KR20010009179A - Epoxy Molding Compound for Semiconductor Encapsulement - Google Patents

Abstract

PURPOSE: An improved epoxy resin composition without using flame retardant of halogen being harmful to humans or equipment is provided for semiconductor device encapsulation. CONSTITUTION: An epoxy resin composition includes an epoxy resin, flame retardant of non-halogen, a hardening agent, an inorganic filler, and the other additives. As the flame retardant of non-halogen, a mixture of red phosphorus and phosphate ester is included so that phosphorus may be about 3 to about 19 parts by weight per 100 parts of the epoxy resin. Additionally, Xylok is included as the hardening agent about 20 to about 100 parts by weight per 100 parts of the epoxy resin. The epoxy resin composition has excellent physical properties such as electric conductivity, formability, tilt, and so forth.

Description

Epoxy resin composition for semiconductor element encapsulation {Epoxy Molding Compound for Semiconductor Encapsulement}

The present invention relates to an epoxy resin composition for semiconductor element encapsulation, and more particularly to an epoxy resin composition comprising an epoxy resin, a non-halogen-based flame retardant, a curing agent, an inorganic filler, and other additives. Red Phosphorus) and a mixture of phosphate esters so as to have a phosphorus content of 3 to 19 parts by weight based on 100 parts by weight of an epoxy resin, and 20 to 100 parts by weight of a Xylok curing agent as 100 parts by weight of an epoxy resin as the curing agent. It is related with the epoxy resin composition for semiconductor element sealing characterized by including.

In recent years, the degree of integration of semiconductor devices has been improved day by day, and thus the size of wirings, the size of devices and the size of multilayer wirings are rapidly progressing. On the other hand, a package that protects a semiconductor device from an external environment is accelerating its size and thickness from the viewpoint of high-density mounting to a printed board, that is, surface mounting.

The resin encapsulated semiconductor device encapsulating a large semiconductor device in a small and thin package must be flame retardant in order to be stably used in electronic products that emit a lot of heat. In most semiconductor manufacturing fields, V- Requires flame retardancy of 0 or higher. In order to secure such flame retardancy, it is common to add and use a flame retardant to an epoxy resin composition.

Conventional flame retardants added to prepare a flame retardant epoxy resin composition are bromine or chlorine-based halogen flame retardants, which are often used in combination with a suitable auxiliary agent. For example, a method of mixing and adding an epoxide bromide compound and antimony trioxide, a method of mixing and adding another halogen-based flame retardant and Sb203 having excellent flame retardant synergistic effect, and the like are known.

However, when the flame-retardant epoxy resin is manufactured using such a halogen-based flame retardant, toxic carcinogens such as dioxine or difuran are generated during incineration or fire. In addition, when combustion, gas such as hydrogen bromide or hydrogen chloride is toxic to the human body, there is a problem that is a major cause of corrosion in the semiconductor chip or lead frame (Lead Frame).

An object of the present invention is to provide an epoxy resin composition for a semiconductor encapsulant having excellent physical properties such as moldability without using a halogen-based flame retardant that is harmful to a human body and a device, and having no harmful effects.

This object of the present invention can be achieved by adding an appropriate amount of a flame retardant and a xylox curing agent that combine red phosphorus and phosphate ester compounds in an appropriate composition ratio.

That is, the present invention is an epoxy resin composition comprising an epoxy resin, a non-halogen-based flame retardant, a curing agent, an inorganic filler, and other additives, wherein the non-halogen-based flame retardant is Red Phosphorus of Formula 1 and phosphoric acid of Formula 2 The mixture of esters is contained so that the phosphorus content is 3 to 19 parts by weight based on 100 parts by weight of the epoxy resin, and 20 to 100 parts by weight of the Xylok curing agent is contained based on 100 parts by weight of the epoxy resin as the curing agent. It relates to the epoxy resin composition for semiconductor element sealing.

Wherein X is a phenylene group and R is an independent hydrogen or alkyl group, respectively.

Hereinafter, the present invention will be described in more detail.

As the epoxy resin of the present invention, a high purity epoxy resin having an equivalent weight of 100 to 250 may be applied as long as it has two or more epoxy groups in one molecule. For example, although generally used cresol novolak resin, phenol novolak resin, biphenyl, biphenyl ether, bisphenol A, dicyclopentadiene, etc. can be used singly or in combination of two or more kinds thereof, From the standpoint of moldability, a biphenyl ether epoxy resin of formula (3) having an epoxy equivalent of 150 to 190 is suitable, and it is preferable to use 5.0 to 15.0 wt% of the total composition.

Provided that R is an independent hydrogen or alkyl group, respectively.

As the non-halogen-based flame retardant of the present invention, it is characterized by using a mixture of the phosphate ester of the formula (1) and the formula (2).

In the present invention, one component of the flame retardant is composed of phosphorus alone and has the advantage of excellent flame retardancy to obtain a good flame retardant effect even in a small amount. In the present invention, the red is preferably coated with a phenol resin and then double coated with an inorganic material in that it has excellent electrical conductivity and moisture resistance. In addition, the present invention uses a phosphate ester component by mixing with a red as a flame retardant, the phosphate ester compound of the present invention is characterized by having a high flash point of more than 250 ℃ compared to the disadvantage that the general phosphate ester compound has a low flash point. The amount of phosphorus and phosphate ester used as a flame retardant is used so that phosphorus content may be 3-19 weight part with respect to 100 weight part of epoxy resins. If the phosphorus content exceeds 19 parts by weight, a stress crack may occur due to volatilization of the flame retardant, or a volatilized flame retardant may be buried on the surface of the molded article. .

In the flame retardant of the present invention as described above, other inorganic flame retardant auxiliaries can be used in combination. Such inorganic flame retardant aids may be metal hydroxides such as zinc borate, magnesium hydroxide, aluminum hydroxide, etc., which are mixed with the above phosphorus compounds to produce a flame retardant synergistic effect, and especially when zinc borate is added. Even an excessively high phenomenon can be prevented. When only phosphorus and phosphate esters are used as a flame retardant, phosphates are generated, and the electrical conductivity is increased by 5 to 10 times compared to that of general halogen flame retardants, resulting in 80 to 120 kW / cm. The actual group acts as an ion trapper to neutralize phosphate, thereby lowering the electrical conductivity to a level of 50 kW / cm. As for the usage-amount of a flame retardant adjuvant, 0-100 weight part is suitable with respect to 100 weight part of epoxy resins. The amount of flame retardant supplements is related to the amount of phosphorus and phosphate esters. Therefore, when a large amount of phosphorus and phosphate esters are used, a relatively small amount of inorganic flame retardant aids are used. need. The use of such inorganic flame retardant aids have a synergistic effect of flame retardancy to enable the use of small amounts of phosphorus and phosphate esters to ensure flame retardancy without major changes in the physical properties of the encapsulant.

In the present invention, when the phosphorus ester and the flame retardant aid are used together, a coupling agent is coated on the inorganic flame retardant aid in advance. When used in combination with phosphorous and phosphate esters and inorganic flame retardant aids, poor dispersion during mixing and poor compatibility with other raw materials can lead to poor molding during semiconductor assembly. In order to increase the compatibility between the organic material and the organic material to excellent moldability, the coupling agent is used by coating the inorganic flame retardant auxiliary. As the coupling agent of the present invention, a silane or amine compound may be used alone or in combination. The amount of the coupling agent used is 0.2 to 10 parts by weight based on 100 parts by weight of the epoxy resin. If the amount is more than 10 parts by weight, the unreacted coupling agent remains, resulting in a weakness in moldability. If the amount is less than 0.2 part by weight, it is difficult to expect the effect of increasing the dispersibility of the flame retardant.

As a hardening | curing agent of the resin composition of this invention, 20-100 weight part of Xylok hardening | curing agents are used with respect to 100 weight part of epoxy resins. If the amount is less than 20 parts by weight, the curing reaction does not occur sufficiently, so that the molding is not performed and the physical properties are significantly lowered. If the amount is more than 100 parts by weight, residues are formed in the encapsulant, resulting in poor reliability and unnecessary cost increase. Becomes

In order to accelerate the curing reaction between the epoxy resin and the curing agent in the epoxy resin composition of the present invention, it is preferable to add a curing accelerator. Examples of curing accelerators are imides such as benzyldimethylamine, triethanolamine, triethylenediamine, dimethylaminoethanol, tertiary amines such as tri (dimethylaminomethyl) phenol, 2-methylimidazole, and 2-phenylimidazole. Organic phosphines such as sol, triphenylphosphine, diphenylphosphine, phenylphosphine, tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate, triphenylphosphine tetraphenylborate and the like. In the present invention, the curing accelerator as described above may be used alone or in combination of two or more, preferably triphenylphosphine alone or mixed with a curing agent to melt to form a melt master batch (MMB). The content is preferably 0.02 to 2.5 parts by weight based on 100 parts by weight of the epoxy resin. If the curing accelerator is used in excess of 2.5 parts by weight, abnormalities occur in the curing reaction, and the physical properties are lowered. If the curing accelerator is used at less than 0.02 parts by weight, the effect of promoting the curing reaction does not appear.

In the epoxy resin composition of the present invention, an inorganic filler may be added. Although most inorganic fillers may be used as the inorganic filler, it is preferable to use high purity molten or synthetic silica having an average particle size of 0.1 to 40 μm. It is preferable to use 74 to 90% by weight based on the epoxy resin composition. If the inorganic filler is used in an amount of less than 74% by weight, it is difficult to obtain sufficient strength, and it is highly likely to cause corrosion of the aluminum pad due to moisture absorption. If the inorganic filler exceeds 90% by weight, the fluidity is poor, so that moldability during semiconductor assembly is poor. It is likely to occur.

In addition to the above components, a surface treatment agent, a colorant, a mold releasing agent, a plasticizer and the like may be added to the semiconductor element encapsulated epoxy resin composition of the present invention as needed.

In the present invention, a plasticizer may be generally used a silicone rubber or epoxy modified silicone oil, and as the release agent, higher fatty acids, higher fatty metal salts, ester waxes, and the like may be used. In addition, carbon black, an organic or inorganic dye, etc. can be used as a coloring agent.

In general, the semiconductor encapsulated epoxy resin composition of the present invention is uniformly mixed with each component of a predetermined amount by a Henschel mixer or a Rodige mixer, and then melt-kneaded using a roll mill or a kneader, and then cooled and pulverized. It can be prepared by the method of obtaining the final powder product by grinding using.

As a method of encapsulating a semiconductor device using the epoxy resin composition of the present invention, a low pressure transfer molding method is most commonly used, but it can also be molded by an injection molding method or a casting method.

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

Example 1

After weighing each component with a composition as shown in Table 1 below, the mixture was uniformly mixed using a Henschel mixer to prepare a primary composition in a powder state, and then the primary composition was mixed and 100 using a 2-roll mill. After melt-kneading at 7 ° C. for cooling in air, the resultant was ground using a hood mixer to prepare a final epoxy resin composition.

The epoxy resin composition thus obtained was measured for flame retardancy by a vertical flame retardancy test, which is a UL94 test method, spiral flow, gel time, and adhesive strength were measured. A test piece was prepared using a bending test mold, and the post was made at 175 ° C. for 6 hours. After curing, the glass transition temperature was measured. After making a sample with a spiral flow mold, using a mortar and mixer, finely powdered, 80 ml of distilled water was added to 2 g of the sample, heated at reflux for 24 hours in an oven at 100 ° C., and then the electrical conductivity was measured and assembled to 50/44 TSOP. The specimens were made and evaluated for moldability such as sticking recovery and tilt. After curing, the moisture absorption rate was evaluated by 168 hours at 85 ° C / 85% RH. The specimens were passed through IR reflow for 245 ° C for 10 seconds and then treated for 168 hours using a pressure cooker test (PCT) at 121 ° C / 100% RH, resulting in corrosion of the chip pads. The condition was evaluated. All measurement results are shown in Table 1.

Example 2

The total of phosphorus and phosphate esters was 0.5% by weight, and the same procedure as in Example 1 was carried out except that 0.5% by weight of zinc borate (Borax), an inorganic flame retardant aid, was used and the measurement results are shown in Table 1.

Example 3

The total of red and phosphate esters was 0.5% by weight, except that 0.5% by weight of aluminum hydroxide, an inorganic flame retardant aid, was used in the same manner as in Example 1, and the measurement results are shown in Table 1.

Example 4

The total of phosphorus and phosphate esters was 0.5% by weight, except that 0.5% by weight of magnesium hydroxide, an inorganic flame retardant aid, was used in the same manner as in Example 1, and the measurement results are shown in Table 1.

Comparative Example 1

The total of phosphorus and phosphate ester was 0.5% by weight, and the same procedure as in Example 1 was carried out except that 0.5% by weight of brominated epoxide bromide and 0.5% by weight of antimony trioxide were used. Shown in

Comparative Example 2

Except for using a phenol novolak curing agent instead of a xyloco hardener was carried out in the same manner as in Example 1 and the measurement results are shown in Table 2.

Comparative Example 3

The total amount of red phosphorus and phosphate ester was 0.5% by weight, and a phenol novolac curing agent was used instead of the xylox curing agent, and 0.5% by weight of zinc borate was used as a flame retardant aid. The coupling agent was applied in the same manner as in Example 1 except that the coupling agent was directly added without coating the inorganic flame retardant and the measurement results are shown in Table 2.

Ingredient Example 1 Example 2 Example 3 Example 4 Biphenyl ether epoxy resin 8.82 8.82 8.82 8.82 Xyloc Curing Agent 5.61 5.61 5.61 5.61 Curing accelerator 0.18 0.18 0.18 0.18 Coupling agent 0.42 0.42 0.42 0.42 Silica 83.0 83.0 83.0 83.0 Epoxy modified silicone oil 0.93 0.93 0.93 0.93 coloring agent 0.20 0.20 0.20 0.20 Wax 0.21 0.21 0.21 0.21 Other preparation 0.01 0.01 0.01 0.01 Flame retardant Of 0.8 0.4 0.4 0.4 Phosphate Ester 0.2 0.1 0.1 0.1 Flame Retardant Supplements Zinc borate 0 0.5 0 0 Aluminum hydroxide 0 0 0.5 0 Magnesium hydroxide 0 0 0 0.5 Spiral Flow (inch) 32 31 40 35 Gel time (sec) 26 26 28 27 Adhesion Strength (kgf / ㎡) 40.25 41.03 46.65 43.05 Glass transition temperature (℃) 104.28 102.34 103.26 106.23 Electrical Conductivity (㎲ / ㎝) 90.9 13.5 78.5 100.5 Formability (Sticking Count) 0/50 0/50 0/50 0/50 Tilt (μm) 7 7 7 7 Hygroscopicity (168 hours PCT) 0.34 0.32 0.33 0.34 Corrosion occurrence (168 hours PCT) 0/50 0/50 0/50 0/50

(Unit: weight%)

Ingredient Comparative Example 1 Comparative Example 2 Comparative Example 3 Biphenyl ether epoxy resin 8.82 8.82 8.82 Hardener Xylock 5.61 0 0 Phenolic novolac 0 5.61 5.61 Curing accelerator 0.18 0.18 0.18 Coupling agent 0.42 0.42 0.42 Silica 83.0 83.0 83.0 Epoxy modified silicone oil 0.93 0.93 0.93 coloring agent 0.20 0.20 0.20 Wax 0.21 0.21 0.21 Other preparation 0.01 0.01 0.01 Flame retardant Of 0 0.8 0.4 Phosphate Ester 0 0.2 0.1 Br-epoxy 0.5 0 0 Flame Retardant Supplements Zinc borate 0 0 0.5 Aluminum hydroxide 0 0 0 Magnesium hydroxide 0 0 0 Sb203 0.5 0 0 Spiral Flow (inch) 35 40 41 Gel time (sec) 27 29 30 Bond strength (kgf / mm2) 39.6 35.2 34.5 Glass transition temperature (℃) 107.3 109.3 108.5 Electrical Conductivity (㎲ / ㎝) 20.5 13.5 24.3 Formability (Sticking Count) 2/50 10/50 15/50 Tilt (μm) 12 26 32 Hygroscopicity (168 hours PCT) 0.32 0.35 0.34 Corrosion occurrence (168 hours PCT) 5/50 7/50 4/50

(Unit: weight%)

The epoxy resin composition for semiconductor element encapsulation containing the non-halogen flame retardant and the xylox curing agent of the present invention is excellent in physical properties such as electrical conductivity, formability, tilt, and the like, and does not cause corrosion. A semiconductor element sealing agent which does not interfere can be provided.

Claims (5)

In the epoxy resin composition comprising an epoxy resin, a non-halogen flame retardant, a curing agent, an inorganic filler, and other additives, a mixture of Red Phosphorus of Formula 1 and the phosphate ester of Formula 2 is epoxy as the non-halogen flame retardant. It is contained so that phosphorus content is 3-19 weight part with respect to 100 weight part of resin, and 20-100 weight part of Xylok hardeners is contained with respect to 100 weight part of epoxy resins as said hardening | curing agent. Epoxy resin composition. [Formula 1] [Formula 2] Wherein X is a phenylene group and R is an independent hydrogen or alkyl group, respectively. The epoxy resin composition for semiconductor element encapsulation according to claim 1, wherein the epoxy resin is a biphenyl ether epoxy resin having an epoxy equivalent of 150 to 190 having a structure represented by the following Chemical Formula 3. [Formula 3] Provided that R is an independent hydrogen or alkyl group, respectively. The inorganic flame retardant according to claim 1, wherein the non-halogen flame retardant is one or more inorganic flame retardants selected from the group consisting of 0 to 100 parts by weight of magnesium hydroxide, aluminum hydroxide, and zinc borate with respect to 100 parts by weight of an epoxy resin mixture. An auxiliary resin is coated with 0.2 to 10 parts by weight of a silane or amine coupling agent based on 100 parts by weight of an epoxy resin and added to the epoxy resin composition for semiconductor element encapsulation. The epoxy resin composition for semiconductor element encapsulation according to claim 1, wherein triphenylphosphine is added in an amount of 0.02 to 2.5 parts by weight based on 100 parts by weight of the epoxy resin as a curing accelerator. The epoxy resin composition for semiconductor element encapsulation according to claim 1, wherein silica having an average particle size of 0.1 to 40 µm is added as an inorganic filler with respect to the whole epoxy resin.