Cover tape and electronic component packaging material

Abstract

To provide a cover tape that can reduce a range of peel strength and an electronic component packaging material using the cover tape.SOLUTION: The cover tape comprises at least a base material layer and heat seal layer, and the heat seal layer has a loss tangent tan δ of less than 1 at temperatures below 150°C in dynamic viscoelasticity measurements at a measurement frequency of 1 Hz.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a cover tape and an electronic component package. [Background technology]

[0002] As electronic devices become smaller, the electronic components used are also becoming smaller and more powerful. In the assembly process of electronic devices, components are automatically mounted on printed circuit boards. To transport such surface-mount electronic components, electronic component packages are used in which electronic components are housed in a carrier tape in which pockets are thermally formed in succession to match the shapes of the electronic components so that the electronic components can be continuously supplied.

[0003] Electronic component packages are produced by placing electronic components in pockets of a carrier tape, overlaying a cover tape having a heat seal layer as a lid material on the top surface of the carrier tape, and continuously heat sealing both ends of the cover tape in the longitudinal direction with a heated sealing bar (see, for example, Patent Document 1).

[0004] When the electronic component package is used, the cover tape is peeled off from the carrier tape, and the electronic components are automatically removed and surface-mounted on an electronic circuit board. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-173673 A Summary of the Invention [Problem to be solved by the invention]

[0006] In recent years, electronic components have become significantly smaller, thinner, and lighter. During the process of mounting electronic components onto electronic circuit boards, if the difference between the maximum and minimum peel strength (hereinafter referred to as the "peel strength range") becomes too large when peeling the cover tape from the carrier tape, the carrier tape will vibrate violently, causing the electronic components to fly out, which can lead to mounting defects.

[0007] Therefore, the present inventors focused on the heat seal layer of the cover tape and investigated the design of the heat seal layer to narrow the peel strength range.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide a cover tape that can narrow the peel strength range, and an electronic component packaging body using the same. [Means for solving the problem]

[0009] In order to solve the above problems, one aspect of the present invention provides a cover tape having at least a base layer and a heat seal layer, in which the heat seal layer has a loss tangent tanδ of less than 1 in a temperature range of 150°C or less when measured using a dynamic viscoelasticity measurement frequency of 1 Hz.

[0010] The above-mentioned cover tape can be heat-sealed to a carrier tape as a lid material, and the peel strength range can be narrowed when peeled off after heat sealing, which makes it possible to prevent electronic components from popping out when the cover tape is peeled off from an electronic component package in the manufacture of electronic devices, thereby preventing poor mounting on an electronic circuit board.

[0011] From the viewpoint of ensuring the seal strength, the heat seal layer may contain a polystyrene-based resin and one or more resins selected from the group consisting of a polyethylene-based resin and an acrylic-based resin.

[0012] In order to narrow the peel strength range, the heat seal layer may have a ratio [G'(30) / G'(150)] of the storage modulus G'(30) at 30°C to the storage modulus G'(150) at 150°C, in dynamic viscoelasticity measurement at a measurement frequency of 1 Hz, of 800 or less.

[0013] From the viewpoint of blocking resistance and reduction of the peel strength range, the heat seal layer has a storage modulus G'(30) of 1.0×10 at 30° C. in dynamic viscoelasticity measurement at a measurement frequency of 1 Hz. 6 Pa or more 1.0×10 8 It may be less than Pa.

[0014] Another aspect of the present invention provides an electronic component packaging body comprising a carrier tape having a storage section, an electronic component stored in the storage section of the carrier tape, and the above-mentioned cover tape heat-sealed to the carrier tape as a lid material.

[0015] The electronic component package described above can have a narrow range of peel strength when the cover tape is peeled off, which can significantly reduce the mounting defect rate of electronic components in the manufacture of electronic devices. Effect of the Invention

[0016] According to the present invention, it is possible to provide a cover tape capable of narrowing the peel strength range, and an electronic component package using the same. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic cross-sectional view showing an embodiment of a cover tape. [Diagram 2] 1 is a partially cutaway perspective view showing one embodiment of an electronic component package. [Diagram 3] FIG. 1 is a diagram illustrating a peel strength range. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Preferred embodiments of the present invention will now be described in detail.

[0019] [Cover tape] The cover tape of this embodiment includes at least a base layer and a heat seal layer.

[0020] FIG. 1 is a schematic cross-sectional view showing an embodiment of a cover tape. The cover tape 50 shown in FIG. 1(a) includes a base layer 1, a heat seal layer 2 provided on one side of the base layer 1, and an intermediate layer 3 provided between the base layer 1 and the heat seal layer 2. The cover tape 52 shown in FIG. 1(b) includes two intermediate layers 3a and 3b provided between the base layer 1 and the heat seal layer 2. The cover tape of this embodiment may have a two-layer structure without an intermediate layer, or may have a structure further including a layer such as an antistatic layer on the opposite side of the base layer 1 from the heat seal layer 2. The cover tape of this embodiment may also have a structure further including a layer such as an antistatic layer on the opposite side of the base layer 1 from the heat seal layer 2, as long as the heat sealability of the heat seal layer is not impaired.

[0021] (base material layer) The substrate layer may be a film formed from a resin composition containing one or more thermoplastic resins selected from the group consisting of polyester resins such as polyethylene terephthalate and polyethylene naphthalate, polyethylene resins, polyolefin resins other than polyethylene resins such as polypropylene, polyamide resins such as nylon, polystyrene resins, and polycarbonate resins. From the viewpoint of mechanical strength, these films are preferably biaxially oriented films, and from the viewpoints of transparency and toughness, more preferably biaxially oriented polyethylene terephthalate films.

[0022] Examples of polystyrene resins include polymers having a molar ratio of 1 / 2 or more of styrene units in the molecular chain, such as polystyrene, high impact polystyrene (HIPS: high impact polystyrene), styrene-butadiene copolymer or its hydrogenation product, styrene-isoprene copolymer or its hydrogenation product, graft copolymer of styrene and ethylene, styrene-butene-butadiene copolymer, copolymer of methacrylic acid and styrene, etc. These can be used alone or in combination of two or more (mixture).

[0023] Examples of polyethylene resins include those having ethylene units in a molecular chain at a molar ratio of 1 / 2 or more, such as low-density polyethylene, linear low-density polyethylene, very low-density polyethylene, ethylene-α-olefin, ethylene-vinyl acetate copolymer, ethylene-(meth)acrylic acid copolymer, ethylene-methyl (meth)acrylate copolymer, ethylene-ethyl (meth)acrylate copolymer, ethylene-propylene rubber, etc. These can be used alone or in combination (mixture) of two or more.

[0024] In order to obtain extrusion stability during film formation, the base layer may contain various additives such as commonly used antioxidants and lubricants.

[0025] The substrate layer may be a single layer or may have a multi-layer structure.

[0026] The thickness of the base layer may be 5 to 100 μm, 10 to 80 μm, or 12 to 30 μm, from the viewpoints of mechanical strength and heat conductivity during heat sealing.

[0027] (Middle class) The intermediate layer can be provided for the purpose of strengthening the adhesive strength between the base layer and the heat seal layer, and can contain a thermoplastic resin. Examples of the thermoplastic resin include: (i) Polyethylene resins such as low-density polyethylene, linear low-density polyethylene, and very low-density polyethylene (ii) Ethylene-1-butene, copolymers of ethylene and unsaturated carboxylic acids, ethylene-(meth)acrylic acid ester copolymers, ethylene-vinyl acetate copolymers, and further terpolymers with acid anhydrides, and mixtures thereof (iii) Styrene-ethylene graft copolymers, styrene-propylene graft copolymers, styrene-ethylene-butadiene block copolymers, and mixtures thereof. etc.

[0028] As the thermoplastic resin, from the viewpoints of the above-mentioned purpose and ease of layer formation, a polyethylene-based resin is preferred, and a low-density polyethylene resin or a linear low-density polyethylene resin is more preferred.

[0029] The intermediate layer may have a structure of two or more layers. In this case, the heat seal layer and the intermediate layer are co-extruded to improve the extrusion stability of the heat seal layer, while another intermediate layer can improve the adhesion between the co-extruded film and the base layer. The intermediate layer having a structure of two or more layers may be, for example, a first intermediate layer on the side in contact with the heat seal layer, which contains 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 base layer, which contains one or more of the resins shown in (i) and (ii) above.

[0030] In order to obtain extrusion stability during film formation, the intermediate layer may contain various additives such as commonly used antioxidants and lubricants.

[0031] 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.

[0032] The cover tape of the present embodiment may have two or more base layers and / or intermediate layers. For example, the base layer and intermediate layer of such a cover tape may have a three-layer structure of base layer / intermediate layer / base layer, or a four-layer structure of intermediate layer / base layer / intermediate layer / base layer.

[0033] When the cover tape of the present embodiment has two or more base layers and / or intermediate layers, a known adhesive can be used to strengthen the adhesive strength between the layers. Examples of the adhesive include isocyanate-based adhesives and ethyleneimine-based adhesives. The adhesive layer preferably has a thickness of 5 μm or less in order to prevent the cover tape from having a large variation in peel strength.

[0034] (Heat seal layer) The heat seal layer can be formed from a resin composition containing a resin such as a polystyrene-based resin, a polyethylene-based resin, or an acrylic-based resin.

[0035] From the viewpoint of narrowing the peel strength range, the heat seal layer can be provided so that in dynamic viscoelasticity measurement at a measurement frequency of 1 Hz, the loss tangent tan δ in a temperature range of 150° C. or less is less than 1. In addition, the heat seal layer may have a peak temperature of the loss tangent tan δ of 150° C. or less in dynamic viscoelasticity measurement at a measurement frequency of 1 Hz.

[0036] The loss tangent tan δ in the dynamic viscoelasticity measurement of the heat seal layer is determined as follows. (i) The resin composition constituting the heat seal layer is formed into a sheet having a thickness of about 1 to 2 mm to prepare a measurement sample. (ii) For the measurement sample, dynamic viscoelasticity measurement is carried out under the following conditions using a rheometer to determine the loss tangent tan δ. [Measurement conditions] Measurement device: Rheometer DHR-2 (manufactured by TA Instruments, Inc.) Measurement mode: Shear mode Measurement jig: Parallel plate φ8mm Frequency: 1Hz Distortion: 0.05% Heating rate: 5℃ / min Measurement temperature: 25~200℃

[0037] The present inventors speculate as follows about the reason why the peel strength range can be narrowed by making the heat seal layer satisfy the above-mentioned condition of the loss tangent tan δ. First, it has been found that when a cover tape with a large peel strength range is heat-sealed with a sealing iron set at normal temperature conditions (for example, about 140°C), the adhesive area tends to be wider than the width of the sealing iron. In such an adhesive area, the adhesive strength of the area protruding from the area pressed by the sealing iron is likely to vary, which is thought to be the cause of the large peel strength range. On the other hand, the loss tangent tan δ is defined as G'' / G' by the storage modulus G' and loss modulus G'' obtained by dynamic viscoelasticity measurement. The fact that tan δ defined by G'' / G' is less than 1 in a temperature range of 150°C or less means that the elastic property is dominant over the viscosity, and the adhesive area is unlikely to spread during heat sealing. It is thought that the cover tape having a heat seal layer that exhibits such behavior can reduce the area of ​​the protruding area described above when heat-sealed with a sealing iron, thereby reducing the peel strength range.

[0038] In order to narrow the peel strength range, the heat seal layer may have a ratio [G'(30) / G'(150)] of the storage modulus G'(30) at 30°C to the storage modulus G'(150) at 150°C in dynamic viscoelasticity measurement at a measurement frequency of 1 Hz of 800 or less, or may be 100 to 600.

[0039] From the viewpoint of blocking resistance and reduction of peel strength range, the heat seal layer is designed to have a storage modulus G'(30) of 1.0×10 at 30°C in dynamic viscoelasticity measurement at a measurement frequency of 1 Hz. 6 Pa or more 1.0×10 8 Pa, and may be less than 5.0 x 10 6 Pa or more 1.0×10 8 Pa, and may be less than 5.0 x 10 6 Pa or more 5.0×10 7 It may be less than Pa.

[0040] From the viewpoint of ensuring the seal strength, the heat seal layer may contain one or more resins selected from the group consisting of a polystyrene resin (hereinafter sometimes referred to as component (A)), a polyethylene resin (hereinafter sometimes referred to as component (B)), and an acrylic resin (hereinafter sometimes referred to as component (C)). In addition, a cover tape having such a heat seal layer can easily ensure the sealability to carrier tapes made of various materials, such as a polystyrene carrier tape or a polycarbonate carrier tape.

[0041] The heat seal layer can contain, as the component (A), a copolymer of a styrene-based hydrocarbon and a conjugated diene-based hydrocarbon, and high-impact polystyrene, or may contain a mixture of these.

[0042] Examples of styrene-based hydrocarbons include styrene, α-methylstyrene, various alkyl-substituted styrenes, etc. Examples of conjugated diene-based hydrocarbons include butadiene, isoprene, etc.

[0043] The (A) component can include a block copolymer (A-1) (hereinafter sometimes referred to as the (A-1) component) of 10% by mass or more and less than 50% by mass of styrene-based hydrocarbons and more than 50% by mass and less than 90% by mass of conjugated diene-based hydrocarbons, and a block copolymer (A-2) (hereinafter sometimes referred to as the (A-2) component) of 50% by mass or more and 95% by mass or less of conjugated diene-based hydrocarbons and 5% by mass or more and 50% by mass or less of conjugated diene-based hydrocarbons.

[0044] Examples of the (A-1) component include styrene-butadiene copolymer, styrene-butylene-butylene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, styrene-ethylene-propylene-styrene copolymer, and styrene-isoprene-styrene copolymer. The (A-1) component may be used alone or in combination of two or more.

[0045] The mass ratio of the styrene-based hydrocarbon to the conjugated diene-based hydrocarbon in the component (A-1) may be from 10 / 90 to 45 / 55, from the viewpoint of easy adjustment of the peel strength and from the viewpoint of film formability, it may be from 30 / 70 to 45 / 55, or it may be from 35 / 75 to 45 / 55.

[0046] From the viewpoint of reducing the peel strength range, the content of the (A-1) component may be 20 to 65 mass%, 35 to 60 mass%, 40 to 55 mass%, or even 40 to 50 mass%, based on the total amount of the heat seal layer.

[0047] Examples of the (A-2) component include styrene-butadiene copolymer, styrene-butylene-butylene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, styrene-ethylene-propylene-styrene copolymer, and styrene-isoprene-styrene copolymer. The (A-2) component may be used alone or in combination of two or more.

[0048] The mass ratio of the styrene-based hydrocarbon to the conjugated diene-based hydrocarbon in the component (A-2) may be 50 / 50 to 95 / 5, 70 / 30 to 90 / 10, or 80 / 20 to 85 / 15.

[0049] From the viewpoint of reducing the peel strength range, the mass ratio of the component (A-2) to the component (A-1) can be 0.3 to 2.0, 0.30 to 1.0, or alternatively 0.50 to 0.90, or may be 0.65 to 0.85.

[0050] From the viewpoints of film formability and blocking resistance of the film, the total content of the (A-1) component and the (A-2) component in the heat seal layer may be 50 to 100 mass%, 50 to 95 mass%, 50 to 90 mass%, 60 to 100 mass%, 60 to 95 mass%, 60 to 90 mass%, or 70 to 90 mass%, based on the total amount of the heat seal layer.

[0051] When the heat seal layer contains the (A-1) component, the (A-2) component, and impact resistant polystyrene (hereinafter sometimes referred to as the (A-3) component), the respective contents may be 30 to 60 parts by mass of the (A-1) component, 20 to 60 parts by mass of the (A-2) component, and 1 to 20 parts by mass of the (A-3) component, or may be 35 to 60 parts by mass of the (A-1) component, 20 to 40 parts by mass of the (A-2) component, and 5 to 15 parts by mass of the (A-3) component, relative to 100 parts by mass in total of the (A-1) component, the (A-2) component, and the (A-3) components.

[0052] The content of component (A) in the heat seal layer may be 50 to 100 mass%, 50 to 95 mass%, 60 to 100 mass%, 60 to 95 mass%, or 70 to 95 mass%, based on the total amount of the heat seal layer.

[0053] The heat seal layer may contain a polystyrene resin other than component (A), such as high-impact polystyrene, general-purpose polystyrene, acrylonitrile-butadiene-styrene copolymer, or styrene-ethylene-propylene-styrene copolymer.

[0054] From the viewpoint of blocking resistance, the content of the polystyrene-based resin other than the (A) component may be more than 0 mass% and 25 mass% or less, 5 to 20 mass%, or 5 to 10 mass%, based on the total amount of the heat seal layer.

[0055] Examples of the component (B) include those exemplified in the description of the base layer, however, copolymers containing (meth)acrylic acid or its alkyl ester as a copolymerization component, such as ethylene-(meth)acrylic acid copolymer, ethylene-methyl(meth)acrylate copolymer, and ethylene-ethyl(meth)acrylate copolymer, are included in the component (C).

[0056] The component (B) can be used alone or in combination (mixture) of two or more types.

[0057] From the viewpoint of reducing the peel strength range, the content of the (B) component in the heat seal layer may be 0 to 20 mass %, 0 to 10 mass %, or 0 to 5 mass %, based on the total amount of the heat seal layer.

[0058] The component (C) may be an ethylene-(meth)acrylic acid copolymer.

[0059] Examples of ethylene-(meth)acrylic acid copolymers include ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), ethylene-methyl methacrylate copolymer (EMMA), ethylene-ethyl acrylate copolymer (EEA), ethylene-methyl acrylate copolymer (EMA), and ethylene-glycidyl methacrylate-methyl acrylate copolymer (EGMA-MA).

[0060] From the viewpoint of ensuring the seal strength at low temperatures, the heat seal layer may contain an ethylene-methyl (meth)acrylate copolymer (C-1) (hereinafter, sometimes referred to as component (C-1)) as component (C-1). As component (C-1), the above-mentioned EMMA, EMA and EGMA-MA can be used.

[0061] From the viewpoint of reducing the peel strength range, the content of the (C) component in the heat seal layer may be 0 to 30 mass %, 0 to 20 mass %, or 0 to 10 mass %, based on the total amount of the heat seal layer.

[0062] When the heat seal layer contains one or more components selected from the group consisting of the (B) component and the (C) component, the total content of the (B) component and the (C) component may be more than 0 mass% and not more than 30 mass%, more than 0 mass% and not more than 20 mass%, or may be 5 to 15 mass%, based on the total amount of the heat seal layer, from the viewpoint of reducing the peel strength range.

[0063] From the viewpoint of reducing the peel strength range, the total content of the (A) component, the (B) component and the (C) component in the heat seal layer may be 70 to 100 mass % or 90 to 100 mass % based on the total amount of the heat seal layer.

[0064] In order to obtain extrusion stability during film formation, the heat seal layer may contain various additives such as commonly used antioxidants and lubricants.

[0065] From the viewpoint of ensuring the seal strength, the thickness of the heat seal layer may be 2 to 50 μm, 2 to 40 μm, or 3 to 30 μm.

[0066] Each of the above-mentioned layers can be made into a film by, for example, an inflation method, a T-die method, a casting method, a calendar method, etc. In this case, the components constituting each layer are blended using a mixer such as a Henschel mixer, a tumbler mixer, or a Meisel mixer, and the blend is directly made into a film using an extruder, or the blend is kneaded and extruded once using a single-screw or twin-screw extruder to obtain pellets, and the pellets are then further extruded using an extruder to make a film.

[0067] The heat seal layer may be formed by a method of forming a film by extrusion molding such as inflation molding or T-die extrusion, a method of dissolving the above-mentioned component (A), component (B) and / or component (C) and other components in a solvent and coating the solution on the film of the base layer, or a method of coating the film as an aqueous emulsion.

[0068] When forming a film for a heat seal layer by extrusion molding, it is preferable to co-extrude with an intermediate layer in order to improve extrusion stability. For example, the resin constituting the intermediate layer and the resin constituting the heat seal layer are melt-kneaded using separate single-screw or twin-screw extruders, and the two are laminated and integrated through a feed block or a multi-manifold die, and then extruded from a T-die to obtain a two-layer film in which the intermediate layer and the heat seal layer are laminated.

[0069] The film for the heat seal layer obtained by extrusion molding may be laminated with a base layer by a general method such as dry lamination or extrusion lamination to form a cover tape.

[0070] The total thickness of the cover tape can be 30 to 100 μm, or may be 35 to 80 μm, or may be 40 to 70 μm. If it is within such a range, it is easy to ensure the strength and sealing property of the tape.

[0071] The cover tape of this embodiment is suitable for packaging electronic components. Examples of electronic components include ICs, LEDs (light-emitting diodes), resistors, liquid crystals, capacitors, transistors, piezoelectric resistors, filters, quartz crystal oscillators, diodes, connectors, switches, volumes, relays, inductors, etc. The electronic components may be intermediate products using the above-mentioned components, or may be final products.

[0072] In the above-mentioned applications, it is preferable to impart antistatic properties to the base layer and the heat seal layer in order to prevent dust adhesion and dissipate the charge of the cover tape itself. To impart antistatic properties, surfactant-type antistatic agents, conductive metal oxide particles, and electronically conductive polymers can be used as commonly used antistatic agents. These antistatic agents can be kneaded into the resin depending on the performance to be expressed, but from the viewpoint of efficiently expressing the effect, they can be applied to both surface layers of the cover tape using a gravure coater or the like.

[0073] Cover tapes for packaging electronic components can, for example, be heat sealed to carrier tapes.

[0074] The carrier tape may be provided with pockets for storing electronic components by pressure forming, vacuum forming, or other methods. Materials that can be easily molded into sheets, such as polyvinyl chloride (PVC), polystyrene (PS), polyester (A-PET, PEN, PET-G, PCTA), polypropylene (PP), polycarbonate (PC), polyacrylonitrile (PAN), and acrylonitrile-butadiene-styrene copolymer (ABS), can be used as the material for the carrier tape. These resins can be used alone or in combination. The carrier tape may be a laminate consisting of multiple layers.

[0075] The cover tape of this embodiment can be used in combination with a carrier tape such as a polystyrene carrier tape or a polycarbonate carrier tape.

[0076] <Electronic component packaging> The electronic component packaging body of this embodiment comprises a carrier tape having a storage section capable of storing an electronic component, the electronic component stored in the storage section of the carrier tape, and a cover tape of this embodiment heat-sealed to the carrier tape as a lid material.

[0077] Fig. 2 is a partially cutaway perspective view showing one embodiment of an electronic component package. The electronic component package 200 shown in Fig. 2 includes an embossed carrier tape 16 provided with a storage section 20, an electronic component 40 stored in the storage section 20, and a cover film 50 heat-sealed to the embossed carrier tape 16. The embossed carrier tape 16 is provided with feed holes 30 that can be used for transporting various electronic components such as ICs in an encapsulation process or the like. In addition, a hole (not shown) for inspecting the electronic components is provided at the bottom of the storage section 20.

[0078] The electronic components and carrier tapes are as described above.

[0079] The electronic device package of this embodiment can be used as a carrier tape body wound into a reel for storing and transporting electronic devices.

[0080] The electronic component package of the present embodiment can be manufactured by a method including a step of heat-sealing the cover tape of the present embodiment to a carrier tape having an electronic component accommodated in an accommodation portion. Since the cover tape of the present embodiment has sufficient blocking resistance, blocking is unlikely to occur even when the cover tape is wound into a roll, and poor payout from the roll can be suppressed, allowing the heat-sealing step to be carried out efficiently.

[0081] The heat sealing of the cover tape can be performed using a member called a sealing iron, which can apply a predetermined amount of heat and a predetermined pressure to the heat seal layer. The cover tape can be heat-sealed to the surface of the carrier tape by pressing such a sealing iron onto the carrier tape from above the cover tape. As a specific method, a repeated sealing method in which the sealing iron is pressed multiple times while the embossed carrier tape is being transported, or a continuous sealing method in which the sealing iron is continuously applied to the cover tape side to heat seal it can be applied.

[0082] The sealing temperature may be from 100 to 240°C, or from 120 to 220°C.

[0083] The electronic component packaging of the present embodiment can have a narrow range of peel strength when the cover tape is peeled off, which can significantly reduce the mounting defect rate of electronic components in the manufacture of electronic devices.

[0084] FIG. 3 is a diagram showing an example of a peel strength chart obtained when a cover tape is peeled in the longitudinal direction. FIG. 3(a) shows a peel strength chart when an example of a cover tape having a heat seal layer in which the loss tangent tanδ is 1 or more in a temperature range of 150° C. or less in a dynamic viscoelasticity measurement at a measurement frequency of 1 Hz is used, and FIG. 3(b) shows a peel strength chart when an example of a cover tape having a heat seal layer in which the loss tangent tanδ is less than 1 is used. In the peel strength chart shown in FIG. 3(a), the peel strength changes significantly in the longitudinal direction of the tape, and the peel strength range R1 exceeds 0.15 N. On the other hand, in the peel strength chart shown in FIG. 3(b), the peel strength range R2 is less than 0.15 N, and such a cover tape is less likely to cause defects such as electronic components popping out due to vibration during peeling compared to the cover tape in (a). EXAMPLES

[0085] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0086] Example 1 As the polystyrene-based resin, 45 parts by mass of a styrene-butadiene copolymer (manufactured by JSR Corporation, product name "TR2000", styrene / butadiene mass ratio = 40 / 60), 25 parts by mass of a styrene-butadiene copolymer (manufactured by Denka Company, product name "CLEAREN 170ZR", styrene / butadiene mass ratio = 83 / 17), and 10 parts by mass of a high-impact polystyrene (manufactured by Toyo Styrene Co., Ltd., product name "HIPS H870") were mixed with 20 parts by mass of an ethylene-1-butene random copolymer (manufactured by Mitsui Chemicals, Inc., product name "TAFMER A-4085S") as a polyethylene-based resin in a twin-screw extruder to obtain a resin composition constituting a heat seal layer. This resin composition and a linear low-density polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., product name "Yumerit 2040F") as a first intermediate layer were co-extruded by a T-die method to obtain a two-layer film (total thickness 30 μm) of a first intermediate layer (thickness 20 μm) / heat seal layer (thickness 10 μm). This two-layer film was laminated by an extrusion lamination method with a biaxially oriented polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., product name "Ester Film E5100", thickness 16 μm) via a second intermediate layer (thickness 13 μm) made of low-density polyethylene resin, to obtain a cover tape of Example 1.

[0087] Example 2 A cover tape was obtained in the same manner as in Example 1, except that 20 parts by mass of linear low-density polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., product name "Yumerit 0540F") was used instead of the ethylene-1-butene random copolymer.

[0088] Example 3 A cover tape was obtained in the same manner as in Example 1, except that 15 parts by mass of ethylene-methyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., product name "Acryft WH303-F", methyl methacrylate content: 18% by mass, ethylene content: 82% by mass) was used as the acrylic resin instead of the ethylene-1-butene random copolymer, and the polystyrene resin had the composition shown in Table 1.

[0089] (Examples 4 to 5) Each cover tape was obtained in the same manner as in Example 1, except that 10 parts by mass of ethylene-methyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., product name "Acryft WH303-F", methyl methacrylate content: 18% by mass, ethylene content: 82% by mass) was used as the acrylic resin instead of the ethylene-1-butene random copolymer, and the polystyrene resin had the composition shown in Table 1.

[0090] Example 6 A cover tape was obtained in the same manner as in Example 1, except that 10 parts by mass of ethylene-methyl acrylate copolymer (manufactured by Japan Polyethylene Corporation, product name "Rexpearl EB240H", methyl acrylate content: 20% by mass, ethylene content: 80% by mass) was used as the acrylic resin instead of the ethylene-1-butene random copolymer, and the polystyrene resin had the composition shown in Table 1.

[0091] Example 7 A cover tape was obtained in the same manner as in Example 1, except that 25 parts by mass of ethylene-methyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., product name "Acryft WH303-F", methyl methacrylate content: 18% by mass, ethylene content: 82% by mass) was used as the acrylic resin instead of the ethylene-1-butene random copolymer, and the polystyrene resin had the composition shown in Table 1.

[0092] (Comparative Examples 1 to 2) Except for using the polystyrene-based resin and the polyethylene-based resin in the compositions shown in Table 1, the same procedures as in Example 1 were carried out to obtain cover tapes.

[0093] Details of the raw materials shown in Tables 1 and 2 are as follows: SBR: Styrene-butadiene copolymer (manufactured by JSR Corporation, product name "TR2000", styrene / butadiene mass ratio = 40 / 60) SBC: styrene-butadiene copolymer (manufactured by Denka Co., Ltd., product name "Clearlen 170ZR", styrene / butadiene mass ratio = 83 / 17) HIPS: High impact polystyrene (manufactured by Toyo Styrene Co., Ltd., product name "HIPS H870") EB: Ethylene-1-butene random copolymer (manufactured by Mitsui Chemicals, Inc., product name "Tafmer A-4085S") LLDPE: Linear low-density polyethylene (manufactured by Ube Maruzen Polyethylene Co., Ltd., product name "Yumerit 0540F") EMMA: Ethylene-methyl methacrylate copolymer (manufactured by Sumitomo Chemical Co., Ltd., product name "Acryft WH303-F", methyl methacrylate content: 18% by mass, ethylene content: 82% by mass) EMA: Ethylene-methyl acrylate copolymer (manufactured by Japan Polyethylene Co., Ltd., product name "Rexpearl EB240H", methyl acrylate content: 20% by mass, ethylene content: 80% by mass)

[0094] [Dynamic viscoelasticity measurement of heat seal layer] The resin compositions constituting the heat seal layer in the examples and comparative examples were molded into sheets having a thickness of about 1 to 2 mm to prepare measurement samples. These measurement samples were subjected to dynamic viscoelasticity measurement at 25 to 200°C using a rheometer (manufactured by TA Instruments, product name "DHR-2") under the conditions of shear mode, heating rate of 5°C / min, frequency of 1Hz, strain of 0.05%, and parallel plate φ8mm.

[0095] Based on the measured storage modulus G' and loss modulus G'', the maximum value of loss tangent tanδ in the temperature range of 150°C or less was determined. The results are shown in the table. The table also shows the storage modulus G'(30) at 30°C, the storage modulus G'(150) at 150°C, and the value of G'(30) / G'(150).

[0096] The cover tapes of each Example and Comparative Example were evaluated by the following methods. The results are shown in Tables 1 and 2.

[0097] [Evaluation of peel strength range] Using a taping machine (manufactured by Nagata Seiki Co., Ltd., product name "NK-600"), a 21.5 mm wide cover tape was heat sealed to a 24 mm wide polystyrene carrier tape (manufactured by Denka Co., Ltd., product name "EC-R") under the conditions of a seal head width of 0.5 mm x 2, a seal head length of 24 mm, a seal pressure of 0.5 kgf, a feed length of 12 mm, and a seal time of 0.3 seconds, to obtain a taping sample. The heat sealing temperature of each cover tape was adjusted and determined so that the average value of the peel strength obtained from the peel strength chart was 0.4 N (± 0.03 N). In each of the examples and comparative examples, the temperature of the seal iron was within the range of 100 to 200 ° C.

[0098] The cover tape was peeled off in the longitudinal direction of the obtained taping sample at a peeling angle of 170° to 180° at a peeling speed of 300 mm per minute in an atmosphere of 23° C. and 50% relative humidity. From the peel strength chart obtained when peeled off for 100 mm, the difference between the maximum and minimum values ​​of the peel strength was calculated, and the peel strength range was evaluated according to the following criteria. <Judgment criteria> A: The difference between the maximum and minimum peel strength is less than 0.15N B: The difference between the maximum and minimum peel strength is 0.15N or more.

[0099] [Table 1]

[0100] [Table 2]

[0101] As shown in Table 1, it was confirmed that the cover tapes of Examples 1 to 7, which have a heat seal layer with a loss tangent tanδ of less than 1 in the temperature range of 150°C or less, can suppress the peel strength range to 0.15 N or less, even when heat sealed to achieve an average peel strength of 0.4 N. [Explanation of symbols]

[0102] 1...base material layer, 2...heat seal layer, 3, 3a, 3b...intermediate layer, 16...embossed carrier tape, 20...accommodation section, 30...feed hole, 40...electronic component, 50, 52...cover tape, 200...electronic component package.

Claims

1. The film has at least a base layer and a heat seal layer, The heat seal layer has a loss tangent tan δ of less than 1 in a temperature range of 150° C. or less in a dynamic viscoelastic measurement at a measurement frequency of 1 Hz.

2. The cover tape according to claim 1 , wherein the heat seal layer contains a polystyrene-based resin and one or more resins selected from the group consisting of a polyethylene-based resin and an acrylic-based resin.

3. 3. The cover tape according to claim 1, wherein the heat seal layer has a ratio [G'(30) / G'(150)] of the storage modulus G'(30) at 30°C to the storage modulus G'(150) at 150°C in a dynamic viscoelastic measurement at a measurement frequency of 1 Hz of 800 or less.

4. The heat seal layer has a storage modulus G'(30) of 1.0×10 at 30° C. in a dynamic viscoelastic measurement at a measurement frequency of 1 Hz. ６ Pa or more 1.0×10 ８ The cover tape according to any one of claims 1 to 3, wherein the viscosity is less than 100 Pa.

5. An electronic component packaging body comprising: a carrier tape having a storage section; an electronic component stored in the storage section of the carrier tape; and the cover tape according to any one of claims 1 to 4, which is heat-sealed to the carrier tape as a lid material.

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