KR100558254B1 - Epoxy molding compound for sealing electronic component - Google Patents

Abstract

The present invention relates to an epoxy resin composition for semiconductors, and more particularly, to an epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a flame retardant, a modified silicone oil, and an inorganic filler, wherein the zinc is represented by Formula 1 as the flame retardant. The present invention relates to an epoxy resin composition for sealing a semiconductor device, using a borate and a polyhedral oligomeric silsesquioxane (POSS) represented by Chemical Formula 2 in combination. Provides the effect of securing sex.

[Formula 1]

[Formula 2]

In which R is a phenyl group.

Semiconductor sealing agent, epoxy resin composition, non-halogen flame retardant, zinc borate, POSS (polyhedral oligomeric silsesquioxane)

Description

Epoxy resin compound for sealing semiconductor elements

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an epoxy resin composition for semiconductors, and relates to an epoxy resin composition for semiconductor encapsulants using zinc borate, which is a non-halogen type, and a polyhedral oligomeric silsesquioxane (POSS), which is a silicone compound. 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. In other words, brominated or chlorinated halogen-based flame retardants and Sb2O3 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. In the case of incineration or fire, epoxy resins for flame retardant semiconductor encapsulants using halogen-based flame retardants are known to produce toxic carcinogens such as dioxin or difuran. In addition, halogen-based flame retardants are toxic to humans due to gases such as HBr and HCl generated during combustion, and act as a major cause of corrosion in semiconductor chips or lead frames. there is a problem. As a countermeasure, new flame retardants such as phosphorus flame retardants such as phosphazene and phosphate esters and nitrogen element-containing resins have been considered. However, phosphorus flame retardants in nitrogen element-containing resins are insufficient in flame retardancy and phosphorus flame retardants are combined with moisture. And a problem that polyphosphoric acid degrades the reliability of the semiconductor.

The present invention provides an epoxy resin composition for a semiconductor encapsulant using a non-halogen flame retardant of zinc borate and a polyhedral oligomeric silsesquioxane (POSS) that is a silicon compound to solve the problems of the prior art as described above. do.

That is, the present invention relates to an epoxy resin composition comprising an epoxy resin, a curing agent, a curing accelerator, a flame retardant, a modified silicone oil, and an inorganic filler, wherein the flame retardant is zinc borate represented by Formula 1 and polyhedral oligomeric represented by Formula 2 It provides an epoxy resin composition for sealing a semiconductor device, characterized by using in combination with silsesquioxane).                         

[Formula 1]

[Formula 2]

In which R is a phenyl group.

The present invention will be described in more detail.

The present invention is an epoxy resin composition comprising 1) an epoxy resin, 2) a curing agent, 3) a non-halogen flame retardant, 4) a curing accelerator, 5) a modified silicone oil, and 6) an inorganic filler as essential components.

The epoxy resin as component 1) of the present invention is used in an amount of 3.5 to 15% by weight in the total composition.

A biphenyl epoxy resin having an ordinary epoxy equivalent of 150 to 250 and an ortho cresol novolac epoxy resin having an epoxy equivalent of 170 to 230 alone and two epoxy resins can be used in combination.                     

As the curing agent of component 2) used in the present invention, conventional phenol novolac resins, cresol novolac resins, Xylok resins, dicyclopentadiene resins, etc. having two or more hydroxyl groups and having a hydroxyl group equivalent of 100 to 200 include It can be used and it can be used individually or in combination of 2 or more types. 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. As for the composition ratio of an epoxy resin and a hardening | curing agent, it is preferable that the epoxy equivalent is 0.8-1.2 with respect to the hydroxyl equivalent, and it is preferable to use 2.0-10.5 weight% of hardening agents with respect to the whole composition.

The non-halogen-based flame retardant of component 3) used in the present invention was obtained by using a zinc borate represented by the following formula (1) and POSS (II) represented by the following formula (2) in combination.

[Formula 1]

[Formula 2]

In which R is a phenyl group.

Zinc borate applied in the present invention (zinc borate) is a compound having a structure as shown in Formula 1, the melting point of 260 ℃ excellent heat resistance, electrical properties, moisture resistance and the dehydration reaction occurs at high temperature, the endothermic phenomenon is seen 530J / g The flame retardant effect is large by the endothermic amount of. 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. POSH (polyhedral oligomeric silsesquioxane) applied to the present invention has a structure as shown in formula (2) and is a hybrid of silica and silicon nanostructured compound having a size of 1 ~ 3nm with excellent heat resistance, moisture resistance, fluidity and thermal decomposition at 550 ℃ By forming a carbon layer (char) on the surface it becomes flame retardant. The content of zinc borate and polyphosphed oligomeric silsesquioxane (POSS) is 0.5 to 6% by weight based on the total resin composition. 0.5-3% by weight of the composition is suitable. When the zinc borate is used in less than 0.5% by weight is difficult to obtain a flame retardant effect, when used in excess of 6% by weight there is a problem that there is a lot of problems that the molding defects occur when the semiconductor assembly is poor. If POSS is used in less than 0.5% by weight, there is a problem that difficult to obtain a flame retardant effect, when used in excess of 6% by weight causes unnecessary cost rise.

As the component 4) used in the present invention, the curing accelerator is a component necessary for promoting the curing reaction of the components 1) and 2), for example, benzyldimethylamine, triethanolamine, triethylenediamine, dimethylaminoethanol, tri ( Tertiary amines such as dimethylaminomethyl) phenol, imidazoles such as 2-methylimidazole and 2-phenylimidazole, organic phosphines such as triphenylphosphine, diphenylphosphine, phenylphosphine, tetra Tetraphenylboron salts such as phenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate, and the like, and may be used alone or in combination of two or more thereof. Is good.

As the modified silicone oil which is component 5) used in the present invention, a silicone polymer having excellent heat resistance is preferred, and silicone oil having an epoxy functional group, silicone oil having an amine functional group, silicone oil having a carboxyl functional group, etc. It can be mixed and used 0.05-1.5 weight% with respect to the whole epoxy resin composition. However, when the silicon oil is used in excess of 1.5% by weight or more, 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 of component 6) used in the present invention preferably use fused or synthetic silica having an average particle of 0.1-35.0 µm, and the amount of the filler should be 70 to 90% by weight based on the total composition. When the inorganic filler is used in an amount of 70% by weight or less, sufficient strength and low thermal expansion cannot be realized, and moisture penetration is facilitated, which is fatal to reliability characteristics. In addition, when the amount of the inorganic filler is 90% by weight or more, the moldability may be deteriorated due to the deterioration of the flow characteristics.

In the composition of the present invention, release agents such as higher fatty acids, higher fatty acid metal salts, ester waxes, coloring agents such as carbon black, organic and inorganic dyes, epoxy silanes, amino silanes, alkyl silanes, and the like, without departing from the object of the present invention. A coupling agent etc. can be used as needed.

As a general method for producing an epoxy resin composition using the raw materials as described above, a predetermined amount is uniformly mixed sufficiently using a Henschel mixer or a Rodige mixer, followed by melt kneading with a roll mill or a kneader, and cooling and pulverizing. A method of obtaining the final powder product is used.

As a method of sealing a semiconductor element using the epoxy resin composition obtained in the present invention, a low pressure transfer molding method is most commonly used, or an injection molding method or a casting method may be used.

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

Example 1-3

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 evaluated for physical properties and reliability by the following method, and for the reliability test, when molding an MQFP-type semiconductor device, molding was performed at 175 ° C. for 60 seconds using an MPS (Multi Plunger System) molding machine. After making it cure after cure at 175 degreeC for 6 hours, the MQFP type | mold semiconductor element was produced.

Physical properties and flame retardancy, reliability and moldability test results of the epoxy resin composition according to the present invention are shown in Table-2. The reliability test was expressed as the degree of package crack occurrence in the thermal shock test.

  * Property evaluation method

  1) Spiral Flow

   Molds were manufactured based on the EMMI standard to evaluate the flow length at molding temperature (175 ℃) and molding pressure of 70Kgf / cm2.

  2) Glass transition temperature (Tg)

   It was evaluated by TMA (Thermomechanical Analyser).

  3) coefficient of thermal expansion (α1)

   Evaluation was made by ASTM D696.

  4) electrical conductivity                     

The cured EMC test piece was crushed to a particle size of about # 400MESH to # 100MESH in a grinder, and weighed 2g ± 0.2mg of the powdered sample into an extraction bottle, put 80CC of distilled water, and extract it for 24 hours in 100 ℃ OVEN. Electrical conductivity was measured using the supernatant.

  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 occurrence of cracking was evaluated by a non-destructive tester SAT (Scanning Acoustic Tomograph).

   a) preconditions

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 and then IR at 235 ° C for 10 seconds. Three passes through the reflow were used to evaluate the presence of package cracks under precondition conditions. If cracks occurred at this stage, the next stage of thermal shock testing of 1,000 cycles was not conducted.

   b) thermal shock test

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

Comparative Example 1-2

As shown in Table 1, each component was weighed to a given composition to prepare an epoxy resin composition in the same manner as in Example, and the results of evaluation of physical properties and reliability are shown in Table 2.

Ingredient (Unit: wt%)                                              Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Epoxy resin 14.6                                              14.6 14.6 14.6 14.6 14.6 Hardener 7.58                                              7.58 7.58 7.58 7.58 7.58 Flame retardant Zinc borate                                              6 0.5 3 _ _ Brominated epoxy resin                                              - - - 1.5 One POSS                                              0.5 3 0.5 - - Sb203                                              - - - One 1.5 Curing accelerator                                              0.27 0.27 0.27 0.27 0.27 Silica                                              70 73 73 74 74 Modified silicone oil                                              0.1 0.1 0.1 0.1 0.1 γ-glycithoxy propyltrimethoxysilane                                              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)

* Hardening agent (Kolong Chemical Co., 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)                                              32 35 34 32 35 Tg (℃)                                              167 167 165 153 154 Electrical Conductivity (㎲ / ㎝)                                              31 32 32 35 32 Flexural Strength (kgf / nm ² at 240 ℃) 13 13 13 14 13 Flexural modulus (kgf / nm ² at 240 ℃) 1440 1450 1444 1440 1442 Flame retardant UL 94 V-0                                              V-0 V-0 V-0 V-0 V-0 responsibility Cracking resistance evaluation (thermal shock test)                                              0 0 0 One 0 Total number of semiconductor devices tested                                              300 300 300 300 300 Formability Void occurrence number (Visual Inspection)                                              0 0 0 0 One Total number of semiconductor devices tested                                              300 300 300 300 300

As shown in Table 2, it can be seen that the resin composition according to the present invention exhibits characteristics that are inferior in terms of reliability and formability while securing flame retardancy compared to the conventional comparative examples.

The resin composition of the present invention is an epoxy resin composition for a flame-retardant semiconductor encapsulant containing no halogen, which provides an epoxy resin composition which is flame retardant and inferior in reliability and moldability.

Claims (3)

1) 3.5-15 wt% epoxy resin; 2) 2.0-10.5 weight percent of hardener; 3) 0.1-0.3 wt% of a curing accelerator; 4) 0.5-6% by weight of zinc borate represented by formula (1) and 0.5-3% by weight of polyhedral oligomeric silsesquioxane (POSS) represented by formula (2) as a flame retardant; 5) 0.05-1.5% by weight of modified silicone oil; And 6) An epoxy resin composition for sealing a semiconductor device, comprising 70 to 90% by weight of an inorganic filler.

In which R is a phenyl group. delete A conventional phenol novolak resin, a creol novolak resin, a xyloc resin, a dicyclopentadiene resin, etc., according to claim 1, having two or more hydroxyl groups as the curing agent, and having a hydroxyl equivalent of 100 to 200, alone or in combination of two or more. The curing accelerators include tertiary amines including benzyldimethylamine, triethanolamine, triethylenediamine, dimethylaminoethanol, tri (dimethylaminomethyl) phenol, 2-methylimidazole, 2-phenylimidazole, and the like. One of tetraphenylboron salts including imidazole, triphenylphosphine, diphenylphosphine, organic phosphine containing phenylphosphine, tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate Above, the modified silicone oil is characterized by using a silicone polymer, silicone oil or silicone oil and a silicone oil having a carboxyl functional group by mixing at least one. The epoxy resin composition for sealing semiconductor elements.