JP2005335397A - Sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet having a mechanical strength capable of dealing with accelerating of packing and mounting by remarkably reducing a contamination due to a wear of the component with the sheet. <P>SOLUTION: The sheet comprises a base layer of a polycarbonate resin and a surface layer containing a polycarbonate resin and a carbon black of 5 to 50 wt.% and provided on at least one side surface of the surface layer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a sheet, and the sheet is used in a packaging container for electronic components. In particular, the present invention relates to a conductive sheet for carrier tape suitable for semiconductor packaging in which contamination of IC or the like caused by detachment of carbon black or the like due to wear when contacting with IC or the like is remarkably reduced.

2. Description of the Related Art Injection trays, vacuum forming trays, magazines, carrier tapes (also referred to as embossed carrier tapes), and the like are used as packaging forms for electronic parts including ICs and electronic parts using ICs. These packaging containers are made by dispersing conductive fillers on the surface in order to prevent the destruction of electronic parts such as ICs due to static electricity. The conductive fillers have a low and uniformly stable surface resistivity. Carbon black that can be obtained is widely used. Sheets made by dispersing carbon black in this thermoplastic resin are (1) mechanical strength and formability are reduced, and (2) the resin containing carbon black on the surface of the sheet is removed by the wear of the packaged electronic parts and the sheet. There is a problem that the electronic components are contaminated. As the improvement method, JP-A-57-205145, JP-A-62-18261 and the like have been proposed for (1), and JP-A-9-7624 and JP-A-9-76425 have been proposed as methods for improving (2). Yes. However, electronic components are becoming more complex, precise, and smaller, and electronic components are being packaged and mounted at higher speeds. Therefore, a packaging material that is less susceptible to contamination and has improved mechanical strength is desired. ing.

The present invention provides a sheet having mechanical strength that can drastically reduce the contamination of the electronic component resulting from the wear of the electronic component and the sheet, and can cope with high-speed packaging and mounting.

The sheet | seat of this invention is a sheet | seat which consists of a base layer of a polycarbonate-type resin, and the surface layer of polycarbonate-type resin and 5 to 50 weight% carbon black on the at least single side | surface.

It is caused by abrasion between the electronic component and the sheet by laminating a surface layer containing a polycarbonate resin and 5 to 50% by weight of carbon black on at least one surface of a base material layer made of a polycarbonate resin. It is possible to obtain a sheet having mechanical strength that can drastically reduce the contamination of electronic components and can cope with high-speed packaging and mounting.

The sheet | seat of this invention has a base material layer and a surface layer. The structure of surface layer / base material layer or surface layer / base material layer / surface layer is a preferred structure. Another layer may be provided between the surface layer and the base material layer.

The base material layer is a base material layer of polycarbonate resin. It is preferably made of a polycarbonate resin and has a viscosity average molecular weight of 25000 or more. Here, the base layer of the polycarbonate-based resin means a case where it is made of only a polycarbonate-based resin, and a case where the polycarbonate-based resin is a main component and also contains other components. Examples of the polycarbonate resin include aromatic polycarbonate resins, aliphatic polycarbonate resins, and aromatic-aliphatic polycarbonates, which are usually classified as engineer plastics. Polycondensation of general bisphenol A and phosgene or Those obtained by polycondensation of bisphenol A and carbonates can also be used.

It is possible to add a small amount of carbon black together with the polycarbonate resin to the base material layer so as not to impair the fluidity. By adding carbon black, the mechanical strength can be further improved, and when the sheet is molded into a packaging container, the sheet thickness becomes thin and the corners of the molded product can be solved. . Carbon black is not particularly limited as long as it can be uniformly dispersed in the base resin. The addition amount may be in a range not impairing the fluidity as described above, and is preferably 0.1 to 10 parts by weight.

For the base material layer, ABS resin, polyethylene resin, polypropylene resin, ethylene, propylene copolymer (for example, ethylene-ethyl acrylate resin, ethylene-vinyl acetate copolymer resin, ethylene-α-olefin copolymer resin, etc.), etc. Other resin components such as polyester resins such as olefin resin, polyethylene terephthalate resin, pobutylene terephthalate resin, etc. can be added, and various additives such as lubricants, plasticizers, processing aids are added as necessary You can also

The surface layer is a surface layer of polycarbonate resin and 5 to 50% by weight of carbon black. Here, the surface layer of the polycarbonate-based resin and 5 to 50% by weight of carbon black means a case where it consists only of the polycarbonate-based resin and 5 to 50% by weight of carbon black and a case where it contains other components. Examples of the polycarbonate-based resin include aromatic polycarbonate-based resins, aliphatic polycarbonate-based resins, and aromatic-aliphatic polycarbonates as well as the polycarbonate-based resins used for the base material layer. Further, those obtained by polycondensation of general bisphenol A and phosgene or polycondensation of bisphenol A and carbonate ester can also be used. It is also possible to add other resin components such as ABS resin, polyethylene terephthalate resin, polybutylene terephthalate resin as other components to the surface layer, and various kinds of lubricants, plasticizers, processing aids and the like as necessary. It is possible to add additives.

The carbon black of the surface layer is furnace black, channel black, acetylene black or the like, and preferably has a large specific surface area, and a high conductivity can be obtained with a small amount added to the resin, for example, ketjen black, acetylene Black is desirable. The addition amount is preferably 5 to 50% by weight based on the polycarbonate resin. If it is less than 5% by weight, a sufficient surface specific resistance value cannot be obtained to prevent the destruction of electronic components due to static electricity. .

A conductive resin composition for forming a surface layer, which is composed of a polycarbonate-based resin and 5 to 50% by weight of carbon black as described above, and further contains other components. This fluidity is JIS-K. The MFI value in the measurement method based on -7210 is preferably at least 2.6 g / 10 min at 240 ° C. under a load of 98.07 N, and further 2.6 g / min at 240 ° C. under a load of 98.07 N. It is preferably 10 minutes or more and 7.0 g / 10 minutes or more under the condition of a load of 98.07 N at 260 ° C. When fluidity falls, it becomes difficult to laminate | stack a surface layer on a base material layer, and also the secondary workability of a sheet | seat falls. The surface specific resistance value of the surface layer is preferably 10 <2> to 10 <10> [Omega].

The sheet is formed by kneading and pelletizing all or part of the raw material of the conductive resin composition of the surface layer using a known method such as an extruder, and the resulting conductive resin composition is used as a base material layer for the thermoplastic resin. In addition, it can be obtained by extrusion by a known method such as an extruder. When kneading the conductive resin composition, it is possible to knead the raw materials all at once. For example, half of the polycarbonate resin and carbon black are kneaded, and the remaining raw materials are added to the kneaded product and kneaded. It is possible to knead step by step as described above, and these can be added when forming a sheet. In order to laminate the conductive resin composition of the surface layer on the base material layer, each is formed into a sheet or film by a separate extruder, and then stepwise by a thermal laminating method, a dry laminating method, an extrusion laminating method, etc. It is possible to laminate, and it is also possible to laminate on a preformed substrate layer by methods such as extrusion coating, but in order to manufacture at a lower cost, a multilayer using a multi-manifold die or feed block It is preferable to obtain a laminated sheet collectively by a coextrusion method.

The overall thickness of the sheet of the present invention is 0.1 to 3.0 mm, and the thickness of the surface layer to be reduced to the overall thickness is preferably 2% to 80%. If the total thickness is less than 0.1 mm, the strength as a packaging container obtained by molding a sheet is insufficient, and if it exceeds 3.0 mm, molding such as pressure forming, vacuum forming, hot plate forming becomes difficult. If the thickness of the surface layer is less than 2%, the surface resistivity of the packaging container obtained by molding the sheet is remarkably high, and sufficient static electricity suppressing effect cannot be obtained. Formability such as hot plate molding is deteriorated.

Hereinafter, the present invention will be described in more detail with reference to examples.
Example Panlite L-1225 of polycarbonate resin (Teijin Chemicals Co., Ltd.) and Ketjen Black EC (Lion AKZO Co., Ltd.) 12% by weight of carbon black were previously kneaded and pelletized by a φ50 mm vent type twin screw extruder to make conductive resin A composition was obtained. The MFI of the obtained conductive resin composition was measured under the conditions of 240 ° C. load 98.07 N and 260 ° C. load 98.07 N according to JIS-K-7210. As a result, 3.7 g / 10 min under the condition of 240 ° C. And 9.8 g / 10 min at 260 ° C. Using the conductive resin composition and the base layer resin Panlite K-1285 (Teijin Kasei Co., Ltd., viscosity average molecular weight 28000), φ65 mm extruder (L / D = 28), φ40 mm extruder A three-layer sheet having an overall thickness of 300 μm and a surface layer thickness of 30 μm on both sides was obtained by a feed block method using a T die having a width of (L / D = 26) and 500 mm.

The following evaluation was performed on this sheet. The results are shown in the table.
Surface specific resistance value Using a Lorester MCP tester manufactured by Mitsubishi Oil Chemical Co., Ltd., the surface resistance value is measured at 10 points at equal intervals in the width direction, and 40 sheets in each of the two rows on the front and back sides of the sheet. The value was defined as the surface resistivity.
Tensile properties Based on JIS-K-7127, a No. 4 test piece was used, and a tensile test was performed with an Instron type tensile tester at a tensile speed of 10 mm / min.
A carbon-desorbed evaluation film is fixed to a shaking table, a 19 mm x 25 mm frame is placed on it, and a QFP 14 mm x 20 mm-64 pin IC is delivered, with a stroke of 30 mm and a speed of 480 reciprocations per minute Then, it was vibrated 800,000 times in the plane direction, and then the presence or absence of deposits on the lead portion of the IC was determined. The state where there was almost no deposits was marked with 、, the case with few deposits was marked with ○, and the case with much deposits was marked with ×.

Claims (7)

A base material layer of a polycarbonate resin, a sheet comprising a surface layer of a polycarbonate resin and 5 to 50% by weight of carbon black on at least one surface thereof. A polycarbonate resin base material layer, comprising at least one surface of a polycarbonate resin and 5 to 50% by weight of carbon black, and having an MFI of 2.6 g / 10 min or more at 240 ° C. × 10 kg load A sheet comprising a surface layer of a resin composition. The sheet according to claim 1 or 2, wherein the polycarbonate resin of the base material layer has a viscosity average molecular weight of 25000 or more. The sheet according to any one of claims 1 to 3, wherein the surface layer has a surface resistivity of 10 2 to 10 10 Ω. The sheet according to any one of claims 1 to 4, which is produced by a coextrusion method using a multi-manifold die or a feed block. The packaging container for electronic components which consists of a sheet | seat as described in any one of Claims 1 thru | or 5. The carrier tape which consists of a sheet | seat as described in any one of Claims 1 thru | or 5.