JP4307302B2 - Cover tape and carrier tape system - Google Patents

Description

  The present invention relates to a carrier tape system used for transporting chip-type electronic components and the like until they are mounted on a substrate, and a cover tape used as a cover material for the carrier tape system.

  In general, a carrier tape is used to convey a chip-type electronic component such as an IC. That is, a cover tape having an easily peelable adhesive layer on a base material on the top surface of the embossed tape by inserting the chip-type electronic component into a recess for storing an electronic component formed at regular intervals on the embossed tape. After heat sealing and encapsulating the electronic component, it is wound into a reel and transported. The carrier tape thus transported is carried to the mounting process on the substrate, the cover tape is peeled off, the chip-type electronic component as the contents is taken out, and the electronic component is mounted on the substrate. If the cover tape is not peeled smoothly, troubles may occur in which the electronic components that are the contents are scattered at the time of peeling. Therefore, the peel strength of the appropriate range is large when peeling the cover tape. Attempts to prevent fluctuations have been proposed (for example, Patent Documents 1 and 2).

For the process control in the process of packing the electronic parts in the carrier tape and the acceptance inspection when using the parts packed in the carrier tape, the cover tape is peeled off and managed at a speed of 300 mm / min. 0806. However, the mounting speed of this electronic component has been increased year by year, and the speed at which the cover tape is peeled off has been increased accordingly. Actually, from the viewpoint of high-speed mounting, the peeling speed of the cover tape is 3000 mm / min to 12000 mm / It is said that it extends to min, and along with this, troubles such as the contents popping out at the time of peeling and the cover tape breaking are increasing. This is because the peel strength measured at 300 mm / min is several times higher than that at the time of high-speed mounting and is applied to the cover tape.
JP-A-5-42968 JP-A-11-301775

  The present invention provides a cover tape and a carrier tape system using the cover tape in which the peel strength is not easily affected by the peel speed, and the peel strength at the time of high-speed mounting is not increased abnormally even in the conventional peel strength management method. It is.

That is, the present invention is a cover tape having at least a base material layer and an easily peelable heat seal layer and having the following requirements.
(1) The total thickness of the cover tape is 40 to 75 μm.
(2) The base material layer has a thickness of 10 to 60 μm and a tensile modulus of 600 to 40000 MPa.
(3) The heat seal layer is mainly composed of a polystyrene resin (a) and a polyethylene resin (b), contains a fatty acid amide, has a thickness of 2 to 30 μm, and has a tensile modulus of 10 to 500 MPa. It is.
As a base material layer of this invention, it is preferable to consist of 1 type, or 2 or more types of resin components of a polyester resin, a nylon resin, a polypropylene resin, a polystyrene-type resin, a polyethylene-type resin, and a polycarbonate resin. On the other hand, the present invention comprises an embossed tape and the cover tape, and the embossed tape comprises a chip type electronic component packaging carrier tape system comprising one or more resin components of polystyrene resin, polycarbonate resin and polyester resin. It is. Further, in the present invention, the average peel strength (P ₃ ) when the heat-sealed embossed tape and the cover tape are peeled at a peeling speed of 300 mm / min is 0.3 to 0.5 N, and the peeling speed is 4500 mm / min. peeling average peel strength when the _{(P 45)} is 0.7～0.9N, and chip-type electronic component packaging carrier according to claim 3 difference _{P 45} and _{P 3} is equal to or less than 0.4N It is a tape system.

  The cover tape of the present invention is a cover tape in which the peel strength when peeling from the carrier tape is not easily affected by the peel speed, and the peel strength at the time of high-speed mounting is not abnormally increased even in the conventional peel strength management method, When the chip-type electronic component such as an IC is peeled off during mounting, the carrier tape system using the cover tape can prevent troubles such as the contents popping out or the cover tape being cut off.

  Hereinafter, the present invention will be described in detail. The cover tape of the present invention necessarily has a base material layer and an easily peelable heat seal layer. Here, “having” may be a two-layer structure of base material layer / heat seal layer, or a multilayer structure such as a base material layer / heat seal layer composed of two or more layers in which different materials are laminated. Means it may be.

  When the base material layer is a single layer, the base material layer is any of polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyolefin resins such as polypropylene, polyamide resins such as nylon, polystyrene resins, polyethylene resins and polycarbonate resins. A film formed from one or two or more thermoplastic resins, and biaxially stretched films of these resins can be suitably used. Furthermore, a biaxially stretched polyethylene terephthalate film is more preferable in terms of transparency and toughness.

  In the present invention, polystyrene resin means polystyrene, high impact polystyrene, styrene-butadiene copolymer or hydrogenated product thereof, styrene-isoprene copolymer or hydrogenated product thereof, graft copolymer of styrene and ethylene, Styrene-butene-butadiene copolymer, methacrylic acid and styrene copolymer, etc. are polymers having a styrene unit in the molecular chain in a molar ratio of 1/2 or more. Can be used.

  Polyethylene resins are low density polyethylene, linear low density polyethylene, ultra low density polyethylene, ethylene-α olefin, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl acrylate copolymer. A polymer, an ethylene-ethyl acrylate copolymer, an ethylene-propylene rubber or the like having an ethylene unit in a molecular chain in a molar ratio of 1/2 or more, and using one or a mixture of two or more thereof Can do.

  In the present invention, it is important to appropriately set the elastic modulus of the base material layer. That is, the base material layer film is 600 to 40000 MPa, more preferably 700 to 5000 MPa in the measurement of tensile elastic modulus based on JIS K-7127. If the tensile elastic modulus is less than 600 MPa, elongation easily occurs due to the stress at the time of peeling the cover tape, and if it exceeds 40000 MPa, the entire cover tape becomes rigid and handling properties are deteriorated.

  Thus, for the purpose of adjusting the elastic modulus of the base material layer and for the purpose of strengthening the adhesive strength between the base material layer film and the heat seal layer, a thermoplastic resin layer was formed on the base material layer film. Two substrate layers can be used. The resin used for this thermoplastic resin layer is not particularly limited as long as it is suitable for the above-mentioned purpose, but polyethylene is easy to obtain an effect corresponding to the above-mentioned purpose and is easy to form a layer. Series resins are preferable, and linear low-density polyethylene resins are more preferable. Further, a mixture layer of ethylene-α olefin and styrene-ethylene-butadiene copolymer or a mixture of ethylene-α olefin and low-density polyethylene is formed on the surface of the two-layered base material layer on the polyethylene resin layer side. It is also possible to form a base material layer having a three-layer structure in which a layer, a mixture layer of ethylene-α olefin and styrene-butadiene copolymer, or the like is laminated.

  When the base material layer has such a multi-layer structure, a commonly used adhesive can be used to strengthen the adhesive strength between the layers. Examples of the adhesive usually used include an isocyanate adhesive and an ethyleneimine adhesive. The adhesive layer preferably has a thickness of 5 μm or less. When exceeding 5 micrometers, there exists a possibility that the tensile elasticity modulus of a base material layer may become high and handling property may fall.

  In the base material layer of the present invention, various additives such as antioxidants and lubricants that are usually used are added in order to obtain extrusion stability when forming a film, as long as the properties of each layer are not impaired. Also good.

  The heat seal layer has a heat seal property with respect to the embossed tape, and is composed of a thermoplastic resin composition exhibiting easy peelability that can be easily peeled off during use. As the resin component, polystyrene resin (a) and polyethylene resin are used. It consists of a mixture of resin (b).

  As the polystyrene resin (a) used for the heat seal layer, polystyrene, high impact polystyrene, styrene-butadiene copolymer or hydrogenated product thereof, styrene-isoprene copolymer or hydrogenated product thereof, styrene and ethylene are used. A styrene unit such as a graft copolymer, a styrene-butene-butadiene copolymer, and a copolymer of methacrylic acid and styrene is included in the molecular chain, and one or a mixture of two or more of these can be used.

  Examples of the polyethylene resin (b) include low density polyethylene, linear low density polyethylene, ultra low density polyethylene, ethylene-α olefin, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene- It has an ethylene unit in the molecular chain such as methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-propylene rubber, and one or a mixture of two or more of these can be used.

  The selection and mixing ratio of the polystyrene-based resin (a) and the polyethylene-based resin (b) adjust the peel strength when peeling the cover tape heat-sealed to the embossed tape, and the heat seal layer. It is necessary to adjust suitably so that the tensile elasticity modulus of may become the range of 10-500 Mpa, Preferably it is 15-300 Mpa, More preferably, it is 15-200 Mpa. If the tensile elastic modulus of the heat-seal layer is less than 10 MPa, it may stretch when it is peeled off from the embossed carrier tape, which may hinder the removal of parts. If it exceeds 500 MPa, the heat-seal layer is hard. Therefore, the increase in peel strength at the time of high-speed peel intended by the present application becomes significant.

  The heat seal layer exhibiting such characteristics varies depending on the material of the embossed tape to be heat sealed, but when the embossed tape is a material described later, a styrene-butadiene copolymer and high impact polystyrene are used as the polystyrene-based resin (a). And 50 to 20% by mass of the polyethylene resin (b).

  Furthermore, the heat seal layer contains a fatty acid amide, which can suppress the dependency of the peel strength on the peel rate when peeling the cover tape heat sealed to the embossed tape. The fatty acid amide is not particularly limited, and ethylene bissteryl amide or erucic acid amide can be used. If the amount added is less than 0.05 parts by mass, the dependency on the peeling rate may not be able to be kept small. If the amount added exceeds 0.8 parts by mass, bleeding out from the heat seal layer becomes remarkable, and easy peel properties. May interfere. Moreover, the said effect can further be heightened by adjusting the surface roughness of a heat seal layer in the range which does not impair transparency.

  The heat seal layer can be formed by a general method, for example, a method of forming a film by extrusion molding such as inflation molding or T-die extrusion, and coating the base layer film by dissolving the resin in a solvent. For example, and by applying as an aqueous emulsion. When a film is formed by extrusion, a soft resin having a low tensile elastic modulus is extruded. Therefore, in order to enhance the extrusion stability, it is preferable to co-extrusion with a support layer. As the resin used for the support layer, a resin having high extrusion stability is preferably used. This support layer is a thermoplastic resin layer that is one layer of the multilayer base material layer in the cover film of the present invention, and preferably a low-density polyethylene resin or ethylene-α-olefin and styrene-ethylene-butadiene copolymer. A mixture mixture, a mixture layer of ethylene-α olefin and low density polyethylene, a mixture layer of ethylene-α olefin and styrene-butadiene copolymer, or the like can be used.

  The film for heat seal layer obtained by the extrusion molding can be laminated with a base material layer by a general method such as dry lamination or extrusion lamination to form a cover tape. In addition, in order to suppress adhesion (blocking phenomenon) between the heat seal layer and the base material layer, a filler is added as an anti-blocking agent within the range that does not impair the transparency, while the surface of the heat seal layer is drawn into the extruded film. By adjusting the surface roughness of the take-up roll at the time of removal, the surface roughness Ra value can be roughened within a range of 0.8 or less.

  The total thickness of the cover tape of the present invention is 40 to 75 μm. If it is less than 40 μm, it is easy to cut when the cover tape is peeled off at a high speed. .

  When used as a cover tape, it is preferable to impart antistatic performance to the base material layer and the sealant layer in order to prevent dust adhesion and dissipate the charged charge of the cover tape itself. A surfactant type, conductive metal oxide fine particles, or an electron conductive polymer can be used as a commonly used antistatic agent. These antistatic agents can be kneaded into the resin according to the performance to be expressed. However, in order to exhibit the effect efficiently, it is preferable to apply to both surface layers with a gravure coater or the like.

  The embossed tape referred to in the present invention is obtained by molding a pocket for housing an electronic component from a sheet-like molded product by a method such as a compressed air molding method or a vacuum molding method. And it is comprised from the 1 type, or 2 or more types of resin component of a polystyrene-type resin, a polycarbonate resin, and a polyester resin. These resins can be blended and used in a single layer configuration. For example, both surface layers may be a laminated structure such as a polycarbonate resin layer and the middle core may be a polystyrene resin layer. Further, for the purpose of preventing troubles caused by static electricity, an embossed tape having antistatic performance maintained can be used. In order to maintain the antistatic performance, an embossed tape kneaded with carbon black or an antistatic agent or an embossed tape coated on the surface is preferably used.

The carrier tape system as used in the present invention means that an electronic component is housed in the embossed tape as described above, the cover tape is heat sealed and covered, and the cover tape is peeled off by a mounting machine called a mounter while the component is mounted on the substrate This is a method for transporting / mounting electronic components to be mounted on the board. The average peel strength (P ₃ ) when the heat-sealed embossed tape and the cover tape are peeled off at a peeling speed of 300 mm / min is 0.3 to 0.5 N, and the average is peeled off at a peeling speed of 4500 mm / min. The peel strength (P ₄₅ ) is preferably 0.7 to 0.9 N, and the difference between P ₄₅ and P ₃ is preferably 0.4 N or less. By adopting such a carrier tape system in which the peel strength is less dependent on the peel speed, it is possible to cope with the recent increase in the mounting speed of electronic components. Further, it is very easy to assume the peel strength at the time of high-speed mounting based on the measurement value of peel strength at 300 mm / min defined in JIS C 0806, which has been conventionally performed.

The present invention will be described more specifically with reference to examples.
Example 1
60 parts by mass of a styrene-butadiene copolymer (Clearene 730L, manufactured by Denki Kagaku Kogyo Co., Ltd.), 30 parts by mass of linear low density polyethylene (Umerit, manufactured by Ube Industries) and 10 parts by mass of high impact polystyrene (HIPS H850, manufactured by Toyo Styrene Co., Ltd.) A 30 μm thick sealant layer made of a resin composition obtained by adding 0.15 parts by mass of stearic acid amide (Fatty Acid Amide S manufactured by Kao Corporation) to a resin comprising a biaxially stretched polyethylene terephthalate (hereinafter referred to as O-PET) film A cover tape made of a laminated base material layer of a polyester film (Toyobo Co., Ltd., thickness 12 μm) and a low density polyethylene film (L719, Ube Industries, Ltd., thickness: 20 μm) was prepared by extrusion lamination. In creating the base material layer, an isocyanate adhesive (EL557 manufactured by Toyo Morton Co., Ltd.) was applied to the O-PET film as an anchor coating agent in order to strengthen the adhesive strength. Further, a high molecular weight type antistatic agent (Bondip manufactured by Konishi Co., Ltd.) was applied to the surface of the base material layer and sealant layer at a thickness of 0.5 μm to impart antistatic properties. In addition, in order to obtain a test piece for measuring the tensile modulus of the base material layer, the low density polyethylene film was formed on the O-PET film in the same manner without using a heat seal layer, and separately laminated base material layer. Got only.

(Example 2)
The same procedure as in Example 1 was performed except that the thickness of the heat seal layer was 8 μm, the base layer O-PET was 16 μm, and the low density polyethylene was 38 μm.
(Example 3)
The same operation as in Example 1 was performed except that a biaxially stretched polypropylene film (thickness: 15 μm) was used for the base material layer.
(Example 4)
A base material layer in which an O-PET film (thickness: 12 μm) and a biaxially stretched nylon film (thickness: 15 μm) were bonded to the base material layer with an isocyanate adhesive and a low density polyethylene resin was laminated in the same manner as in Example 1 was used. Except that, the same procedure as in Example 1 was performed.

(Comparative Example 1)
The same operation as in Example 1 was performed except that the thickness of the O-PET of the base material layer was 5 μm.
(Comparative Example 2)
An O-PET film (thickness 8 μm) and a biaxially stretched nylon film (thickness 15 μm) were bonded to the base material layer with an isocyanate-based adhesive, and low density polyethylene was laminated to a thickness of 30 μm by extrusion coating. As the sealant layer, a layer having a thickness of 2 μm made of ethylene-butyl acrylate, ethylene-ethyl acrylate, and antimony-doped tin oxide was formed by gravure coating.

(Evaluation methods)
1. Measurement of tensile elastic modulus Using a film of a base material layer and a heat seal layer of each example and comparative example, using a dumbbell No. 4 piece according to JIS K-7127, measuring at a tensile speed of 50 mm / min, The evaluation results are shown in Tables 1 and 2.
2. Measurement of peel strength The cover tape produced in each Example and Comparative Example was heat-sealed to an embossed tape using a clearlen sheet C (manufactured by Denki Kagaku Kogyo Co., Ltd.). The heat sealing conditions are a seal iron temperature of 160 ° C., a seal iron width of 0.4 mm × 2, two times of sealing, and a seal pressure of 0.34 MPa. The measurement of peel strength was made by hand because there is no device that can be peeled off at 4500 mm / min with a commercially available device. In order to eliminate the difference between apparatuses, the self-made apparatus was designed so that the speed could be freely adjusted to 300 mm / min to 4500 mm / min. When peeling, the embossed tape was fixed to the support with double-sided tape, and the cover tape was peeled about 20 cm in length so that the peeling angle of the cover tape was 170 to 180 degrees. Tables 1 and 2 collectively show the results of evaluation at each peeling rate and the difference in peel strength.

Claims (4)

A cover tape having at least a base material layer and an easily peelable heat seal layer and having the following requirements.
(1) The total thickness of the cover tape is 40 to 75 μm.
(2) The base material layer has a thickness of 10 to 60 μm and a tensile modulus of 600 to 40000 MPa.
(3) The heat seal layer is composed mainly of a polystyrene resin (a) and a polyethylene resin (b) composed of a mixture of a styrene-butadiene copolymer and a high impact polystyrene , and the mixing ratio thereof is (a) 50 to 50 80 mass% (b) 50-20 mass%, and this heat seal layer is 0.05-0.8 mass part fatty acid amide with respect to a total of 100 mass parts of said (a) and (b). It has a thickness of 2 to 30 μm and a tensile modulus of 10 to 500 MPa. The cover tape according to claim 1, wherein the base material layer is composed of one or more resin components of polyester resin, nylon resin, polypropylene resin, polystyrene resin, polyethylene resin, and polycarbonate resin. 3. A chip-type electronic component packaging carrier tape comprising an embossed tape and the cover tape according to claim 1 or 2, wherein the embossed tape comprises one or more resin components of polystyrene resin, polycarbonate resin and polyester resin. system. The average peel strength (P ₃ ) when the heat-sealed embossed tape and the cover tape are peeled off at a peeling speed of 300 mm / min is 0.3 to 0.5 N, and the average is peeled off at a peeling speed of 4500 mm / min. peel strength _{(P 45)} is 0.7～0.9N, and chip-type electronic component packaging carrier tape system according to claim 3 difference _{P 45} and _{P 3} is equal to or less than 0.4 N.