KR20130103937A - Method of preparing emc mold cleaning sheet having improved dispersibility - Google Patents

Abstract

PURPOSE: A method for manufacturing an epoxy molding compound (EMC) mold washing sheet is provided to obtain variant properties inside a mold by improving the oil dispersibility without occurring fumes or odor. CONSTITUTION: A method for manufacturing an EMC mold washing sheet comprises the following steps: heating and melting one or more wax among polypropylene wax and polyethylene wax in which the Tg is between 65°C and 80°C; forming a mixture of 10-30 parts by weight of a cleaning agent, 10-50 parts by weight of an inorganic filler, and 1-10 parts by weight of an additive based on 100 parts by weight of one or more polymer among butadiene rubber (BR), styrene butadiene rubber (SBR), ethylene-propylene-diene monomer rubber (EDPM), nitrile rubber (NR), nitrile butadiene rubber (NBR), and chloroprene rubber (CR) in the melted wax; and molding the mixture into the shape of a sheet.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of producing an EMC mold cleaning sheet having improved dispersibility,

The present invention relates to a process for producing an EMC mold cleaning sheet having improved dispersibility, and more particularly, to a process for producing a sheet for cleaning an EMC mold with improved dispersibility, comprising the steps of preliminarily melting and mixing wax having a Tg of a predetermined temperature range, The present invention also relates to a method for manufacturing an EMC mold cleaning sheet excellent in workability by providing an effective releasing property while maintaining a constant coating performance.

Semiconductor devices such as transistors, integrated circuits (IC), high density integrated circuits (LSI), etc. are typically resin-encapsulated by plastic packaging. Such resin encapsulation is carried out by using a thermosetting resin composition such as an epoxy resin composition or the like, and performing casting, compression molding, injection molding, transfer molding, especially mass transfer productivity with excellent productivity and workability. However, the above-described transfer molding is carried out continuously when the semiconductor element is resin-encapsulated by the transfer molding using the epoxy resin composition, because the molding die or the die is not releasing the mold releasing agent in the epoxy resin composition agent, which causes the molding to fail.

That is, in the above molding, the mold release agent contained in the epoxy resin composition flows out from the resin composition to the inner surface of the cavity formed by the upper mold and the lower mold to cause a mold-demolding action. The spilled mold release agent is gradually deteriorated as it accumulates on the inner surface and oxidizes, forming a hard oxidized mold-depigmenting agent layer (where the surface of the layer is not as smooth as the inner surface of the mold). Further, the molding is carried out on the surface of the oxidized and deteriorated mold-defoliating agent layer, whereby the surface pattern of the oxidized and deteriorated mold-defoliating agent layer is transferred to the surface of the molded article so that the surface of the molded article becomes rough and uneven .

When such oxidized and deteriorated mold-depigmenting agent layer is once formed on the inner surface of the mold at the time of molding, the epoxy resin composition and further the mold-releasing agent are not oxidized and deteriorated from the resin composition to the surface of the mold, The mold-defoliating agent can not provide sufficient mold-demolding action.

Generally, when a product is molded using a thermosetting resin, in particular, an EMC molding process for semiconductor manufacturing requires high-quality product reliability. In order to form such a high-quality product, a cleaning operation to remove contaminants remaining in a semiconductor mold must be performed from time to time. In addition, a release agent is coated on the surface of the mold to facilitate detachment of the thermosetting resin by repeated operations.

Such a cleaning and releasing process is indispensable, and its importance becomes more important as semiconductor devices become more highly integrated. In particular, the mold release process directly affects the quality of the semiconductor device. If the mold releasing property is not properly performed on the surface of the mold, it takes much time to repair the product as well as the entire product. Therefore, Are being developed in tandem with the high integration of semiconductor devices.

In the case of the melamine resin used as the EMC mold cleaning material, there is a problem that the formalin generation occurs while being cured. In the case of the rubber sheet, since the oil dispersibility is poor, the composition component is cured at a high temperature of 150 to 180 ° C, ) And odor are generated.

In order to solve the above problems, it is an object of the present invention to provide an EMC mold cleaning composition which is improved in oil dispersibility and is free from fume or odor and is excellent in mold releasability.

In order to achieve the above object,

Melting by heating at least one wax selected from polyethylene wax and polypropylene wax having a Tg of 65 to 80 ° C;

Butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene diene monomer rubber (EDPM), nitrile rubber (NR), nitrile-butadiene rubber (NBR), chloroprene rubber (CR) in the molten wax Forming a mixture based on 100 parts by weight of the at least one polymer selected from 10 to 30 parts by weight of the detergent, 10 to 50 parts by weight of the inorganic filler and 1 to 10 parts by weight of the additive; And

And molding the mixture into a sheet form. The present invention also provides a method for manufacturing an EMC mold cleaning sheet.

The method of manufacturing a cleaning sheet for an EMC mold according to the present invention improves the dispersibility of the composition and evaporates so that fume and odor are not generated and the continuous coating performance is imparted to the inside of the mold, The workability is excellent and environmental pollution can be prevented.

Hereinafter, the present invention will be described in detail.

The manufacturing method of the EMC mold cleaning sheet according to the present invention comprises the steps of melting by heating at least one wax selected from polyethylene wax and polypropylene wax having a Tg of 65 to 80 ℃; Butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene diene monomer rubber (EDPM), nitrile rubber (NR), nitrile-butadiene rubber (NBR), chloroprene rubber (CR) in the molten wax Forming a mixture based on 100 parts by weight of the at least one polymer selected from 10 to 30 parts by weight of the detergent, 10 to 50 parts by weight of the inorganic filler and 1 to 10 parts by weight of the additive; And molding the mixture into a sheet form.

The cleaning sheet of the present invention is characterized by comprising a polymer rubber, a cleaning agent, an inorganic filler, an additive, a wax and a silicone oil, wherein the wax component is preliminarily melted and compounded.

The wax may be one or a mixture of two or more of polyethylene wax, polypropylene wax, carnauba wax, montan wax and ester wax, preferably polyethylene wax and polypropylene wax. In order to maximize the effect of addition of the releasing material including wax, a releasing material having various Tg and molecular weight can be used. However, the use of various Tg waxes can lead to various problems in the dispersion in the composition.

When a wax having an excessively high Tg is used, it is required to heat the wax at a temperature equal to or higher than Tg in the compounding / dispersing process, so that the thermal properties of the rubber are lowered and the process becomes longer for complete dispersion. On the other hand, when a wax having a low Tg is used, wax is naturally dispersed in a mixing process for forming a cleaning sheet, but a fume and odor are generated due to heat during a molding process, causing a problem in the process. And also has disadvantages in that it is disadvantageous in terms of physical properties such as coating persistence, releasability and secondary staining property.

Therefore, it is preferable to use a wax having a Tg of 65 to 80 占 폚. By using a wax having a Tg of 65 to 80 占 폚, it is possible to prevent fume and odor from being generated. However, when such a wax is directly added to a cleaning composition and mixed, there is a problem in dispersibility. Therefore, in the production method of the present invention, even when a wax having a relatively high Tg is used by pre-melting the wax in advance at a temperature of Tg or higher without directly blending the solid wax and kneading it in a kneader or a roll, . Therefore, by using wax having a constant temperature range of Tg, deterioration of the physical properties of the sheet can be prevented, and mixing through preliminary melting can reduce the dispersion step and improve the dispersibility.

The wax in the composition of the present invention is preferably 20 to 35 parts by weight based on 100 parts by weight of the rubber component. When the wax content is less than 20 parts by weight, sufficient coating performance can not be exhibited in the mold. When the wax content exceeds 35 parts by weight, breakage occurs easily due to the decrease in strength upon curing of the rubber, But also may cause defects in the manufacture of semiconductors. Also, when the amount of wax is excessive, it takes a long time to harden the rubber, and some of the wax may be self-carbonized and become a source of contamination.

Since the wax is susceptible to heat resistance, it is preferable to mix it with silicone oil having heat resistance rather than wax alone. Liquid silicone oil can also be mixed well with rubber.

The silicone oil improves the mold coatability and improves releasability of the product after molding the semiconductor product. Since the silicone oil itself is in a liquid form, it is difficult to mix it with rubber alone. Silicone oil alone does not disperse evenly when mixed with rubber, and rubber sheet formation can not be achieved. Therefore, as the silicone oil is added in the state where the wax is present, it is improved in compatibility with the rubber, and the silicone oil can have coating and releasability. The silicone oil that can be used is either a reactive silicone oil having reactive groups such as an amino group, an amine group, an epoxy group phenyl group, or a non-reactive silicone oil such as a dimethyl silicone oil. In the case of the silicone oil containing the reactive group, since the coating can be continued for a long time on the surface of the mold, persistence of the mold coating ability is increased. In the case of the non-reactive silicone oil, the emulsion of the wax is increased, So that it can be used more effectively.

The base material for preparing the cleaning composition of the present invention is a polymer, which is a natural or synthetic rubber. The rubber component is cured by the action of the curing agent contained in the mold when heat and pressure are applied to the inside of the mold, and is formed in the shape of the inside of the mold.

It is required to be formed in the shape of the mold inside the mold so as to exactly coincide with the inside of the mold so that the coating components can flow out to the outside while the rubber is molded so that the coating can be accurately formed on the inner surface of the mold. Therefore, the polymer component used in the present invention must be able to have a precise shape in the mold of the semiconductor mold, and to allow the coating components to flow easily.

Polymer components include butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene diene monomer rubber (EDPM), nitrile rubber (NR), nitrile-butadiene rubber (NBR), and chloroprene rubber (CR). At least one mixture selected or a modification thereof. Of these, butadiene rubber and styrene-butadiene rubber having a 1,2-syndiotactic arrangement having a stereoregular arrangement in the butadiene rubber are preferable.

Detergents include glycol ethers, ketones, amino alcohols, pyrrole, imidazoles, and imidazolines, and may be used in one or more combinations.

The glycol ethers include ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, polyethylene glycol dimethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, Diethylene glycol diethyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether, and may be used in one or more combinations.

Aminoalcohols include monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N, N-dimethylethanolamine, N, N-dibutylethanolamine, N- Methyl-N, N-diethanolamine, 2-amino-2-methylpropanol, 3-aminopropanol and 2-aminopropanol and may be used in one or more combinations.

The imidazole is selected from the group consisting of 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-benzyl- -Methylimidazolyl- (1) '] ethyl-s-triadine, which may be used in one or more combinations.

Imidazoline is selected from the group consisting of 2-methylimidazoline, 2-methyl-4-ethylimidazoline, 2-phenylimidazoline, 1-benzyl- 2-methylimidazolinyl- (1) '] ethyl-s-triazine, 2,4-diamino-6 [2'-methyl -4'-imidazolinyl- (1) '] ethyl-s-triazine, 1-cyanoethyl-2-methylimidazoline and 1-cyanoethyl- And may be used in one or more combinations.

The content of the detergent may be set in a range of preferably 10 to 30 parts by weight, more preferably 15 to 25 parts by weight, based on 100 parts by weight of the polymer rubber. When the content of the cleaning agent is less than 10 parts by weight, it is difficult to exhibit a satisfactory cleaning effect on the mold. When the content exceeds 30 parts by weight, the composition adheres to the mold, The efficiency is deteriorated, which is not preferable.

The inorganic filler may include silica, alumina, carbon black, calcium carbonate, calcium silicate, aluminum hydroxide, titanium oxide, titanium dioxide, titanium hydroxide, and the like. The content of the inorganic filler may be set in the range of preferably 10 to 50 parts by weight based on 100 parts by weight of the rubber. When the content of the inorganic filler is less than 10 parts by weight, thermal expansion is increased and the cured rubber itself is poor in heat resistance, crack resistance and moisture resistance. When the content is more than 50 parts by weight, It is difficult to obtain moldability, which is not preferable.

Also, the cleaning composition of the present invention may contain an additive, which is a known material used in general rubber compounding, and includes a crosslinking agent, an antioxidant, a separation aid, and the like. The content of the additive is preferably 1 to 10 parts by weight based on 100 parts by weight of the rubber.

The crosslinking agent causes a crosslinking reaction between the rubber molecule chains to form a rubber cured product. Examples include 2,5-dimethyl-2,5-bis- (t-butylperoxy), dt-butylperoxide, 2,5- (t-butylperoxy-i-propyl) -benzene, dicumylperoxide, 4,4-di-t-butylperoxy-n-butylvalerate, t-butylperoxy Benzoate, 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, benzoyl peroxide, bis- (2,4-dichlorobenzoyl) -peroxide and the like.

The separation assisting agent may be imidazole or imidazolyl which may be used alone or in combination with an organic solvent such as water, methanol, ethanol, n-propane, etc., or an alcohol such as toluene, Can be increased.

The thickness of the formed sheet is preferably 5 to 10 mm. The thickness of the sheet can be suitably produced by adjusting the pressure in the mold. If the thickness of the sheet is less than 5 mm, unfilling may occur in the mold, which is undesirable because the process takes a long time, and when it exceeds 10 mm, economical efficiency and efficiency are lowered.

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to the examples.

Example

Example 1

(Tg: 80 DEG C) preliminarily melted together with 70 g of a silica filler and 9.5 g of an additive (1 g of stearic acid, 5 g of titanium dioxide, 1 g of antioxidant and 2.5 g of dicumyl peroxide) was added to 100 g of a rubber component containing 70 g of SBR and 30 g of EPDM. ) Were mixed and kneaded and then molded into a sheet shape, and the mold was subjected to mold cleaning at 180 DEG C and 2000 to 2300 PSi for 6 minutes. The results are shown in Table 1 below.

Comparative Example 1

70 g of a silica filler, 9.5 g of an additive (1 g of stearic acid, 5 g of titanium dioxide, 1 g of antioxidant and 2.5 g of dicumyl peroxide) and 100 g of paraffin wax (Tg: 53 캜) preliminarily melted were added to 100 g of a rubber component containing 70 g of SBR and 30 g of EPDM, Were mixed and kneaded, and then molded into a sheet shape. The mold was subjected to mold cleaning at 180 DEG C and 2000 to 2300 PSi for 6 minutes. The results are shown in Table 1 below.

Comparative Example 2

70 g of a silica filler, 30 g of polyethylene wax (Tg: 80 캜), and additives (1 g of stearic acid, 5 g of titanium dioxide, 1 g of an antioxidant and 2.5 g of a crosslinking agent) were mixed and kneaded in 100 g of a rubber component containing 70 g of SBR and 30 g of EPDM, And the mold was cleaned in a mold at 180 ° C for 6 minutes under a pressure of 2000 to 2300 PSi. The results are shown in Table 1 below.

Comparative Example 3

Spray release agent wax (YL-504B, purchased from Yongil Co., Ltd.) was sprayed onto the mold to improve the releasability of the mold. The results are shown in Table 1 below.

division Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Dysplasia ◎ △ ○ △ Coating persistence ◎ × △ △ Secondary stain
(poor peeling) ◎ △ × △ Workability ◎ ○ ◎ × Mold surface stain ◎ ○ ○ ○

◎: Very good, ○: Excellent, △: Normal, ×: Poor

Referring to Table 1, it can be confirmed that Example 1, which was obtained by preliminary melting of wax having a high Tg, is excellent in releasability, coating persistence, stain resistance and workability as compared with Comparative Examples 1 to 3. The polyethylene wax having a relatively high Tg was preliminarily melted and used beforehand. The polyethylene wax was superior to the Comparative Example 1 having a low Tg in terms of coating durability and releasability, and was more excellent in coating persistence and secondary staining property than Comparative Example 2 using a solid wax. And in Comparative Example 3 using spray, it is not uniformly sprayed, which is disadvantageous in terms of workability.

Claims (5)

Melting by heating at least one wax selected from polyethylene wax and polypropylene wax having a Tg of 65 to 80 ° C;
Butadiene rubber (BR), styrene-butadiene rubber (SBR), ethylene-propylene diene monomer rubber (EDPM), nitrile rubber (NR), nitrile-butadiene rubber (NBR), chloroprene rubber (CR) in the molten wax Forming a mixture based on 100 parts by weight of the at least one polymer selected from 10 to 30 parts by weight of the detergent, 10 to 50 parts by weight of the inorganic filler and 1 to 10 parts by weight of the additive; And
Method of producing a sheet for cleaning the EMC mold comprising the step of molding the mixture in the form of a sheet.
The method of claim 1,
The content of the wax is 20 to 35 parts by weight based on 100 parts by weight of the polymer manufacturing method of the EMC mold cleaning sheet, characterized in that.
The method of claim 1,
Wherein the thickness of the sheet is 5 to 10 mmm.
The method of claim 1,
Wherein the inorganic filler is at least one selected from silica, alumina, carbon black, calcium carbonate, calcium silicate, aluminum hydroxide, titanium oxide, titanium dioxide and titanium hydroxide.
The method of claim 1,
Wherein the additive comprises at least one selected from the group consisting of stearic acid, titanium dioxide, an antioxidant, and dicumyl peroxide.