JPH0723425B2 - Resin-sealed semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to an epoxy resin composition, particularly an epoxy resin composition suitable for encapsulation of electronic parts, electric parts, especially semiconductor devices.

(Prior Art) Epoxy resin has excellent electrical properties, mechanical properties, moisture resistance, etc., and is therefore used as a highly reliable insulating material for semiconductor devices.
Widely used for sealing and impregnating electronic and electric parts.

In particular, as a sealing material for semiconductor devices, resin-based sealing has become the mainstream of semiconductor packaging in recent years because it is cheaper and can be mass-produced as compared with conventional hermetic sealing methods using ceramics and metals.

The characteristics required of resin as a semiconductor encapsulation material are mainly 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 Au wire connecting the chip and frame. It can be raised as something. In recent years, the Al wiring has become finer and the chip size has become larger along with the high integration of semiconductor elements. On the other hand, the miniaturization and thinning of packages have been rapidly progressing. Due to such trends in semiconductor encapsulation technology, when surface mounting a flat package, 260 ° C
It is necessary to endure the solder of 5-10 seconds. The flat package has a small resin thickness above and below the element, and if it is immersed in solder at 260 ° C, the resin cracks and moisture resistance decreases. One way to deal with these problems is to reduce the internal stress of the resin, but when using a commonly used stress-reducing technology, for example, a modified resin by adding rubber, etc., as a resin for semiconductor encapsulation, It has the drawback of reducing moisture resistance.

(Problems to be Solved by the Invention) A conventional epoxy resin composition has a large internal stress, and when a large element is sealed, thermal shock easily causes Au wire open or resin crack. Moreover, the resin is easily peeled off from the frame by a treatment such as solder dipping, which causes a defect.

An object of the present invention is to improve the difficulties found in such conventional epoxy resins, to provide an epoxy resin composition having low stress, good adhesion to a frame material, and high humidity resistance, Another object is to provide a highly reliable resin-sealed semiconductor device.

[Structure of Invention]

(Means for Solving Problems) When the present invention is outlined, the first invention of the present invention is as follows: (a): epoxy resin (b): phenol resin as a curing agent (c): 1.8-as a curing accelerator Diazabicyclo (5,4,
0) Undecene-7 or its salt (d): Epoxy-modified silicone compound (e): Inorganic filler The present invention relates to an epoxy resin composition, which further comprises the second aspect of the present invention. The invention relates to a resin-encapsulated semiconductor device, which is encapsulated with a cured product of the epoxy resin composition according to the first invention.

Hereinafter, the configuration of the present invention will be described in detail.

The epoxy resin (a) component used in the present invention is generally known and is not particularly limited. For example, bisphenol A type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, etc. glycidyl ether type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, linear fatty acid epoxy resin, alicyclic epoxy resin, complex Epoxy resins having two or more epoxy groups in one molecule such as cyclic epoxy resins and halogenated epoxy resins can be mentioned. However, these epoxy resins are of one type or two types.
You may use in the mixed system of 1 or more types. Further, 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. Further, a glycidyl ether type epoxy resin is most suitable as the epoxy resin, and excellent properties can be obtained particularly when a novolac type epoxy resin having an epoxy equivalent of 170 to 300 is used.

Examples of the phenol resin (b) component as a curing agent used in the present invention include novolac type phenolic resins such as phenol novolac resin, cresol novolac resin, tert-butylphenol novolac resin, nonylphenol novolac resin, and resol type phenol resin, bisphenol A. And so on.

These phenolic resins may be used alone or in a mixture of two or more kinds. Therefore, the mixing ratio of the epoxy resin (a) component and the phenol resin (b) component is
Equivalent ratio of epoxy equivalent of epoxy resin and phenolic hydroxyl group equivalent of phenol resin (epoxy equivalent / OH equivalent) is
It is preferable to set it to 0.5 to 1.5. If the equivalence ratio deviates from this range, the strength will decrease, which is not preferable.

1.8-diazobicyclo (5,4,0) undecene-7 (hereinafter abbreviated as DBU) as a curing accelerator used in the present invention and its salt (c) component include phenol salt, 2-ethylhexanoate and olein. Acid salt, P-toluene sulfonate, formate, etc. are listed.

Of particular note in the present invention is the usage of the DBU.

DBU is known as a curing accelerator for epoxy resin compositions (for example, Japanese Patent Laid-Open No. 55-5929), but compared to phosphorus compound-based curing accelerators such as triphenylphosphine, the electrical conductivity of the cured resin is higher. Characteristics are inferior, and particularly when used as a sealing material for a resin-sealed semiconductor device, the moisture resistance reliability of a bias-pressure cooker test by an element for an Al wiring corrosion resistance test is insufficient.

However, the DBU exhibits specificity when used in combination with the epoxy-modified silicone compound (d) component described below. That is, when DBU and an epoxy-modified silicone compound are added to a phenol curing agent-based epoxy resin composition, high adhesion to a frame material, which is not found in a triphenylphosphine curing accelerator-based epoxy resin composition, is exhibited and low stress is applied. In spite of this, a resin composition which is comparable to the resin for encapsulating a semiconductor using triphenylphosphine in moisture resistance can be obtained.

These properties are obtained only when DBU and an epoxy-modified silicone compound are used in combination, and are not seen when DBU is used alone or when an epoxy-modified silicone compound and another participation promoter are used. DBU is a liquid at room temperature, and it is difficult to disperse it uniformly in a powdered resin / inorganic filler mixture. Further, if the inorganic filler is mixed in a liquid state as it is, adsorption of the filler to the surface cannot be avoided, and a discrepancy occurs between the added amount and the catalytic activity. Therefore, when DBU is melt-mixed with a phenol resin that is a curing agent in advance,
A resin composition which is easy to handle and has good characteristics can be obtained. The same procedure can be applied to DBU salt that is liquid at room temperature.

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

For example, the general formula: A polyglycidoxypropylmethylsiloxane represented by the general formula: A polyglycidoxypropylmethyl-dimethylsiloxane copolymer represented by the general formula: Polyglycidoxypropyl methyl polyether methyl siloxane copolymer represented by R: polyether, general formula: A poly (epoxycyclohexyl) ethylmethylsiloxane represented by the general formula: Oryepoxycyclohexylethylmethyl represented by
Examples include dimethyl siloxane copolymer.

These epoxy-modified silicone compounds may be added directly to the composition of other resins, or may be pre-melt mixed with the epoxy resin or the phenol resin before use. These epoxy-modified silicone compounds may be used alone or in combination of two or more. The preferred amount of the epoxy-modified silicone compound added is 0.05 to 5% by weight, based on the total weight of the resin composition, and the addition of more than this amount is not preferable because it causes deterioration of moldability.

Examples of the inorganic filler (e) component used in the present invention include fused silica powder, crystalline silica powder, glass fiber, talc, alumina powder, calcium silicate powder, calcium carbonate powder, barium sulfate powder, and magnesia powder. Of these, fused glass powder and crystalline silica powder are most preferable. These inorganic fillers may be used alone or in a mixture of two or more kinds.

The epoxy resin composition containing the components (a) to (e) according to the present invention as essential components may be added with other additive components such as natural waxes, synthetic waxes, and metal salts of linear fatty acids, if necessary. Release agents such as acid amides, esters or paraffins, chlorinated paraffins, flame retardants such as bromotoluene, hexabromobenzene, antimony trioxide, coloring agents such as carbon black, silane coupling agents, etc. But it doesn't matter.

The epoxy resin composition according to the present invention is, for example, thoroughly mixed with a mixer, and then uniformly mixed by adding a melt mixing treatment with a hot roll or a kneader, and then subjected to compression, transfer or injection molding. It

The resin-encapsulated semiconductor device according to the present invention can be easily manufactured by encapsulating the semiconductor device with the epoxy resin composition described above. The most common sealing method is a low-pressure transfer molding method, but it goes without saying that a sealing method such as injection molding, compression molding or casting can also be applied.

When the epoxy resin composition for encapsulation is used for encapsulation, a resin-encapsulated semiconductor device encapsulated with a cured product of the composition can be finally obtained by heat curing. Heating at 150 ° C. or higher is particularly desirable for curing.

The semiconductor device referred to in the present invention is an integrated circuit, a large-scale integrated circuit, a transistor, a thyristor, a diode, or the like, and is not particularly limited to these.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples without departing from the technical idea of the present invention.

Examples 1 to 3 Cresol novolac type epoxy resin (A) having an epoxy equivalent of 200, enol novolac resin (B) having a molecular weight of 700,
DBU, poly (epoxycyclohexyl) ethyl methyl - dimethylcyclopropane hexane copolymer (formula Si (CH _{3 2} 0
xSi (CH ₃ ) (CH ₂ CH ₂ C ₆ H ₁₀₀ ) -Oy, x / y = 20, molecular weight 35000 and later abbreviated as PECSi), poly (glycidyloxy) propylmethyl-dimethylsiloxane copolymer (general formula x / y = 40, molecular weight after 45000 is abbreviated as PGSi), fused silica (C), silane coupling (D), carnauba wax (E) in a mixing ratio (parts by weight) shown in Table 1 in a mixer. After mixing, the mixture was kneaded with a roll, cooled, and pulverized to obtain an epoxy resin-based molding material. The DBU was prepared by previously melt-mixing with a phenol resin.

Example 4 When mixing the blending components shown in Example 1 in the proportions shown in Table 1, a mixture obtained by previously melting and mixing the epoxy resin component and the PECSi component was used. Thereafter, the same operation as in Examples 1 to 3 was performed to obtain a molding material.

Example 5 When mixing the compounding components shown in Example 1 in the proportions shown in Table 1, a phenol resin component and a PECSi component which were previously melt-mixed were used. Thereafter, the same operation as in Examples 1 to 3 was performed to obtain a molding material.

Comparative Examples 1 to 3 Cresol novolac type epoxy resin having an epoxy equivalent of 200, phenol novolac resin having a molecular weight of 700, DBU, TPP
(Triphenylphosphine), PECSi, and polydimethylsiloxane were mixed in the proportions shown in Table 1, and a molding material for comparison was obtained by the same operation as in the example.

Using the above various epoxy resin compositions, test pieces were prepared under transfer molding conditions of 180 ° C. for 3 hours,
The flexural strength and flexural modulus were measured. In addition, the above various epoxy resin compositions are molded on iron-nickel alloy (Ni42%) plate which is a material for semiconductor frame, force is applied to the plate in a horizontal method, and the load when the resin is peeled off is measured to face the frame. The adhesion was examined. The results are shown in Table 2.

Furthermore, the various epoxy resin component materials of Examples and Comparative Examples were used to seal a semiconductor device for humidity resistance test (test element for aluminum wiring corrosion check) under the condition of 180 ° C. for 3 minutes to obtain the obtained moisture resistance. A humidity resistance test was conducted by applying 15 V to the test semiconductor device under high temperature and high pressure steam of 125 ° C. (B
-PCT). The results are shown in Table 3.

Next, solder dipping resistance was tested. Similar to the above, various epoxy resin molding materials of Examples and Comparative Examples were used to mold a type resistance test element for checking aluminum wiring corrosion in a flat package with a thickness of 2 mm at 175 ° C. for 3 hours, and then at 180 ° C. * 4Hr after cure. Then 85 ℃ × 85% R
The test semiconductor device subjected to the moisture absorption treatment of H and 72 Hr was immersed in a solder bath at 260 ° C. for 5 seconds, and then subjected to a moisture resistance test under high temperature and high pressure steam at 127 ° C. to examine the occurrence of defects. The results are shown in Table 4.

As shown in Tables 2 to 4, the epoxy resin composition of the present invention has better adhesion to the frame material and lower elasticity than the conventional epoxy resin composition, and has a high reliability. As a resin with high stress and high adhesion, it can be seen that it is suitable for sealing and impregnating electronic parts and electric parts.

Further, the epoxy resin composition of the present invention is applied to a resin-encapsulated semiconductor device, has high moisture resistance reliability, and has good frame-resin adhesion, and thus is particularly suitable for a flat package for solder immersion. You can see that

[Effects of the Invention] The epoxy resin composition according to 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 suitable for sealing and impregnating electronic parts and electric parts. Further, it is advantageously applied to a resin-sealed semiconductor device.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H01L 23/31 (72) Inventor Ken Uchida 1 Komukai Toshiba-cho, Kawasaki City, Kanagawa Prefecture Within Toshiba Research Institute, Inc. (56) Reference JP 61-12724 (JP, A) JP 60-69131 (JP, A) JP 60-124617 (JP, A) JP 63-46216 ( JP, A)

Claims (7)

[Claims] 1. An epoxy resin (a): a phenolic resin as a curing agent (c): 1.8-diazabicyclo (5,5) as a curing accelerator.
4,0) Undecene-7 or its salt (d): Epoxy-modified silicone compound (e): Inorganic filler A semiconductor device is encapsulated by a cured product of an epoxy resin composition containing an essential component. A resin-encapsulated semiconductor device. 2. The equivalent ratio (epoxy equivalent / CH equivalent) of the epoxy equivalent of the epoxy resin and the OH equivalent of the phenol resin is 0.5.
The resin-encapsulated semiconductor device according to claim 1, which is within a range from to 1.5. 3. A curing accelerator, wherein 1.8-diazabicyclo (5,4,0) undecene-7 or a salt thereof is previously melt-mixed with a phenol resin.
Item 7. A resin-encapsulated semiconductor device according to item. 4. The resin-encapsulated semiconductor device according to claim 1, wherein the epoxy-modified silicone compound component is a dimethylsiloxane derivative having an alicyclic epoxy group. 5. The resin-encapsulated semiconductor device according to claim 1, wherein the epoxy-modified silicone compound is in the range of 0.05 to 5% by weight of the total resin composition. 6. The resin-encapsulated semiconductor device according to claim 1, wherein the epoxy-modified silicone compound is previously melt-mixed with an epoxy resin or a phenol resin which is a curing agent. 7. The resin-sealed mold according to claim 1, wherein the main component of the inorganic filler of the epoxy resin composition is a composite system of one or two selected from fused silica and crystalline silica. Semiconductor device.