JP2011225263A - Cover tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover tape having a preferable sealability to a carrier tape of a thermoplastic resin, causing no adhesion of an electronic part to the tape when being baked at 60-80°C in a heat-sealed state, and hardly causing the tape cut when peeling.SOLUTION: The cover tape includes at least a base material layer, an intermediate layer and a heat seal layer, and contains 25-50 pts.mass of an inorganic filler with a median diameter (D50) of less than 50 nm, and 20-60 pts.mass of the inorganic filler with a median diameter (D50) of 50-300 nm for 100 pts.mass of the thermoplastic resin which constitutes the heat seal layer and has an acid value of 1-20 mgKOH/g. The heat seal layer is preferably an acrylic resin with a glass transition temperature of 45-80°C, and with silica particles. The intermediate layer preferably contains straight chain low density polyethylene, with a melting point of 70-120°C.

Description

  The present invention relates to a cover tape used for a package of electronic parts.

Along with the miniaturization of electronic components, the electronic components used are also miniaturized and high-performance, and at the same time, components are automatically mounted on a printed circuit board in the assembly process of the electronic device. The surface-mounting electronic component is stored in a carrier tape in which embossed pockets that can be stored in accordance with the shape of the electronic component are interlocked. After storing the electronic components, a cover tape is stacked on the upper surface of the carrier tape as a cover material, and both ends of the cover tape are continuously heat-sealed in the length direction with a heated seal bar to form a package. As the cover tape, a biaxially stretched polyester film is used as a base material and a heat seal layer of a thermoplastic resin is laminated.

Electronic components such as ICs (integrated circuits), LSIs (large scale integrated circuits), and LEDs (light emitting diodes) packaged in sealing resin, etc., heat when soldering after mounting if the sealing resin absorbs moisture In the process, cracking of the sealing resin called solder cracks may occur, and it is necessary to perform a baking process in order to remove moisture contained in the sealing resin. In order to improve the mass productivity of such electronic components, it is necessary to increase the baking temperature and shorten the baking time. Recently, the cover tape is heat-sealed to the carrier tape in a 60 to 80 ° C. environment for about 24 to 72 hours. On the other hand, in order to heat-seal the carrier tape in a short time to improve productivity, the heat-seal layer, which is the outermost layer of the cover tape that is thermally bonded to the carrier tape, is softened at a low temperature. A plastic resin is used. For this reason, the conventional cover tape has a problem that the storage component adheres to the heat seal layer due to the baking treatment under the above conditions. In addition, the baking treatment increases the peeling strength when peeling the cover tape from the carrier tape, and the cover tape is broken.

As a countermeasure against component adhesion by baking treatment, a method in which 0.1 to 50% by mass of silica particles are added to an EVA heat seal layer so that fine particles protrude from the surface of the heat seal layer and the thermoplastic resin and the component do not come into contact with each other. Has been proposed (see Patent Document 1). However, although this method exhibits good sealing properties for paper carrier tapes, it is difficult to obtain sufficient heat sealing properties for carrier tapes made of thermoplastic resins such as polystyrene and polycarbonate. On the other hand, in the case of a cover tape used for a carrier tape made of a thermoplastic resin, a heat seal made of, for example, polymethacrylic acid, polyester, polyurethane, vinyl chloride-vinyl acetate copolymer resin or the like for the purpose of suppressing blocking of the cover tape A method of adding an inorganic filler such as silica to the layer has been proposed (see Patent Documents 2 and 3). However, these inventions did not consider the adhesion of the stored electronic component to the cover tape when the electronic component was stored in the carrier tape and baked at a temperature of 60 to 80 ° C. As for the problem at the time of baking the cover tape, there is an example of considering preventing the cover tape from being peeled off by baking (see Patent Document 4). It was not considered as an issue.
On the other hand, with the recent high-speed mounting of electronic components, there is a problem that the film breaks when peeling the cover tape from the carrier tape. As a countermeasure, a base material such as a biaxially stretched polyester film and a heat seal layer A method of providing a layer having excellent impact resistance and tear propagation resistance, such as polypropylene, nylon, and polyurethane, is proposed (see Patent Document 5). However, even when these methods are used, it is difficult to sufficiently suppress film breakage when the cover tape is peeled off from the carrier tape after the baking treatment.

JP 9-2079888 A Japanese Patent Laid-Open No. 9-201922 JP-A-10-95448 JP-A-8-244839 JP 2000-327024 A

The present invention has good sealability with a short heat seal against a carrier tape made of a thermoplastic resin such as polystyrene or polycarbonate, and at the same time baked at 60-80 ° C. with the cover tape heat sealed to the carrier tape. In such a case, the stored electronic component does not adhere to the cover tape, and when the cover tape is peeled off from the carrier tape after baking, it is possible to provide a highly transparent cover tape that does not easily break the tape. .

As a result of intensive studies on these problems, the present inventors have made the above-mentioned heat seal layer by adding an inorganic filler having a specific particle size distribution to a thermoplastic resin having an acid value in a specific range. The present inventors have found that the problem can be solved and have completed the present invention.
That is, the present invention comprises at least a base material layer, an intermediate layer, and a heat seal layer, and a median diameter (D50) with respect to 100 parts by mass of a thermoplastic resin having an acid value of 1 to 20 mgKOH / g constituting the heat seal layer. The cover tape is characterized in that it contains 25 to 50 parts by mass of an inorganic filler of less than 50 nm and 20 to 60 parts by mass of an inorganic filler having a median diameter (D50) of 50 to 300 nm. The thermoplastic resin constituting the heat seal layer is preferably an acrylic resin having a glass transition temperature of 45 to 80 ° C., and the inorganic filler is preferably silica particles. Further, the resin constituting the intermediate layer preferably contains linear low density polyethylene, and the melting point thereof is preferably 70 to 120 ° C., and the resin constituting the intermediate layer is a linear low polymer polymerized with a metallocene catalyst. Those containing density polyethylene are preferred.

On the other hand, the heat seal layer is composed of at least one of conductive tin oxide particles, conductive zinc oxide particles, conductive titanium oxide particles, carbon nanotubes, conductive polymers, polymer-based antistatic resins, antistatic agents, and ionic liquids. The surface resistance value of the surface of the heat seal layer is preferably 10 12 Ω or less. Furthermore, an acrylic resin or an ester resin containing at least one of conductive tin oxide particles, conductive zinc oxide particles, conductive titanium oxide particles, carbon nanotubes, and a conductive polymer between the intermediate layer and the heat seal layer A cover tape having a charge transfer layer made of an olefin resin is preferred.
The present invention includes an electronic component package using the cover tape as a cover material for a carrier tape made of a thermoplastic resin.

According to the present invention, it has good sealing properties with a short heat seal against a carrier tape made of a thermoplastic resin such as polystyrene or polycarbonate, and at the same time, the cover tape is baked at 60 to 80 ° C. while being heat sealed to the carrier tape. Even in such a case, it is possible to obtain a cover tape with good transparency in which the stored electronic component does not adhere to the cover tape, and when the cover tape is peeled off from the carrier tape after baking, the tape does not easily break.

The cover tape of the present invention comprises at least a base material layer, an intermediate layer, and a heat seal layer. The base material layer is a layer made of biaxially stretched polyethylene terephthalate (PET), polynaphthalate (PEN), or the like. As these base material layers, those obtained by applying or kneading an antistatic agent for antistatic treatment, or those subjected to corona treatment or easy adhesion treatment can be used. Moreover, when the thickness of these base material layers is too thin, the tensile strength of the cover tape is low, and when the cover tape is peeled off, a “film break” is likely to occur. On the other hand, if it is too thick, the adhesiveness of the cover tape tends to be lowered, and the cost is increased.

As the resin constituting the intermediate layer provided between the base material layer and the heat seal layer, polyethylene resin, polypropylene resin, ethylene-vinyl acetate random copolymer resin, ethylene-acrylate random copolymer resin, ethylene-methacrylate ester Examples include random copolymer resins, ethylene-α-olefin copolymer resins such as ethylene-1-butene random copolymer resins, etc., but linear low density that has particularly high flexibility and high rigidity and high tear strength at room temperature. The use of polyethylene (LLDPE) is preferred. LLDPE includes those polymerized with a Ziegler type catalyst (t-LLDPE) and those polymerized with a metallocene catalyst (m-LLDPE), but m-LLDPE has high tear strength. A cover tape using this resin for the intermediate layer is preferable in that the cover tape is less likely to be broken particularly when peeled from the carrier tape after baking.

  The m-LLDPE is a copolymer resin of ethylene with an olefin having 3 or more carbon atoms as a comonomer, preferably a linear, branched or aromatic nucleus substituted with 3 to 18 carbon atoms. Examples of the linear monoolefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, -Octadecene and the like. Examples of the branched monoolefin include 3-methyl-1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2-ethyl-1-hexene and the like. Moreover, styrene etc. are mentioned as a monoolefin substituted by the aromatic nucleus. These comonomers can be copolymerized with ethylene singly or in combination of two or more. In this copolymerization, polyenes such as butadiene, isoprene, 1,4-hexadiene, dicyclopentadiene, and 5-ethylidene-2-norbornene may be copolymerized. The α-olefin content in the copolymer resin is generally 1 to 20 mol%.

When LLDPE is used for the intermediate layer, the resin preferably has a melting point of 70 to 120 ° C., more preferably 80 to 110 ° C. When the melting point exceeds 120 ° C., the intermediate layer cannot be sufficiently softened when the cover tape is heat-sealed, so that the difference between the maximum value and the minimum value (range) when peeling the cover tape becomes too large. Sometimes. On the other hand, in the case of LLDPE having a melting point of less than 70 ° C., when the cover tape is heat-sealed, the intermediate layer tends to protrude from the end of the cover tape due to heat and pressure of the heat-seal, and the heat-sealing iron may become dirty. As for the thickness of this intermediate | middle layer, 10-50 micrometers is common, Preferably it is 10-40 micrometers. If the thickness of the intermediate layer is less than 10 μm, the total thickness of the cover tape is so thin that it may break at the time of peeling. If the thickness exceeds 50 μm, the heat of the heat seal iron reaches the heat seal layer because the total thickness of the cover tape is thick. It becomes difficult to obtain sufficient peel strength when the cover tape is heat sealed to the carrier tape.

The heat seal layer of the present invention has 25 to 50 parts by mass of an inorganic filler having a median diameter (D50) of less than 50 nm and a median diameter (D50) of 50 to 300 nm with respect to 100 parts by mass of a specific thermoplastic resin described later. It consists of a resin composition containing 20-60 parts by mass of an inorganic filler.

Examples of the thermoplastic resin constituting the heat seal layer include acrylic resins, ethylene vinyl acetate resins, styrene resins, and mixed resins and copolymer resins of two or more of these. And in this invention, it is important that the acid value of resin which comprises a heat seal layer exists in the range of 1-20 mgKOH / g. When the acid value of the resin constituting the heat seal layer is less than 1 mgKOH / g, the adhesion of the electronic component to the cover tape cannot be suppressed even when the electronic component is baked at a temperature of 60 to 80 ° C. On the other hand, if the acid value exceeds 20 mgKOH / g, sufficient peel strength cannot be obtained with respect to the polystyrene carrier tape.

The thermoplastic resin having an acid value of 1 to 20 mgKOH / g is prepared by copolymerizing a compound having a carboxyl group such as acrylic acid, methacrylic acid, and crotonic acid, as well as acrylic acid ester, methacrylic acid ester, and crotonic acid ester. In addition to the method of generating a carboxyl group by hydrolyzing to give an acid value, a method of hydrolyzing maleic acid after copolymerization can obtain a resin having an acid value adjusted to the above range, Commercially available resins can also be used.

As a resin component used for the heat seal layer, acrylic resin is extremely excellent in sealability when heat-sealed at low temperature and in a short time with respect to polystyrene, polycarbonate or the like which is a resin constituting the carrier tape. This is preferable in that an acid value resin can be obtained. In particular, an acrylic resin having a glass transition temperature of 45 to 80 ° C., more preferably 50 to 75 ° C. is less likely to cause electronic component adhesion in a temperature environment of 60 to 80 ° C. by adding an inorganic filler, and polystyrene. Excellent heat sealability for polycarbonate and polycarbonate materials.

As the acrylic resin constituting the heat seal layer, acrylic esters such as methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, It is a resin obtained by polymerizing one or more of α, β-ethylenically unsaturated monocarboxylic acids such as methacrylic acid esters such as cyclohexyl methacrylate and crotonic acid esters, and may be a resin obtained by copolymerizing two or more of these. .

The inorganic filler added to the heat seal layer of the present invention is an inorganic filler such as spherical or crushed talc particles, silica particles, alumina particles, mica particles, calcium carbonate, and magnesium carbonate. In particular, silica particles can be used more suitably because they can easily obtain the target particle size of the present application, have good dispersibility, and have little decrease in transparency when added to the heat seal layer.

It is more preferable to subject the inorganic filler, particularly silica fine particles, to surface treatment with at least one aliphatic oxide-modified polysiloxane selected from the group consisting of polysiloxane modified with propylene oxide or polysiloxane modified with ethylene oxide. By treating the surface of the inorganic filler with these polysiloxanes, the adhesiveness between the resin constituting the heat seal layer and the inorganic filler becomes stronger, so the mechanical strength of the heat seal layer can be improved, and the carrier A stable peel strength is easily obtained when the cover tape is peeled from the tape.

In the present invention, the inorganic filler having a median diameter (D50) of less than 50 nm is 25 to 50 parts by mass and the median diameter (D50) is 50 to 300 nm with respect to 100 parts by mass of the resin component as described above. It consists of a resin composition containing 20-60 parts by mass of an inorganic filler.
By containing an inorganic filler having the above particle diameter in the heat seal layer, not only can blocking be suppressed when the cover tape is wound, but also 60 to 60 for the purpose of removing moisture from the electronic components housed in the carrier tape. During the baking process at 80 ° C., it is possible to suppress adhesion of the storage component to the cover tape. Also, by adding fillers having different particle diameters, in addition to the effect of suppressing the adhesion of the storage component, it is possible to suppress a decrease in the transparency of the cover tape. Inspection of lead bending, etc. can be performed through the cover tape.

In the present invention, the heat seal layer includes at least conductive tin oxide particles, conductive zinc oxide particles, conductive titanium oxide particles, carbon nanotubes, conductive polymers, polymer-based antistatic resins, antistatic agents, and ionic liquids. By including one, the surface resistance value of the surface of the heat seal layer can be 10 12 Ω or less. As the conductive acid value tin particles, the conductive acid value zinc particles, and the conductive acid value titanium particles, spherical or needle-shaped particles can be used. For spherical ones, the weight average primary particle size is 300 nm or less, for acicular ones the minor axis is 300 nm or less, preferably for spherical ones the median diameter (D50) is 200 nm or less, and for acicular ones the minor axis is 200 nm. It is as follows. When the particle diameter or the short diameter exceeds 300 nm, the transparency of the cover tape is lowered, and it may be difficult to check the parts stored in the carrier tape through the cover tape. The addition amount is 100 to 1000 parts by mass, preferably 200 to 600 parts by mass with respect to 100 parts by mass of the thermoplastic resin constituting the heat seal layer. When the addition amount is less than 100 parts by mass, it is difficult to obtain a surface resistance value of 10 12 Ω or less even when conductive particles are added. Further, when the amount exceeds 1000 parts by mass, not only the cost is increased, but also the relative amount of the thermoplastic resin is reduced, so that it is difficult to obtain sufficient peel strength by heat sealing.

When using a carbon nanotube, the addition amount is 2 to 15 parts by mass, preferably 3 to 10 parts by mass with respect to 100 parts by mass of the thermoplastic resin constituting the heat seal layer. When the addition amount is less than 2 parts by mass, the effect of imparting conductivity by adding carbon nanotubes is not sufficient, while when it exceeds 15 parts by mass, not only the cost increases, but also the transparency of the cover tape decreases, It may be difficult to inspect the storage parts through the cover tape. The conductive polymer is polyaniline, polypyrrole, polythiophene, or the like. When the conductive polymer is used, the addition amount is 2 to 20 parts by mass with respect to 100 parts by mass of the thermoplastic resin constituting the heat seal layer. Preferably it is 3-10 mass parts. When the addition amount is less than 2 parts by mass, the effect of imparting conductivity by addition of the conductive polymer is not sufficient. On the other hand, when the addition amount exceeds 20 parts by mass, not only the cost increases, but also the transparency of the cover tape decreases. It may be difficult to inspect the storage parts through the cover tape.

Examples of the polymer antistatic agent include polystyrene sulfonic acid and acrylic resin having a quaternary ammonium base in the side chain. When using a polymer type antistatic resin, the addition amount is 20-100 mass parts with respect to 100 mass parts of the thermoplastic resin which comprises a heat seal layer, Preferably it is 30-60 mass parts. When the addition amount is less than 20 parts by mass, the effect of imparting conductivity due to the addition of the polymer antistatic resin is not sufficient. On the other hand, when it exceeds 100 parts by mass, not only the cost increases, but also polystyrene, polycarbonate, etc. It tends to be difficult to obtain sufficient peel strength by heat sealing to a plastic carrier tape. Various antistatic agents such as nonionic, cationic, anionic, and betaine can be used as the antistatic agent. When using antistatic resin, the addition amount is 0.5-5 mass parts with respect to 100 mass parts of thermoplastic resins which comprise a heat seal layer, Preferably it is 1-3 mass parts. When the amount added is less than 0.5 parts by mass, the effect of imparting conductivity due to the addition of the polymer antistatic resin is not sufficient, while when it exceeds 5 parts by mass, heat is applied to a plastic carrier tape such as polystyrene or polycarbonate. It becomes difficult to obtain a sufficient peel strength by the seal, and when the cover tape is peeled off, the peel strength varies easily. Various ionic liquids such as imidazolium, pyridinium, ammonium, phosphonium, and sulfonium can be used. When using ionicity, the addition amount is 0.5-10 mass parts with respect to 100 mass parts of thermoplastic resins which comprise a heat seal layer, Preferably it is 1-5 mass parts. When the addition amount is less than 0.5 parts by mass, the effect of imparting conductivity by adding the ionic liquid is not sufficient. On the other hand, when it exceeds 10 parts by mass, not only the cost increases, but also plastics such as polystyrene and polycarbonate It tends to be difficult to obtain sufficient peel strength by heat sealing to a manufactured carrier tape.

The dried thickness of the heat seal layer of the cover tape of the present invention is 0.1 to 5 μm, preferably 0.1 to 3 μm, and more preferably 0.15 to 0.5 μm. When the thickness of the heat seal layer is less than 0.1 μm, the heat seal layer may not exhibit sufficient peel strength. On the other hand, when the thickness of the heat seal layer exceeds 5 μm, the cost is likely to increase, and the peel strength tends to vary when the cover tape is peeled off.

In the present invention, a charge transfer layer may be provided between the intermediate layer and the heat seal layer. The charge transfer layer is made of an acrylic resin, an ester resin, or an olefin resin containing at least one of conductive tin oxide particles, conductive zinc oxide particles, conductive titanium oxide particles, carbon nanotubes, and a conductive polymer. Become. Acrylic resins include acrylic esters such as methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate, and methacrylic esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and cyclohexyl methacrylate. A resin obtained by polymerizing at least one of the above, or a resin obtained by copolymerizing two or more of these. Ester resins are resins obtained by condensation polymerization of dicarboxylic acids such as terephthalic acid, isophthalic acid, succinic acid, glutaric acid, and adipic acid, and dialcohols such as ethylene glycol, propylene glycol, butylene glycol, and cyclohexanedimethanol. It may be a resin obtained by copolymerizing two or more of these. A polyethylene elastomer obtained by condensation polymerization of dicarboxylic acid and polyethylene glycol can also be used. The olefin-based resin is a resin containing 50% by mass or more of an ethylene component, copolymerized with ethylene and methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and styrene-butadiene. A resin containing 50% by mass or more of an olefin component obtained by hydrogenating a copolymer can be preferably used.

The conductive tin oxide particles, conductive zinc oxide particles, conductive titanium oxide particles, carbon nanotubes, and conductive polymer used in the charge transfer layer are of the same type as the heat seal layer and used in the same amount. be able to. The thickness of the charge transfer layer is preferably 0.2-2 μm, more preferably 0.5-1.5 μm. When the thickness of the charge transfer layer is less than 0.2 μm, the electrostatic diffusion effect due to the charge transfer layer may not be sufficiently exhibited. On the other hand, if the thickness of the charge transfer layer exceeds 2 μm, the cost increases, and the transparency of the cover tape tends to decrease.

The method for producing the cover tape of the present invention is not particularly limited, and a general method can be used. For example, an anchor coating agent such as polyurethane, polyester, polyolefin, or polyethyleneimine is applied on the surface of the biaxially stretched polyethylene terephthalate film of the base material layer, and a resin composition mainly composed of m-LLDPE serving as an intermediate layer is formed as T. The film is extruded from a die and coated on the application surface of the anchor coating agent to form a two-layer film composed of a base material layer and an intermediate layer. Furthermore, the surface of the intermediate layer is coated with the resin composition constituting the heat seal layer of the present invention using, for example, a gravure coater, reverse coater, kiss coater, air knife coater, Mayer bar coater, dip coater, etc. Can be obtained. In this case, before coating, the intermediate layer surface is preferably subjected to corona treatment or ozone treatment, particularly preferably corona treatment.

As another method, the intermediate layer is formed into a film by the T-die casting method or the inflation method, and the biaxially stretched PET film is bonded to each film via an anchor coating agent such as polyurethane, polyester, or polyolefin. The target cover tape can also be obtained by a dry laminating method.

Furthermore, the target cover tape can be obtained also by the sand lamination method as another method. That is, the film constituting the intermediate layer 1 is formed by a T-die casting method or an inflation method. Next, between the intermediate layer film and the base layer film, a molten m-LLDPE resin composition as a main component is supplied to form the intermediate layer 2, and the base layer / intermediate layer 2 / intermediate layer A laminated film having the structure 1 is prepared. In this method, a cover tape is obtained by forming a heat seal layer on the surface of the intermediate layer 1 in the same manner as described above. In the case of this method as well, it is common to use an anchor coating agent coated on the surface on which the base layer film is laminated, as in the above method.

In addition to the above steps, if necessary, at least one surface of the cover tape can be subjected to antistatic treatment. Examples of antistatic agents include anionic, cationic, nonionic, and betaine surfactant antistatic agents, polymer antistatic agents, and conductive agents such as roll coaters and lippers using gravure rolls. Can be applied by coater, spray, etc. In order to uniformly apply these antistatic agents, the film surface is preferably subjected to a corona discharge treatment or an ozone treatment before the antistatic treatment, and a corona discharge treatment is particularly preferred.

  The cover tape is used as a cover material for a carrier tape that is a storage container for electronic components. The carrier tape is a belt-like object having a width of about 8 mm to 100 mm having a recess for accommodating electronic components. When heat-sealing using a cover tape as a lid material, the carrier tape material is not particularly limited, and commercially available materials can be used, for example, polystyrene, polyester, polycarbonate, polyvinyl chloride, and the like. Carrier tapes are those in which conductivity is imparted by kneading carbon nanotubes into the resin, those in which an antistatic agent or conductive filler is kneaded, or surfactant type antistatic agents or polypyrrole on the surface, An antistatic property can also be used by applying a coating liquid in which a conductive material such as polythiophene is dispersed in an organic binder such as acrylic.

The electronic component packaging body of the present invention is packaged by, for example, storing the electronic components in the electronic component storage portion of the carrier tape and then using the cover tape as a lid and continuously sealing both edges in the longitudinal direction of the cover tape. It is obtained by winding it on a reel. Electronic parts and the like are stored and transported by packaging in this form. An electronic component package containing electronic components, etc. is intermittently peeled off the cover tape while being conveyed by a feed hole provided at the longitudinal edge of the carrier tape, and the presence of the electronic components etc. by the pickup device, It can be taken out while checking the direction and position.

  Furthermore, when peeling off the cover tape, if the peel strength is too small, the cover tape may be peeled off and the stored parts may fall off. If it is too large, it will be difficult to peel off the carrier tape and the cover tape will be peeled off. Since there exists a possibility that a fracture | rupture may generate | occur | produce at the time of peeling work, what has a peeling strength of 0.05-1 N / mm is preferable when heat-sealing at 120-220 degreeC.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these.
The following resins and conductive materials were used as raw materials for the cover tapes of Examples and Comparative Examples of the present invention.
(Interlayer resin)
(a) -1: m-LLDPE: LL-UL (Futamura Chemical Co., Ltd.), thickness 40 μm, melting point 102 ° C.
(a) -2: m-LLDPE: UL-1 (manufactured by Tamapoli), thickness 40 μm, melting point 108 ° C.
(a) -3: t-LLDPE: GA807 (manufactured by Sumitomo Chemical Co., Ltd.), thickness 40 μm, melting point 117 ° C.
(a) -4: m-LLDPE: HR543 (manufactured by KF Film Co., Ltd.), thickness 40 μm, melting point 123 ° C.
In addition, about melting | fusing point of an intermediate | middle layer, it is the value measured according to the method of JISK7122.

(Charge transfer layer resin)
(b) -1: Resin composition 1: RMd-142 (manufactured by Solvex), polyester resin, 200 parts by mass of antimony-doped tin oxide per 100 parts by mass of polyester resin
(b) -2: Resin composition 2: AT-161SE-20 (manufactured by Unitika), maleic acid-modified ethylene-ethyl acrylate copolymer resin, containing 160 parts by mass of conductive tin oxide with respect to 100 parts by mass of resin (Conductive material blended in the charge transfer layer)
(C) Conductive filler 1: Pastoran (manufactured by Mitsui Mining & Smelting), spherical antimony-doped tin oxide, median diameter (D50) 20 nm

(Resin for heat seal layer)
(d) -1: Acrylic resin 1: Dianal BR-116 (manufactured by Mitsubishi Rayon Co., Ltd.), glass transition temperature 50 ° C., acid value 7 mg KOH / g
(d) -2: Acrylic resin 2: Dianal BR-106 (manufactured by Mitsubishi Rayon Co., Ltd.), glass transition temperature 50 ° C., acid value 3.5 mgKOH / g
(d) -3: Acrylic resin 3: Dianal BR-77 (manufactured by Mitsubishi Rayon Co., Ltd.), glass transition temperature 80 ° C., acid value 18.5 mgKOH / g
(d) -4: Acrylic resin 4: Dianal BR-84 (manufactured by Mitsubishi Rayon Co., Ltd.), glass transition temperature 105 ° C., acid value 6.5 mgKOH / g
(d) -5: Acrylic resin 5: Dianal BR-107 (manufactured by Mitsubishi Rayon Co., Ltd.), glass transition temperature 50 ° C., acid value 0 mgKOH / g
(d) -6: Acrylic resin 6: ARUFON UC-3000 (manufactured by Toa Gosei Co., Ltd.), glass transition temperature 65 ° C., acid value 74 mgKOH / g
(Inorganic filler added to heat seal layer)
(e) -1: Inorganic filler: NanoBYK3650 (manufactured by Big Chemie Japan), silica filler, median diameter (D50) 20 nm
(e) -2: Inorganic filler: MEK-ST-ZL (manufactured by Nissan Chemical Co., Ltd.), silica filler, median diameter (D50) 100 nm
(e) -3: Inorganic filler: MEK-ST-2040 (manufactured by Nissan Chemical Co., Ltd.), silica filler, median diameter (D50) 200 nm
(Conductive filler added to heat seal layer)
(f): Conductive filler: FSS-10M (manufactured by Ishihara Sangyo Co., Ltd.), acicular antimony-doped tin oxide, median diameter (D50) average major axis 2 μm, average minor axis 0.1 μm

Example 1
A thickness of 40 μm comprising [(a) -1: m-LLDPE] polymerized with a metallocene catalyst after coating a polyester anchor coating agent on the surface of a 12 μm thick biaxially stretched polyester film by a gravure method. Was laminated by a dry lamination method to obtain a laminated film composed of a biaxially stretched polyester layer and an m-LLDPE layer. The m-LLDPE surface of this film was subjected to corona treatment. A mixture obtained by adding 50 parts by mass of an antimony-doped tin oxide dispersed aqueous solution [conductive filler (c)] to 100 parts by mass of a polyester resin emulsion containing conductive tin oxide [(b) -1: resin composition]. The mixture was prepared, and applied to the surface of the laminated film on the corona treatment side by a gravure method so that the dry thickness was 0.2 μm, thereby forming a charge transfer layer. Furthermore, on the coating surface of the charge transfer layer, 100 parts by mass of a random copolymer resin of butyl methacrylate and methyl methacrylate [(d) -1: acrylic resin] as a heat seal layer, [(e) -1: By applying a solution obtained by dissolving 50 parts by mass of inorganic filler] and 20 parts by mass of [(e) -2: inorganic filler] in 2-butanone so as to have a thickness after drying of 0.6 μm, antistatic properties are obtained. A cover tape for carrier tape having a function was obtained.

(Examples 2-11, Comparative Examples 1-5)
A cover tape was prepared in the same manner as in Example 1 except that the resin or resin composition described in Table 1 or 2 was used as a raw material for the intermediate layer, the charge transfer layer, or the heat seal layer.

(Evaluation methods)
The evaluation shown below was performed about the cover tape for carrier tapes of the electronic component produced by each Example and each comparative example. These results are summarized in Tables 1 and 2.
(1) Haze value The haze value was measured using an integrating sphere type measuring device according to the measuring method A of JIS K 7105: 1998. The results are shown in the haze values in Tables 1 and 2.
(2) Baking resistance 50 electronic components (Stanley LED: 1.6 mm × 0.8 mm) were placed on the heat-seal layer surface of the cover tape stretched horizontally and placed in an 80 ° C. environment for 24 hours. After taking out from the 80 ° C environment, leave it in an atmosphere of 23 ° C and 50% relative humidity for 1 hour, and then turn the cover tape upside down in an atmosphere of 23 ° C and 50% relative humidity, so that the electronic components become cover tape. The number of adhered particles was counted. The number of parts attached to the cover tape is indicated as “excellent” if it is in the range of 0-5, “good” if it is in the range of 6-10, and “bad” if it exceeds 10 parts. did.
(3) Using a sealing taping machine (Shibuya Kogyo Co., Ltd., ETM-480), seal head width 0.5 mm × 2, seal head length 32 mm, seal pressure 0.1 MPa, feed length 4 mm, seal time 0.1 seconds × 8 times seal iron temperature from 140 ° C to 190 ° C at intervals of 10 ° C 5.5mm wide cover tape 8mm wide polycarbonate carrier tape (manufactured by Denki Kagaku Kogyo Co., Ltd.) and polystyrene carrier tape (Electrochemical Industry Co. Manufactured). After leaving for 24 hours in an atmosphere having a temperature of 23 ° C. and a relative humidity of 50%, the cover tape was peeled off at a speed of 300 mm / min and a peeling angle of 180 ° in an atmosphere having a temperature of 23 ° C. and a relative humidity of 50%. A sample having an average peel strength in the range of 0.3 to 0.9 N when heat-sealed at 140 ° C. and 190 ° C. seal iron temperature is defined as “excellent” and heat sealed at either 140 ° C. or 190 ° C. seal iron temperature. When the average peel strength was in the range of 0.3 to 0.9 N, “good” was indicated, and those having an average peel strength other than the above were indicated as “bad”.
(4) Low temperature sealing property Under the same conditions as the above (3) sealing property, heat resistance was applied to a polycarbonate carrier tape at 160 ° C. and a peel strength of 0.4 N or more was obtained. Those having a peel strength of 2N or more and less than 0.4N were judged as “good”, and those having a peel strength of less than 0.2N were judged “bad”.
(5) Cutting resistance after baking treatment (3) Under the same conditions as the sealing property, heat sealing is performed on the polystyrene carrier tape so that the peel strength is 0.5N, 1.0N, and 1.5N. It was put in a ℃ environment for 24 hours. After removal, the carrier tape with the cover tape sealed is left for 24 hours in an atmosphere with a temperature of 23 ° C and a relative humidity of 50%. Pasted. The cover tape was peeled off by 50 mm from the upper part of the affixed carrier tape, the cover tape was sandwiched between clips, and a weight having a mass of 1000 g was attached to the clip. After that, when the weight was naturally dropped, even if the initial peel strength was 1.5N, the cover tape was not cut off, “excellent”, and when the initial peel strength was 1.0N, the cover tape was not cut, “good”, peel strength Was observed as “bad” when cutting was observed at 1.0 N. In addition, the case where the seal temperature was 220 ° C. and the peel strength was less than 1.0 N was described as “not evaluated”.
(6) Surface Resistance Value Using a Hiresta UPMCP-HT450 manufactured by Mitsubishi Chemical Corporation, the surface resistance value of the heat seal layer was measured by the method of JIS K6911 at an ambient temperature of 23 ° C., an atmospheric humidity of 50% RH, and an applied voltage of 10V. The results are shown in the column of surface resistance values in Tables 1 and 2.

The cover tape of the present invention can be applied to various small electric parts in addition to electronic parts.

Claims (7)

An inorganic medium having a median diameter (D50) of less than 50 nm with respect to 100 parts by mass of a thermoplastic resin comprising at least a base material layer, an intermediate layer, and a heat seal layer, and having an acid value of 1 to 20 mgKOH / g. A cover tape comprising 25 to 50 parts by mass of a filler and 20 to 60 parts by mass of an inorganic filler having a median diameter (D50) of 50 to 300 nm.   The cover tape according to claim 1, wherein the thermoplastic resin constituting the heat seal layer is an acrylic resin having a glass transition temperature of 45 to 80 ° C., and the inorganic filler is silica particles. The cover tape according to claim 1 or 2, wherein the resin constituting the intermediate layer contains linear low-density polyethylene and has a melting point of 70 to 120 ° C. The cover tape according to claim 3, wherein the resin constituting the intermediate layer contains linear low-density polyethylene polymerized with a metallocene catalyst. The heat seal layer comprises at least one of conductive tin oxide particles, conductive zinc oxide particles, conductive titanium oxide particles, carbon nanotubes, conductive polymers, polymer-based antistatic resins, antistatic agents, and ionic liquids. The cover tape according to claim 1, wherein the cover tape has a surface resistance value of 10 12 Ω or less on the surface of the heat seal layer.   Acrylic resin, ester resin, olefin containing at least one of conductive tin oxide particles, conductive zinc oxide particles, conductive titanium oxide particles, carbon nanotubes, and conductive polymers between the intermediate layer and the heat seal layer The cover tape according to claim 1, wherein the charge transfer layer is made of a resin.   The electronic component packaging body which used the cover tape of any one of Claims 1-6 as a cover material of the carrier tape which consists of thermoplastic resins.