KR100599863B1 - Epoxy Resin Composition for Encapsulating Semiconductor Device - Google Patents

Abstract

The present invention relates to an epoxy resin composition for sealing semiconductor devices, and more particularly, to an epoxy resin composition comprising epoxy resin, a curing agent, a curing accelerator, a modified silicone oil, and an inorganic filler as essential components. The present invention relates to an epoxy resin composition for semiconductor element sealing, wherein zinc borate is added. According to the present invention, excellent flame retardancy is achieved without using a halogenated flame retardant, and at the same time, semiconductor element sealing exhibits excellent properties in terms of moldability and reliability. The epoxy resin composition for this can be provided.

Epoxy resin, semiconductor element, encapsulant, phosphazene, zinc borate, flame retardancy, formability, reliability

Description

Epoxy Resin Composition for Encapsulating Semiconductor Device

The present invention relates to an epoxy resin composition for sealing semiconductor elements, and more particularly, to an epoxy resin composition for sealing semiconductor elements, wherein phosphazene and zinc borate are added as a flame retardant.

In general, flame retardancy is required in manufacturing an epoxy resin for semiconductor encapsulant, and most semiconductor companies require UL-94 V-0 as flame retardant. In order to secure such flame retardancy, a flame retardant is used to manufacture an epoxy resin for a semiconductor encapsulant, and bromine epoxy and antimony trioxide are mainly used to prepare an epoxy resin for a semiconductor encapsulant to ensure flame retardancy. That is, bromine or chlorine-based halogen-based flame retardants and antimony trioxide having excellent flame retardant synergistic effects are widely used as flame retardants as flame retardants for imparting flame retardancy in manufacturing epoxy resins for semiconductor encapsulants. However, it is known that toxic carcinogens such as dioxin or difuran are generated in case of incineration or fire in the case of epoxy resin for semiconductor encapsulant having flame retardancy by using halogen-based flame retardant. In addition, halogen-based flame retardants are toxic to humans due to gases such as HBr and HCl generated during combustion, and are a major cause of corrosion of semiconductor chips, wires, and lead frames. There is a problem such as working.

The present invention is to solve the problems of the prior art as described above, to provide an epoxy resin composition for sealing a semiconductor device showing excellent properties in terms of moldability and reliability while achieving excellent flame resistance without using a halogenated flame retardant. The purpose.

That is, the present invention is an epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a modified silicone oil, and an inorganic filler as essential components, wherein the flame retardant is zinc phosphazene represented by the following formula (1) and zinc represented by the following formula (2). It is related with the epoxy resin composition for semiconductor element sealing characterized by adding a borate.

[Formula 1]

Wherein R and R 'are each a hydrogen atom or a methyl group, and n is an integer of 1 to 4.

[Formula 2]

The present invention will be described in more detail below.

In the composition of the present invention, as the epoxy resin, a biphenyl epoxy resin having an epoxy equivalent of 150 to 250 and an ortho cresol novolac epoxy resin having an epoxy equivalent of 170 to 230 may be used alone or in combination. The content of the epoxy resin in the total composition is 3.5 to 15% by weight.

As a hardening | curing agent contained in the composition of this invention, normal phenol novolak resin, cresol novolak resin, Xylok resin, dicyclopentadiene resin, etc. which have two or more hydroxyl groups and whose hydroxyl equivalent is 100-200, respectively is independent. Or two or more kinds can be used. However, from the viewpoint of price and moldability, it is preferable to use at least 50% by weight of the phenol novolac-type resin as a whole of the curing agent.

The use ratio of the epoxy resin and the curing agent is preferably used in the range of 0.8 to 1.2 epoxy equivalent to the hydroxyl equivalent, and the amount of the curing agent in the total composition is preferably in the range of 2 to 10.5% by weight.

In the present invention, a non-halogen phosphazene and zinc borate are used in combination as a flame retardant.

The phosphazene (phosphazene) applied in the present invention is a material having a structure as shown in the following formula (1), the decomposition temperature is 350 ℃, excellent moisture resistance, heat resistance, the carbon layer is formed when burning at high temperatures and the outside oxygen and heat Blocks the flame retardant effect.

Wherein R and R 'are each a hydrogen atom or a methyl group, and n is an integer of 1 to 4.

The content of the phosphazene in the total composition is 0.5 to 10% by weight. If the content exceeds the upper limit, it is difficult to obtain a corresponding flame retardancy, causing unnecessary cost rise, and if less than the lower limit, the desired degree of flame retardancy cannot be achieved.

Zinc borate applied in the present invention (zinc borate) is a material having a structure as shown in the following formula (2) has a melting point of 260 ℃ and excellent heat resistance, electrical properties, moisture resistance, the dehydration reaction occurs at high temperature, the endothermic phenomenon is seen 530J / Excellent flame retardant effect is shown by the endothermic amount of g. In addition, the decomposed combustion products form a stable carbon layer (Char), resulting in an excellent flame retardant effect than conventional halogen-based flame retardants.

The content of the zinc borate in the total composition is 0.5 to 6% by weight. If the content exceeds the upper limit, there is a problem that there is a lot of problems that there is a possibility of poor molding when assembling the semiconductor due to the lack of fluidity, if the lower than the lower limit can not achieve the degree of flame retardancy.

The curing accelerator included in the composition of the present invention is a component necessary for promoting the curing reaction of the epoxy resin and the curing agent, for example benzyldimethylamine, triethanolamine, triethylenediamine, dimethylaminoethanol, tri (dimethylaminomethyl) Tertiary amines such as phenol, imidazoles such as 2-methylimidazole and 2-phenylimidazole, organic phosphines such as triphenylphosphine, diphenylphosphine and phenylphosphine, tetraphenylphosphonium Tetraphenyl boron salts, such as tetraphenyl borate and triphenyl phosphine tetraphenyl borate, etc. can be used, These can be used individually or in combination of 2 or more types. The content of the curing accelerator in the total composition is in the range of 0.1 to 0.3% by weight.

As the modified silicone oil included in the composition of the present invention, a silicone polymer having excellent heat resistance is used, specifically, a silicone oil having an epoxy functional group, a silicone oil having an amine functional group, a silicone oil having a carboxyl functional group, or the like alone or 2 or more types may be mixed and used. The content of the modified silicone oil in the total composition is in the range of 0.05 to 1.5% by weight. If the silicone oil is used in excess of 1.5% by weight, surface contamination is likely to occur and the resin bleed may be long, and when used at less than 0.05% by weight, sufficient low modulus of elasticity may not be obtained.

Inorganic fillers contained in the composition of the present invention is preferably used melt or synthetic silica having an average particle size of 0.1 ~ 35㎛. The content of the inorganic filler in the total composition is in the range of 73 to 90% by weight. When the inorganic filler is used at less than 73% by weight, sufficient strength and low thermal expansion cannot be realized, and moisture permeation becomes easy, which is fatal to reliability characteristics. In addition, when the filling amount of the inorganic filler is more than 90% by weight, there is a fear that the moldability due to the deterioration of the flow characteristics.

Moreover, in the composition of this invention, release agents, such as a higher fatty acid, a higher fatty acid metal salt, and ester wax, coloring agents, such as carbon black and an organic and inorganic dye, epoxy silane, amino silane, and alkyl silane, in the range which does not impair the objective of this invention. Coupling agents such as these may be further added.

As a method of producing the epoxy resin composition of the present invention using the above-mentioned components, a predetermined amount of the compound is uniformly mixed uniformly using a Henschel mixer or a Rodige mixer, followed by melt kneading with a roll mill or a kneader, cooling, The method of obtaining the final powder product after grinding may be used.

As a method of sealing a semiconductor device using the epoxy resin composition obtained in the present invention, a low pressure transfer molding method, which is generally used, may be preferably used. In addition, molding may be performed by injection molding, casting, or the like. Can be.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are provided for the purpose of explanation and not intended to limit the present invention.

Examples 1 to 3

To prepare the epoxy resin composition for sealing a semiconductor device of the present invention, as shown in Table 1, each component was weighed, and then uniformly mixed using a Henschel mixer to prepare a powdery primary composition. After melt kneading at 100 ° C. for 7 minutes, an epoxy resin composition was prepared by cooling and pulverizing.

The epoxy resin composition thus obtained was molded at 175 ° C. for 60 seconds using an MPS (Multi Plunger System) molding machine, and then cured at 175 ° C. for 6 hours to prepare an MQFP semiconductor device.

The semiconductor device manufactured as described above was tested for flame retardancy, reliability, and moldability, and is shown in Table 2. The reliability test was expressed as the degree of package crack occurrence in the thermal shock test.

Comparative Examples 1 and 2

As shown in Table 1 below, each component was basis weighted according to a given composition to prepare an epoxy resin composition in the same manner as in Example, and physical properties were evaluated in the same manner.

Composition Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Epoxy resin 9.1 11.2 11.5 14.8 14.5 Hardener 5.08 6.98 5.18 7.38 7.68 Flame retardant Phosphazene 10 0.5 5 - - Brominated epoxy resin - - - 1.5 One Zinc borate 0.5 6 3 - - Sb ₂ O ₃ - - - One 1.5 Curing accelerator 0.27 0.27 0.27 0.27 0.27 Silica 74 74 74 74 74 Modified silicone oil 0.1 0.1 0.1 0.1 0.1 γ-glycithoxypropyltrimethoxy silane 0.43 0.43 0.43 0.43 0.43 Carbon black 0.27 0.27 0.27 0.27 0.27 Carnauba Wax 0.25 0.25 0.25 0.25 0.25 Sum 100 100 100 100 100

* Epoxy Resin (Kukdo Chemical, YDCN-500-7P)

* Brominated epoxy resin (Kukdo Chemical, YDB-400)

* Hardening agent (KOLON Emulsifying Company, KPH-2001)

* Hardening accelerator (HOKKO, TPP)

* Modified silicone oil (Dow Corning Toray, SF-8421EG)

Evaluation Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Spiral Flow (inch) 36 37 38 32 35 Tg (℃) 160 161 162 153 154 Electrical Conductivity (㎲ / ㎝) 31 32 32 35 32 Flexural strength (kgf / mm²at 240 ℃) 13 13 13 14 13 Flexural modulus (kgf / mm²at 240 ℃) 1420 1415 1410 1440 1442 Flame retardant UL 94 V-0 V-0 V-0 V-0 V-0 V-0 Formability Void occurrence number (Visual Inspection) 0 0 0 One 0 Total number of semiconductor devices tested 3000 3000 3000 3000 3000 responsibility Crack resistance evaluation (thermal shock test) 0 0 0 0 One Total number of semiconductor devices tested 3000 3000 3000 3000 3000

[Property evaluation method]

1) Spiral Flow

Molds were manufactured based on the EMMI standard, and the flow length was evaluated at a molding temperature of 175 ° C. and a molding pressure of 70 Kgf / cm ² .

2) Glass transition temperature (Tg)

It was evaluated by TMA (Thermomechanical Analyser).

3) Electrical conductivity

The cured EMC test piece was crushed into a particle size of about # 400MESH to # 100MESH in a grinder, and weighed 2g ㅁ 0.2mg of the powdered sample into an extraction bottle. Electrical conductivity was measured using the supernatant.

4) Flexural Strength, Flexural Modulus

Hardened EMC molded specimens (125 x 12.6 x 6.4 mm) were prepared and the width and thickness of the center of the specimen were measured on a UTM tester with a micrometer measuring 0.001 mm.

5) Flame retardant

It evaluated according to UL 94 V-0 standard.

6) Crack resistance evaluation (reliability test)

After pre-condition, after 1,000 cycles in a thermal shock environment tester (Temperature Cycle Test), the crack occurrence was evaluated by a non-destructive tester SAT (Scanning Acoustic Tomograph).

(a) Precondition

SOJ-type semiconductor device made of epoxy resin composition was dried at 125 ° C for 24 hours, and then subjected to 5 cycles of thermal shock test, and then left for 168 hours under 85 ° C / 85% relative humidity condition, followed by IR for 235 ° C and 10 seconds. Three passes through the reflow are used to first evaluate the presence of package cracks under precondition conditions. If cracks occur at this stage, the next stage, the 1,000 cycle thermal shock test, is not conducted.

(b) thermal shock test

After 1,000 cycles of leaving the semiconductor package that passed the preconditions for 10 minutes at -65 ° C, 5 minutes at 25 ° C, and 10 minutes at 150 ° C for 1 cycle, the inside of the semiconductor package was And external cracks are evaluated.

According to the present invention, it is possible to provide an epoxy resin composition for sealing a semiconductor device that exhibits excellent flame retardancy and excellent properties in formability and reliability without using a halogenated flame retardant.

Claims (4)

In the epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a modified silicone oil, and an inorganic filler as essential components, 0.5 to 5% by weight of phosphazene represented by the following formula (1) is used as a flame retardant, compared to the total composition, An epoxy resin composition for sealing a semiconductor device, wherein the zinc borate represented by Formula 2 is used in an amount of 0.5 to 6 wt% based on the total composition. [Formula 1]

Wherein R and R 'are each a hydrogen atom or a methyl group, and n is an integer of 1 to 4. [Formula 2]

delete The method of claim 1, wherein the content of the epoxy resin in the total composition is 3.5 to 15% by weight, the content of the curing agent is 2 to 10.5% by weight, the content of the curing accelerator is 0.1 to 0.3% by weight, the modified silicone The content of oil is 0.05 to 1.5% by weight, the content of the inorganic filler is an epoxy resin composition for sealing a semiconductor device, characterized in that 73 to 90% by weight. The method of claim 1, As the epoxy resin, a biphenyl epoxy resin having an epoxy equivalent of 150 to 250 or an ortho cresol novolac epoxy resin having an epoxy equivalent of 170 to 230 is used alone or in combination, The phenolic novolac resin, cresol novolac resin, Xylok resin or dicyclopentadiene resin having two or more hydroxyl groups and a hydroxyl equivalent of 100 to 200 as the curing agent may be used alone or in combination of two or more kinds thereof. Use, As the curing accelerator, imidazoles, organic phosphines, or tetraphenylboron salts are used alone or in combination of two or more thereof, As the modified silicone oil, a silicone oil having an epoxy functional group, a silicone oil having an amine functional group, or a silicone oil having a carboxyl functional group may be used alone or in combination of two or more kinds thereof. The inorganic filler is epoxy resin composition for semiconductor element sealing, characterized in that the use of molten or synthetic silica having an average particle size of 0.1 ~ 35㎛.