KR960010307B1 - Epoxy resin composition for encapsulating semiconductor element - Google Patents

Abstract

The resin composition comprises epoxy resin of cresol nobolak type, curing agent, curing accelerator, plasticizer, inorganic filler and 0.1-20wt.% high functional epoxy resin of formula(I) with respect to the total resin composition. In formula, R1 and R2 is (CH2)nCH3 or H2; n is 0 or over 1.

Description

Epoxy Resin Composition for Semiconductor Device Sealing

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for semiconductor element encapsulation that realizes low stress, high heat resistance, and high moisture resistance required for a semiconductor element encapsulation resin composition in accordance with a large capacity of a semiconductor, a small size, and a thin package.

IC and LSI packages are rapidly diversifying as electrical, electronic components and sets become smaller and thinner. In particular, although chips are getting larger, packages are getting thinner, smaller, and have higher pin counts. The mounting method is also being changed to the surface mounting method, and recently, a TSOJ (Thin Small Out-line J-Bend Package) having a thickness of about 1 mm has been introduced and realized. This is an intermediate step between SOJ (Small Out-line J-Bend Package) / QFP (Quad Flat Package) and Tape Automated Bonding (TAB). In response to such a package change, the resin composition for semiconductor element sealing also demands more stringent lower stress, higher heat resistance, and higher moisture resistance than the prior art.

Conventional low-stressing techniques include the addition of plasticizing agents such as modified silicone oil or CTBN to reduce internal stress and fillers (JP-A-63-230725, 62-7723, 62-106920, 62-260817). Although a method of lowering the coefficient of thermal expansion by increasing the amount thereof is known (Japanese Patent Laid-Open No. 62-106920), the above methods cause serious manufacturing problems such as deterioration of heat resistance, moldability, and wear of equipment during manufacturing, respectively. . On the other hand, in order to improve the heat resistance, the use of multifunctional epoxy resins (Japanese Patent Laid-Open Nos. 62-7723, 62-2913) and the use of bismaleimide excellent in heat resistance (Japanese Laid-Open Patent Nos. Although it is known that this technology is also a problem that is lowered moisture resistance due to the glass transition temperature rise.

Accordingly, an object of the present invention is to provide a resin composition suitable for ultra-thin highly integrated IC sealing by using a high-performance epoxy resin capable of imparting moisture resistance, heat resistance and low stress.

That is, the present invention is a epoxy resin composition for sealing a semiconductor device containing a cresol noblock type epoxy resin, a phenol noblock type curing agent, a curing accelerator, an inorganic filler, and the like, wherein the cresol noblock type epoxy resin is represented by the following general formula (I): It is characterized by containing a high-performance epoxy resin.

(Wherein R ₁ , R ₂ are H or (CH ₂ ) _n CH ₃ groups and n is 0 or an integer of 1 or more.)

The high functional epoxy resin of the general formula (I) of the present invention can be synthesized by the following route, for example. That is, a round bottom flask equipped with a dropping funnel and a reflux condenser is an epoxy resin (Japanese Chemical) and a nonpolar organic solvent (CCl ₄ , C ₂ H ₄₎ Cl ₂ );

Dissolve by adding, replacing, and dissolving 0.1-1% by weight of benzoylpyoxide (Aldrich) as a catalyst to the epoxy resin and dropping NBS (1-bromo-2,5-Pyrrolidinedion: manufactured by Aldrich) dropwise while stirring sufficiently. After reflux, reflux for 2-6 hours.

Br-substituted epoxy resin of the following structural formula (III) obtained in this was dissolved in well-dried diethyl ether or THF (tetrahydrofuran), and after checking that magnesium was dissolved, O-methylhydroxylamine (CH ₃ ONH ₂ : Aldrich) Product) and the reaction is stirred for 4-8 hours in a warm state.

Epoxy resin of the following structural formula (IV) substituted with the amine group obtained in this way with the maleimide (product of the Mitsubishi emulsification product) of the following structural formula (V);

(Herein, the definition of the group for R ₁ , R ₂ is the same as the general formula (I).)

It is dissolved in DMF, refluxed and reacted for several hours to finally obtain a high functional epoxy resin of general formula (I) of the present invention.

When referring to the epoxy resin composition for sealing a semiconductor device of the present invention in more detail, based on the epoxy resin component mixed with an olso-cresol noblock type epoxy resin and the high-performance epoxy resin of the general formula (I), a phenol noblock type curing agent, In addition, triphenylphosphine, an organic phosphine compound, was added as a curing accelerator, and high purity molten silica was added as a filler, epoxy modified silicone oil was added as a modifier, other mold release agents, colorants, and organic and inorganic flame retardants were added. It is created.

Thus, the preferable composition example of the resin composition of this invention is summarized as follows.

Cresol noblock type epoxy resin 0.1-20% by weight

High Performance Epoxy Resin 0.1-20% by weight

Curing agent 1.0-10.0 wt%

Curing accelerator 0.1-1.0 wt%

Coupling agent 0.5-2.0 wt%

0.1-0.5% by weight of colorant

Filler 65.0-85.0 wt%

Release agent 0.1-1.0 wt%

Organic flame retardant 1.0-5.0 wt%

Inorganic flame retardant 0.5-3.0 wt%

Plasticizer 0.5-5.0 wt%

The resin composition of the present invention is best to have the composition as described above, as the epoxy resin used in the present invention is used an allocresol noblock type resin excellent in heat resistance, in particular epoxy equivalent of 190-220, impurity content of 10ppm or less It should be a high purity epoxy resin. In addition, a phenol noblock type resin is used as a curing agent, and a softening point of 80-100 ° C., a hydroxyl equivalent weight of 100-120, and a resin having an impurity content of 10 ppm or less should be used.

On the other hand, as a high functional epoxy of the general formula (I) used characteristically in this invention, it is good to use it as an imide-epoxy at 0.1-20.0 weight% with respect to the whole resin composition, Preferably it is 1.0-10.0 weight%.

If the amount used is less than 0.1% by weight, there is no heat and moisture resistance. If the amount is more than 20% by weight, resin bleed and mold contamination may occur, resulting in poor moldability and many problems in gelation time and post-curing conditions. Cause.

As the filler used in the present invention, high purity fused silica is used, and a particle size of 10 μm to 30 μm may be preferably used. In addition, amines, imidazole derivatives, and organophosphine compounds are generally used as curing accelerators. In the present invention, trephenylphosphine is used as the organic phosphine compound, and 2-methylimidazole, 2-methyl- is used as the imidazole derivative. Preference is given to using 4-ethylimidazole or the like.

In the present invention, as the coupling agent used for the surface treatment of the inorganic filler, a silane coupling agent is used, and in particular, gamma-glycidoxypropyltrimethoxysilane is most preferably used. In addition, as a plasticizer, silicone rubber or epoxy modified silicone oil is generally used. In order to increase compatibility with high integration of a semiconductor, the plasticizer used in the present invention is an adduct of phenol nobloc resin and epoxy modified silicone oil. Used.

Other release agents use carnauba wax or montan wax at 0.1-1.0% by weight, and carbon black 0.1-0.5% by weight, and organic flame retardant is brominated epoxy resin and inorganic flame retardant antimony trioxide. It was.

In order to make the composition of the present invention as described above, the inorganic filler is first surface-treated as a coupling agent, and then the remaining medicament is uniformly mixed in a Henschel mixer or other premixer, using a kneader or a roll mill at about 5 to about 90 ° C. Melt-mix for 20 minutes and then cool to powder using a grinder.

When sealing the semiconductor device using the powder composition, the powder is put into a tableting machine and tableted. The resin composition in the tablet form thus prepared is preheated using a high frequency preheater, and then molded in a transfer molding press at 170-180 ° C. for 90-120 seconds to seal the semiconductor device.

As described above, the resin composition prepared according to the present invention is prepared by adding a high-performance epoxy resin to the existing cresol noblock type epoxy resin to improve heat resistance and moisture retention as an epoxy resin in order to prepare an epoxy resin composition for semiconductor element sealing. It is possible to provide a resin composition suitable for sealing an ultra-thin high-integration semiconductor having improved glass transition temperature compared to the conventional one.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention is not limited to Examples.

Example 1-4

The compositions are uniformly mixed in a Henschel mixer according to the compositions shown in Table-1 below to form a powdery primary composition. Then, the mixture was kneaded at 100 ° C. for 10 minutes using a kneader, and then cooled and pulverized to prepare an epoxy resin molding material. The physical properties of the epoxy resin composition thus obtained were measured in the following manner, and the results are shown in Table 2 below.

1) Spiral Flow: According to EMMI standard, mold is made and measured at molding temperature of 175 ℃ and molding pressure of 70kgf / cm ² .

2) Glass Transition Temperature (Tg): Measured using TMA measuring equipment.

3) Modulus of elasticity E (kgf / mm ² ): measured by ASTM D190 using UTM.

4) Thermal expansion coefficient α (° C ^-1 ): measured by ASTM D96.

5) Moisture absorption rate (%): After leaving the molded product in 121 ℃ 2 atm steam for 48 hours to measure the saturated moisture absorption.

6) Crack resistance: The molded chip was subjected to 2,000 times of thermal shock tests under test conditions of 30 minutes at -55 ° C and 30 minutes at 150 ° C for 1 cycle.

[Comparative Example]

According to the composition of Table-1 and carried out in the same manner as in Example 1-4 and measured the physical properties and the results are shown in the following Table-2.

Table-1

TABLE 2

^{* In the} crack resistance value, the denominator represents the number of samples and the molecule represents the number of defects.

As shown in the results shown in Table 2, the resin composition according to the present invention not only has a moldability which is inferior to that of the comparative example, but also has excellent heat resistance and moisture resistance than the comparative example, and as a result, the crack resistance is significantly improved. It can be seen that it is an excellent resin composition for sealing semiconductor elements.

Claims (2)

In the epoxy resin composition for sealing a semiconductor device containing a cresol noblock type epoxy resin, a curing agent, a curing accelerator, a plasticizer, and a high functional epoxy, the high functional epoxy resin containing an epoxy resin represented by the following general formula (I): Epoxy resin composition for sealing semiconductor elements. (Wherein R ₁ , R ₂ are H or (CH ₂ ) _n CH ₃ groups and n is 0 or an integer of 1 or more.) The epoxy resin composition for semiconductor element sealing according to claim 1, wherein the high-performance epoxy resin is contained in an amount of 0.1 to 20.0% by weight based on the total resin composition.