Cover tape and electronic component packaging containing the same

Abstract

The object is to provide a cover tape in which the antistatic layer is prevented from falling off. [Solution] The cover tape has a base layer, a heat seal layer, and an antistatic layer on the side of the base layer opposite the heat seal layer, and the antistatic layer contains an acid-modified olefin resin and an antistatic agent.

Description

[Technical Field]

[0001] The present invention relates to a cover tape and an electronic component packaging body including the same. [Background technology]

[0002] With the miniaturization of electronic devices, the electronic components used have also become smaller and more high-performance. In addition, the assembly process of electronic devices now involves automatically mounting electronic components onto printed circuit boards. These chip-type surface-mount electronic components are housed in a carrier tape with a continuous series of thermoformed storage pockets that conform to the shape of the electronic components. After placing the electronic components in each storage pocket, a cover tape is placed on top of the carrier tape as a lid material, and both ends of the cover tape are continuously heat-sealed along its length using a heated sealing iron to create a package for the electronic components.

[0003] On the other hand, with the miniaturization of electronic components, problems in the mounting process are becoming more frequent, such as electronic components sticking to the cover tape and flying off due to static electricity generated when peeling the cover tape from the carrier tape in order to remove the electronic components. Therefore, static electricity countermeasures for carrier tape and cover tape have become an important issue. For example, Patent Document 1 proposes forming an antistatic layer on the base material layer side of the cover tape. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2013 / 054867 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] However, it was found that when an antistatic layer is formed on the base material layer side of the cover tape, during the heat sealing process to the carrier tape, the cover tape, when fed through the guide rolls of the sealing machine, rubs against the antistatic layer on the base material layer side and the guide rolls, which may cause the antistatic layer to detach and become foreign matter that could be mixed in. Therefore, the present invention aims to provide a cover tape in which the detachment of the antistatic layer is suppressed. [Means for solving the problem]

[0006] In response to the above-mentioned problems, the inventors of the present invention conducted thorough research and found that in a cover tape having a base layer, a heat-seal layer, and an antistatic layer on the side of the base layer opposite to the heat-seal layer, the detachment of the antistatic layer is suppressed by providing the antistatic layer with an acid-modified olefin resin and an antistatic agent.

[0007] In this disclosure, the following measures can be taken to solve the above problems. [1] A cover tape having a base layer, a heat seal layer, and an antistatic layer on the side of the base layer opposite to the heat seal layer, wherein the antistatic layer contains an acid-modified olefin resin and an antistatic agent. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a cover tape in which the detachment of the antistatic layer is suppressed. [Modes for carrying out the invention]

[0009] One embodiment of this disclosure will be described in detail below, but the scope of this disclosure is not limited to the embodiment described herein, and various modifications can be made without departing from the spirit of this disclosure. Each embodiment disclosed herein can be combined with any other features disclosed herein. Furthermore, if multiple upper and lower limits are given for a particular parameter, any combination of these upper and lower limits can be used to create a suitable numerical range. Also, the lower and / or upper limits of the numerical ranges described herein may be replaced with numerical values ​​within that range, as shown in the examples. The expression "X~Y" indicating a numerical range means "X or greater and Y or less". If a particular description given for one embodiment also applies to other embodiments, that description may be omitted in the other embodiments.

[0010] Each configuration and its combinations in each embodiment are examples, and configurations can be added, omitted, replaced, and otherwise modified as appropriate, without departing from the spirit of this disclosure. This disclosure is not limited by the embodiments. Each aspect disclosed herein can be combined with any other features disclosed herein.

[0011] [Cover tape] A first embodiment of this disclosure relates to a cover tape. The cover tape according to the first embodiment has a base layer, a heat seal layer, and an antistatic layer on the side of the base layer opposite to the heat seal layer. Furthermore, the antistatic layer contains an acid-modified olefin resin and an antistatic agent.

[0012] <Layer configuration> The cover tape according to the first embodiment has at least an antistatic layer, a base layer, and a heat seal layer in this order.

[0013] <Base material layer> The base material layer is a layer containing a thermoplastic resin, and is preferably composed of a film formed by forming a thermoplastic resin into a film. As the thermoplastic resin constituting the base material layer, polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyolefin resins such as polypropylene, polycarbonate resins, etc. are preferable. Further, it is more preferable that the base material layer is composed of a biaxially stretched film.

[0014] The average thickness of the base material layer is generally arbitrarily set from the range of 5 to 50 μm in consideration of the mechanical properties of the cover tape, etc. In one embodiment, the average thickness of the base material layer is preferably 5 to 30 μm, more preferably 8 to 20 μm, and even more preferably 10 to 16 μm. The measurement of the thickness of the layer is performed using a laser microscope (manufactured by KEYENCE: VK-8510) after cutting out 20 mm square sections at 5 locations at equal intervals in the width direction of the cover tape and smoothing the end faces so that the layer structure can be judged. The average thickness of the cover tape means the average value of the thickness from one surface of the cover tape to the other surface. The average thickness of each layer of the cover tape is measured at 5 locations for each layer, and the arithmetic average value thereof is taken as the average thickness.

[0015] At least one surface of the base material layer may be surface-treated. As the surface treatment, sandblast treatment, corona discharge treatment, plasma treatment, etc. can be adopted. In one embodiment, it is preferable that the surface on the side where the antistatic layer of the base material layer is laminated is surface-treated. By surface-treating the base material layer, the adhesion strength between the base material layer and the antistatic layer is likely to be improved. Further, an anchor coat layer may be provided on the surface on the antistatic layer side and / or the surface on the heat seal layer side of the base material layer. The anchor coat layer can be formed by applying an arbitrary anchor coating agent. As the anchor coating agent, polyurethane resin, polyester resin, polyolefin resin can be used.

[0016] <Heat seal layer> The heat seal layer contains a thermoplastic resin that exhibits heat-sealing properties to the carrier tape and is easily peelable during use. Preferred thermoplastic resins for the heat seal layer include ethylene-based resins such as polyethylene (e.g., low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), very low-density polyethylene (VLDPE), etc.), ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-butene-1 random copolymer; and styrene-based resins such as styrene-butadiene copolymer (SB), styrene-butadiene-styrene block copolymer (SBS) or its hydrogenated derivative (SEBS), polystyrene (PS), styrene-butadiene copolymer (SBC), and high-impact polystyrene (HIPS). These thermoplastic resins may be used individually or in combination of two or more.

[0017] In one embodiment, the heat seal layer preferably contains a styrene-based resin as its main component. In this disclosure, "contains a styrene-based resin as its main component" means that the styrene-based resin is present in an amount of more than 50% by mass relative to the total amount (100% by mass) of all resin components. The proportion of styrene-based resin in the heat seal layer is preferably more than 50% by mass and 100% by mass or less, more preferably 70 to 100% by mass, and particularly preferably more than 70% by mass and 100% by mass or less. In one preferred embodiment, the heat seal layer more preferably comprises at least one styrene resin selected from SB, SEBS, and SBC as its main component.

[0018] The average thickness of the heat seal layer is generally determined from the viewpoint of heat sealability with the carrier tape. In the cover tape according to the first embodiment, the average thickness of the heat seal layer is preferably 1 to 25 μm, more preferably 2 to 20 μm, and preferably 3 to 15 μm.

[0019] In one embodiment, the heat seal layer may contain one or more antistatic agents, as described later. By containing antistatic agents, the heat seal layer becomes a layer that possesses both heat sealability and antistatic properties.

[0020] <Antistatic layer> The antistatic layer is a layer provided on the side of the base layer opposite to the heat-seal layer. The antistatic layer contains an antistatic agent and an acid-modified olefin resin as a binder resin. By having an antistatic layer, the cover tape can be given an antistatic effect, making it easier to prevent dielectric breakdown of electronic components due to static electricity and preventing dust from adhering to the surface of the cover tape due to static electricity. The total content of the acid-modified olefin resin and the antistatic agent in the antistatic layer is preferably 50% by mass or more, may be 65% by mass or more, may be 75% by mass or more, may be 90% by mass or more, or may be 100% by mass. The average thickness of the antistatic layer is preferably 0.05 to 2.0 μm, more preferably 0.1 to 1.0 μm, and even more preferably 0.1 to 0.5 μm.

[0021] Acid-modified olefin resins are preferably copolymers having a structure in which an unsaturated carboxylic acid is randomly copolymerized or graft copolymerized with an olefin resin. Specific examples of olefin resins that form the backbone of acid-modified olefin resins include low-density polyethylene, high-density polyethylene, polypropylene, ethylene-butene-1 copolymer, ethylene-propylene copolymer, and polybutadiene. Unsaturated carboxylic acids are unsaturated carboxylic acids and their anhydrides that have at least one radical polymerizable bond (especially a double bond) and at least one carboxyl group in one molecule. Specific examples include acrylic acid, acrylic acid esters such as ethyl acrylate and butyl acrylate, methacrylic acid esters such as methacrylic acid, ethyl methacrylate and butyl methacrylate, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, and the like. The acid-modified olefin resin may contain two or more compounds as unsaturated carboxylic acids, with maleic anhydride and ethyl acrylate being preferred. When maleic anhydride and ethyl acrylate are included, the molar ratio of maleic anhydride to ethyl acrylate is preferably 1:2 to 1:25, preferably 1:3 to 1:20, and preferably 1:4 to 1:8.

[0022] In acid-modified olefin resins, the proportion of the acid-modified component is preferably 0.5 to 10 mol%, more preferably 0.8 to 5 mol%, and even more preferably 1 to 2 mol%, from the viewpoint of improving adhesion to the substrate layer.

[0023] The melting point of the acid-modified olefin resin is preferably 70 to 130°C, more preferably 80 to 120°C, and even more preferably 98 to 110°C. In one embodiment, the melting point of the acid-modified olefin resin is preferably 98°C or higher.

[0024] Acid-modified olefin resins can be produced by polymerizing a predetermined monomer using known methods such as interfacial polymerization, solution polymerization, or suspension polymerization, or they can be obtained commercially in the form of aqueous emulsions with water as the main dispersion medium or solutions with organic solvents as the main solvent. From the viewpoint of environmental compatibility, it is preferable to use acid-modified olefin resins in the form of aqueous emulsions. Aqueous emulsions of acid-modified olefin resins can be produced, for example, by the methods described in Japanese Patent Publication No. 3699935 and Japanese Patent Publication No. 3759160. Examples of commercially available products include the "Arrowbase (registered trademark)" products from Unitika Ltd., with product numbers SA-1200, SB-1200, SE-1200, and SB-1010. Such commercially available products are aqueous emulsions of acid-modified olefin resins. As the acid-modified olefin resin, two or more acid-modified olefin resins with different compositions, molecular weights, and / or melting points may be used. In this case, it is sufficient that each of the two or more acid-modified olefin resins falls within the range described above.

[0025] The antistatic agent is selected from the viewpoint of easily achieving the surface resistivity required for the cover tape. In one embodiment, the antistatic agent may be selected from magnesium silicate, metal oxide particles, and carbon nanotubes. Examples of metal oxide particles include tin oxide, zinc oxide, indium oxide, titanium oxide, aluminum oxide, and antimony-doped tin oxide (ATO). The average particle size of the antistatic agent is preferably 0.01 to 1 μm, more preferably 0.01 to 0.5 μm, and even more preferably 0.01 to 0.2 μm. The value obtained from the volume particle size distribution curve using a laser diffraction particle size analyzer (e.g., "LS-230" manufactured by Beckman Coulter) at 50% of the cumulative volume can be used as the average particle size of the antistatic agent. Examples of carbon nanotubes include single-walled carbon nanotubes (SWCNTs) formed from a single layer of graphene, and multi-walled carbon nanotubes (MWCNTs) formed from two or more layers of graphene (e.g., 2 to 20 layers, typically 2 to 60 layers).

[0026] Furthermore, when magnesium silicate or metal oxide particles are used, the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is preferably 1:9 to 5:5, more preferably 1:9 to 4:6, and even more preferably 1:9 to 3:7. Furthermore, when using carbon nanotubes, the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is preferably 70:30 to 99:1, more preferably 80:20 to 98:2, and even more preferably 90:10 to 97:3.

[0027] The antistatic layer may further contain wax. Suitable waxes include carnauba wax, rice wax, candelilla wax (derived from plants), paraffin wax, microcrystalline wax (derived from petroleum), and synthetic waxes such as olefin wax, ester wax, ketone wax, and amide wax, or any combination thereof. The wax content relative to the total components constituting the antistatic layer is preferably 5 to 50% by mass, more preferably 5 to 40% by mass, and even more preferably 5 to 20% by mass. The average particle size of the wax is preferably less than 4 μm, more preferably 0.05 to 3.5 μm, and even more preferably 0.08 to 3.2 μm. The 50% cumulative volume particle diameter measured using the Cole counter method can be used as the average particle diameter of the wax. When using a commercially available wax, the catalog value may be used as the average particle diameter.

[0028] In one embodiment, the cover tape has an antistatic layer, a base layer, an intermediate layer, a heat seal layer, and an antistatic heat seal layer in this order.

[0029] <Middle class> An intermediate layer may be provided to strengthen the adhesive strength between the base layer and the heat seal layer, and may contain a thermoplastic resin. (i) Polyethylene resins such as low-density polyethylene, linear low-density polyethylene, and ultra-low-density polyethylene (ii) Ethylene-1-butene, copolymers of ethylene and unsaturated carboxylic acids, ethylene-(meth)acrylic acid copolymers, ethylene-vinyl acetate copolymers, and terpolymers with acid anhydrides, and mixtures thereof. (iii) Styrene-ethylene graft copolymers, styrene-propylene graft copolymers, styrene-ethylene-butadiene block copolymers, and mixtures thereof These are some examples.

[0030] For the intermediate layer, polyethylene resin is preferred for the above-mentioned purposes and because it is easy to form the layer, and low-density polyethylene resin and linear low-density polyethylene resin are more preferred.

[0031] Furthermore, the intermediate layer may have a structure of two or more layers. In this case, by producing a co-extruded film of the heat seal layer and the intermediate layer, the extrusion stability of the heat seal layer can be increased, while the adhesion between the co-extruded film and the substrate layer can be improved by the other intermediate layer. The intermediate layer having a structure of two or more layers may, for example, be a first intermediate layer on the side in contact with the heat seal layer, containing one or more of the resins shown in (i), (ii), and (iii) above, and a second intermediate layer on the side in contact with the substrate layer, containing one or more of the resins shown in (i) and (ii) above. The formation of the intermediate layer can be carried out using general methods.

[0032] The intermediate layer may contain various additives, such as commonly used antioxidants and lubricants, from the viewpoint of obtaining extrusion stability when forming the film.

[0033] The thickness of the intermediate layer may be 3 to 70 μm, 5 to 60 μm, or 10 to 50 μm, from the viewpoint of ensuring the adhesive strength between the base layer and the heat seal layer and the peel strength of the cover tape.

[0034] (ii) or (iii) thermoplastic resin may be used as the anchor coating agent, in which case the average thickness of the layer is preferably 50 to 7000 nm, and more preferably 100 to 5000 nm.

[0035] <Antistatic heat seal layer> The cover tape according to the first embodiment may further include an antistatic heat seal layer. The antistatic heat seal layer may be provided on top of the heat seal layer. By having an antistatic heat seal layer, an antistatic effect can be imparted to the cover tape, making it easier to prevent the electronic components from being dielectric broken down by static electricity. Note that if the heat seal layer contains an antistatic agent, it is not necessary to provide an antistatic heat seal layer on top of the heat seal layer.

[0036] The antistatic heat seal layer is a layer containing an antistatic agent. The antistatic agent is selected from the viewpoint of easily achieving the surface resistivity required for the cover tape and easily achieving the aforementioned transmittance. In one embodiment, the antistatic agent may be selected from conductive fine particles such as barium sulfate, tin oxide, zinc oxide, indium oxide, titanium oxide, aluminum oxide, and antimond-doped tin oxide (ATO); ionic liquids containing cyclic quaternary nitrogen-containing cations; cationic surfactants such as quaternary ammonium salts; polyalkylene oxides (e.g., polyethylene glycol, polypropylene glycol, polybutylene glycol, ethylene oxide-propylene oxide copolymer, etc.), polyalkylene glycols such as polyether esters having a polyoxyalkylene structure and ester bonds.

[0037] As an ionic liquid containing a cyclic quaternary nitrogen-containing cation (hereinafter simply referred to as "ionic liquid"), from the viewpoint of easily achieving the aforementioned transmittance and easily imparting the desired antistatic properties, for example, 1,3-dimethylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium acetate, 1-butyl-3-dimethylimidazolium phosphate, 1,3-dimethylimidazolium hydrozine sulfate, etc. can be used.

[0038] As quaternary ammonium salts, from the viewpoint of easily achieving the aforementioned transmittance and easily imparting the desired antistatic properties, for example, trimethyl laurylammonium methyl sulfate, ethyl dimethyl stearylammonium ethyl sulfate, ethyl dimethyl oleylammonium ethyl sulfate, ethyl dimethyl laurylammonium ethyl sulfate, ethyl dimethyl stearylammonium metasulfonium, ethyl dimethyl laurylammonium metasulfonium, etc. can be used.

[0039] Furthermore, the antistatic heat seal layer may contain the antistatic agent and a binder resin. The binder resin can be polyurethane resin, acrylic resin, polyvinyl chloride resin, ethylene-vinyl acetate resin, polyester resin, butadiene resin, hydrogenated styrene resin, acrylic-modified polyester resin, etc., either alone or in combination of two or more.

[0040] If the cover tape includes an antistatic heat seal layer, it is preferable that it contains at least one selected from ionic liquid, ATO, and aluminum oxide. Furthermore, when incorporating the aforementioned preferred antistatic agent, the proportion of the antistatic agent is preferably 90% by mass or less of the total mass of the resin composition constituting the antistatic heat seal layer.

[0041] From the viewpoint of achieving both antistatic properties and the aforementioned transmittance, the average thickness of the antistatic heat seal layer is preferably 0.01 to 2.0 μm, and more preferably 0.1 to 0.7 μm.

[0042] (Total thickness of the cover tape) In the first embodiment, the total thickness of the cover tape is preferably 40 to 65 μm from the viewpoint of easily achieving the various physical properties required for the cover tape. Alternatively, the total thickness of the cover tape may be 40 to 60 μm, 45 to 60 μm, or 45 to 55 μm.

[0043] (Surface resistivity of the cover tape) In one embodiment, the surface resistivity of the antistatic layer side of the cover tape, measured in accordance with JIS K6911 at an ambient temperature of 23°C, ambient humidity of 50% RH, and applied voltage of 10V, is 1 × 10⁻⁶ 5 ~1 × 10 12 It is preferable that the ratio is Ω / □, and 2.5 × 10 5 ~5×10 11 It is more preferable that Ω / □ is 5 × 10 5 ~5×10 10 It is even more preferable that the ratio is Ω / □. The surface resistivity of the anti-static layer side of the cover tape after the friction test is preferably 1×10 13 Ω / □ or less, more preferably 1×10 10 Ω / □ or less, and even more preferably 1×10 8 Ω / □ or less. Also, the ratio of the surface resistivity of the anti-static layer side of the cover tape after the friction test to that before the friction test (after friction test / before friction test) is preferably 100 or less, more preferably 10 or less, and even more preferably 5 or less. The surface resistivity before and after the friction test can be measured as follows. Similar to the surface resistivity evaluation of the cover tape, measure the surface resistivity at an ambient temperature of 23°C and an ambient humidity of 50%RH (this value is taken as "before the friction test"). Then, at the measured location, rub the surface by moving a paper wipe and a 2 kg weight (shape: cylinder with a diameter of 70 mm) back and forth once under a load applied to the paper wipe (friction test). Measure the surface resistivity after the friction test in the same manner as before the friction test (this value is taken as "after the friction test").

[0044] The cover tape of the present disclosure exhibits anti-static performance even in a low humidity environment. In one embodiment, according to JIS K6911, the surface resistivity of the anti-static layer side of the cover tape measured at an ambient temperature of 23°C, an ambient humidity of 12%RH (low humidity environment), and an applied voltage of 10V is preferably 1×10 5 ~5×10 13 Ω / □, more preferably 2.5×10 5 ~2.5×10 13 Ω / □, and even more preferably 5×10 5 ~1×10 13 Ω / □.

[0045] <Method for manufacturing the cover tape> The cover tape according to the first embodiment can be manufactured by laminating the aforementioned layers (for example, an antistatic layer, a base layer, and a heat-seal layer). Below, one embodiment of a method for manufacturing a cover tape having an antistatic layer, a base layer, an intermediate layer, a heat-seal layer, and an antistatic heat-seal layer will be described.

[0046] The manufacturing method according to this embodiment includes laminating an antistatic layer, a base layer, an intermediate layer, a heat seal layer, and an antistatic heat seal layer. Preferably, the thermoplastic resin for each layer is selected. The lamination method is not particularly limited, and a general method can be used. For example, a resin composition constituting the intermediate layer and a resin composition constituting the heat seal layer are extruded from separate single-screw extruders and laminated in a multi-manifold die to form a two-layer film consisting of an intermediate layer and a heat seal layer. Furthermore, a base layer coated with an anchor coating agent on its surface and the two-layer film are laminated by a dry lamination method to form a three-layer film consisting of a base layer, an intermediate layer, and a heat seal layer. At this time, a second intermediate layer may be formed between the base layer and the two-layer film. Furthermore, an antistatic layer is formed by applying the resin composition constituting the antistatic layer to the surface of the base layer using, for example, a gravure coater, reverse coater, kiss coater, air knife coater, Meyer bar coater, dip coater, etc. Furthermore, it is preferable to perform corona discharge treatment or ozone treatment on the surface of the substrate layer before applying the resin composition constituting the antistatic layer, and corona discharge treatment is particularly preferable. In addition, the antistatic heat seal layer is formed by applying the resin composition constituting the antistatic heat seal layer to the surface of the heat seal layer using, for example, a gravure coater, reverse coater, kiss coater, air knife coater, Meyer bar coater, dip coater, etc.

[0047] Alternatively, a three-layer film consisting of a base layer, an intermediate layer, and a heat-seal layer is formed by sand lamination using a method similar to that described above. This method involves forming a heat-seal layer by T-die casting or inflation, a base layer with an anchor coating agent applied to its surface, and an intermediate layer formed by T-die casting. Furthermore, an antistatic layer and an antistatic heat-seal layer are formed using the same method as described above.

[0048] [Application] The cover tape according to the first embodiment can be used as a cover tape for electronic component packaging.

[0049] [Electronic component packaging] A second embodiment of this disclosure relates to an electronic component packaging. A package containing electronic components (hereinafter referred to as "electronic component package") can be obtained, for example, by placing electronic components in recesses on a carrier tape, then using a cover tape as a lid, and continuously heat-sealing both longitudinal edges of the cover tape using a hot iron or the like, before winding it onto a reel. Electronic components are stored and transported in this packaged form. The electronic component package according to the second embodiment can be used for storing and transporting various electronic components such as connectors, ICs, diodes, transistors, capacitors, resistors, and LEDs. Because the electronic component package according to the second embodiment includes the aforementioned cover tape, it is easier to suppress the inclusion of detached antistatic layers as foreign matter.

[0050] The electronic component packaging is transported using holes called sprocket holes, which are located along the longitudinal edge of the carrier tape, and the cover tape is intermittently peeled off. The electronic components are then removed by a component mounting device, which checks their presence, orientation, and position, and then mounted onto the circuit board.

[0051] The carrier tape included in the electronic component packaging according to the second embodiment is a strip-shaped material with a width of approximately 4 mm to 100 mm and having a recess for housing electronic components. When heat-sealing the cover tape according to the first embodiment as a lid material, the material constituting the carrier tape is not particularly limited, but carrier tapes containing polystyrene resin, polyester resin, or polycarbonate resin can be suitably used. The carrier tape may be one in which conductivity is imparted by kneading carbon black or carbon nanotubes into the resin, one in which a surfactant-type antistatic agent such as cationic, anionic, or nonionic, or a long-lasting antistatic agent such as polyether ester amide is kneaded into the resin, or one in which antistatic properties are imparted by applying a coating solution to the surface in which a surfactant-type antistatic agent or a conductive material such as polypyrrole or polythiophene is dispersed in an organic binder such as acrylic.

[0052] Furthermore, the electronic component packaging can be inspected with an IR camera over the cover tape to detect defects in the electronic components inside and to recognize circuits printed on the electronic components. The cover tape according to the first embodiment has high transmittance in the near-infrared region, so it is also easily visible by an IR camera.

[0053] A non-limiting list of exemplary embodiments and combinations of exemplary embodiments of this disclosure is provided below. [1] A cover tape having a base layer, a heat seal layer, and an antistatic layer on the side of the base layer opposite to the heat seal layer, A cover tape wherein the antistatic layer contains an acid-modified olefin resin and an antistatic agent. [2] The cover tape according to [1], wherein the acid-modified olefin resin is an olefin resin that has been acid-modified with an unsaturated carboxylic acid component. [3] The cover tape according to [1] or [2], wherein the melting point of the acid-modified olefin resin is 98°C or higher. [4] The cover tape according to any one of [1] to [3], wherein the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is 1:9 to 5:5. [5] The cover tape according to any one of [1] to [4], wherein the antistatic agent contains at least one material selected from the group consisting of magnesium silicate, metal oxide particles, and carbon nanotubes. [6] The surface resistivity of the antistatic layer side under a 23°C × 12%RH atmosphere is 10 13 A cover tape described in any of [1] to [5], which is less than or equal to Ω / □. [7] The cover tape according to any one of [1] to [6], wherein the antistatic layer further contains wax. [8] The cover tape according to [7], wherein the average particle size of the wax is less than 4 μm. [9] A cover tape according to any one of [1] to [8], having an antistatic layer, a base layer, an intermediate layer, a heat seal layer, and an antistatic heat seal layer in this order.

[10] Cover tape for electronic component packaging, as described in any of [1] to [9]. Electronic component packaging, including the cover tape described in any of

[11] [1] through

[10] . [Examples]

[0054] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0055] The various raw materials used in the examples are as follows: <Antistatic layer> • Antistatic agent 1: Magnesium silicate "Laponite S482" (manufactured by BYK), flake-shaped (short side: 1 nm, long side: 25 nm) • Antistatic agent 2: Tin oxide "Ceramase S-8" (manufactured by Taki Chemical Industry Co., Ltd.), aqueous dispersion • Antistatic agent 3: Phosphate-doped tin oxide "9747SN" (manufactured by Tokushiki Co., Ltd.), aqueous dispersion • Antistatic agent 4: Antimono dop tin oxide (ATO) "TDL-1" (manufactured by Mitsubishi Materials Electronic Chemicals Co., Ltd.), aqueous dispersion, average particle size 0.1 μm • Antistatic agent 5: Carbon nanotube "HW002B" (manufactured by KJ Special Paper Co., Ltd.), single-wall carbon nanotube aqueous dispersion, concentration 0.2% by mass • Acid-modified olefin resin 1: "Arrowbase (registered trademark) SD-1200" (manufactured by Unitika Corporation), aqueous dispersion, melting point 105℃ • Acid-modified olefin resin 2: "Arrowbase (registered trademark) SA-1200" (manufactured by Unitika Corporation), aqueous dispersion, melting point 100℃ • Acid-modified olefin resin 3: "Arrowbase (registered trademark) SE-1200" (manufactured by Unitika Corporation), aqueous dispersion, melting point 95℃ • Acid-modified olefin resin 4: "Arrowbase (registered trademark) SB-1200" (manufactured by Unitika Corporation), aqueous dispersion, melting point 85℃ • Acrylic resin 1: Acrylic copolymer aqueous dispersion "NK Polymer EC-242" (manufactured by Shin-Nakamura Chemical Co., Ltd.) • Polyester resin 1: Polyester aqueous dispersion, "Eritel (registered trademark) KA-3556" (manufactured by Unitika Corporation) • Wax 1: "Polylon L-618" (manufactured by Chukyo Oils Co., Ltd.), olefin wax aqueous dispersion, average particle size 0.1 μm • Wax 2: "Chemipearl W-100" (manufactured by Mitsui Chemicals, Inc.), olefin wax aqueous dispersion, average particle size 3.0 μm (Coulter counter method) • Wax 3: "Chemipearl W-400" (manufactured by Mitsui Chemicals, Inc.), olefin wax aqueous dispersion, average particle size 4.0 μm (Coulter counter method) Thickness: 0.2 μm

[0056] <Base material layer> • Polyester resin: Biaxially oriented polyethylene terephthalate "Ester Film E5100" (manufactured by Toyobo Co., Ltd.) Thickness: 16 μm • Anchor coating agent: Polyurethane resin (a reaction product of polyester resin ("LIOSTAR1000", manufactured by artience, Inc. (main component)) and a curing agent ("LIOSTAR500H", manufactured by artience, Inc.) mainly composed of hexamethylene diisocyanate / isophorone diisocyanate))

[0057] <Middle class> • Ethylene-based resin 1: Linear low-density polyethylene "Yumerit 0540F" (manufactured by Ube Maruzen Polyethylene Co., Ltd.) Thickness: 20 μm

[0058] <Heat seal layer> • Styrene-based resin 1: Styrene-butadiene rubber "TR" (manufactured by ENEOS Material Co., Ltd.) • Styrene-based resin 2: Styrene-butadiene copolymer "ClearLene" (manufactured by Denka Co., Ltd.) • Styrene resin 3: High-impact polystyrene "HIPS E640N" (manufactured by Toyo Styrene Co., Ltd.) • Ethylene-based resin 2: Ethylene-1-butene copolymer "Tafmer A" manufactured by Mitsui Chemicals, Inc. Thickness: 5 μm

[0059] <Antistatic heat seal layer> • Antistatic agent 6: Antimond-doped tin oxide "SN-100D" (manufactured by Ishihara Sangyo Co., Ltd.) • Acrylic resin 2: Acrylic copolymer "NK Polymer EC-242" (manufactured by Shin-Nakamura Chemical Co., Ltd.), glass transition temperature 60°C Thickness: 0.2~0.5μm

[0060] [Example 1] The cover tape of Example 1 was obtained using the resins and other materials listed in Table 1. Specifically, a resin composition for the heat seal layer was obtained by kneading and extruding at 210°C using a single-screw extruder. This resin composition and the polyethylene resin constituting the intermediate layer were extruded from separate single-screw extruders and laminated extruded at 225°C using a multi-manifold T-die extruder to obtain a two-layer film with a heat seal layer thickness of 5 μm and an intermediate layer thickness of 20 μm. On the other hand, a two-component curable polyurethane anchor coating agent was applied to a biaxially oriented polyethylene terephthalate film (16 μm thick) constituting the base layer using a roll coater, and a laminated film was obtained by bonding the coated surface to the surface of the intermediate layer of the two-layer film described above. Furthermore, an antistatic layer was applied to the base layer and dried. Then, an antistatic heat seal layer was applied to the heat seal layer and dried to obtain a cover tape.

[0061] [Examples 2-11, Comparative Examples 1-6] The materials were changed to those listed in Table 1, but otherwise the preparation was carried out in the same manner as in Example 1.

[0062] <Evaluation Method> The cover tapes prepared in each example and comparative example were evaluated as follows. The results are shown in Table 1. (1) Measurement of the surface resistivity of the cover tape Using a Highresta UX MCP-HT800 manufactured by Nitto Seiko Analytech Co., Ltd., the surface resistivity of the antistatic layer side surface of the cover tape was measured according to the JIS K6911 method, at an ambient temperature of 23°C, an ambient humidity of 50% RH or 12% RH (low humidity environment), and an applied voltage of 10V (500V was used if surface resistivity could not be obtained).

[0063] (2) Evaluation of adhesion between the substrate layer and the antistatic layer The surface resistivity was measured at an ambient temperature of 23°C and an ambient humidity of 50%RH, and this value was defined as "before the friction test." Next, at the measurement site, a 2kg weight (shaped: cylindrical with a diameter of 70mm) was applied to a JK Wiper "150-S" (paper rag) manufactured by Nippon Paper Crecia Co., Ltd. The paper rag and the weight were moved back and forth once to rub the surface, and the surface resistivity was measured again in the same manner as before the friction test, and this value was defined as "after the friction test." The criteria for evaluating adhesion are as follows: Good: Both the "before friction test" and "after friction test" measurements were 10. 13The friction coefficient is less than or equal to Ω / □, and the ratio of the friction coefficient after the friction test to the friction coefficient before the friction test ("after friction test" / "before friction test") is 100 or less. OK: Both the "before friction test" and "after friction test" measurements are 10. 13 The value is less than or equal to Ω / □, and the ratio of "after friction test" to "before friction test" ("after friction test" / "before friction test") is greater than 100. Unacceptable: The measurement value after the friction test is 10 14 Ω / □ or more

[0064] [Table 1]

[0065] As shown in Table 1, the cover tapes of Examples 1 to 11 obtained "Good" or "Acceptable" results in the adhesion evaluation, and even in low humidity environments, the surface resistivity was 10 13 It was confirmed that the value was less than or equal to Ω / □. On the other hand, in Comparative Examples 1 to 4, where resins other than acid-modified olefin resin were used as the resin for the antistatic layer, it was confirmed that the antistatic layer peeled off during the friction test, and the surface resistivity after the friction test was higher than that before the friction test. In Comparative Example 5, which did not contain an antistatic agent in the antistatic layer, the surface resistivity value was high even before the friction test. In Comparative Example 6, which did not include a binder resin in the antistatic layer, the antistatic layer was found to have peeled off during the friction test, and the surface resistivity after the friction test was found to be higher than before the friction test.

Claims

1. A cover tape having a base layer, a heat seal layer, and an antistatic layer on the side of the base layer opposite to the heat seal layer, A cover tape wherein the antistatic layer contains an acid-modified olefin resin having a melting point of 98°C or higher, and an antistatic agent, and does not contain wax with an average particle size of 4 μm or larger.

2. The cover tape according to claim 1, wherein the acid-modified olefin resin is an olefin resin modified with an unsaturated carboxylic acid component.

3. The cover tape according to claim 1, wherein the mass ratio of the acid-modified olefin resin to the antistatic agent in the antistatic layer is 1:9 to 5:

5.

4. The cover tape according to claim 1 or 2, wherein the antistatic agent contains at least one material selected from the group consisting of magnesium silicate, metal oxide particles, and carbon nanotubes.

5. The surface resistivity of the antistatic layer under a 23°C × 12% R.H. atmosphere is 10. １３ The cover tape according to claim 1 or 2, wherein the Ω / □ is less than or equal to Ω.

6. The cover tape according to claim 1 or 2, wherein the antistatic layer further contains wax having an average particle size of less than 4 μm.

7. The cover tape according to claim 1 or 2, comprising the antistatic layer, the base material layer, the intermediate layer, the heat seal layer, and the antistatic heat seal layer in this order.

8. A cover tape according to claim 1 or 2, for use in packaging for electronic components.

9. An electronic component packaging comprising the cover tape described in claim 1 or 2.

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