Resin sheet, container, carrier tape, and electronic component package

Abstract

A resin sheet comprising: a base material sheet that contains a polystyrene-based resin; and a surface layer that is laminated on at least one surface of the base material sheet and that contains an electrically conductive material and a thermoplastic resin, wherein a durometer D-type surface hardness of the resin sheet as measured in compliance with JIS-K-7215 is not less than 67 but less than 80.

Description

[Technical Field]

[0001] The present invention relates to a resin sheet, a container, a carrier tape, and an electronic component package. [Background technology]

[0002] Vacuum-formed trays and embossed carrier tapes obtained by heat-forming resin sheets are used as packaging containers for intermediate products of industrial products such as electronic devices and automobiles. Resin sheets having a laminated structure in which a surface layer containing a thermoplastic resin and a conductive material such as carbon black is laminated on a base layer made of a thermoplastic resin are used as packaging sheets for ICs and various parts that contain ICs, which are sensitive to static electricity (see, for example, Patent Documents 1 to 3 listed below).

[0003] In manufacturing the embossed carrier tape, a resin sheet is molded using a molding means such as press molding to provide a container portion that matches the shape of the parts to be transported. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-76422 [Patent Document 2] Japanese Patent Application Publication No. 9-76425 [Patent Document 3] Japanese Patent Application Publication No. 9-174769 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, various electronic components such as capacitors, resistors, ICs, LEDs, connectors, and switching elements have become increasingly miniaturized. The size of the containers in the carrier tapes used to transport these tiny components has become increasingly small, making it easier for the nozzles that pick up components to come into contact with the carrier tape during component mounting. If the nozzle contact causes excessive deformation of the container opening, it can lead to pickup problems, such as making it impossible to remove the component. There are also other factors that can cause component pickup problems. If the tiny components housed in the container move or tilt during transport, they become difficult to pick up. For this reason, high precision is required when molding the containers for tiny components.

[0006] An object of the present invention is to provide a resin sheet that has sufficient formability and yet excellent resistance to deformation due to localized loads, as well as a container, a carrier tape, and an electronic component package obtained using the same. [Means for solving the problem]

[0007] One aspect of the present invention relates to the following [1] to [7]. [1] A resin sheet comprising a base sheet containing a polystyrene-based resin and a surface layer containing a conductive material and a thermoplastic resin laminated on at least one surface of the base sheet, the resin sheet having a durometer D surface hardness of 67 or more but less than 80 as measured in accordance with JIS-K-7215. [2] When dynamic viscoelasticity measurements were performed, the storage modulus E'1 at 25°C was 1.0 x 10 8 Pa or more 1.0×10 10 Pa or less, and the storage modulus E'2 at the loss tangent peak temperature +20°C is 1.0 x 10 6 The resin sheet according to the above [1], wherein the elastic modulus is 0.001 Pa or less. [3] The resin sheet according to [1] or [2] above, wherein the base sheet contains one or more resins selected from the group consisting of general-purpose polystyrene resins and high-impact polystyrene resins in a total amount of 50% by mass or more, based on the total amount of styrene-based resins. [4] A resin sheet comprising a base sheet containing a thermoplastic resin and a surface layer containing a conductive material and a thermoplastic resin laminated on at least one surface of the base sheet, wherein, when dynamic viscoelasticity measurement is performed, the storage modulus E'1 at 25°C is 1.0 × 10 8 Pa or more 1.0×10 10 Pa or less, and the storage modulus E'2 at the loss tangent peak temperature +20°C is 1.0 x 10 6 A resin sheet having a resistance of 0.05 Pa or less. [5] A container which is a molded product of the resin sheet according to any one of [1] to [4] above. [6] A carrier tape, which is a molded article of the resin sheet according to any one of the above [1] to [4], and is provided with a storage portion capable of storing an article. [7] An electronic component packaging body comprising the carrier tape according to [6] above, an electronic component accommodated in the accommodation portion of the carrier tape, and a cover film adhered to the carrier tape as a lid material.

[0008] In order to solve the above-mentioned problems, one aspect of the present invention provides a resin sheet comprising a base sheet containing a polystyrene-based resin and a surface layer containing a conductive material and a thermoplastic resin laminated on at least one surface of the base sheet, the resin sheet having a durometer D surface hardness of 67 or more but less than 80 as measured in accordance with JIS-K-7215.

[0009] With the resin sheet, since the surface hardness is 67 or more, deformation due to a local load can be sufficiently suppressed, and since the base sheet contains a polystyrene resin and the surface hardness is less than 80, a molded product can be obtained with sufficient precision when molding by press molding or the like. With a carrier tape formed from such a resin sheet, in applications where very small parts are to be transported, it is possible to have a well-formed storage section and to sufficiently suppress deformation due to contact with a pickup nozzle, thereby making it possible to suppress the occurrence of the above-mentioned pickup failure.

[0010] When the resin sheet was subjected to dynamic viscoelasticity measurement, the storage modulus E'1 at 25°C was 1.0 × 10 8 Pa or more 1.0×10 10 Pa or less, and the storage modulus E'2 at the loss tangent peak temperature +20°C is 1.0 x 10 6 It may be less than Pa.

[0011] The base sheet may contain at least one resin selected from the group consisting of general-purpose polystyrene resin and high-impact polystyrene resin in a total amount of at least 50 mass % based on the total amount of polystyrene resins.

[0012] Another aspect of the present invention is a resin sheet comprising a base sheet containing a thermoplastic resin and a surface layer containing a conductive material and a thermoplastic resin laminated on at least one surface of the base sheet, wherein the resin sheet has a storage modulus E'1 of 1.0 × 10 at 25°C when dynamic viscoelasticity is measured at a measurement frequency of 1 Hz. 8 Pa or more 1.0×10 10 Pa or less, and the storage modulus E'2 at the loss tangent peak temperature +20°C is 1.0 x 10 6 To provide a resin sheet having a modulus of elasticity of 0.05 Pa or less.

[0013] Since the storage modulus E'1 and the storage modulus E'2 of the resin sheet are within the above-mentioned specific ranges, the resin sheet has both the property of being resistant to deformation due to a local load and the formability that allows a molded product to be obtained with sufficient precision when subjected to heat molding such as press molding. A carrier tape formed from such a resin sheet can have a well-formed storage section when used to transport very small parts, and can also ensure sufficient resistance to deformation due to contact with a pickup nozzle, making it possible to suppress the occurrence of the above-mentioned pickup failure.

[0014] Another aspect of the present invention provides a container which is a molded article of the above-mentioned resin sheet.

[0015] Another aspect of the present invention provides a carrier tape that is a molded article of the resin sheet described above and is provided with a storage portion that can store an article.

[0016] Another aspect of the present invention provides an electronic component package comprising the above-mentioned carrier tape, an electronic component accommodated in an accommodating portion of the carrier tape, and a cover film adhered to the carrier tape as a lid material. [Effects of the Invention]

[0017] According to the present invention, it is possible to provide a resin sheet from which a carrier tape having sufficient formability and excellent resistance to deformation under local load can be obtained, as well as a container, a carrier tape, and an electronic component packaging body obtained using the same. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an embodiment of a resin sheet. [Figure 2] FIG. 1 is a partially cutaway perspective view showing an embodiment of a carrier tape. [Figure 3] 1 is a partially cutaway perspective view showing an embodiment of an electronic component package. [Figure 4] FIG. 10 is a diagram for explaining a method for evaluating the formability of a resin sheet. DETAILED DESCRIPTION OF THE INVENTION

[0019] Preferred embodiments of the present invention will be described in detail below.

[0020] [Resin sheet] The resin sheet of this embodiment includes a base sheet containing a thermoplastic resin, and a surface layer containing a conductive material and a thermoplastic resin laminated on at least one surface of the base sheet.

[0021] Fig. 1 is a schematic cross-sectional view showing an embodiment of a resin sheet according to the present embodiment. Resin sheet 10 shown in Fig. 1(a) comprises a base sheet 1 and a surface layer 2 provided on one side of the base sheet 1. Resin sheet 12 shown in Fig. 1(b) comprises a base sheet 1, a surface layer 2 laminated on one side of the base sheet, and a second surface layer 3 laminated on the other side of the base sheet. The surface layer 2 and the second surface layer 3 may have the same composition or different compositions.

[0022] (First resin sheet) The resin sheet of this embodiment may comprise a base sheet containing a polystyrene-based resin and a surface layer containing a conductive material and a thermoplastic resin laminated on at least one side of the base sheet (hereinafter also referred to as a "first resin sheet").

[0023] The first resin sheet has a durometer D surface hardness measured in accordance with JIS-K-7215 of 67 or more and less than 80. A surface hardness of 67 or more makes it possible to sufficiently suppress deformation due to a local load, and since the base sheet contains a polystyrene resin and the surface hardness is less than 80, a molded product can be obtained with sufficient precision when molding, such as by press molding.

[0024] The surface hardness can be determined by the following procedure. (i) The measurement sample is made by stacking resin sheets cut to a size of 5 cm in length and 5 cm in width so that the total thickness is 2 mm or more. (ii) The surface hardness of the above measurement sample is measured at 23°C using a rubber / plastic hardness tester GS-702N TYPE D (manufactured by Teclock Corporation). The measurement sample is positioned so that the pressure reference surface is the surface layer of the resin sheet. (iii) The above measurement is carried out 10 times, and the average value is taken as the surface hardness.

[0025] The first resin sheet may have a surface hardness of 70 or more and less than 78, or 72 or more and less than 76, from the viewpoint of further improving the resistance to deformation due to a local load.

[0026] When the resin sheet of this embodiment has two surface layers, it may be one that satisfies the above surface hardness when one surface layer is used as the pressure reference surface (i.e., a resin sheet whose surface hardness on at least one main surface satisfies the above condition), or it may be one that satisfies the above surface hardness when both surface layers are used as the pressure reference surfaces (i.e., a resin sheet whose surface hardness on both main surfaces satisfies the above condition).

[0027] From the viewpoint of achieving a high level of both moldability and deformation resistance against a local load, the first resin sheet is selected to have a storage modulus E'1 of 1.0×10 at 25°C when subjected to dynamic viscoelasticity measurement. 8 Pa or more 1.0×10 10 Pa or less, and the storage modulus E'2 at the loss tangent peak temperature (hereinafter sometimes referred to as "Tg") + 20°C is 1.0 × 10 6 The dynamic viscoelasticity of the resin sheet may be measured under the following conditions.

[0028] The resin sheet is cut into a length of 40 mm and a width of 3 mm to prepare a measurement sample. The measurement sample is subjected to dynamic viscoelasticity measurement using a dynamic viscoelasticity measuring device RAS-G2 (manufactured by TA Instruments) under the following measurement conditions. [Measurement conditions] Deformation mode: Linear tension Measurement temperature: 20℃~200℃ Measurement frequency: 1Hz Heating rate: 10℃ / min Initial static tensile load: 0.2N Initial gap distance (at 20°C): 10 mm

[0029] When the thickness of the resin sheet exceeds 1 mm, the width of the measurement sample may be adjusted to a range of 3 to 10 mm before the dynamic viscoelasticity measurement is performed.

[0030] From the viewpoint of further improving the resistance to deformation due to a local load, the storage modulus E'1 is set to 1.0 × 10 9 It may be more than Pa.

[0031] From the viewpoint of further improving the moldability, the storage modulus E'2 is set to 5.0 × 10 5 In order to suppress unintended deformation of the sheet due to heating, the storage modulus E'2 may be 1.0×10 Pa or less. 3 Pa or more, and 4 It may be more than Pa.

[0032] Examples of the polystyrene resin contained in the base sheet include general-purpose polystyrene resin, high-impact polystyrene resin, and copolymers of styrene and monomers other than styrene-based monomers. These polystyrene resins can be used alone or in combination of two or more.

[0033] The general-purpose polystyrene resin is generally known as GPPS, and is mainly composed of styrene as a monomer, but may contain one or more aromatic vinyl compounds such as o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinylanthracene, 1,1-diphenylethylene, etc. as minor components. Commercially available resins can also be used as the general-purpose polystyrene resin.

[0034] The general-purpose polystyrene resin may have a weight average molecular weight (Mw) of 80,000 to 220,000, or 140,000 to 220,000. In this specification, the weight average molecular weight (Mw) can be determined from a molecular weight distribution curve calculated in terms of standard polystyrene by a conventional method using GPC.

[0035] The high-impact polystyrene resin is generally known as HIPS, and can be a polystyrene resin containing finely divided graft rubber grafted with a styrene-based monomer. The styrene-based monomer is primarily styrene, and can contain one or more of the above-mentioned aromatic vinyl compounds other than styrene as minor components. The graft rubber is formed by graft copolymerizing a rubber component with a styrene-based monomer to form graft branches. The rubber component in the graft rubber is, for example, a diene rubber containing 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, or 2-methylpentadiene as a monomer. The graft rubber can also be a thermoplastic elastomer of a styrene-conjugated diene block copolymer with a diene component of 50% by mass or more.

[0036] From the viewpoint of transparency, the particle size of the graft rubber in the impact-resistant polystyrene resin may be 2.0 μm or more and 3.0 μm or less, or 2.3 μm or more and 2.7 μm or less. The particle size of the graft rubber means the average particle size of the graft rubber measured by a laser diffraction particle analyzer.

[0037] The high impact polystyrene resin may have a weight average molecular weight (Mw) of 150,000 to 210,000, or 150,000 to 190,000.

[0038] Examples of the monomer other than the polystyrene-based monomer in the copolymer include conjugated diene monomers, acrylonitrile, and methyl methacrylate. The conjugated diene monomer may be any compound having a conjugated double bond in its structure, such as 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and 2-methylpentadiene.

[0039] Examples of the copolymer include a styrene-conjugated diene block copolymer, an AS resin, an ABS resin, an AES resin, and an MS resin.

[0040] The styrene-conjugated diene block copolymer can be a polymer containing a polymer block mainly composed of a styrene-based monomer and a polymer block mainly composed of a conjugated diene monomer in its structure. The conjugated diene monomer may be any compound having a conjugated double bond in its structure, such as 1,3-butadiene (butadiene), 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and 2-methylpentadiene.

[0041] From the viewpoint of formability, the first resin sheet may contain a polystyrene-based resin in an amount of 50% by mass or more, 60% by mass or more, or 100% by mass based on the total amount of resin components contained in the base sheet.

[0042] From the viewpoint of formability, the first resin sheet may be one in which the base sheet contains one or more resins selected from general-purpose polystyrene resins and high-impact polystyrene resins in a total amount of 50% by mass or more, or 60% by mass or more, based on the total amount of polystyrene-based resins.

[0043] From the viewpoint of imparting practical impact resistance to the resin sheet, the base sheet may contain a general-purpose polystyrene resin and a high-impact polystyrene resin, and the mass ratio thereof [GPPS:HIPS] may be 0:100 to 90:10.

[0044] The substrate sheet may contain a conductive material, a filler, a plasticizer, a processing aid, an antioxidant, an antiblocking agent, and the like.

[0045] The thickness of the substrate sheet can be set appropriately depending on the application, and may be, for example, 50 μm to 3 mm, 100 μm to 1 mm, or 150 to 600 μm.

[0046] The thickness of the base sheet can be 60 to 99% of the thickness of the entire resin sheet. When surface layers are provided on both sides of the base sheet, the thickness of the base sheet may be 60 to 98% of the thickness of the entire resin sheet. When surface layers are provided on only one side of the base sheet, the thickness of the base sheet may be 60 to 99% of the thickness of the entire resin sheet.

[0047] The thermoplastic resin contained in the surface layer may be a polystyrene resin, a polyolefin resin, a polycarbonate resin, or a polyester resin. These thermoplastic resins may be used alone or in combination of two or more.

[0048] Examples of polystyrene resins include those mentioned above and hydrogenated styrene thermoplastic elastomers, such as polystyrene-poly(ethylene / propylene) block (SEP), polystyrene-poly(ethylene / propylene) block-polystyrene (SEPS), polystyrene-poly(ethylene / butylene) block-polystyrene (SEBS), and polystyrene-poly(ethylene-ethylene / propylene) block-polystyrene (SEEPS).

[0049] Examples of polyolefin resins include polyethylene resins such as high-density polyethylene, very-low-density polyethylene, and linear low-density polyethylene; polypropylene resin; ethylene-α-olefin copolymers obtained by copolymerizing ethylene with C3 or higher α-olefin hydrocarbons such as propylene, 1-butene, and 1-hexene; and copolymers of olefins and monomers having polar groups copolymerizable with olefins. Examples of copolymers of olefins and monomers having polar groups copolymerizable with olefins include ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-ethyl acrylate copolymers, ethylene-methacrylic acid ester copolymers, ethylene-vinyl acetate-vinyl chloride copolymers, and terpolymers with acid anhydrides.

[0050] Examples of polycarbonate resins include aromatic polycarbonate resins, aliphatic polycarbonate resins, and aromatic-aliphatic polycarbonate resins. Aromatic polycarbonate resins are generally classified as engineering plastics, and can be obtained by polycondensation of bisphenol A and phosgene or polycondensation of bisphenol A and a carbonate ester. Aromatic polycarbonate resins are preferred in terms of mechanical strength.

[0051] The polyester resin may be a resin obtained by polycondensation of a dicarboxylic acid and a diol. Examples of dicarboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, 2-methylterephthalic acid, 4,4'-diphenyldicarboxylic acid, 5-sulfoisophthalic acid, 2,6-naphthalenedicarboxylic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, and maleic anhydride. These may be used alone or in combination of two or more. Examples of diols include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, 1,3-propanediol, and 1,4-butanediol. These may be used alone or in combination of two or more.

[0052] Examples of the conductive material contained in the surface layer include carbon black, graphite, CNT, graphite, Ketjenblack, etc. These conductive materials can be used alone or in combination of two or more.

[0053] The conductive material may be in the form of particles, and in this case, the average primary particle size of the conductive material may be 10 nm to 5.0 μm, or may be 20 to 50 nm. The average primary particle size of the particles is determined by the following method. First, a particle sample is dispersed in chloroform for 10 minutes using an ultrasonic disperser at 150 kHz and 0.4 kW to prepare a dispersion sample. This dispersion sample is then sprinkled and fixed on a carbon-reinforced support film, which is then photographed using a transmission electron microscope (JEOL, JEM-2100). From the image magnified 50,000 to 200,000 times, the particle diameters of 1,000 or more randomly selected particles (maximum diameter for non-spherical shapes) are measured using an Endter device, and the average value is taken as the average primary particle diameter.

[0054] The content of the conductive material in the surface layer can be 10 to 30 mass % based on the total mass of the surface layer, and may be 15 to 25 mass %.

[0055] The surface layer has a surface resistivity of 10 4 ~10 8 When the surface resistivity of the surface layer is in this range, it becomes easy to prevent damage to electronic components due to static electricity and damage to electronic components due to the inflow of electricity from the outside.

[0056] The surface layer may contain various additives such as lubricants, plasticizers, and processing aids.

[0057] The thickness of the surface layer can be appropriately set depending on the application, and may be, for example, 2 μm to 50 μm.

[0058] (Second resin sheet) When the resin sheet of this embodiment was subjected to dynamic viscoelasticity measurement, the storage modulus E'1 at 25°C was 1.0 × 10 8 Pa or more 1.0×10 10 Pa or less, and the storage modulus E'2 at the loss tangent peak temperature (hereinafter sometimes referred to as "Tg") + 20°C is 1.0 × 10 6 (Hereinafter, this may also be referred to as a "second resin sheet.") The dynamic viscoelasticity measurement of the resin sheet is carried out under the above-mentioned conditions.

[0059] A second resin sheet having storage modulus E'1 and storage modulus E'2 within the above-mentioned specific ranges can combine the property of being resistant to deformation under localized load with the moldability that allows a molded body to be obtained with sufficient precision when molded by press molding or the like.

[0060] The base sheet and surface layer of the second resin sheet can be configured in the same manner as the base sheet and surface layer of the first resin sheet.

[0061] The resin sheet of this embodiment can be formed into a shape suited to the intended use by a known thermoforming method such as vacuum forming, pressure forming, or press forming.

[0062] The resin sheet of this embodiment can be used as a material for packaging containers for active components such as ICs, components equipped with ICs, passive components such as capacitors and connectors, and mechanical components, and can be suitably used for vacuum-formed trays, magazines, carrier tapes with embossing (embossed carrier tapes), etc.

[0063] [Manufacturing method of resin sheet] The resin sheet according to this embodiment can be manufactured by a general method. For example, as a base layer forming composition for forming a base sheet, a mixture of the raw materials constituting the base sheet or the raw materials constituting the base sheet are kneaded using a known method such as an extruder, and pelletized pellets are prepared. As a surface layer forming composition for forming a surface layer, a mixture of the raw materials constituting the surface layer or the raw materials constituting the surface layer are kneaded and pelletized using a known method such as an extruder, and these pellets are used to form a resin sheet by a known method such as an extruder. The extruder temperature can be set, for example, to 200 to 300 ° C.

[0064] The base sheet and the surface layer may be formed by molding the base layer-forming composition and the surface layer-forming composition into sheets or films using separate extruders, and then laminating them in stages by a thermal lamination method, a dry lamination method, an extrusion lamination method, or the like; alternatively, a surface layer made of the surface layer-forming composition may be laminated by a method such as extrusion coating on one or both sides of a base sheet that has been molded in advance from the base layer-forming composition.

[0065] Alternatively, the resin sheet can be produced by a multilayer coextrusion method, such as extrusion molding using a multi-layer T-die with a multi-manifold or T-die extrusion molding using a feed block, in which the raw materials (e.g., the above-mentioned pellets) constituting the base sheet and the surface layer are fed into separate extruders. This method is preferred because it allows the resin sheet to be obtained in one step.

[0066] [container] The container of this embodiment is a molded article of the resin sheet of this embodiment described above. The container can be obtained by molding the resin sheet of this embodiment into a shape appropriate for the intended use.

[0067] As the molding method, known thermoforming methods such as vacuum molding, pressure molding, and press molding can be used.

[0068] The molding temperature is, for example, 120 to 200° C. When molding is performed using a mold, for example, a resin sheet heated to a temperature higher than the peak temperature of the loss tangent may be placed in the mold, and after molding, the molded product may be released from the mold at a temperature lower than the peak temperature of the loss tangent.

[0069] [Carrier tape] The carrier tape of this embodiment is a molded product of the resin sheet according to the above embodiment, and is provided with a storage section capable of storing an article. Fig. 2 is a perspective view showing one embodiment of the carrier tape. The carrier tape 100 shown in Fig. 2 is an embossed carrier tape made of a molded product 16 of the resin sheet according to this embodiment, in which a storage section 20 is provided by embossing. The molded product 16 is provided with feed holes 30 that can be used for transporting various electronic components such as ICs during processes such as encapsulating them.

[0070] The carrier tape of this embodiment can be wound up in a reel shape.

[0071] The carrier tape of this embodiment is suitable as a packaging container for 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 or final products using the above components.

[0072] According to the carrier tape formed from the resin sheet of this embodiment, when used to transport extremely small components, it is possible to have a well-formed storage section and to sufficiently suppress deformation caused by contact with the pickup nozzle.

[0073] [Electronic component packaging] The electronic component packaging body of this embodiment includes the carrier tape of this embodiment described above, electronic components accommodated in storage sections of the carrier tape, and a cover film adhered to the carrier tape as a lid material. Fig. 3 is a partially cutaway perspective view showing one embodiment of the electronic component packaging body. The electronic component packaging body 200 shown in Fig. 3 includes an embossed carrier tape made of a resin sheet molded article 16 according to this embodiment, which is provided with storage sections 20 and feed holes 30, electronic components 40 accommodated in the storage sections 20, and a cover film 50 adhered to the embossed carrier tape.

[0074] Examples of the cover film include those disclosed in Japanese Patent Nos. 4630046 and 5894578.

[0075] The cover film can be attached by heat sealing to the upper surface of the embossed carrier tape containing the electronic components.

[0076] The electronic component package of this embodiment can be used as a carrier tape wound into a reel for storing and transporting electronic components. [Example]

[0077] The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0078] [Preparation of resin sheet] (Examples 1 to 9 and Comparative Examples 1 to 4) The raw materials shown in Tables 1 and 2 were each weighed out to obtain the composition ratios (parts by mass) shown in the tables, and mixed uniformly using a high-speed mixer. The mixture was then kneaded using a φ30 mm vented twin-screw extruder and pelletized using a strand cut method to obtain a resin composition for forming a surface layer.

[0079] Separately, the raw materials shown in Tables 1 and 2 were weighed out so as to have the composition ratios (parts by mass) shown in the tables, and mixed uniformly in a high-speed mixer to obtain a resin composition for forming a base sheet.

[0080] Using pellet-shaped resin compositions for forming a surface layer and resin compositions for forming a base sheet, a resin sheet having a laminated structure of surface layer / base sheet / surface layer was produced by a feed block method using a φ65 mm single-screw extruder (L / D=28) for forming the base sheet and a φ40 mm single-screw extruder (L / D=26) and a 500 mm wide T-die for forming the surface layer. The thicknesses of the base sheet and surface layer were adjusted so that the resin sheet had a thickness of 200 μm and the thickness ratio of surface layer / base sheet / surface layer was 1:18:1.

[0081] Details of the raw materials shown in Tables 1 and 2 are as follows. GPPS: General-purpose polystyrene resin (manufactured by Toyo Styrene Co., Ltd., product name "Toyo Styrol GP G200C") HIPS: High-impact polystyrene resin (manufactured by Toyo Styrene Co., Ltd., product name "Toyo Styrol HI E640N") EEA: Ethylene-ethyl acrylate copolymer resin (manufactured by ENEOS NUC, product name "DPDJ-6169") HDPE: High-density polyethylene resin (manufactured by Prime Polymer, product name "Hi-Zex 5000H") SEBS: Hydrogenated styrene-based thermoplastic elastomer (manufactured by Asahi Kasei Corporation, product name "Tuftec P2000") SBC: Styrene-butadiene block copolymer (manufactured by Denka, product name "Clearen 200TR") ABS: ABS resin (manufactured by Denka, product name "Denka ABS SE-10") PC: Polycarbonate resin (Teijin, product name "Panlite L-1225L") PBT: Polybutylene terephthalate resin (manufactured by Mitsubishi Engineering Plastics Corporation, product name "NOVADURAN 5010R8 M") CB: Carbon black (manufactured by Denka, product name "Denka Black Granules", average primary particle diameter 35 nm)

[0082] [Evaluation of resin sheets] The resin sheet was sampled in the extrusion direction and evaluated by the following methods. The results are summarized in Tables 1 and 2.

[0083] (1) Surface hardness of resin sheet In accordance with JIS-K-7215, the surface hardness of the resin sheet was measured by the following procedure. (i) Twelve resin sheets, each 0.2 mm thick and cut to a size of 5 cm long and 5 cm wide, were stacked to form a measurement sample. (ii) The surface hardness of the above measurement samples was measured at 23°C using a rubber / plastic hardness tester GS-702N TYPE D (manufactured by Teclock Corporation). (iii) The above measurement was carried out 10 times, and the average value was taken as the surface hardness.

[0084] (2) Dynamic viscoelasticity of resin sheet A 0.2 mm thick resin sheet was cut into a length of 40 mm and a width of 3 mm to prepare a measurement sample. Dynamic viscoelasticity measurements were performed on this measurement sample using a dynamic viscoelasticity analyzer RAS-G2 (manufactured by TA Instruments) under the following measurement conditions, and the storage modulus E'1 at 25°C and the storage modulus E'2 at the peak temperature of loss tangent (tanδ) Tg + 20°C were calculated. [Measurement conditions] Deformation mode: Linear tension Measurement temperature: 20℃~200℃ Measurement frequency: 1Hz Heating rate: 10℃ / min Initial static tensile load: 0.2N Initial gap distance (at 20°C): 10 mm

[0085] (3) Part pressing evaluation A 0.2 mm-thick resin sheet was cut into a 5 cm long and 5 cm wide piece to prepare an evaluation sample. Four multilayer ceramic capacitors (0.4 mm long x 0.2 mm wide x 0.2 mm high) were placed on the surface of the evaluation sample, each positioned at the four corners of a 2 cm square. A 5 cm long, 5 cm wide, 0.2 mm thick, 4.0 g stainless steel plate was then placed on top of the capacitors. A 100-1000 g weight was then placed on the stainless steel plate and allowed to stand for 1 minute. The depth of the dent on the evaluation sample surface was measured using a VK-X100 laser microscope (Keyence Corporation). The weight of the weight at which the dent depth reached 5 μm or more (hereinafter referred to as the "dent load") was determined, and the deformation resistance to a load applied to a very small area was evaluated according to the following criteria. The multilayer ceramic capacitor had electrodes (0.1 mm long) on ​​both ends, and because the distance between the electrodes was small, the electrodes came into contact with the resin sheet. <Judgment criteria> A: The dent load is over 1000g (when the weight is 1000g, the dent depth on the resin sheet surface is less than 5μm) B: The dent load is between 800g and 1000g. C: The dent load is 500g or more and less than 800g D: The dent load is less than 500g

[0086] (4) Evaluation of formability A 0.2 mm-thick resin sheet was slit into 8 mm widths, and both sides of the sheet were heated to Tg°C + 20°C (calculated in (2) above) using a contact heater in a press molding machine. Five containers with an opening measuring 0.23 mm (dimension A) × 0.43 mm (dimension B) and 0.25 mm (depth D) were then molded using upper and lower molds (see Figure 4). Note that Figure 4(a) is a top view of the container, and Figure 4(b) is a schematic cross-sectional view taken along line II in Figure 4(a). The container 110 shown in Figure 4 has a concave shape with a bottom wall 7 and side walls 5 and 6 extending from the periphery of the bottom wall 7. The upper mold was designed so that the angles θ1 and θ2 formed between the inner surface of the bottom wall 7 and the inner surface of the side wall 6 were right angles. The A-dimension cross section (see Figure 4(b)) obtained by cutting out the center of the B-dimension of the obtained container was observed with a laser microscope VK-X100 (manufactured by Keyence Corporation), and the angle (θ) between the bottom and side of the inside of the container was measured at two points each, and the average value of the measurements at a total of 10 points was taken as the pocket angle θp. From the obtained pocket angle θp, the formability was evaluated according to the following criteria. <Judgment criteria> A: Pocket angle θp is less than 92.0° B: Pocket angle θp is 92.0° or more and less than 94.0° C: Pocket angle θp is 94.0° or more and less than 96.0° D: Pocket angle θp is 96.0° or more

[0087] [Table 1]

[0088] [Table 2] [Explanation of symbols]

[0089] 1...base material sheet, 2...surface layer, 3...second surface layer, 5, 6...side wall portion, 7...bottom wall portion, 10, 12...resin sheet, 20...accommodation portion, 30...sprocket hole, 40...electronic component, 50...cover film, 100...carrier tape, 200...electronic component packaging body.

Claims

1. The present invention comprises a substrate sheet containing a polystyrene-based resin, and a surface layer containing a conductive material and a thermoplastic resin, the surface layer being laminated on at least one surface of the substrate sheet, A resin sheet having a durometer D surface hardness of 67 or more but less than 80 as measured in accordance with JIS-K-7215.

2. When dynamic viscoelasticity was measured, the storage modulus E'1 at 25°C was 1.0 × 10 ８ Pa or more 1.0×10 １０ Pa or less, and the storage modulus E'2 at the loss tangent peak temperature +20°C is 1.0 × 10 ６ The resin sheet according to claim 1, wherein the modulus of elasticity is 0.05 Pa or less.

3. 2. The resin sheet according to claim 1, wherein the base sheet contains one or more resins selected from the group consisting of general-purpose polystyrene resins and high-impact polystyrene resins in a total amount of 50% by mass or more based on the total amount of styrene-based resins.

4. A container which is a molded product of the resin sheet according to any one of claims 1 to 3.

5. A carrier tape comprising a molded article of the resin sheet according to any one of claims 1 to 3, the carrier tape being provided with a storage portion capable of storing an article.

6. An electronic component package comprising: the carrier tape according to claim 5; an electronic component accommodated in the accommodation portion of the carrier tape; and a cover film adhered to the carrier tape as a lid material.

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