JPH0597965A - Epoxy resin composition - Google Patents

Abstract

(57) [Summary] (Corrected) [Structure] General formula (1) (In the formula, n represents an integer of 0 or more), and a resin composition containing an essential component of an epoxy resin obtained by epoxidizing the phenol aralkyl resin, wherein An epoxy resin composition in which the hydroxyl group of the phenol aralkyl resin is 0.5 to 1.5 mol with respect to 1 mol of the epoxy group. [Effect] The resin composition has a low elastic modulus, a low linear expansion coefficient and a low water absorption coefficient, and also has excellent heat resistance. Furthermore, since it has excellent solder crack resistance and solder moisture resistance, it can be used as a semiconductor sealing material.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an epoxy resin composition. More specifically, it relates to an epoxy resin composition having a low elastic modulus, a low coefficient of linear expansion and a low water absorption, and excellent heat resistance and solder crack resistance.

[0002]

2. Description of the Related Art Conventionally, diodes, transistors, I
As a method of sealing a semiconductor element such as C or LSI, a so-called resin sealing method using an epoxy resin or the like is widely used. In particular, a resin composition containing an epoxy resin or a novolac type phenol resin as a main component is inexpensive as a raw material,
Due to its excellent heat resistance, moldability, and electrical characteristics, it has become the mainstream of resin encapsulation methods.

By the way, the recent progress in semiconductor element-related technology is extremely fast and diversified, and the conventional epoxy resin or novolac type phenol resin-based resin composition is used as a sealing material. There are various problems that cannot be solved by the method.

[0004] For example, the chip size is increased with the high integration of ICs, and conversely, the package shape tends to be smaller and thinner due to further expansion of surface mounting. That is, it becomes necessary to encapsulate a large chip in a small and thin package, and at this time, thermal stress causes cracks, which is a serious problem.

Further, in the soldering process, the package itself is rapidly exposed to a high temperature of 200 ° C. or more, so that the moisture in the package is rapidly expanded and a crack is generated in the package to improve the reliability of the semiconductor. It is causing the decrease.

Various epoxy compositions have been proposed in order to solve these problems, but sufficient effects have not been obtained yet.

For example, JP-A-59-105018 proposes a sealing resin composition using a polycondensation product of phenol and aralkyl ether as a curing agent. However, although this resin composition is excellent in terms of low water absorption and low elastic modulus, it has poor heat resistance due to its low glass transition temperature and is not satisfactory in terms of solder crack resistance.

Further, JP-A-61-168620 proposes an epoxy resin composition having excellent heat resistance. Since the composition uses a polyfunctional epoxy resin, the crosslink density is increased and the heat resistance is excellent. But,
The water absorption is high, and the frequency of cracks is particularly high in the soldering process, which is not satisfactory.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and the elastic modulus, linear expansion coefficient and water absorption coefficient are low, and the heat resistance and solder crack resistance are excellent. An object is to provide an epoxy resin composition.

[0010]

DISCLOSURE OF THE INVENTION The inventors of the present invention solve the above problems with a phenol aralkyl resin and an epoxy resin composition containing an epoxy resin obtained by epoxidizing the phenol aralkyl resin as an essential component. That is, the present invention has been achieved.

That is, the present invention has the general formula (1)

[0012]

[Chemical 2] (In the formula, n represents an integer of 0 or more), and a resin composition containing an epoxy resin obtained by epoxidizing the phenol aralkyl resin as an essential component. This is an epoxy resin composition in which the hydroxyl group of the phenol aralkyl resin is 0.5 to 1.5 mol with respect to 1 mol of the epoxy group.

The greatest feature of the epoxy resin composition of the present invention is that it has a low elastic modulus, a linear expansion coefficient and a water absorption coefficient, and also has excellent heat resistance. All of these characteristics are extremely important as an epoxy resin composition for semiconductor encapsulation, and an epoxy resin composition having all of these characteristics has hitherto not been known. This is possible for the first time by using a phenol aralkyl resin and an epoxy resin containing an epoxy resin obtained by epoxidizing the phenol aralkyl resin as an essential component.

The epoxy resin composition of the present invention contains a phenol aralkyl resin represented by the general formula (1) and an epoxy resin obtained by epoxidizing the phenol aralkyl resin as essential components, but other phenols. Resins, other epoxy resins, curing accelerators, various fillers and the like may be added as long as the object of the present invention is not impaired.

The phenol aralkyl resin used in the present invention is generally obtained by condensing phenol with α, α'-dimethoxyparaxylene, α, α'-dichloroparaxylene and the like by Friedel-Crafts reaction. it can. A typical product is marketed under the trade name of Milex XL (manufactured by Mitsui Toatsu Chemicals, Inc.). In the phenol aralkyl resin, n in the general formula (1) is an integer of 0 or more, and preferably 0 to 20 for the purpose of the present invention.

The epoxy resin used in the present invention is obtained by epoxidizing the above-mentioned phenol aralkyl resin. A known method can be applied to the epoxidation method. That is, in the presence of a hydrogen halide acceptor,
In the temperature range of 40 to 120 ° C., the phenol aralkyl resin is epoxidized with epihalohydrin, preferably epichlorohydrin.

Examples of hydrogen halide acceptors include alkali metal hydroxides such as potassium hydroxide and sodium hydroxide. The hydrogen halide acceptor is preferably added slowly to the heated mixture of phenol aralkyl resin and epihalohydrin to maintain the pH of the reaction mixture at about 6.5-10.

The proportion of epihalohydrin used in the epoxidation reaction depends on the OH group content of the phenol aralkyl resin, but usually 2.0 to 30 per 1 equivalent of the OH group.
An equivalent amount, preferably 2.0 to 10 equivalents, of excess epihalohydrin is used. The method of removing the excess acceptor substance and the by-produced salt from the reaction product is usually carried out by a means such as washing with water.

As described above, the epoxy resin used in the present invention is, in the presence of a hydrogen halide acceptor,
An epoxy resin (hereinafter referred to as an essential epoxy resin) obtained by epoxidizing a phenol aralkyl resin represented by the general formula (1) with epihalohydrin. , Glycidyl ethers such as resole phenolic resins, glycidyl ethers of alcohols such as butanediol, polyethylene glycol, polypropylene glycol, glycidyl esters of carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, aniline, isocyanuric It is also possible to use in combination an active hydrogen bonded to a nitrogen atom of an acid or the like with a glycidyl group, an alicyclic epoxy resin in which an intramolecular olefin is epoxidized (hereinafter referred to as a combined epoxy resin).

The amount of the combined epoxy resin used is preferably less than 50% by weight based on the total amount of the essential epoxy resin and the combined epoxy resin. When the content is 50% by weight or more, the above-mentioned characteristics, which are the greatest feature of the epoxy resin composition of the present invention, that is, the elastic modulus, the linear expansion coefficient and the water absorption rate are low, and the heat resistance is excellent can be maintained. It is not preferable because it disappears.

Further, in the present invention, the phenol aralkyl resin represented by the above general formula (1) is used as a curing agent, but in addition, a novolac resin, a dicyclopentadiene-modified phenol resin, a resol type phenol resin or the like It is also possible to use a combined use phenol resin).

The usable amount of these combined phenol resins is preferably less than 50% by weight based on the total amount of the phenol aralkyl resin and the combined phenol resin which are the constituents of the present invention. When the content is 50% by weight or more, the above-mentioned characteristics, which are the greatest feature of the epoxy resin composition of the present invention, that is, the elastic modulus, the linear expansion coefficient and the water absorption rate are low, and the heat resistance is excellent can be maintained. It is not preferable because it disappears.

The softening point of these combined phenol resins is 6
The range of 0 to 120 ° C and the OH group equivalent of 90 to 500 are preferable, and the softening point is more preferably 65 to 100 ° C and OH.
The base equivalent is in the range of 95 to 400. Softening point or OH
When the base equivalent is out of the above range, the above-mentioned characteristics which are characteristic of the epoxy resin composition of the present invention cannot be maintained, which is not preferable. These combined phenol resins may be used alone or as a mixture of two or more kinds.

The mixing ratio of the essential epoxy resin and the phenol aralkyl resin as a curing agent is preferably in the range of 0.5 to 1.5 mol of the hydroxyl group of the phenol aralkyl resin with respect to 1 mol of the epoxy group of the epoxy resin. If it is out of this range, the above-mentioned characteristics which are the characteristics of the epoxy resin composition of the present invention cannot be maintained, which is not preferable.

When the combined epoxy resin and / or combined phenol resin is used, the total hydroxyl group content is 0.5 to 1.5 relative to 1 mole of the total epoxy group.
It is preferably in the molar range.

In the epoxy resin composition of the present invention, a compound that accelerates the reaction between the epoxy group of the epoxy resin and the hydroxyl group such as phenol aralkyl resin which is the curing agent resin can be used as the curing accelerator.

Examples of the curing accelerator include amines such as triethylamine, benzyldimethylamine, triethanolamine, tris (dimethylaminomethyl) phenol, triethylamine, triethylenetetramine, metaxylenediamine, and dimethylbenzylamine;
Methylimidazole, 2-ethylimidazole, 1,2
-Imidazoles such as methyl imidazole, 2-ethyl-4-methyl imidazole, 2-undecyl imidazole, 2 phenyl imidazole, triphenylphosphine, tributylphosphine, tricyclohexylphosphine, methyldiphenylphosphine, butylphenylphosphine, diphenylphosphine, phenyl Organic phosphines such as phosphine, octylphosphine, 1,2-bis (diphenylphosphino) methane, tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, 2-ethyl-4-
Examples thereof include tetraphenylboron salts such as methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate.

The amount added is 0.00 based on the epoxy resin.
1% to 5% by weight is preferred. Addition amount is 0.001
If it is less than 5% by weight, the reaction between the epoxy groups of the epoxy resin and the hydroxyl groups of the curing agent resin takes too long, which is not preferable. On the other hand, if it exceeds 5% by weight, the above-mentioned characteristics which are characteristic of the epoxy resin composition of the present invention cannot be maintained, which is not preferable.

Further, in the present invention, as the inorganic filler, crystalline silica, fused silica, alumina, clay, titanium white, zircon, boron, beryllia, magnesia, zirconia, forsterite, steatite, spinel,
One or more kinds of mullite, titania, barium sulfate, quartz glass, aluminum hydroxide, potassium titanate, silicon carbide, silicon nitride, alumina, glass fiber and the like can be blended.

Further, according to the present invention, higher fatty acids, higher fatty acid metal salts, esters, natural waxes, synthetic waxes, acid amides, mold releasing agents such as paraffin, bromine compounds, antimony, phosphorus are added as necessary. Flame retardant such as carbon black, colorant such as carbon black, silane coupling agent such as epoxysilane, aminosilane, vinylsilane, alkylsilane, organic titanate, and other additives such as flexibility-imparting agent Good.

As a general method for producing the epoxy resin composition of the present invention using the above-mentioned raw materials, a raw material mixture having a predetermined amount is thoroughly mixed with a mixer or the like, and then kneaded with a hot roll, an extruder or the like. Then, a method of cooling and pulverizing can be mentioned.

As a method of encapsulating a semiconductor using the epoxy resin composition of the present invention, a low-pressure transfer molding method is generally used, but injection molding, compression molding, casting or the like method is adopted. You can also

The epoxy resin composition of the present invention obtained as described above has low elastic modulus, linear expansion coefficient and water absorption and has excellent heat resistance. It can be used as a laminated material or an adhesive.

[0034]

EXAMPLES The present invention will be described in more detail with reference to production examples, examples, comparative examples and test examples.

Production Example 1 50 g of Milex XL-225 (softening point 93 ° C.) manufactured by Mitsui Toatsu Chemicals, Inc. and 150 g of epichlorohydrin were mixed, and a stirrer, a thermometer, a Dean Stark azeotropic distillation trap, and a dropping funnel were mixed. It was charged into a reaction vessel equipped with. After heating the mixture to 115 to 119 ° C. with stirring,
64 g of 47% aqueous sodium hydroxide solution was added dropwise at the same temperature over 2 hours, the distilled water was continuously separated and collected, and the epichlorohydrin phase was returned to the reactor. After the dropping is completed, the reaction is completed by removing the distilled water. After this, excess epichlorohydrin was distilled under reduced pressure, the reaction product was dissolved in 200 g of methyl isobutyl ketone, sodium chloride and sodium hydroxide were filtered, and the solvent was distilled off under reduced pressure to obtain an essential epoxy resin. Epoxy equivalent is 240 g / e
q and the softening point were 75 degreeC. This resin is called resin A.

Example 1 Resin A produced in Production Example 1, softening point 8 as a curing agent resin
Miles XL-22, manufactured by Mitsui Toatsu Chemicals, Inc. at 0 ° C
5 (this resin is referred to as resin B), triphenylphosphine (hereinafter referred to as TPP) as a curing accelerator, fused silica as a filler, carnauba wax as a release agent, carbon black as a colorant, and a coupling agent. Glycidoxypropyltrimethoxysilane was blended in a weight ratio shown in [Table 1], and roll kneading was performed under the conditions of a kneading temperature of 100 ° C to 110 ° C and a kneading time of 5 minutes. The sheet-shaped kneaded product was cooled and then pulverized to obtain an epoxy resin composition.

Next, the composition was added to 200 kg / cm ² , 1
A molded product having a predetermined shape was produced by compression molding at 70 ° C. for 5 minutes, and post-cured at 175 ° C. for 5 hours. The glass transition temperature, linear expansion coefficient, flexural modulus, and water absorption of the obtained molded product were evaluated.

Glass transition temperature (unit: ° C.): The temperature at the bending point was determined as the glass transition temperature from the temperature-linear expansion curve of the molded product using a TMA device manufactured by Rigaku Denki. The temperature was measured from room temperature to 250 ° C., and the temperature rising rate was 2 ° C./min.

Linear expansion coefficient (unit: × 10 ^-5 / ° C); the value from room temperature to the glass transition temperature was determined.

Flexural modulus (unit: kg / mm ² ); 4 mm × 127 mm × 1 using Shimadzu autograph
Molded product of 0 mm, test speed 2 mm / min, distance between fulcrums 6
It was performed at 4 mm.

Water absorption rate (unit:%); 50 mm × 50 mm
It was determined from the change in weight after boiling a molded product of × 2 mm at 100 ° C. for 24 hours. The obtained results are shown in [Table 1].

Example 2 and Comparative Examples 1 and 2 Using the raw materials shown in [Table 1], molded articles were obtained in the same manner as in Example 1, and the respective properties were evaluated in the same manner. The obtained results are shown in [Table 1].

[0043]

[Table 1]

Test Example The epoxy resin compositions produced in Examples 1 and 2 and Comparative Examples 1 and 2 were tableted and subjected to low pressure transfer molding,
Under conditions of 175 ° C., 70 kg / cm ² and 120 seconds, a 6 × 6 mm chip for a solder crack test is sealed in a 52p package, and a solder moisture resistance test is 3 mm × 6.
The mm chip was encapsulated in a 16p SOP package.

The following solder crack test and solder moisture resistance test were conducted on the sealed test element. Solder crack test; sealed test element at 85 ℃, 8
After being left in an environment of 5% RH for 72 hours and then immersed in a solder bath at 260 ° C. for 10 seconds, external cracks were observed with a microscope and the number of cracked elements was counted.

Solder moisture resistance test; 8 sealed test elements
Leave for 72 hours in an environment of 5 ° C and 85% RH, then 2
After soaking in a solder bath at 60 ° C. for 10 seconds, a pressure cooker test (125 ° C., 100% RH) was performed to measure the time at which the circuit open defect rate was 50%. The test results are shown in [Table 2].

[0047]

[Table 2]

[0048]

The epoxy resin composition of the present invention has a low elastic modulus, a linear expansion coefficient and a water absorption coefficient, and also has excellent heat resistance. Furthermore, since it has excellent solder crack resistance and solder moisture resistance, it can be used as a semiconductor sealing material. Further, by utilizing the above characteristics, it can be used in a wide range of fields such as for paints, for lamination and for adhesives,
It is extremely useful in industry.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H01L 23/31

Claims (1)

[Claims] 1. General formula (1) [Chemical formula 1] (In the formula, n represents an integer of 0 or more), and a resin composition containing, as an essential component, an epoxy resin obtained by epoxidizing the phenol aralkyl resin. An epoxy resin composition in which the hydroxyl group of the phenol aralkyl resin is 0.5 to 1.5 mol with respect to 1 mol of the epoxy group.