing agent B, the effect becomes marked.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention pertains] The present invention. The present invention relates to an epoxy resin composition for encapsulation and a resin-encapsulated semiconductor device using the same, and particularly to a highly reliable and flame-retardant epoxy resin composition for encapsulation and a resin-encapsulated semiconductor device using the same. .

[Technical background of the invention and its problems]

It is well known that flame retardants comprising halogen compounds are used to make epoxy resin compositions flame retardant. In addition, in order to enhance the flame retardant effect, a technique of using antimony trioxide as an antimony aid is also well known. When used in combination with antimony dioxide, flame retardant effects can be obtained even if the amount of halogen compounds is reduced, so most of the flame-retardant epoxy resin compositions currently on the market for sealing semiconductor devices and electronic components are made using halogen compounds. This type uses a combination of antimony trioxide and antimony trioxide.

JP-A-50-108400 describes a heat-resistant epoxy resin molding material for sealing, and in its examples as well, a norogen compound and antimony trioxide are used in combination. In these known techniques, the curing accelerator and curing catalyst are amine compounds, etc., and are not organic phosphine compounds.

On the other hand, the technology of using an organic phosphine compound in a highly reliable epoxy resin composition for sealing and a resin-encapsulated semiconductor device using the same is well known and is disclosed in Japanese Patent Application Laid-Open No. 56-13095.
3, Japanese Patent Publication No. 57-60779.

Although Japanese Patent Publication No. 57-60779 mentions a technique for making an epoxy resin composition for sealing flame retardant, there is no mention of a technique for making it flame retardant using a halogen compound alone, and the examples are This is an example of flame retardation achieved by combining a halogen compound and antimony trioxide. Regarding epoxy resin compositions for sealing and techniques for making resin-encapsulated semiconductor devices using the same flame retardant, when using organic phosphine compounds, there is no known technique for using a halogen compound alone except for antimony trioxide. Not yet.

By the way, it is true that by using an organic phosphine compound, a highly reliable encapsulating evo resin composition and a resin encapsulated semiconductor device using the same can be obtained, but especially when it is made flame retardant. However, the conventional technology had insufficient cooling and heating cycle characteristics.

Next, the thermal cycle characteristics referred to herein will be described in detail using an example in which a semiconductor device is sealed.

Conventionally, hermetic sealing using metals, ceramics, etc. has been employed as a sealing technology for semiconductor devices, but recently resin sealing using epoxy resin has become mainstream because it is economically advantageous.

However, conventional resin-sealed semiconductor devices have the following drawbacks.

FIG. 1 shows a cross-sectional view of a semiconductor device sealed using ceramics. Semiconductor element 1 has lead pin 2
is electrically connected to by a thin bonding wire 3, but the bonding wire 3 exists in the space 4,
It is not subjected to mechanical stress. On the other hand, in a resin-sealed semiconductor device, as shown in a cross-sectional view in FIG. The bonding wire 10 is subjected to mechanical stress due to the sealing resin. Since the thermal expansion coefficients of the sealing resin and the embedded components are different, if a resin-encapsulated semiconductor device is repeatedly exposed to high and low temperatures, it will no longer be able to withstand the stress caused by the difference in thermal expansion coefficients, and the bonding wire will 10
However, it has the disadvantage of being prone to disconnection or poor contact.

Even if the high reliability technology disclosed in Japanese Patent Publication No. 57-60779 is used, such drawbacks have not been satisfactorily solved in the case where the sealing resin is made flame retardant.

[Purpose of the invention]

The purpose of the present invention is to improve the drawbacks of such conventional epoxy resin compositions for sealing and resin-encapsulated semiconductor devices using the same, and to provide highly reliable and flame-retardant sealing epoxy resin compositions. An object of the present invention is to provide an epoxy resin composition and a resin-sealed semiconductor device using the same.

[Summary of the invention]

In order to achieve the above object, the inventors of the present invention have made extensive research, and as a result, by making the epoxy resin using an organic phosphine compound flame retardant with a halogen compound alone, the thermal cycle characteristics are significantly improved, resulting in high reliability. It is possible to obtain an epoxy resin for soil using resin technology, and also to add 1 to the hardening agent.
When a compound having at least two thornol hydroxyl groups in the molecule is used, the self-improvement effect is remarkable, and in particular, when a grafted novolac-type thornol resin is used, the most severe properties are obtained. This discovery led to the completion of the present invention.

That is, the epoxy resin composition for sealing of the present invention has (al
Epoxy resin (b) A curing agent or/and an acid anhydride curing agent having at least two phenolic hydroxyl groups in one molecule (C1 contains organic phosphine compounds and (di halogen compounds), (eJ does not contain antimony trioxide) It is characterized by

This is a flame-retardant epoxy resin composition for sealing.

Further, the resin-sealed semiconductor device of the present invention is a resin-sealed semiconductor device formed by sealing a semiconductor device with an epoxy resin composition, in which the epoxy resin composition contains (Al in one molecule of epoxy resin (b) A curing agent or/and an acid anhydride curing agent (containing a Cl organic phosphine compound and an FDL halogen compound (not containing EL antimony trioxide)) having at least two tunol hydroxide groups.

This is a flame-retardant resin-sealed semiconductor device.

The reason for the phenomenon in which excellent properties are obtained only when an organic phosphine compound and a halogen compound are combined without using antimony trioxide in the present invention has not yet been elucidated, but this phenomenon cannot be predicted at all from conventional and advanced technology. That's true. This is a unique phenomenon that is only found when organic phosphine compounds are used as curing accelerators (curing catalysts), and this phenomenon does not occur when other substances other than organic phosphine compounds, such as amine compounds, are used. This is because no such phenomenon was observed, and there was no significant difference in the thermal cycle characteristics whether antimony trioxide was used in combination or a halogen compound was used alone.

The epoxy resin used in the present invention is a commonly known one and is not particularly limited. For example, Totosufunol A type epoxy resin, Tsuunol novolac type epoxy resin, cresol novolac type epoxy resin, etc. Glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, assembled aliphatic epoxy resin, alicyclic epoxy resin Examples include epoxy resins having two or more epoxy groups in one molecule, such as resins, heterocyclic epoxy resins, and halogenated epoxy resins.

These epoxy resins may be used alone or in a mixed system of two or more.

More preferable epoxy resins used in the present invention are epoxy resins having an epoxy weight of 7o to 3000 novolac type epoxy resins, such as phunor nopolac type epoxy resins, cresol novolac type epoxy resins, halogenated phenol novolac type epoxy resins, etc. be.

These epoxy resins have a chlorine ion content of 110PP.
Hereinafter, it is desirable that the content of the hydrolyzable ring system is o, IBg>% or less. The reason for this is that if chlorine ions exceeding 110 PP'f: or hydrolyzable ring systems exceeding 0.1% by weight are contained, the aluminum electrodes of the sealed semiconductor device are likely to be corroded.

The curing agent having at least two phenolic hydroxyl groups in one molecule used in the present invention includes phenolic resins, polyoxystyrene, polyhydric phenol compounds, and modified products thereof. Phenol novolac resin, cresol novolac resin, ter
Novolak type phenolic resins such as t-butylphenol novolak resin, nonylphenol novolak resin,
These include resol type phenol resin, phenol aralkyl resin, polyparaoxystyrene, Hibisphenol A, and modified products of these compounds. Among these, novolak-type phenolic resins and modified products thereof are preferred, and novolak-type phenolic resins grafted with a nidistomer component are particularly preferred.

Further, these curing agents can be used alone or in a mixed system in which two or more of them are appropriately combined.

As the acid anhydride used in the present invention, any aliphatic alicyclic or aromatic carboxylic anhydride or substituted carboxylic anhydride thereof can be used.

As such an acid anhydride.

For example, maleic anhydride, succinic anhydride, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, trimetic anhydride, pyromellitic anhydride, nadic anhydride (3,6-nindomethyt/-1, 2.3,6
-Tetrahydrophthalic anhydride #), methylnadic anhydride, 3.3: 4.4'-benzophenonetetracarboxylic anhydride, tetracyprom hepthalic anhydride, chlorendic anhydride, etc., and this group consists of these! One or more types of buildings selected from l1 are used.

Each of these curing agents may be used alone, or both may be used in an appropriate proportion.

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 within 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.

In the present invention, by using an organic phosphine compound as a curing accelerator, the moisture resistance and high-temperature electrical properties of resin-encapsulated semiconductor devices are significantly improved compared to when conventional curing accelerators such as imidazole and amines are used. It can be improved.

The organic phosphine compounds used in the present invention include a tertiary phosphine compound with the formula CI) 1 R2-P'CI) 3 in which R1-R3 are all organic groups, and a first phosphine compound in which R2R3 are both hydrogen. There is. Specifically, triphenylphosphine,
These include tributylphosphine, tricyclohexylphosphine, methyldiphenylphosphine, butylphenylphosphine, diphenylphosphine, phenylphosphine, octylphosphine, and the like. Further, R] may be an organic group containing an organic phosphine. Examples include 1,2-bis(diphenylphosphino)ethane and bis(diphenylphosphino)methane.

Among these, arylphosphines are preferred, and triarylphosphines such as triphenylphosphine are particularly preferred. Further, one or more of these organic phosunine compounds may be used in a mixed system. However, the lever)
The amount of the organic phosphine compound to be blended may generally be within the range of o, ooi to 20% by weight of the resin component (epoxy resin and curing agent), but particularly preferred properties are obtained within the range of 0.101 to 5% by weight.

By specifically controlling the blending amount of the organic phosphine compound within this range, a resin-sealed semiconductor device with excellent characteristics can be obtained.
be able to.

If the amount is less than 0.001% by weight, the effect of the addition will be difficult to notice, and the epoxy resin composition will take a long time to cure, while if it exceeds 20% by weight, it will have an adverse effect on quality.

The halogen compound used in the present invention is:

A compound containing Ω halogens such as fluorine, bromine, and iodine, and its purpose is to impart flammability.

Halogenated epoxy resins such as brominated novolac type epoxy resins, brominated bisphenol A type epoxy resins, brominated novolac type phenol resins, brominated bisphenol A, -M polyparaoxystyrene, tetrabromophthalic anhydride, chlorene anhydride Reactive halogen compounds such as halogenated curing agents such as Dick's are preferred;
Non-reactive halogen compounds such as 1,2.3.4-tetrabromobutane can also be used.

The most preferred type of halogen is a bromine compound.

The amount of halogen-containing violet in the composition is preferably in the range of 0.1 to 40% by weight. This is because if the content is less than 0.1% by weight, the flame retardant effect will not be sufficient, and if it exceeds 40% by weight, the electrical properties will tend to deteriorate.

The epoxy resin composition for sealing of the present invention may contain an inorganic brightening agent and other additives, if necessary.

Inorganic photonic agents include fused silica, crystalline silica,
Generally known materials such as glass fiber, talc, alumina, calcium silicate, calcium carbonate, barium sulfate, and magnesia can be used. Among these, fused silica and crystalline silica are most preferred because of their high purity and low thermal expansion. Two or more of these fillers can also be used in combination.

The blending amount of the inorganic photonic agent is preferably about 1.5 to 4 times the total weight of the epoxy resin and curing agent.

Examples of other additives include natural waxes and synthetic waxes. Metal salts of straight chain fatty acids, mold release agents such as acid amide esters or paraffins, coloring agents such as carbon black, silane coupling agents, etc. may be added and blended in an adjacent room.

Use the resin composition for sealing of the present invention as a molding material. . -1, crab 21□1. .

The raw material composition is selected to have a certain composition. For example, a semiconductor device can be easily encapsulated using an epoxy resin composition of an epoxy resin molding material by thoroughly mixing it with a mixer and then melting it with a hot roll or mixing it with a kneader. It can be easily manufactured. The most common method for sealing is low-pressure transfer molding, but sealing can also be performed by injector molding, compression molding, casting, or the like.

The epoxy resin for sealing and the composition are 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. 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 thyristor, a diode, etc., and is not particularly limited.

[Embodiments of the invention]

Example 1-6 Cresol novolak type epoxy resin with epoxy equivalent of 220 (epoxy resin A), AX-formed novolac type epoxy resin with epoxy equivalent of 290 (epoxy resin B, 14 element content: 35% by weight), bromine with epoxy equivalent of 400 Bisphenol A type epoxy resin (epoxy resin C1 bromine content 50% by weight) Novolac type phenolic resin (phenol resin A) with hydroxyl group equivalent of 1070, grafted novolac type phenolic resin (phenol resin B) with hydroxyl group equivalent of 120, hydroxyl group equivalent of 1240 Brominated polyparaoxystyrene (bromine content 50%), tetrahydrophthalic anhydride, triphenylphosphine curing accelerator, antimony trioxide, fused silica powder, carnauba wax, carbon black, silane coupling agent ((j = glycidoxyglosine) Ten types of transfer molding materials, including comparative examples, were prepared by selecting the compositions (parts by weight) of biltrimethquine silane) shown in Table 1 and mixing each composition with a mixer and kneading with heated rolls.

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

For sealing, heat the molding material to 90'C in a Koshoha preheater.
This was done by bend molding at 70°C for 2 minutes and then after-curing at 180°C for 4 hours.

The flame retardancy of these molding materials was evaluated before conducting the reliability evaluation of the MO8 type integrated circuit sealed with resin.The evaluation of flammability was based on UL standard 94 Those satisfying v-0 were considered to be flame retardant.The results are shown in Table 2.

As a result, Comparative Example 2 did not satisfy the flame retardancy and was excluded from the evaluation. T-Valve Evaluation Test 1 Two thermostats at +200°C and -65°C were prepared, and 100 resin-sealed semiconductor devices each were placed in the thermostat at +200°C and left for 30 minutes.

After that, take it out and leave it at room temperature for 5 minutes, then heat it to 65°C.
It was left in a constant temperature bath at C for 30 minutes. Thereafter, it was taken out and left again at room temperature 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 check for defects. The results are shown in Table 3.゛The defect was caused by a disconnection or poor contact of the bonding wire. ・Accumulated T-Turn Bottom 41 White Evaluation Test 2 Apply IOV in steam at 120°C and 2 atm to check for disconnection due to corrosion of the χ aluminum wiring. A moisture resistance test (bias PCT) was conducted and the results are shown in Table 4.

[Effects of the Invention] As is clear from the purpose of the present invention, the summary description, and the examples, the present invention makes it possible to obtain a highly reliable resin-sealed semiconductor device. .

[Brief explanation of drawings]

FIG. 1 is a sectional view of a semiconductor device in a semirac package, and FIG. 2 is a sectional view of a resin-sealed semiconductor device. 1.8... Semiconductor element 2.9... Lead pin 3.
10... Bonding wire 4... Space 5... Semilux 6.
...Metal plate 7...Seal material 11...
...Sealing resin agent Patent attorney Noriyuki Chika (and 1 other person) Continuation from page 1 ■Int, C1,' Identification code Internal office reference number 0 Author Naoko Kihara Inside Saiwai Ward, Kawasaki City d office

Claims (1)

[Scope of Claims] 1. A curing agent having at least two tunol hydroxyl groups in one molecule of the al epoxy resin (b). A flame-retardant sealing epoxy resin composition 2 characterized by containing a halogen compound, the sealing according to claim 1, wherein the epoxy resin is a novolac type epoxy resin having an epoxy equivalent of 170 to 300. epoxy resin composition 3 for sealing, epoxy resin composition 4 for sealing according to claim 1, wherein the curing agent is a novolac-type funol resin or/and a modified product thereof;
The epoxy resin composition 5 for sealing according to claim 3, wherein the curing agent is a grafted novolac-type funol resin, and the epoxy resin composition 5 for sealing according to claim 1, wherein the halogen compound is a bromine compound. Epoxy resin composition 6, Claim 1 in which the halogen compound is a halogenated epoxy resin Epoxy resin composition 7 for sealing according to Claim 1, wherein the halogen compound is a brominated novolac type epoxy resin Claim 6 Epoxy resin composition 8 for sealing according to Claim 1, wherein the halogen compound is a halide of a curing agent having a thunol hydroxyl group and/or a halide of an oxygen hydrate curing agent. epoxy resin composition 9, the halogen content in the composition is 0.
The epoxy resin composition IO for sealing according to claim 1 is within the range of 1 to 40% by weight, and the epoxy resin composition according to claim 1 contains fused silica or/and crystalline silica. Epoxy resin composition for sealing 11, a resin-encapsulated semiconductor device formed by sealing a semiconductor device with an epoxy resin composition, in which the epoxy resin composition contains at least 2 A curing agent or/and an acid anhydride curing agent that breaks down the hydroxyl groups of the two-noryl group (a flame-retardant curing agent containing a C1 organic phosphine compound and a (dl) halogen compound and not containing (el) antimony trioxide). Claim 11: The resin-sealed semiconductor device 12 is characterized in that the epoxy resin is a novolak-type epoxy resin having an epoxy equivalent of 170 to 300.
A resin-encapsulated semiconductor device 13 according to Claim 11, wherein the curing agent is a novolac-type Funol resin or/and a modified product thereof; A resin-encapsulated semiconductor device 14 according to Claim 11, wherein the curing agent is grafted. The resin-sealed semiconductor device 15 according to claim 13, which is a novolac-type Funol resin, and the resin-sealed semiconductor device 16, according to claim 11, wherein the halogen compound is a bromine compound, the halogen compound is a halogenated epoxy resin, the resin-sealed semiconductor device 17 according to claim 11, and the resin-sealed part according to claim 16, wherein the halogen compound is a brominated novolak epoxy resin. Semiconductor device 18, resin-sealed semiconductor device 19 according to claim 11, wherein the halogen compound is a halide of a curing agent having a thunol hydroxide group and/or a halide of an acid anhydride curing agent, epoxy resin The halogen compound in the composition is 0.1
The resin-sealed semiconductor device 20 according to claim 11 in which the epoxy resin composition contains fused silica and/or crystalline silica in a range of 40% by weight Resin-encapsulated semiconductor device