JPH10259239A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, low in stress, highly adhesive to frame materials, high in reliability under humid conditions and suitable for sealing semiconductor devices, by beforehand melting a curing accelerator in a curing agent. SOLUTION: This composition essentially comprises (A) an epoxy resin, (B) a phenolic resin as the curing agent, (C) 1,8-diazabicyclo(5,4,0)undecene-7 or its salt as the curing accelerator, (D) an epoxy-modified silicone compound having an epoxy group at the terminal or inside of its siloxane chain, and (E) an inorganic filler, wherein the component C is molten in and mixed with the component B beforehand. It is preferable that the equivalent ratio of epoxy equivalents of the component A to equivalents of the phenolic OH group (epoxy equivalents/OH equivalents) is 0.5 to 1.5, and that the component D is a dimethylsiloxane derivative having an alicyclic epoxy group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition, and more particularly to an epoxy resin composition suitable for sealing electronic parts, electric parts, and especially semiconductor devices.

[0002]

2. Description of the Related Art Epoxy resin has electrical properties, mechanical properties,
Because of its excellent moisture resistance and the like, it is widely used as a highly reliable insulating material for sealing and impregnating semiconductor devices, electronic components, and electrical components.

Particularly, as a sealing material for a semiconductor device, resin sealing has become the mainstream of semiconductor packaging in recent years, since it can be mass-produced at a lower cost than a conventional ceramic or metal hermetic sealing method. I have.

[0004] The characteristics required of a resin as a semiconductor encapsulating material are corrosion resistance against disconnection failure due to corrosion of Al wiring on the element and thermal shock resistance against disconnection failure due to thermal shock of an Au wire connecting a chip and a frame. And the like. Recently, the Al wiring has been further miniaturized and the chip size has been increased with the increase in the degree of integration of the semiconductor element, while the size and thickness of the package have been rapidly reduced.

In view of such trends in semiconductor encapsulation technology, when a flat package is surface-mounted, it is necessary to withstand solder at 260 ° C. for 5 to 10 seconds. In the flat package, the resin thickness above and below the element is thin, and when immersed in solder at 260 ° C., cracking of the resin and reduction in moisture resistance occur.

As a countermeasure against these problems, one method is to lower the internal stress of the resin. However, a commonly used low stress technology, for example, a modified resin obtained by adding rubber or the like is used as a resin for semiconductor encapsulation. In such a case, there is a disadvantage that the moisture resistance is reduced.

[0007]

As described above, the conventional epoxy resin composition has a large internal stress, and when a large-sized element is sealed, an Au wire open or a resin crack is easily generated by thermal shock. Further, the resin is easily peeled off from the frame by a treatment such as solder immersion, which causes a defect.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide an epoxy resin composition having low stress, good adhesion to a frame material, and high reliability in moisture resistance. To provide.

[0009]

In order to solve the above-mentioned problems, the present invention is directed to claim 1, wherein (a): an epoxy resin, (b): a phenol resin as a curing agent,
(C): 1.8-diazabicyclo (5,4,0) undecene-7 or a salt thereof as a curing accelerator, (d): an epoxy-modified silicone compound having an epoxy group at a terminal or inside a siloxane chain, (e) ): An inorganic filler as an essential component, and the 1.8-diazabicyclo (5,4,
0) Provide an epoxy resin composition in which undecene-7 or a salt thereof is melt-mixed in advance with the phenol resin.

According to a second aspect of the present invention, the equivalent ratio of the epoxy equivalent of the epoxy resin to the phenolic hydroxyl equivalent of the phenol resin (epoxy equivalent / OH equivalent) is in the range of 0.5 to 1.5. Item 1. An epoxy resin composition according to item 1, is provided.

According to a third aspect of the present invention, there is provided an epoxy resin composition according to the first aspect, wherein the epoxy-modified silicone compound is a dimethylsiloxane derivative having an alicyclic epoxy group.

According to a fourth aspect of the present invention, the epoxy-modified silicone compound is contained in an amount of 0.05 to 5% of the total resin composition.
The epoxy resin composition according to claim 1, which is in the range of% by weight.

According to a fifth aspect of the present invention, there is provided an epoxy resin composition according to the first aspect, wherein the epoxy-modified silicone compound is previously melt-mixed with the epoxy resin or the phenol resin.

In addition to the above, the invention of claim 6 provides the epoxy resin composition according to claim 1, wherein the main component of the inorganic filler is one or two selected from fused silica and crystalline silica. .

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.

The epoxy resin (a) component used in the present invention is generally known and is not particularly limited.

Examples of usable resins include glycidyl ether type epoxy resins such as bisphenol A type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, and wire. Epoxy resins having two or more epoxy groups in one molecule, such as aliphatic aliphatic epoxy resin, alicyclic epoxy resin, heterocyclic epoxy resin, and halogenated epoxy resin.

These epoxy resins may be used as a mixture of two or more.

It is desirable that these epoxy resins have a chlorine ion content of 10 ppm or less and a hydrolyzable chlorine content of 0.1% by weight or less. As the epoxy resin, a glycidyl ether type epoxy resin is most suitable, and excellent characteristics can be obtained particularly when a novolak type epoxy resin having an epoxy equivalent of 170 to 300 is used.

The phenolic resin (b) as a curing agent used in the present invention includes a phenolic novolak resin, a cresol novolak resin, a tert-butylphenol novolak resin, a novolak type phenol resin such as a nonylphenol novolak resin, a resol type phenol resin, Bisphenol A and the like can be mentioned.

These phenolic resins may be used as a mixture of two or more.

The mixing ratio of the epoxy resin (a) component to the phenol resin (b) component is such that the equivalent ratio of the epoxy equivalent of the epoxy resin to the phenolic hydroxyl equivalent of the phenol resin (epoxy equivalent / OH equivalent) is 0. 0.5-1.5
It is preferable that If the equivalent ratio deviates from this range, the strength is undesirably reduced.

1.8-diazabicyclo (5,4,0) undecene-7 as a curing accelerator used in the present invention
(Hereinafter abbreviated as DBU) and its salt (c) component include phenol salt, 2-ethylhexanoate, oleate, p-toluenesulfonate, formate and the like.

Of particular note in the present invention is that D
It is a usage mode of BU.

DBU is known as a curing accelerator for an epoxy resin composition (see, for example,
No. 5929), the electrical properties of the cured resin are inferior to those of phosphorus compound-based curing accelerators such as triphenylphosphine, and especially when used as a sealing material for resin-encapsulated semiconductor devices, Al wiring corrosion resistance test Is insufficient in the humidity resistance reliability of the bias-pressure cooker test using the test element.

However, the DBU exhibits specificity when used in combination with the epoxy-modified silicone compound (d) described later. That is, when DBU and the epoxy-modified silicone compound are added to the phenolic curing agent-based epoxy resin composition, high adhesion to the frame material, which is not seen in the triphenylphosphine curing accelerator-based epoxy resin composition, is exhibited, and low stress Nevertheless, a resin composition which is comparable to a resin composition for encapsulating a semiconductor using triphenylphosphine in terms of moisture resistance reliability can be obtained.

These properties are obtained only when DBU and the epoxy-modified silicone compound are used in combination, and are not seen when DBU alone or when the epoxy-modified silicone compound and another curing accelerator are used.

DBU is liquid at room temperature, and it is difficult to uniformly disperse it in a mixture of powdered resin and inorganic filler.
Further, if the filler is mixed with the inorganic filler in a liquid state, the adsorption of the filler on the surface cannot be prevented, and a discrepancy occurs between the added amount and the catalytic activity.

If DBU is melt-mixed with a phenol resin as a curing agent beforehand, a resin composition which is easy to handle and has good properties such as flexural strength can be obtained.

The same treatment can be applied to the salt of DBU which is liquid at room temperature.

The epoxy-modified silicone compound (d) used in the present invention may be any component having an epoxy group at the terminal or inside of the siloxane chain.

Examples of usable polymers include polyglycidoxypropylmethylsiloxane represented by the following general formula (1), polyglycidoxypropylmethyl-dimethylsiloxane copolymer represented by the following general formula (2), Polyglycidoxypropylmethylpolyethermethylsiloxane copolymer represented by the general formula (3), poly (epoxycyclohexyl) ethylmethylsiloxane represented by the following general formula (4), and the following general formula (5)
Polyepoxycyclohexylethylmethyl represented by-
And dimethylsiloxane copolymer.

[0033]

Embedded image These epoxy-modified silicone compounds may be directly added to another resin composition, or may be used by being melt-mixed in advance with an epoxy resin or a phenol resin.

These epoxy-modified silicone compounds may be used as a mixture of two or more.

The preferable addition amount of the epoxy-modified silicone compound is 0.05 to 5% by weight based on the total weight of the resin composition, and the addition of more than that is not preferable because it causes a decrease in moldability.

The inorganic filler (e) used in the present invention
Examples of the component include fused silica powder, crystalline silica powder, glass fiber, talc, alumina powder, calcium silicate powder, calcium carbonate powder, barium sulfate powder, magnesia powder, and the like. Silica powder is most preferred.

These inorganic fillers may be used as a mixture of two or more kinds.

The epoxy resin composition comprising the components (a) to (e) as essential components according to the present invention may optionally contain other additional components such as natural waxes, synthetic waxes, and straight-chain fatty acid metals. Release agents such as salts, acid amides, esters or paraffins, flame retardants such as chlorinated paraffin, bromotoluene, hexabromobenzene, antimony trioxide, coloring agents such as carbon black, silane coupling agents, etc. It can be added.

The epoxy resin composition of the present invention is thoroughly mixed by, for example, a mixer, and further uniformly mixed by adding a melt-mixing process using a hot roll or a mixing process using a kneader or the like, followed by compression, transfer, or injection. Provided for molding.

By sealing a semiconductor device using the resin composition of the present invention, a resin-sealed semiconductor device can be easily manufactured. The most common sealing method is a low-pressure transfer method, but a sealing method by injection molding, compression molding, casting or the like can also be applied.

When sealing with an epoxy resin composition, a resin-sealed semiconductor device sealed with a cured product of this composition can be obtained by heat curing. It is particularly desirable to heat to 150 ° C. or higher during curing.

The semiconductor device according to the present invention includes an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, and the like, but is not particularly limited thereto.

[0043]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples unless departing from the technical idea of the present invention. (Examples 1 to 3) Cresol novolak type epoxy resin having an epoxy equivalent of 200 (A), phenol novolak resin having a molecular weight of 700 (B), DBU, poly (epoxycyclohexyl) ethylmethyl-dimethyl represented by the following general formula (6) Siloxane copolymer (x / y = 2 in the following formula)
0, molecular weight 35,000, abbreviated as PECSi hereinafter),
Poly (glycidoxy) propylmethyl-dimethylsiloxane copolymer represented by the following general formula (7) (x / y = 40, molecular weight 45000, hereinafter abbreviated as PGSi), fused silica (C), silane coupling agent ( D) and carnauba wax (E) were mixed in a mixing ratio (parts by weight) shown in Table 1 below using a mixer, kneaded and cooled with a roll, and then pulverized to obtain the epoxy of Examples 1 to 3. A resin composition was obtained. The DBU used was previously melt-mixed in a phenol resin.

[0044]

Embedded image

[0045]

[Table 1] (Example 4) When the respective components shown in Example 1 were mixed at the ratio shown in Table 1 above, the epoxy resin component and PECS were mixed.
What melt-mixed the i component beforehand was used. Thereafter, the same operation as in Examples 1 to 3 was performed to obtain the epoxy resin composition of Example 4. (Example 5) When the respective components shown in Example 1 were mixed at the ratios shown in Table 1 above, the phenol resin component and PEC were mixed.
What was previously melt-mixed with the Si component was used. Thereafter, the same operation as in Examples 1 to 3 was performed to obtain the epoxy resin composition of Example 5. (Comparative Examples 1 to 3) A cresol novolak type epoxy resin having an epoxy equivalent of 200, a phenol novolak resin having a molecular weight of 700, DBU, TPP (triphenylphosphine), PECSi, and polydimethylsiloxane were prepared as shown in Table 1 above.
The epoxy resin compositions of Comparative Examples 1 to 3 were obtained by the same operation as in the examples.

Using each of the above epoxy resin compositions, 18
A test piece was prepared at 0 ° C for 3 hours under transfer molding conditions.
The volume resistivity, flexural strength and flexural modulus were measured.
Further, these epoxy resin compositions are formed on an iron-nickel alloy (Ni 42%) plate as a material for a semiconductor frame, and a force is applied to the plate in a horizontal direction to measure a load when the resin is peeled off. The sex was examined.

The results are shown in Table 2 below.

[0048]

[Table 2] Further, a semiconductor element for a moisture resistance test (a test element for checking corrosion of aluminum wiring) was sealed at 180 ° C. for 3 minutes using the epoxy resin compositions of Examples and Comparative Examples, and the obtained moisture resistance was obtained. The test semiconductor device was subjected to a moisture resistance test by applying a voltage of 15 V under a high-temperature and high-pressure steam of 125 ° C. (B-PCT).

The results are shown in Table 3 below.

[0050]

[Table 3] Next, the solder immersion resistance was tested. Using the epoxy resin compositions of Examples and Comparative Examples, the same moisture resistance test element as described above was placed in a flat package having a thickness of 2 mm at 175 ° C.
After molding under the conditions of time, after-curing was performed at 180 ° C. for 4 hours. Thereafter, a moisture absorption treatment was performed at 85 ° C. × 85% RH for 72 hours and immersed in a 260 ° C. solder bath for 5 seconds. Thereafter, a moisture resistance test was conducted under high-temperature and high-pressure steam at 127 ° C. to examine the occurrence of defects.

The results are shown in Table 4 below.

[0052]

[Table 4] As shown in Tables 2 to 4, the epoxy resin composition of the present invention has better adhesion to the frame material than the epoxy resin composition of the comparative example, and has low elasticity.
As a highly reliable resin with low stress and high adhesion,
It can be seen that it is suitable for sealing and impregnation of electric components.

When the epoxy resin composition of the present invention is applied to a resin-encapsulated semiconductor device, it has high moisture resistance reliability and good adhesion between the frame and the resin. It turns out that it is suitable for packages and the like.

[0054]

As described above, the epoxy resin composition of the present invention is excellent in characteristics such as moisture resistance reliability, low internal stress, and high adhesion to a frame base material, and is used for sealing electronic parts and electric parts. It is advantageously applied to impregnation and impregnation, and to a resin-sealed semiconductor device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 23/31 (72) Inventor Ken Uchida 1 Toshiba-cho, Komukai-shi, Kawasaki-shi, Kanagawa Inside Toshiba Research Institute, Ltd.

Claims (6)

[Claims] (A): an epoxy resin; (b): a phenolic resin as a curing agent; and (c): 1.8-diazabicyclo (5,4,0) undecene-7 or a salt thereof as a curing accelerator. (D): an epoxy-modified silicone compound having an epoxy group at a terminal or inside of a siloxane chain; (e): an inorganic filler as an essential component, and the 1.8-diazabicyclo (5,4,0) undecene-7. Or an epoxy resin composition in which a salt thereof is melt-mixed in advance with the phenol resin. 2. The epoxy resin according to claim 1, wherein the equivalent ratio of the epoxy equivalent of the epoxy resin to the phenolic hydroxyl equivalent of the phenolic resin (epoxy equivalent / OH equivalent) is in the range of 0.5 to 1.5. Composition. 3. The epoxy resin composition according to claim 1, wherein the epoxy-modified silicone compound is a dimethylsiloxane derivative having an alicyclic epoxy group. 4. The epoxy resin composition according to claim 1, wherein said epoxy-modified silicone compound is in the range of 0.05 to 5% by weight of the total resin composition. 5. The epoxy resin composition according to claim 1, wherein the epoxy-modified silicone compound is melt-mixed in advance with the epoxy resin or the phenol resin. 6. The epoxy resin composition according to claim 1, wherein the main component of the inorganic filler is one or two selected from fused silica and crystalline silica.