JP2000021247A - Conductive plastic sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive plastic sheet having anti-static performance for protecting an electronic component included and sufficient mechanical strength, and preventing malfunction caused by halation in image processing for quality inspection, as for an emboss carrier tape. SOLUTION: This conductive plastic sheet has a coating layer of conductive paint containing carbon black and an inorganic filler on at least one side of a base sheet made of resin composition, and a surface specific resistance value of the coating layer is 1×104 Ω or more but less than 1×108 Ω, and the surface glossiness is 30% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a storage package for storing, transporting, and mounting electronic components. The package has a function of protecting the electronic components, aligning the electronic components for mounting on a printed circuit board, and taking out the package. The present invention relates to an electrically conductive plastic sheet suitable for a plastic carrier tape, an embossed carrier tape using the sheet, and a package in which electronic components are packaged using the embossed carrier tape.

[0002]

2. Description of the Related Art Surface mounting of electronic components has been progressing due to rationalization of production and adaptation to small-quantity multi-product production, and plastic embossed carrier tapes have attracted attention as a packaging form applicable to this. The embossed carrier tape sheet is required to have an antistatic property for protecting the electronic components as contents from static electricity, a mechanical strength for being damaged by an external pressure, and a thickness of the embossed carrier tape. ICs called chip-type electronic components among electronic components
And the like have a relatively large weight, so that the waist strength, that is, the flexural modulus must be large.

Various materials have been proposed as suitable for this use. For example, a sheet made of a vinyl chloride resin, a polyester resin, a polystyrene resin, a polycarbonate resin, or the like provided with conductivity is generally used. . As a method for imparting conductivity for antistatic performance, carbon black is kneaded into these resins to form a sheet, or a coating containing carbon black is coated on the surface of a base sheet made of these resins. Is generally used. In particular, the method of kneading carbon black into a resin is difficult to disperse depending on the type of the resin and carbon black and the amount of carbon black added, and the mechanical strength such as bending strength and impact resistance is reduced. In addition, a sheet having a very good surface appearance cannot be obtained.

As a method for producing an embossed carrier tape, the above-described sheet is formed into a predetermined shape by a vacuum forming method, a pressure forming method, a press forming method, or the like. Further, in a process called taping, an electronic component such as an IC is inserted into a molding pocket portion of the embossed carrier tape, and a product sealed with a cover tape serving as a cover material is wound around a reel to produce a package. In this taping step, as one of quality inspections of the electronic component, the electronic component is illuminated with light from above immediately after it is inserted into the molding pocket portion of the embossed carrier tape and photographed by a camera to perform image processing. Inspection of the lead for bending and lifting. At this time, if the surface of the carrier tape inside the forming pocket is glossy, halation occurs and the machine stops due to malfunction, so the surface of the carrier tape sheet is required to be glossless. Conventionally, a carrier tape sheet has been used, for example, by roughening the sheet surface during sheeting. In addition, in the case where conductivity is imparted by coating with a conductive paint, there is a problem that even if the surface of the bent sheet is roughened, the effect is reduced by the coating.

[0005]

SUMMARY OF THE INVENTION The present invention is to solve such a problem in a conventional embossed carrier tape sheet, and has an antistatic performance and a sufficient mechanical strength for protecting electronic components as contents. In order to solve the problem of malfunction due to halation at the time of image processing at the time of quality inspection, a conductive plastic sheet having a non-glossy surface by providing a coating layer of a conductive paint containing an inorganic filler, An object of the present invention is to provide an embossed carrier tape using a sheet, and a package in which electronic components are packaged using the embossed carrier tape.

[0006]

The present invention provides a conductive plastic sheet comprising a base material sheet made of a resin composition and a coating layer of a conductive paint containing carbon black and an inorganic filler provided on at least one surface of the base sheet. The conductive plastic sheet has a surface specific resistance value of 1 × 10 ⁴ Ω or more and less than 1 × 10 ⁸ Ω on the sheet coating layer side and a surface glossiness of 30% or less. Further, using the conductive plastic sheet, an embossed carrier tape for packaging electronic components, which is molded so that the coating layer of the conductive paint is inside the molding pocket, and further,
This is an electronic component package in which electronic components are inserted into the embossed carrier tape for electronic component packaging and sealed with a cover tape.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The resin composition used in the present invention is not particularly limited, but may be a polystyrene resin composition,
One selected from a polyester resin composition, a polycarbonate resin composition, a polyvinyl chloride resin composition, and a polyolefin resin composition, or a blend thereof, a polymer alloy, or the like is used. Various additives such as an antioxidant, a stabilizer, an ultraviolet absorber, a lubricant, a filler, and the like can be added to these resin compositions as needed as long as the basic performance is not deteriorated. In addition, carbon black for coloring may be contained, and in that case, the addition amount is suitably 0.3 to 3 parts by weight based on 100 parts by weight of the resin composition excluding the carbon black for coloring. If the amount is less than 0.3 part by weight, the corners of the pockets after the embossed carrier tape is formed, which tends to be particularly thin, are undesirably transparent. If it is added in excess of 3 parts by weight, sufficient coloring is possible, and if it is added in an amount of 3 parts by weight or more, it becomes undesirable in terms of physical properties.

The base sheet produced using the above resin composition may be a single-layer sheet made of a single resin composition or a multi-layer sheet obtained by laminating two or more resin compositions. . The method for producing the base sheet is not particularly limited, but a general method such as a T-die extrusion method and a calendar method is used. In the case of a multi-layer sheet, a laminating method is a co-extrusion method in which a plurality of extruders melt extrude and guide it to a multi-layer die or a feed block to form a sheet, or a single-layer sheet or film forming each layer is coated with an appropriate adhesive. Dry lamination method, etc., which is used for bonding

At least one surface of the substrate sheet of the present invention is coated with a conductive paint containing carbon black and an inorganic filler. The conductive paint used has a resin component, carbon black, an inorganic filler and a solvent as main components. As the resin component, an acrylic resin, a polyester resin, a polyester urethane resin, a polyvinyl chloride resin, or the like is used. As the carbon black, those having an average particle diameter of less than 0.08 mm are preferably used.
Although the inorganic filler is not particularly limited, alumina (A
l2O3), aluminum silicate, antimony oxide (Sb
₂ O ₃ ), barium titanate (BaTiO ₄ ), calcium carbonate, calcium sulfate, iron oxide (Fe ₂ O ₃ ), mica, silica (SiO ₂ ), silicon carbide (SiC), talc (MgSiO ₃ ), titanium oxide (TiO ₂ ), zircon oxide (ZrO ₂ ), zircon silicate, glass fiber and the like are used. As the solvent, an ester, an alcohol, a hydrocarbon, or the like is used.As the ester, ethyl acetate, butyl acetate, or the like is used. For example, toluene, xylene, turpentine oil or the like is used. Although the content of each main component is not particularly limited, the range of 1 to 50% by weight of the resin component, 1 to 15% by weight of the carbon black, 5 to 20% by weight of the inorganic filler, and 35 to 90% by weight of the solvent. Appropriate.
In addition to these main components, a dispersant, a plasticizer, and the like may be appropriately used as additives in the conductive paint.

The method for applying the conductive paint in the present invention is not particularly limited, but a method such as a gravure coating method, a roll coating method, and a dip coating method is used. If sufficient adhesion strength cannot be obtained, the surface coated with the sheet may be subjected to a corona treatment or a primer treatment with another coating agent.
The specific resistance value of the coating layer side surface of the inorganic filler-containing conductive paint is preferably 1 × 10 ⁴ Ω or more and less than 1 × 10 ⁸ Ω. If it is 1 × 10 ⁸ Ω or more, the surface resistivity of the pocket portion after forming the embossed carrier tape becomes large, and the effect of preventing electrostatic breakdown of the electronic component cannot be exhibited. On the other hand, if it is less than 1 × 10 ⁴ Ω, it is not preferable because the electronic components of the contents are destroyed when electricity is supplied from outside.

[0011] The surface glossiness of the coating layer side surface of the inorganic filler-containing conductive paint is in the range of 30% or less, more preferably 25% or less. If it is 30% or more, there is a problem of malfunction due to halation at the time of the image processing described above, which is not preferable. The sheet thickness of the present invention is 0.15
1.00 mm, especially 0.20 to 0.50
The range of mm is appropriate for the thickness of the embossed embossed carrier tape.

The method of manufacturing the embossed carrier tape for packaging electronic parts using the conductive plastic sheet of the present invention is not particularly limited, but the vacuum forming method and the pressure forming method conventionally used as the forming method of the embossed carrier tape have been used. It is produced by a press molding method or the like. The method of manufacturing a package in which electronic components are wrapped using the embossed carrier tape is not particularly limited, but the electronic component is inserted into a molding pocket portion of the embossed carrier tape by a taping machine and sealed by a cover tape. Is done.

[0013]

EXAMPLES The present invention will be described below by way of examples, which are merely examples, and the present invention is not limited thereto. << Examples 1-4 >> As an inorganic filler-containing conductive paint,
A polyvinyl chloride resin, carbon black, talc, and a solvent (a mixed solvent of toluene / methyl ethyl ketone / ethyl acetate) are blended in a weight ratio of 30: 6: 11: 53, and a dispersant, a plasticizer, and an antioxidant are mixed. Was appropriately added and mixed by a ball mill for 30 minutes to produce. This conductive paint was applied to one surface of a 0.3 mm-thick base sheet shown below by a gravure coating method (200 lines, using a gravure roll having a plate depth of 30 μm) to prepare a carrier tape sheet. [Example 1] Using a polystyrene resin "H640" (manufactured by Nippon Polystyrene Co., Ltd.), a polystyrene sheet having mirror-finished both surfaces was prepared by a T-die extrusion method. [Example 2] Polyester-based copolymer resin "PETG6"
763 "(manufactured by Eastman Chemical Co., Ltd.), and a polyester sheet having both surfaces of the sheet mirror-finished was produced by a T-die extrusion method. [Example 3] Amorphous polyester sheet "AST4"
(Manufactured by Kanebo Gosen Co., Ltd.). Example 4 A vinyl chloride sheet "VSS 1202" (manufactured by Sumitomo Bakelite Co., Ltd.) was used.

Example 5 The same conductive paint was applied on both sides of the same base sheet as in Example 1 by the same method to produce a carrier tape sheet. Example 6 The same conductive paint was applied on both sides of the same substrate sheet as in Example 3 by the same method to produce a carrier tape sheet.

Comparative Example 1 As a conductive paint containing no inorganic filler, polyvinyl chloride resin, carbon black, and a solvent (a mixed solvent of toluene / methyl ethyl ketone / ethyl acetate) in a weight ratio of 30: 6: 64 were used. The mixture was mixed at a ratio, and after appropriately adding a dispersant, a plasticizer and an antioxidant, the mixture was mixed by a ball mill for 30 minutes to prepare a mixture. This conductive paint was applied to one surface of the same polystyrene sheet (0.3 mm thick) as in Example 1 by the same method to prepare a carrier tape sheet. Comparative Example 2 The same conductive paint as in Comparative Example 1 was applied to one surface of the same amorphous polyester sheet (0.3 mm thick) as in Example 3 by the same method to produce a carrier tape sheet. << Comparative Example 3 >> Using the same polyester copolymer resin “PETG6763” as in Example 2, a polyester sheet (thickness: 0.3 mm) having both surfaces of the sheet matted was produced by a T-die extrusion method. The same conductive paint as in Comparative Example 1 was applied to one surface of the obtained base sheet by the same method to prepare a carrier tape sheet.

With respect to the sheets of Examples 1 to 6 and Comparative Examples 1 to 3, sheet characteristics shown below were measured by the following methods. The results are shown in Tables 1 to 3. Surface specific resistance: The surface specific resistance on the conductive coating surface side was measured according to JIS-K-6911. Gloss: The gloss on the conductive coating surface side was measured according to JIS-K-7105. Using the sheets of Examples 1 to 6 and Comparative Examples 1 to 3, the carrier tape was formed by pressure forming using a carrier tape forming machine so that the conductive coating surface side was inside the forming pocket. The results of measuring the glossiness inside the molding pocket of the obtained carrier tape in accordance with JIS-K-7105 are shown in Tables 1 to 3. Next, the obtained carrier tape was put on a taping machine, and while the IC was inserted as an electronic component, a quality inspection of a lead portion of the IC was performed by image processing. Tables 1 to 4 indicate that inspection was possible without any problem, and x indicates that inspection was difficult due to halation.
3 is shown.

[0017]

[Table 1]

[0018]

[Table 2]

[0019]

[Table 3]

As shown in Tables 1 and 2, the conductive plastic sheet of the example of the present invention had no particular problem and was useful as a carrier tape sheet. Further, as shown in Table 3, the sheets of Comparative Examples 1 and 2 were difficult to perform quality inspection by image processing due to halation. Comparative Example 3
The gloss of the sheet was 20%, but the gloss increased to 50% when molded, and quality inspection by image processing was difficult due to halation.

[0021]

The conductive plastic sheet according to the present invention has no problem of malfunction due to halation at the time of image processing at the time of quality inspection, which is a problem of the conventional embossed carrier tape sheet, and the content of the electronic component as a content is reduced. It has antistatic performance and sufficient mechanical strength for protection and is optimal as a sheet for embossed carrier tape.

 ──────────────────────────────────────────────────の Continued on the front page F term (reference) 4F100 AA01B AA37B AK01A AK12 AK15 AK22 AL01 BA02 CA23B CC00B GB15 GB41 JG01B JG03 JG04B JK01 JK14B JN21B YY00B 5G307 GA02 GC02

Claims (3)

[Claims] 1. A conductive plastic sheet provided with a coating layer of a conductive paint containing carbon black and an inorganic filler on at least one surface of a base sheet made of a resin composition, wherein the surface ratio of the sheet coating layer is reduced. A resistance value of 1 × 10 ⁴ Ω or more and less than 1 × 10 ⁸ Ω;
A conductive plastic sheet having a surface gloss of 30% or less. 2. An embossed carrier tape for packaging electronic parts, wherein the conductive plastic sheet according to claim 1 is molded so that a coating layer of a conductive paint is inside a molding pocket. 3. An electronic component package in which an electronic component is inserted into the embossed carrier tape for electronic component packaging according to claim 2 and sealed with a cover tape.