JP4438464B2 - Cover tape for packaging electronic parts - Google Patents

Description

  The present invention relates to a cover tape that can be heat-sealed out of a package having a function of protecting electronic components from contamination, arranging them for mounting on an electronic circuit board, and taking them out when storing, transporting, and mounting the electronic components. is there.

  In recent years, surface mount electronic components such as ICs, transistors, diodes, capacitors, and piezoelectric element resistors have been continuously equipped with trays and pockets that have embossed pockets that can be accommodated according to the shape of the electronic components. The carrier tape is supplied in the form of a package comprising a carrier tape formed in the above and a cover tape that can be heat sealed to the carrier tape. The electronic components of the contents are automatically taken out from the carrier tape after the tray and cover tape are peeled off and are surface-mounted on the electronic circuit board.

  The strength at which the cover tape is peeled off from the carrier tape is referred to as peel strength. However, if the strength is too low, there is a problem that the cover tape is detached and the electronic components as contents are dropped when the package is transferred. Conversely, if it is too strong, the carrier tape vibrates when the cover tape is peeled off, causing a phenomenon of jumping out of the storage pocket immediately before the electronic component is mounted, that is, a jumping trouble.

At present, the mechanism of the commercially available cover tape when it is peeled off from the carrier tape is classified into three types: interface peeling type, transfer peeling type and cohesive failure type. The interfacial peeling type peels off the sealing surface of the cover tape and the carrier tape, the transfer peeling type means that the heat sealant layer itself is transferred to the carrier tape at the time of peeling, and the cohesive failure type means heat. It is of a type that peels when another layer different from the sealant layer or the heat sealant layer itself (hereinafter referred to as sealant) is torn. Compared only with the state when peeling the cover tape heat-sealed to the carrier tape, each type has advantages and disadvantages, but the interface peeling type has the same sealing surface and peeling surface, so the influence of the shape, material, and properties of the carrier tape Easy to receive, peel strength becomes unstable and cheap. In the transfer peeling type, the adhesive layer needs to be a thin film because of the mechanism, so-called heat sealing lacquer must be used, and the peeling strength tends to be sensitive to the sealing temperature, making it difficult to obtain an appropriate peeling strength. In the cohesive failure type, the adhesive layer and the release layer are different, so the peel strength is less dependent on the sealing conditions. Further, it has a great advantage that it is not affected by the shape, material, and properties of the carrier tape. However, since a layer different from the heat sealant layer is involved during peeling, layers other than the heat sealant layer may peel off. Further, it is difficult to set the position at which the sealant breaks, and the heat sealant layer remains on the surface of the carrier tape at the time of peeling, and the contents cannot be taken out (hereinafter referred to as delamination). Since the sealant is designed to be easy to tear, it is often an alloy of multiple resins that are difficult to mix, and they may not be evenly mixed, which deteriorates the transparency of the cover tape or aggregates May make a fault. For example, when a composition of a block copolymer of polyethylene, polystyrene, elastomeric styrene-butadiene-styrene or styrene-isoprene-styrene shown in Patent Document 1 is used, formation of a heat sealant layer is poor in transparency. Therefore, the visibility in the inspection process after inserting a part in the pocket of a carrier tape and heat-sealing a cover tape worsens.
Japanese Patent No. 1347759

  In order to solve the above-described problems, an object of the present invention is to provide a cover tape having a peel strength that is less dependent on seal temperature and changes with time, has a stable seal, and is excellent in transparency.

The present invention
(1) A film composed of at least three layers of a heat sealant layer, an intermediate layer, and a base material layer, and the melt flow rate with respect to 100 parts by weight of polyethylene in which the melt flow rate of the intermediate layer is 10 to 30 g / 10 min. A cover tape for packaging electronic parts, comprising a resin composition to which 5 to 100 parts by weight of a methyl methacrylate-styrene copolymer having an amount of 10 to 60 g / 10 min is added, and having a haze of 40% or less ,
(2) A film comprising at least three layers of a heat sealant layer, an intermediate layer, and a base material layer, and the melt flow rate is 100 parts by weight of polyethylene with the melt flow rate of the intermediate layer being 10 to 30 g / 10 min. 5 to 100 parts by weight of methyl methacrylate-styrene copolymer having a rate of 10 to 60 g / 10 min, and 1 hydrogenated styrene-butadiene-styrene block copolymer having a melt flow rate of 30 to 250 g / 10 min A cover tape for packaging electronic parts, comprising a resin composition to which 50 parts by weight is added and having a haze of 40% or less,
(3) The cover tape for packaging electronic parts according to (1) or (2), wherein the base material layer is a film obtained by laminating at least one kind of polyester, polypropylene, and nylon biaxially stretched films,
(4) The intermediate layer is composed of one or more layers, and at least the intermediate layer adjacent to the heat sealant layer causes cohesive failure when being peeled after sealing, according to any one of (1) to (3) Cover tape for packaging electronic parts,
(5) An alloy containing 1 to 60 parts by weight of a filler having a particle size of 0.2 to 20 μm with respect to 100 parts by weight of a thermoplastic resin having a heat sealant softening temperature of 40 to 130 ° C. (1) to ( 4) Cover tape for packaging electronic parts according to any one of items
(6) The cover tape for packaging electronic parts according to (5), wherein the thermoplastic resin is polymethyl methacrylate or vinyl chloride-vinyl acetate copolymer,
(7) The filler is oxide particles mainly containing any one of silicon, magnesium and calcium, or any one of polyolefin particles, polyacrylate particles and polystyrene particles, or an alloy thereof (4 ) To (5), the electronic component packaging cover tape according to any one of
(8) The biaxially stretched film of the base material layer has a thickness of 5 to 30 μm, the intermediate layer has a thickness of 5 to 50 μm, and the heat sealant layer has a thickness of 0.2 to 3 μm (1) to (7 ) Cover tape for packaging electronic parts according to any one of
(9) The intermediate layer resin is formed so that the peel strength between the cover tape and the carrier tape in which the pockets for storing the electronic components are continuously formed is 10 to 120 cN per 1 mm of the seal width. The cover tape for electronic component packaging according to any one of (1) to (8),
It is.

  According to the present invention, the peel strength can be arbitrarily set within a range of 10 to 120 cN per mm, and the cover tape whose conventional peeling mechanism is interfacial peeling or the like has a large dependency on the sealing condition of the peel strength. Although there is a problem that changes with time depending on the storage environment, in the present invention, the peeling is caused by the cohesive failure mechanism, so that a stable peeling strength can be obtained. In addition, the delamination problem that the cohesive failure layer remains on the surface of the carrier tape at the time of peeling, and the problem of transparency inhibition caused by alloying a plurality of resins that are difficult to be compatible for cohesive failure can be solved.

  The components of the cover tape 1 of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing the layer structure of the cover tape of the present invention. FIG. 2 is a cross-sectional view showing the use state of the cover tape of the present invention heat-sealed to a carrier tape. The outer layer 2 is a biaxially stretched film made of polyester, polypropylene, or nylon, and has a thickness of 5 to 5. It is a 30 μm transparent and highly rigid film. If the thickness is 5 μm or less, the rigidity is lost and the cover tape is easily cut. If it exceeds 30μ, it is too hard and the seal becomes unstable.

The intermediate layer 3 includes one or more layers, and includes at least an intermediate layer 3B adjacent to the heat sealant layer as a layer that causes cohesive failure when peeled after sealing. In addition, the intermediate layer 3A may be included as a layer that can also serve as a cushion.
The intermediate layer 3B has 5 to 100 parts by weight of a methyl methacrylate-styrene copolymer having a melt flow rate of 10 to 60 g / 10 min and 100 parts by weight of polyethylene having a melt flow rate of 10 to 30 g / 10 min. A methyl methacrylate-styrene copolymer having a melt flow rate of 10 to 60 g / 10 min is 5 to 100 parts by weight of polyethylene having a certain alloy or a melt flow rate of 10 to 30 g / 10 min. It is a film having a thickness of 5 to 50 μm, comprising 100 parts by weight of an alloy of 1 to 50 parts by weight of a hydrogenated styrene-butadiene-styrene block copolymer having a melt flow rate of 30 to 250 g / 10 min. As the method for forming the intermediate layer, the extrusion laminating method is inexpensive and desirable from the viewpoint of hygiene. The melt flow rate of polyethylene is less than 10 g / 10 min, the melt flow rate of methyl methacrylate-styrene copolymer is less than 10 g / 10 min, or the melt flow rate of hydrogenated styrene-butadiene-styrene block copolymer is In the case of less than 30 g / 10 minutes, if an extrusion laminating method is used as a processing method, the film has low spreadability and an appropriate film cannot be formed. In addition, the melt flow rate of polyethylene exceeds 30 g / 10 min, the melt flow rate of methyl methacrylate-styrene copolymer exceeds 60 g / 10 min, or the hydrogenated styrene-butadiene-styrene block copolymer When the melt flow rate exceeds 250 g / 10 min, the necking is severe and an appropriate film cannot be formed. When the content of the methyl methacrylate-styrene copolymer is less than 5 parts by weight with respect to 100 parts by weight of polyethylene, cohesive failure of the intermediate layer does not occur. When the amount exceeds 100 parts by weight, mixing is worsened and film formation becomes impossible. If the content of the hydrogenated styrene-butadiene-styrene block copolymer is less than 1 part by weight with respect to 100 parts by weight of polyethylene, cohesive failure tends to occur, and the desired strength cannot be obtained. If it exceeds 50 parts by weight, the thickness of the film varies during extrusion lamination. If the thickness of the intermediate layer is less than 5 μm by the extrusion laminating method, the thickness variation is large, and an appropriate peel strength cannot be obtained during heat sealing. If it is 20 μm or more, delamination is likely to occur during peeling.

  The heat sealant layer 5 is made of an alloy containing 1 to 60 parts by weight of a filler having a particle size of 0.2 to 20 μm with respect to 100 parts by weight of polymethyl methacrylate or vinyl chloride-vinyl acetate copolymer, and has a thickness of 0. 2 to 3 μm. Although it does not specifically limit as a filler, Oxide particles which have any one of silicon, magnesium, and calcium as a main component, for example, silica, talc, etc., or any one of polyethylene particles, polyacrylate particles, polystyrene particles or These alloys are preferred. As a method for forming the layer, a gravure coating method is most desirable. Examples of polymethacrylate include methyl methacrylate-butyl methacrylate copolymer. This can change the softening temperature in the range of 40 to 130 ° C. by changing the copolymerization ratio. Examples of the vinyl chloride-vinyl acetate copolymer include those such as Dick Seal A-100Z series (manufactured by Dainippon Ink & Chemicals, Inc.). The softening temperature can be adjusted by the product number. If the softening temperature is less than 40 ° C, there is a possibility of blocking during storage of the cover tape, and if it exceeds 130 ° C, it is necessary to increase the temperature condition at the time of heat sealing, in which case the carrier tape itself may be damaged. .

  If the particle size of the filler is less than 0.2 μm or the number of added parts is less than 1 part by weight, when the cover tape is stored in a high temperature environment of 60 or more, a so-called blocking phenomenon that prevents unwinding occurs. Moreover, if the particle system of a filler exceeds 20 micrometers or an addition part number exceeds 60 weight part, transparency will deteriorate and cloudiness will exceed 40%. If the thickness of the heat sealant layer is less than 0.2 μm, it is extremely difficult to make the thickness constant, and it becomes impossible to obtain a stable peel strength. If the thickness exceeds 3 μm, cohesive failure occurs in the heat sealant layer, and peeling is also caused. The strength becomes unstable. In order to impart an antistatic effect, an antistatic treatment layer or a conductive layer may be provided on the outer layer side, that is, on the front and back surfaces of the biaxially stretched film.

  In this case, the resin of the heat sealant layer is formed so that the peel strength between the cover tape 1 and the carrier tape 6 is 10 to 120 gcN, more preferably 10 to 70 cN per 1 mm of the seal width. When the peel strength is lower than 10 cN, there is a problem in that the cover tape is removed during transportation of the package, and the electronic component as the contents falls off. On the other hand, if it is higher than 120 cN, the carrier tape vibrates when the cover tape is peeled off, causing a phenomenon of jumping out of the storage pocket immediately before mounting the electronic component, that is, a jumping trouble. According to the present invention, it is possible to obtain the desired performance with low dependency on the sealing conditions and little change with time in the peel strength due to the storage environment.

  Further, since the cover tape is configured to have a haze of 40% or less, preferably 35% or less, the internal electronic components sealed in the carrier tape can be confirmed visually or by a machine. If it is higher than 40%, it is difficult to confirm the electronic components inside.

Examples of the present invention are shown below, but the present invention is not limited to these examples.
A biaxially stretched polyester film with a film thickness of 25 μm is used as the outer layer, and the intermediate layer is formed into a film thickness of 30 μm by extrusion lamination method (extrusion temperature: 280 ° C.) according to the formulation shown in Tables 1 and 2, and heat sealant The layer was formed into a film thickness of 1 μm by a grabure coating method to obtain a cover tape having the layer structure shown in FIG.
After slitting the obtained cover tape to a width of 5.5 mm, heat sealing is performed with a carrier tape made of PET of 8 mm width, and when the cover tape is stored in an environment of peeling mechanism, peeling strength, haze and 60 ° C. The state was measured. The characteristic evaluation results are shown in Table 1 for the examples and Table 2 for the comparative examples.

The following symbols and display names in Tables 1 and 2 were used.
PE: Polyethylene MS: Methyl methacrylate-styrene copolymer SEBS: Styrene-ethylene-butadiene-styrene copolymer Vinyl acetate: Vinyl chloride-vinyl acetate copolymer Acrylic: Polymethyl methacrylate Talc: Talc Silica: Silicon dioxide Wax: Low molecular weight tetrafluoroethylene resin Crosslinked acrylic: Polymethylmethacrylate crosslinked particles Crosslinked styrene: Polystyrene crosslinked particles

  The present invention relates to a cover tape that can be heat-sealed out of a package having a function of protecting electronic components from contamination, arranging them for mounting on an electronic circuit board, and taking them out when storing, transporting, and mounting the electronic components. is there.

It is sectional drawing which shows the layer structure of the cover tape of this invention. It is sectional drawing which heat seals the cover tape of this invention to a carrier tape, and shows the use condition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cover tape 2 Outer layer 3 Middle layer 3A Layer which can also play a cushion role 3B Layer adjacent to heat sealant layer 4 Heat sealant layer 5 Sealing part 6 Carrier tape

Claims (9)

A cover tape for packaging electronic parts comprising at least three layers of a heat sealant layer, an intermediate layer, and a base material layer,
The intermediate layer polyethylene emissions 1 00 parts by weight of a melt flow rate 10 to 30 g / 10 min,
5 to 100 parts by weight of a methyl methacrylate-styrene copolymer having a melt flow rate of 10 to 60 g / 10 minutes,
And a resin composition to which 1 to 50 parts by weight of a hydrogenated styrene-butadiene-styrene block copolymer having a melt flow rate of 30 to 250 g / 10 minutes is added, and the haze is less than 30%. Cover tape for packaging electronic parts. Wherein the substrate layer is polyester, polypropylene, among the biaxially oriented film of nylon, for packaging electronic components cover tape according to claim 1, wherein the film laminated at least one kind of film. The intermediate layer is made of one or more layers, electrons according to any one of claims 1 to 3, characterized in that cause cohesive failure when the intermediate layer adjacent to at least the heat sealant layer is peeled off after sealing Cover tape for parts packaging. Claim 1-3 heat sealant layer is a filler 1 to 60 parts by weight inclusive alloy is the particle size of 0.2~20μm per 100 parts by weight of the thermoplastic resin is a softening temperature of 40 ° C. to 130 DEG ° C. The cover tape for electronic component packaging in any one of. The cover tape for packaging electronic parts according to claim 4, wherein the thermoplastic resin is polymethyl methacrylate or a vinyl chloride-vinyl acetate copolymer. 6. The filler is oxide particles mainly containing any one of silicon, magnesium and calcium, or any one of polyolefin particles, polyacrylate particles and polystyrene particles, or an alloy thereof. The cover tape for electronic component packaging as described. The thickness of the biaxially oriented film of the base layer is 5 to 30 [mu] m, the a thickness of the intermediate layer is 5 to 50 [mu] m, the thickness of the heat sealant layer is a is of Claims 1 to 6 0.2 to 3 .mu.m The cover tape for electronic component packaging in any one.  An electronic component package formed by heat-sealing a cover tape and a carrier tape in which pockets for storing electronic components are continuously formed,
An electronic component packaging cover tape, wherein the cover tape is the electrical component packaging cover tape according to any one of claims 1 to 7. The electronic component package according to claim 8, wherein the peel strength when peeling the cover tape from the carrier tape is 10 to 120 cN per 1 mm of the seal width.

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