KR20030019977A - Conductive polymer films for carrier tape body - Google Patents

Abstract

PURPOSE: Conductive polymer films for carrier tape body are provided to control sheet resistance within a range of 10¬4 to 10¬10 ohm/area and prevent static electricity by improving a structure of the polymer film. CONSTITUTION: An intermediate polymer layer(1) is used for forming a support body. A conductive layer(3) is formed by coating a conductive coating solution on an upper surface and a lower surface of the intermediate polymer layer(1). The conductive coating solution is formed with conductive polymer of 0.5 to 15 weight percent, binder of 10 to 50 weight percent, binder hardener of 0.05 to 10 weight percent, and the remaining components. A styrene-based polymer layer(2) is formed between the intermediate polymer layer(1) and the conductive layer(3).

Description

Conductive Polymer Films for Carrier Tape Body

The present invention relates to a polymer film for a carrier tape body, and more particularly, to a carrier tape including an intermediate polymer layer constituting a support and a conductive layer formed by applying a predetermined conductive coating solution to upper and lower surfaces of the intermediate polymer layer. It relates to a polymer film for the body.

Precision electronic components such as various semiconductor integrated circuit chips must be transported in an antistatic treatment container to prevent damage to the components due to static electricity generated during transportation.

Conventional containers used for transporting IC chips include IC shipping trays and carrier tapes. The shipping trays may be subjected to separate heat treatment after packaging or upon purchaser's request, and are generally transported in a package called carrier tape. Here, the carrier tape is composed of a body to hold the chip again and a cover called a cover tape. The present invention relates to a polymer film for the body of the two components.

Commonly used antistatic products use different materials depending on the degree of conductivity. 10 ⁹ when requesting the ohm / square or more surface resistance level is to use the surface active agent to the coating material to the mixture or to the surface of the polymer. On the other hand, when high conductivity of 10 ⁴ to 10 ⁷ ohms / area is required, conductive carbon black is mainly mixed with polymer or coated on the surface. For the transportation of precision electronic components such as semiconductor IC chips, the surface resistance of about 10 ⁴ ~ 10 ⁶ ohms / area is required. Therefore, a film is made of a conductive compound mixed with a conductive polymer and a styrene polymer.

When the conductive carbon black is mixed with the polymer, it is a general phenomenon that the mechanical strength is weakened, and thus, a polymer film for a carrier tape body having a three-layer structure is used to compensate for this disadvantage. In other words, based on the acrylonitrile-butadiene-styrene block copolymer (ABS) film, a thin conductive layer made of a conductive compound in which conductive carbon black is mixed with a styrene polymer is used. The laminated film made by adhering to both surfaces of ABS film is mainly used (Ref .: US4478903). The ABS layer, which is an intermediate layer of this three-layer structure, serves to maintain the mechanical strength required by the carrier tape, and the conductive layer bonded to both surfaces serves as an antistatic property. The carrier tape body having such a structure can also obtain an antistatic effect while maintaining mechanical strength.

However, the body material composed of conductive carbon black and styrene-based polymer is suitable material for antistatic purpose through the enhancement of conductivity, but because black conductive carbon black is mixed with this material, black impurities may occur due to scratches during use. There is a disadvantage in that it does not generate particulate impurities can not use the material consisting of the conventional conductive carbon black. In order to compensate for this, indium oxide, tin oxide, or metal powder may be mixed with a polymer, but these particles are not black like conductive carbon black, but they also act as impurities. There is no effectiveness.

Therefore, it is urgent to develop a new body material that can maintain a surface resistance of less than 10 ⁶ ohms / area after embossing without generating black or particulate impurities.

It is an object of the present invention to provide an antistatic polymer film that can be used as a raw material for carrier tape bodies by controlling the surface resistance in the range of 10 ⁴ to ^{10 10} ohms / area.

1 is a polymer film structure (single layer structure) as a first side of the present invention.

Fig. 2 is a polymer film structure (three layer structure) as the second side of the present invention.

<Code Description of Main Parts of Drawing>

1: middle polymer layer 2: styrene polymer layer

3: conductive layer

1 and 2, the intermediate polymer layer 1 constituting the support and the conductive layer 3 formed by applying a predetermined conductive coating liquid on the upper and lower surfaces of the intermediate polymer layer 1 are formed. A polymer film for a carrier tape body is disclosed.

Means for achieving the object of the present invention can be divided into two types according to the structure of the intermediate polymer layer, one is to configure the polymer layer of a single layer rather than the existing three-layer structure, the other As described above, the three-layer structure is maintained.

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

First, the polymer film for the carrier tape body as the first side of the present invention is implemented to include an intermediate polymer layer of a single layer structure.

The reason why the conventional polymer film for carrier tape has a three-layer structure is as follows. When conductive carbon black is mixed with styrene-based polymers to enhance conductivity, the mechanical properties of the compound, especially impact strength, are significantly reduced due to the carbon black particles. When the body is manufactured with a single layer, mechanical strength is weak and the body material breaks during the packaging process. Occurs. In order to compensate for the brittleness, the carrier tape body material for packaging a semiconductor IC chip using an ABS resin in the intermediate polymer layer and a conductive carbon black mixture for imparting conductivity to both surfaces is used. At this time, the ABS resin layer, which is the middle polymer layer, maintains the mechanical strength, thereby maintaining the mechanical strength of the carrier tape.

The three-layer structure is a technique only when mixing particulate fillers (eg conductive carbon black). That is, in the case of applying the conductive coating solution for imparting conductivity, the conductive carbon black is not mixed, and the thickness of the coating layer is a few microns, so that there is no decrease in mechanical strength due to the conductive layer coating. Therefore, in the case of forming a conductive layer on the surface of the intermediate polymer layer by applying a conductive coating solution, a styrene-based polymer, particularly preferably ABS, is used alone and a conductive layer is formed on the surface of the intermediate polymer layer. The polymer monolayer alone can maintain the mechanical properties that can be used for the carrier tape.

The intermediate polymer layer composed of a single layer as described above is applicable to any polymer as long as it can maintain only mechanical properties. That is, a copolymer of styrene with a monomer comprising at least one selected from acrylonitrile, butadiene, isoprene, or a part of butadiene hydrogenated resin and at least one selected from polystyrene, amorphous polyethylene terephthalate, polycarbonate, polyvinyl chloride, and the like. This may be included. Preferably, it is preferable to use ABS used as an intermediate layer of the existing three-layer structure as it is, but need not be limited thereto, and may be used by mixing several styrene-based polymers as necessary. For example, styrene-based polymers used on both surfaces of an existing three-layer structure are generally a mixture of high impact polystyrene (HIPS) and styrene-butadiene copolymer (styrene-butadiene copolymer (SB or SBS)) Even if the polymer combination is used as it is, it can be used as an intermediate polymer layer of the carrier tape. In this case, since the adhesiveness with the existing cover tape is excellent, there is an advantage that the conventional heat or pressure adhesive tape can be used as is.

In addition, the polymer film for a carrier tape body as a second aspect of the present invention is implemented including an intermediate polymer layer of a three-layer structure.

First, it maintains the existing three-layer structure as it is, but implements a body free of impurities. Three-layer structure using styrene-based polymer in the state that conductive carbon black, which is the main cause of impurities, is removed from conductive compounds on both surfaces. After manufacturing a laminated film of the finally can be implemented by applying a coating liquid consisting of a conductive polymer on the surface.

The conventional three-layer polymer film for carrier tape body has three layers of co-extrusion of a styrene-based polymer layer (for example, ABS resin) on the middle layer, and a conductive compound composed of conductive carbon black and styrene-based polymer on both surfaces. It was prepared by the method.

In the present invention, the above-mentioned three-layer coextrusion as shown in FIG. 2 is prepared by applying a known intermediate polymer layer 1 as it is, but instead forming a styrene-based polymer layer 2 instead of the conductive compound laminated on both surfaces. do.

Applying a conductive coating solution made of a conductive polymer to the surface of the support thus made on the surface and then heating it to volatilize the solvent, the conductive layer (3) is formed on the surface of the intermediate layer can be produced a polymer film.

Hereinafter, the conductive layer 3 used in the polymer film for the carrier tape body as the first side and the second side will be described in detail.

The conductive coating liquid used for the conductive layer 3 contains 0.5 to 15 parts by weight of the conductive polymer, 10 to 50 parts by weight of the organic binder, 0.05 to 10 of the binder curing agent and other known residual components. Other known residual components include, for example, less than 5 parts by weight of antioxidant, 40-85 parts by weight of solvent, and the like.

The conductive coating liquid of the composition can be carried out through a known method. In other words, using a gravure, kiss bar, knife or coma method to coat a thickness of 0.5 to 10 microns, and leave it at 40 to 110 degrees Celsius and dried for 1 to 20 minutes, the solvent is volatilized to form a conductive layer consisting of the above-mentioned various components Can be formed.

A detailed description of each component of the conductive coating solution is as follows.

As the conductive polymer in the conductive coating solution of the present invention, any conductive polymer such as polyaniline, polythiophene, polypyrrole, or the like may be used. Modified conductive polymers may also be used, for example, polyaniline substituted with sulfonyl group, polythiophene substituted with alkyl group having 4 to 10 carbon atoms, polythiophene substituted with ethylenedioxy group, and the like. In the case of conductive polymers, a solution containing monomers, oxidants, and dopants is coated and heated to form a conductive film by directly synthesizing the conductive polymers on the surface of the polymer film or sheet, or a conductive polymer, which is already in the form of a polymer, is mixed with a suitable binder and a solvent. By forming a conductive coating solution and then applying it to the surface of the polymer and dried to form a conductive film on the surface of the polymer can be obtained the same effect.

An organic binder should be used to improve adhesion between the conductive polymer and the styrene-based polymer, which is a base resin. Representative organic binders that can be used in the conductive coating solution of the present invention include carbonyl group, hydroxyl group, ester group, acryl group, urethane group, and carboxyl. And resins modified with functional groups such as groups, carboxylic acids, styrene groups, amide groups, imide groups, maleic acid and maleic anhydride. In addition, the resin having each functional group may be used alone, or two or more kinds thereof may be mixed and a binder composed of two or more kinds of components may be used. For example, the acrylic binder containing an ester group, the acrylic binder with an epoxy group, etc. belong to this. In particular, the use of a binder having a glass transition temperature of about 0 degrees Celsius or more may ensure the physical properties of the coated conductive layer. In the case of using these organic binders, in order to prevent deformation of the surface conductive layer during the embossing process by applying heat and pressure, a binder having a glass transition temperature of 0 degrees Celsius or more and an elongation of at least 10% should be used. If the elongation is less than 10%, there is a high possibility that the dimensional difference after molding of heat shrinkability between the conductive layer and the styrene-based polymer, which is the base resin, during the heating process.

When the conductive layer needs to be cured, a curing agent may be mixed with the binder and cured. Typical curing agents include melamine and isocyanate when acrylic binder is used. Although the content of the curing agent varies depending on the degree of curing and curing time, it is generally used in the range of 0.05 to 10 parts by weight with respect to the binder content, and the content of the curing agent is 0.05 parts by weight. If less than the hardening effect is less than 10 parts by weight of mixing hardening time is very fast workability is reduced.

As other known residual components, the solvent is not limited to a particular kind. Examples of the solvent usable in the present invention include one selected from methacresol, chloroform, imidazole, toluene, ethyl alcohol, distilled water, isopropyl alcohol, normal butanol, methanol, ethyl acetate or two or more kinds of the solvents. It can mix and use mutually in the ratio of 5: 95-95: 5.

The same effect can be obtained by directly coating the conductive coating solution on the surface of the body layer or by first coating the surface of the body layer with a binder or a primer and then applying the conductive coating solution thereon. When two or more types of binders are used in combination, or in some cases, primers and binders used for primer treatment are different from each other, if the primers and binders are compatible with each other, the same adhesion enhancing effect can be obtained. In addition, when the binder or primer component is mixed with the base polymer in advance, the same effect as that of the primer treatment can be obtained.

Since the body layer manufactured by the present invention does not use carbon black, it may have a color of the polymer itself used as a body material. If you want a special color, you can mix a small amount of pigment that can show that color.

The present invention will be described in more detail with reference to the following examples. However, these examples do not limit the scope of the present invention.

<Example 1>

0.005 mmol of polyaniline doped with dodecylbenzenesulfonic acid (DBSA), 0.05 mmol of styrene-based binder in which polystyrene (HIPS; Cheil Industries, HF-1690) and SBS (Kumho Chemical, KTR602) were mixed in a weight ratio of 85:15 toluene solvent After mixing the mixture in the ultrasonic bath for 36 hours sonicated to make a conductive coating solution. The solution was coated on a surface of a 0.3 mm thick ABS film and then dried to form a conductive layer having a thickness of about 2 microns on the surface of the ABS film.

The film thus produced had a green color with a surface resistance of 10 ⁵ Ω / □ and an adhesive force of 3B by the ASTM D3359 method. The peeling strength of the semiconductor IC chip packaging cover tape (Sumitomo, Japan, Z7302) was applied to the film by applying heat for 0.4 seconds at 150 degrees Celsius, and the peel strength was 56 gf.

<Example 2>

Example 2 was carried out under the same procedure as in Example 1, except that the surface of the ABS was pretreated with an acrylic primer before the conductive coating solution was applied and then the conductive coating solution was applied.

The surface resistivity of the conductive ABS film thus prepared was 10 ⁵ Ω / □, which was the same as that of Example 1, while the adhesive strength by the ASTM D3359 method was improved to 5B. The peeling strength of the semiconductor IC chip packaging cover tape (Sumitomo, Japan, Z7302) was applied to the film by applying heat at 150 degrees Celsius for 0.4 seconds, and then the peeling strength was 55 gf as in Example 1.

<Example 3>

Example 3 is the same as Example 1, but the conductive coating solution was diluted 1: 1 with toluene in a weight ratio to form a conductive layer on the ABS film surface by the same method.

The ABS film thus produced had a surface resistance of 10 ⁷ Ω / □, and an adhesive force of ASTM D3359 method was 3B. The peeling strength of the semiconductor IC chip packaging cover tape (Sumitomo, Japan, Z7302) was bonded to the film by applying heat at 150 degrees Celsius for 0.4 seconds, and then the peel strength was 50 gf.

<Example 4>

Example 3 was carried out under the same procedure as in Example 1, except that a black ABS film was used by mixing 2 parts by weight of carbon black for pigment in preparing the ABS film.

The ABS film thus produced had a surface resistance of 10 ⁷ Ω / □, and an adhesive force of ASTM D3359 method was 3B. The peeling strength of the semiconductor IC chip packaging cover tape (Sumitomo Nippon, Z7302) was applied to the film by applying heat for 0.4 seconds at 150 degrees Celsius, and the peel strength was 50 gf.

Example 5

0.05 mmol of 3,4-polyethylenedioxythiophene and 0.05 mmol of a urethane binder were added to a 50:50 mixed solvent of distilled water and ethyl alcohol to prepare a conductive coating solution. The solution was pretreated with a 0.3 mm thick ABS film with an acrylic primer and then coated with a conductive coating solution on the surface of the film, followed by heat drying to form a conductive layer having a thickness of about 2 microns on the surface of the ABS film.

The film thus produced had a light blue color with a surface resistance of 10 ⁵ Ω / □, and an adhesive force of 5B by ASTM D3359. The peeling strength of the semiconductor IC chip packaging cover tape (Sumitomo, Japan, Z7302) was bonded to the film by applying heat at 150 degrees Celsius for 0.4 seconds, and the peel strength was 47 gf.

<Example 6>

In Example 5, the intermediate layer was coated with an ABS resin, and a film in which polystyrene (Cheil Industries, HF-1690) and SBS (Kumho Chemical, KTR602) were mixed by 85:15 (weight ratio) on both surfaces was coextruded. The procedure was the same as in Example 4 except for the use.

The film thus produced had a light blue color with a surface resistance of 10 ⁵ Ω / □, and an adhesive force of 5B by ASTM D3359. The peeling strength of the semiconductor IC chip packaging cover tape (Sumitomo, Japan, Z7302) was bonded to the film by applying heat for 0.4 seconds at 150 degrees Celsius, and the peel strength was 48 gf.

According to the present invention, since the surface resistance can be adjusted in the range of 10 ⁴ to ^{10 10} ohms / area, it is possible to manufacture a conductive polymer film without generation of impurities, thereby manufacturing a carrier tape body for transporting semiconductor IC chips in which generation of impurities is prevented. can do. In addition, according to the present invention, instead of the conventional carrier tape body material having a three-layer structure, it is possible to manufacture a body material having a simple single layer structure.

Claims (7)

Polymer film for carrier tape body comprising an intermediate polymer layer constituting the support and a conductive layer formed by applying a predetermined conductive coating solution on the upper and lower surfaces of the intermediate polymer layer The method of claim 1, The conductive coating solution is a polymer film for a carrier tape body, characterized in that it comprises 0.5 to 15 parts by weight of the conductive polymer, 10 to 50 parts by weight of the binder, 0.05 to 10 of the binder curing agent and other known residual components. The method of claim 1, A polymer film for a carrier tape body, characterized by further forming a styrene-based polymer layer between the intermediate polymer layer and the conductive layer. The method according to any one of claims 1 to 3, The conductive polymer is a polyaniline, polythiophene, polypyrrole and a polymer film for a carrier tape body, characterized in that it comprises at least one selected from the group of modified conductive polymer modified therefrom. The method according to any one of claims 1 to 3, The binder is at least one selected from a carbonyl group, a hydroxyl group, an ester group, an acrylic group, a urethane group, a carboxyl group, a carboxylic acid, a styrene group, an amide group, an imide group, a maleic acid, a resin having a functional group of maleic anhydride, or a resin modified therefrom. Polymer film for a carrier tape body, characterized in that. The method according to any one of claims 1 to 3, A polymer film for a carrier tape body, further comprising a primer layer comprising the binder of claim 4 under the conductive layer. The method according to any one of claims 1 to 3, The intermediate polymer layer may be a copolymer of styrene with a monomer containing at least one selected from acrylonitrile, butadiene, isoprene, or a resin in which a part of butadiene is hydrogenated, polystyrene, amorphous polyethylene terephthalate, polycarbonate, polyvinyl chloride, and the like. Polymer film for a carrier tape body, characterized in that it comprises at least one selected from the group.