Sheet for electronic component packaging

Abstract

To provide a sheet for electronic component packaging which can effectively suppress generation of flash or fiber ends while maintaining satisfactory formability.SOLUTION: An sheet for electronic component packaging is equipped with a substrate sheet in which a substrate layer A and a substrate layer B are alternately laminated, where a heat distortion temperature difference between the substrate layer A and the substrate layer B is higher than 0°C and lower than 23°C, the thickness of each layer of the substrate layer A is 10 to 60 μm, the thickness of each layer of the substrate layer B is 1 to 50 μm, the average value of the thickness of each layer of the substrate layer A is more than the average value of the thickness of each layer of the substrate layer B, and the substrate layer A and the substrate layer B contains different thermoplastic resins as main components.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a sheet for packaging electronic components. [Background technology]

[0002] Trays (e.g., injection trays, vacuum-formed trays), magazines, carrier tapes (e.g., embossed carrier tapes), etc. are used as packaging containers for semiconductors and electronic components, particularly integrated circuits (ICs) and electronic components equipped with ICs. Examples of thermoplastic resins used to form packaging containers for these electronic components include polystyrene-based resins, ABS-based resins, polyvinyl chloride-based resins, polypropylene-based resins, polyester-based resins, polyphenylene ether-based resins, and polycarbonate-based resins. Furthermore, from the perspective of preventing damage to or destruction of ICs due to static electricity, packaging containers have also been proposed in which, for example, a conductive layer made of a resin containing a conductive agent such as conductive carbon black is provided on the surface of a base layer made of ABS-based resin (Patent Documents 1 and 2, etc.).

[0003] The above-mentioned packaging container can be obtained by molding a sheet for packaging electronic components using a known method, such as a method in which a packaging sheet heated with hot air is placed against a mold and vacuumed to form it, or a method in which a packaging sheet heated with radiant heat is sandwiched between a pair of molds and pressed to form it. However, burrs and fluff can occur during molding. If these burrs and fluff fall into the component storage area (pocket) and adhere to the electronic component, they can cause defects in the electronic component. In recent years, with the miniaturization of electronic components, there has been a strong demand to reduce defects caused by the adhesion of burrs and fluff.

[0004] Furthermore, in recent years, with the development trends of AI / IoT and automation in automobiles and communication devices, the number of electronic components and semiconductors mounted is increasing, and the shapes of electronic components and semiconductors are becoming more complex and diverse. Therefore, there is a demand for packaging sheets for electronic components that combine the reduction of the above-mentioned burrs and fuzz and the formability suitable for manufacturing packaging containers that can accommodate components with complex and diverse shapes.

[0005] To address this issue, it has been proposed to incorporate polyolefin, styrene-butadiene-styrene block copolymer, styrene-ethylene-butylene-styrene block copolymer, or the like into the base layer or conductive layer (for example, Patent Documents 3 and 4). However, these conventional methods do not sufficiently suppress burrs and fluff. Furthermore, in the method of suppressing the occurrence of burrs and fluff by changing the resin composition, depending on the composition, the formability of the sheet may be reduced, making it difficult to form pockets in the desired shape. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-174769 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-292805 [Patent Document 3] International Publication No. 2006 / 030871 [Patent Document 4] Japanese Patent Application Laid-Open No. 2003-170547 Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide a sheet for packaging electronic components, which can effectively suppress the generation of burrs and fluff while maintaining good formability suitable for producing packaging containers that can accommodate components with complex and diverse shapes, and a molded product comprising the sheet. [Means for solving the problem]

[0008] As a result of extensive research into the above-mentioned problems, the inventors of the present application have found that: The present inventors have found that all of the above-mentioned problems can be solved by providing an electronic component packaging sheet that includes a base sheet formed by alternately laminating base layers A and B each containing different thermoplastic resins as main components, in which the average thickness of each layer of base layer A is greater than the average thickness of each layer of base layer B, and in which the difference in heat distortion temperature between base layer A and base layer B is greater than 0°C and less than 23°C, and have thus completed the present invention. That is, the present invention has the following aspects. [1] A sheet for packaging electronic components comprising a base sheet in which base layer A and base layer B are alternately laminated, The difference in heat distortion temperature between the base layer A and the base layer B is higher than 0°C and lower than 23°C, the thickness of each layer of the base layer A is 10 to 60 μm, the thickness of each layer of the base layer B is 1 to 50 μm, and the average value of the thickness of each layer of the base layer A exceeds the average value of the thickness of each layer of the base layer B; The sheet for packaging electronic components, wherein the base material layer A and the base material layer B contain different thermoplastic resins as main components. [2] The sheet for packaging electronic components according to [1], wherein the number of layers obtained by alternately laminating the base material layer A and the base material layer B is 3 to 9. [3] The sheet for packaging electronic components according to [1] or [2], wherein the adhesive strength between the base material layer A and the base material layer B is 4N or more. [4] The sheet for packaging electronic components according to any one of [1] to [3], wherein the average thickness of each layer of the base material layer A is 1.001 times or more the average thickness of each layer of the base material layer B. [5] The sheet for packaging electronic components according to any one of [1] to [4], wherein the base layer A contains an ABS resin as a main component. [6] The sheet for packaging electronic components according to any one of [1] to [5], wherein the base material layer B contains a thermoplastic resin other than a PC-based resin as a main component. [7] A molded article comprising the sheet for packaging electronic parts according to any one of [1] to [6]. [8] The molded article according to [7], which is a container. [9] The molded article according to [7], which is a carrier tape. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a sheet for packaging electronic components, which can effectively suppress the generation of burrs and fluff while maintaining good formability suitable for producing packaging containers that can accommodate components with complex and diverse shapes, and a molded product comprising the sheet. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing the evaluation criteria for formability of the sheet for packaging electronic components according to the example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below, but the present invention is not limited to the following embodiments. [Electronic component packaging sheet] The electronic component packaging sheet according to this embodiment (hereinafter sometimes simply referred to as "the sheet") is an electronic component packaging sheet comprising a base sheet in which base material layers A and B are alternately laminated, wherein the difference in heat distortion temperature between the base material layers A and B is greater than 0°C and less than 23°C, the thickness of each layer of the base material layer A is 10 to 60 μm, the thickness of each layer of the base material layer B is 1 to 50 μm, the average thickness of each layer of the base material layer A exceeds the average thickness of each layer of the base material layer B, and the base material layers A and B contain different thermoplastic resins as main components. The sheet for packaging electronic components according to this embodiment can effectively suppress the occurrence of burrs and fluff while maintaining good formability suitable for producing packaging containers that can accommodate components with complex and diverse shapes.

[0012] (Base sheet) The sheet for packaging electronic components according to this embodiment includes a base sheet. The base sheet has a multilayer structure in which base layer A and base layer B are alternately laminated. By including such a multilayer structure, the sheet for packaging electronic components according to this embodiment can effectively suppress the generation of burrs and fluff. Furthermore, the formability of the sheet for packaging electronic components when it is molded into a carrier tape or the like is not reduced, and pockets of a desired shape can be formed. The number of layers obtained by alternately laminating substrate layers A and B, i.e., the total number of layers in the substrate sheet, is not particularly limited as long as the effects of the present invention according to the present embodiment are achieved. From the viewpoint of controlling the thickness of each layer during the formation of the substrate sheet, the total number of layers is preferably 2 to 70, more preferably 2 to 60, even more preferably 3 to 30, even more preferably 3 to 12, and even more preferably 3 to 9. By setting the total number of layers in the substrate sheet within the above range, it becomes easier to obtain a substrate sheet of the desired thickness while suppressing the generation of burrs and fluff. In one embodiment, it is preferable that the total number of laminated substrate layers A is greater than the total number of laminated substrate layers B. By designing the total number of laminated substrate layers A to be greater than the total number of laminated substrate layers B, the resin layers constituting both surfaces of the substrate sheet each become substrate layers A. With such a configuration, for example, when other layers such as conductive layers are provided on both surfaces of the substrate sheet, the interlayer adhesion between the substrate sheet and the other layers tends to be good.

[0013] <Base layer A and base layer B> The base layer A and base layer B constituting the base sheet contain different thermoplastic resins as their main components. Here, "contained as a main component" means that the proportion of the thermoplastic resin (the thermoplastic resin contained as the main component) in the resin composition (100% by mass) constituting base layer A or base layer B is higher than the proportion of each of the other components in the resin composition, for example, 50% by mass or more. In one embodiment, the proportion of the thermoplastic resin in the resin composition constituting base layer A or base layer B may be 100% by mass. In one embodiment, when the resin composition constituting base layer A or base layer B is composed of two thermoplastic resins, "contained as a main component" means that the proportion of one of the two thermoplastic resins (the thermoplastic resin contained as the main component) in the resin composition (100% by mass) constituting base layer A or base layer B is greater than 50% by mass. Furthermore, "different thermoplastic resins" not only refers to different types of thermoplastic resins but also includes thermoplastic resins with different physical properties. That is, the base layer A and the base layer B may contain different types of thermoplastic resins as the main component, or may contain the same thermoplastic resin as the main component but with different physical properties. From the viewpoint of making it easy to check the thickness of each layer during the formation of the base sheet, it is preferable that the base layer A and the base layer B contain different types of thermoplastic resins as the main component.

[0014] The base material layer A and the base material layer B have different heat distortion temperatures, and the difference in heat distortion temperatures is preferably higher than 0°C and less than 23°C, more preferably 3°C or higher and less than 23°C, even more preferably 4°C to 20°C, and even more preferably 4.2°C to 20°C. When the heat distortion temperature difference is 4.2°C to 20°C, it may be 4.7°C to 20°C, 5°C to 20°C, 10°C to 20°C, higher than 10°C and equal to or lower than 20°C, or 19°C to 20°C. By setting the heat distortion temperature difference between the base material layer A and the base material layer B within the above range, the sheet for packaging electronic components can easily maintain good formability not only in molding methods capable of high-speed mass production, such as vacuum forming, pressure forming, and vacuum pressure forming, but also in molding methods suitable for producing packaging containers for components with complex and diverse shapes, such as press forming and match mold forming, and the occurrence of burrs and fluff can be easily effectively suppressed. The heat distortion temperatures of base material layer A and base material layer B are not limited as long as the sheet for packaging electronic components maintains good formability suitable for manufacturing packaging containers for components with complex and diverse shapes and effectively suppresses the generation of burrs and fluff, even if the heat distortion temperature of base material layer A is higher than that of base material layer B, or even if the heat distortion temperature of base material layer B is higher than that of base material layer A. Preferably, the heat distortion temperature of base material layer B is higher than that of base material layer A, and the difference in heat distortion temperatures is higher than 0°C and less than 23°C, more preferably 3°C or higher but less than 23°C, even more preferably 4°C to 20°C, and even more preferably 4.2°C to 20°C. When the heat distortion temperature difference is 4.2°C to 20°C, it may be 4.7°C to 20°C, 5°C to 20°C, 10°C to 20°C, higher than 10°C but less than 20°C, or 19°C to 20°C. By setting the difference in heat distortion temperature between the base layer A and the base layer B within the above range, the sheet for packaging electronic components can easily maintain good formability not only in molding methods that enable high-speed mass production, such as vacuum forming, pressure forming, and vacuum pressure forming, but also in molding methods that are suitable for producing packaging containers that can accommodate parts with increasingly complex and diverse shapes, such as press forming and match mold forming, and can easily and effectively suppress the generation of burrs and fluff.

[0015] Here, as a method for producing a packaging container using an electronic component packaging sheet containing a thermoplastic resin, there is a thermoforming method in which the electronic component packaging sheet is molded by vacuum forming, pressure forming, vacuum pressure forming, press molding, match mold molding, etc. When molding by these thermoforming methods, the electronic component packaging sheet may be heated to plasticize it, or the mold may be heated. Here, vacuum forming is a forming method in which a thermoplastic resin sheet such as a thermoforming sheet is heated and softened, a vacuum is created between the mold and the sheet, and the sheet is tightly attached to the mold at atmospheric pressure to form the sheet. Pressure forming is a molding method in which a thermoplastic resin sheet such as a thermoforming sheet is heated and softened, and the sheet is then tightly attached to a mold using pressure from compressed air to form the sheet. Vacuum and pressure forming is a thermoforming method that combines vacuum forming and pressure forming. Press molding is a molding method in which a thermoplastic resin sheet such as a thermoforming sheet is heated and softened, and then the plasticized sheet is pressed between upper and lower dies to form a mold. Matched mold molding is a molding method in which a pair of heated male and female molds are brought into contact with a thermoplastic resin sheet such as a thermoforming sheet.

[0016] Generally, vacuum forming, pressure forming, and vacuum pressure forming methods involve heating and softening an electronic component packaging sheet with hot air at 400 to 600°C, and then using air pressure such as vacuum or compressed air to tightly pressurize the electronic component packaging sheet into a mold. While these methods allow for high-speed mass production, they are not suitable for manufacturing packaging containers with complex and diverse shapes. On the other hand, in general, in the press molding method, the electronic component packaging sheet is heated and softened with radiant heat of 100 to 300°C, and then the electronic component packaging sheet is brought into contact with a pair of dies and appropriately pressed to be molded. This makes it possible to mold the electronic component packaging sheet in a way that reproduces the details of the dies, and is suitable for producing packaging containers with complex and diverse shapes. In addition, in the match mold molding method, a pair of molds is heated to 100 to 300°C, and then the electronic component packaging sheet is brought into contact with the molds and molded by applying appropriate pressure. This makes it possible to reproduce the molds in minute detail, making it suitable for producing packaging containers with complex and diverse shapes.

[0017] In one embodiment, by setting the difference in heat distortion temperature between the base layer A and the base layer B within the above range, the electronic component packaging sheet can easily maintain good moldability and effectively suppress the generation of burrs and fuzz, even when the electronic component packaging sheet is molded by a press molding method in which the electronic component packaging sheet is heated and softened with radiant heat at 100 to 300°C and then brought into contact with a pair of dies to be molded, or when the electronic component packaging sheet is molded by a matched mold molding method in which a pair of dies is heated to 100 to 300°C and then the electronic component packaging sheet is brought into contact with the dies to be molded.

[0018] (thermoplastic resin) Examples of thermoplastic resins include polystyrene resins (PS resins), ABS resins, polyester resins, polycarbonate resins (PC resins), acrylonitrile-styrene binary copolymers (AS resins), etc. These thermoplastic resins may be used alone or in combination of two or more. Examples of PS resins include polystyrene resins, rubber-modified styrene resins (rubber-g-styrene resins (GPPS) or high impact styrene resins (HIPS)), etc. PS resins may be used alone or in combination of two or more. Examples of aromatic vinyl monomers for forming PS resins include styrene, alkyl-substituted styrenes (e.g., vinyltoluene, vinylxylene, p-ethylstyrene, p-isopropylstyrene, butylstyrene, pt-butylstyrene, etc.), halogen-substituted styrenes (e.g., chlorostyrene, bromostyrene, etc.), and α-alkyl-substituted styrenes in which an alkyl group is substituted at the α-position (e.g., α-methylstyrene, etc.). These aromatic vinyl monomers may be used alone or in combination of two or more. Of these monomers, styrene, vinyltoluene, α-methylstyrene, etc., are usually preferred, with styrene being particularly preferred. The PS resin preferably has an MFR measured in accordance with ISO 1133 of 1 to 30 g / 10 min, more preferably 2 to 25 g / 10 min.

[0019] ABS resins are primarily composed of a terpolymer of diene rubber, aromatic vinyl monomer, and vinyl cyanide monomer, typically referring to resins or resin compositions primarily composed of an acrylonitrile-butadiene-styrene terpolymer. Specific examples include acrylonitrile-butadiene-styrene terpolymers and mixtures of acrylonitrile-butadiene-styrene terpolymers and acrylonitrile-styrene binary copolymers. Among these, acrylonitrile-butadiene-styrene terpolymers are preferred as ABS resins, and mixtures of acrylonitrile-butadiene-styrene terpolymers and acrylonitrile-styrene binary copolymers are even more preferred. These polymers may contain, in addition to the above-mentioned monomer units, minor components of the styrene-based monomer, such as α-methylstyrene, vinyltoluene, dimethylstyrene, chlorostyrene, and vinylnaphthalene. Furthermore, trace components of vinyl cyanide monomers include those containing monomers such as methacrylonitrile, ethacrylonitrile, and fumaronitrile. Although the description of trace components will be omitted below, those containing these components are also included within the scope of not impairing the effects of the present invention. The ABS resins may be used alone or in combination of two or more. The MFR of the ABS resin measured in accordance with the ISO 1133 standard is preferably from 1 to 30 g / 10 min, more preferably from 2 to 25 g / 10 min.

[0020] Examples of polyester-based resins include polyester resins obtained from aromatic polyfunctional carboxylic acids or aliphatic polyfunctional carboxylic acids and polyfunctional glycols, and hydroxycarboxylic acid-based polyester resins. Examples of polyester resins obtained from aromatic polyfunctional carboxylic acids or aliphatic polyfunctional carboxylic acids and polyfunctional glycols include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene adipate, polybutylene adipate, and other copolymers thereof. Other copolymers include polyester resins copolymerized with polyalkylene glycols, polycaprolactone, and the like. Examples of hydroxycarboxylic acid-based polyester resins include polylactic acid, polyglycolic acid, polycaprolactone, and the like. In this embodiment, copolymers of the polyester resins exemplified above can also be used. The polyester-based resins may be used alone or in combination of two or more. The MFR of the polyester resin measured in accordance with the ISO 1133 standard is preferably from 1 to 30 g / 10 min, more preferably from 2 to 25 g / 10 min.

[0021] PC resins are resins derived from dihydroxy compounds, and among these, resins derived from aromatic dihydroxy compounds are preferred, and aromatic dihydroxy compounds (bisphenols) in which two aromatic dihydroxy compounds are bonded via a certain type of bonding group are particularly preferred. These resins can be produced by known production methods, and the production method is not particularly limited. Commercially available resins can also be used. The PC resins can be used alone or in combination of two or more types. The MFR of the PC resin measured in accordance with the ISO 1133 standard is preferably from 1 to 30 g / 10 min, more preferably from 2 to 25 g / 10 min.

[0022] AS-based resins are resins containing, as the main component, a binary copolymer of acrylonitrile and a styrene-based monomer. Examples of styrene-based monomers include styrene, alkyl-substituted styrenes (e.g., vinyltoluene, vinylxylene, p-ethylstyrene, p-isopropylstyrene, butylstyrene, pt-butylstyrene, etc.), halogen-substituted styrenes (e.g., chlorostyrene, bromostyrene, etc.), and α-alkyl-substituted styrenes in which an alkyl group is substituted at the α-position (e.g., α-methylstyrene, etc.). These styrene-based monomers may be used alone or in combination of two or more. Among these styrene-based monomers, styrene, vinyltoluene, α-methylstyrene, etc., are usually preferred, with styrene being particularly preferred.

[0023] The substrate layer A or B is preferably composed of a resin composition containing at least one resin selected from the thermoplastic resins described above as a primary component. For example, when the substrate layer A or B contains a PS-based resin as a primary thermoplastic resin, the PS-based resin content may be higher than the other components in the resin composition, for example, 50% by mass or more, and one or more modifiers may be included in an amount of 50% by mass or less. Examples of modifiers that can be included include styrene-diene block copolymers such as styrene-butadiene (SB) block copolymers, hydrogenated olefin-styrene block copolymers, and polyolefins. In one embodiment, when the substrate layer A or B contains a PS-based resin as a primary component and one modifier, the substrate layer A or B may contain less than 50% by mass of the modifier. Furthermore, when substrate layer A or substrate layer B contains a polycarbonate (PC) resin as the main thermoplastic resin, the PC resin may be contained in a proportion higher than the proportion of each of the other components in the resin composition, for example, 50% by mass or more, and one or more modifiers may be contained in a range of 50% by mass or less. Examples of modifiers that can be mixed include ABS resin, polyethylene terephthalate resin, and polybutylene terephthalate resin. In one embodiment, when substrate layer A or substrate layer B contains a PC resin as the main component and one modifier, substrate layer A or substrate layer B may contain the modifier in a range of less than 50% by mass. Similarly, when the base layer A or the base layer B contains ABS resin, polyester resin, AS resin, etc. as the main component, one or more resin components can be added as a modifier in a range of 50 mass% or less. If necessary, various additives such as lubricants, plasticizers, processing aids, etc. may be added to the resin composition.

[0024] In one embodiment, the thermoplastic resin contained in the base layer A is preferably an ABS resin. If the base layer A is a layer containing an ABS resin as a main component, the formability of the resulting sheet for packaging electronic components can be easily maintained and burrs can be more effectively suppressed. The proportion of the ABS resin contained in the base layer A is preferably within a range that allows adjustment so that the difference in heat distortion temperature between the base layer A and the base layer B is greater than 0° C. and less than 23° C., and is more preferably 50% by mass or more, even more preferably 60 to 100% by mass, even more preferably 80 to 100% by mass, and even more preferably 100% by mass, relative to the total mass of the resin composition constituting the base layer A. Furthermore, from the viewpoints of strength and moldability, the ABS resin more preferably contains butadiene rubber in an amount of 5 to 30%.

[0025] When the base layer A is a layer containing an ABS resin as a main component, the base layer A may contain an ABS resin and another thermoplastic resin. The other thermoplastic resin is preferably a resin compatible with the ABS resin, more preferably a PC resin or an AS resin. When the base layer A contains an ABS resin and the other thermoplastic resin, the mass ratio of the ABS resin to the other thermoplastic resin (ABS resin / other thermoplastic resin) in the resin composition constituting the base layer A may be in the range of 99 / 1 to 50 / 50.

[0026] Furthermore, when the base layer A is a layer containing an ABS resin as a main component, the base layer B is preferably a layer containing a thermoplastic resin other than an ABS resin as a main component. If the base layer B is a layer containing a thermoplastic resin other than an ABS resin as a main component, the occurrence of burrs and fluffing can be more effectively suppressed. Examples of the thermoplastic resin contained as a main component in the base layer B include PC resin, AS resin, PS resin, and polyester resin. However, a resin that can be prepared so that the difference in heat distortion temperature between the base layer A and the base layer B is greater than 0°C and less than 23°C is preferred. Resins other than PC resins, i.e., AS resin, PS resin, and polyester resin, are more preferred, and AS resin is even more preferred. When the base layer B contains an AS-based resin as a main component, the proportion of the AS-based resin in the resin composition constituting the base layer B is preferably 50 mass % or more, more preferably 60 to 100 mass %, and even more preferably 70 to 100 mass %, relative to the total mass of the resin composition. In one embodiment, it is preferred that substrate layer A is a layer containing an ABS resin as a main component, and substrate layer B is a layer containing an AS resin as a main component. By configuring substrate layer A and substrate layer B in this manner, it becomes easier to adjust the difference in heat distortion temperature between substrate layer A and substrate layer B to be higher than 0°C and less than 23°C, and / or it becomes easier to adjust the adhesive strength between substrate layer A and substrate layer B to be sufficient.

[0027] Furthermore, when the base layer B is a layer containing a thermoplastic resin other than an ABS resin as a main component, the base layer B may contain another thermoplastic resin different from the main thermoplastic resin. For example, when the base layer B contains an AS resin as a main component, the other thermoplastic resin may be an ABS resin, a PC resin, a PS resin, or a polyester resin, and preferably a PC resin. In this case, the base layer A may contain an ABS resin as a main component. By configuring the base layer A and the base layer B in this way, it becomes easier to adjust the difference in heat distortion temperature between the base layer A and the base layer B to be higher than 0°C and lower than 23°C, and / or it becomes easier to adjust the adhesive strength between the base layer A and the base layer B to be sufficient.

[0028] (Recycled material) In addition to the resins described above, each of which accounts for 100% by mass, the base material layer A and / or the base material layer B may contain recycled materials. The recycled materials are obtained by crushing and re-pelletizing the "edges" that are generated when both ends of the sheet extruded from the die are trimmed during extrusion molding of a laminate sheet during the production of a sheet for packaging electronic components, and the beginning of the sheet when it is wound up, which are parts that cannot be used as a product as is. Even when recycled materials are added in this way, it is extremely important from the viewpoint of productivity that the properties of the produced packaging sheet are good. In one aspect, the recycled material may be derived from the sheet for packaging electronic components to be manufactured. That is, the sheet for packaging electronic components according to this embodiment, which includes a base sheet and, optionally, a conductive layer, may be pulverized and re-pelletized to obtain a recycled material, which may be contained in the base layer A and / or the base layer B. Here, the amount of recycled material contained in base layer A or base layer B is preferably within a range that can be adjusted so that the difference in heat distortion temperature between base layer A and base layer B is greater than 0°C and less than 23°C even when recycled material is added, and is preferably 50 parts by mass or less, and more preferably 30 parts by mass or less, per 100 parts by mass of base layer A or base layer B. When base layer A and / or base layer B contain recycled material, the heat distortion temperature can be calculated from the type and amount of thermoplastic resin used to make the recycled material and the type and amount of the conductive layer. When the recycled material content in base layer A and / or base layer B is within the above range, the electronic component packaging sheet can easily maintain good formability not only in molding methods that enable high-speed mass production, such as vacuum forming, pressure forming, and vacuum pressure forming, but also in molding methods that are suitable for producing packaging containers for parts with complex and diverse shapes, such as press forming and match mold forming, and can easily effectively suppress the generation of burrs and fluff.

[0029] (layer thickness) The thickness of each layer of the base layer A constituting the base sheet is preferably 10 to 60 μm, more preferably 20 to 60 μm. The thickness of each layer of the base layer B is preferably 1 to 50 μm, more preferably 15 to 50 μm. Furthermore, in the sheet for packaging electronic components according to this embodiment, the average thickness of each layer of the base layer A exceeds the average thickness of each layer of the base layer B. By alternately laminating base layers A and B containing different thermoplastic resins as main components and making the average thickness of each layer of the base layer A exceed the average thickness of each layer of the base layer B, it is possible to effectively suppress the generation of burrs and fluff during sheet punching. In this specification, the "thickness of each layer" refers to the maximum thickness of each layer. The thickness of each layer of the base layers A and B in the base sheet can be measured, for example, by observing the cross section of the base sheet using a microscope or the like. The individual layers of the base layer A included in the base sheet may all have the same thickness or may have different thicknesses. From the viewpoint of preventing the sheet from becoming tangled when rolled up, it is preferable that the individual layers of the base layer A all have the same thickness. Similarly, the individual layers of the base layer B may all have the same thickness or may have different thicknesses, but from the viewpoint of preventing the sheet from becoming tangled when rolled up, it is preferable that the individual layers of the base layer B all have the same thickness.

[0030] (Layer thickness accuracy) The thickness of each layer constituting the base sheet can be measured by observation using a microscope or the like, as described above in the "Layer Thickness" section. The layer thickness accuracy can be calculated based on the difference between the target thickness during production of the electronic component packaging sheet and the actual measured thickness of the layer thickness measured in this way. For example, a difference between the target thickness and the actual measured thickness of the surface layer or base layer of the sheet during film formation of the sheet of ±10% to 20% can be judged as "good," a difference of less than ±10% can be judged as "excellent," and a difference of more than ±20% can be judged as "unacceptable." The measurement position of the film in the layer can be the same for both comparisons, but for example, both ends and / or the center of the cross section in the direction perpendicular to the sheet's machine direction (TD direction) can also be measured.

[0031] The burrs and fuzz that occur during sheet molding are thought to be caused by the resin being stretched during punching. While reducing the thickness of the substrate portion of the sheet can relatively reduce the occurrence of burrs and fuzz, simply reducing the thickness of the substrate portion makes it difficult to meet the physical properties required of an electronic component packaging sheet. The present inventors have discovered that by using a multilayer substrate sheet and reducing the thickness of each layer, the occurrence of burrs and fuzz due to resin stretching can be reduced. Furthermore, they have discovered that the occurrence of burrs and fuzz can be more effectively reduced by alternately laminating two types of substrate layers A and B, each containing different thermoplastic resins as main components, and by designing the average thickness of each layer of substrate layer A to be greater than the average thickness of each layer of substrate layer B. In the electronic component packaging sheet according to this embodiment, which has such a configuration, substrate layer B serves as a "dividing layer" for substrate layer A, effectively suppressing the elongation of the resin in substrate layer A. Furthermore, the sheet for packaging electronic components according to this embodiment, which includes such a base sheet, also has good formability suitable for producing packaging containers that can accommodate components with increasingly complex and diverse shapes.

[0032] The average thickness of each layer of the base layer A is preferably 10 to 60 μm, more preferably 20 to 60 μm. The average thickness of each layer of the base layer B is preferably 1 to 50 μm, more preferably 15 to 50 μm. Here, "the average thickness of each layer of the base layer A" refers to the value obtained by dividing the total thickness of the base layer A in the base sheet by the number of layers of the base layer A. In other words, when the thickness of one layer of the base layer A is "a1," it means the value calculated by (a1 + a2 + a3 + ··· + an) / n. Here, "n" refers to the total number of layers of the base layer A in the base sheet. The same applies to the base layer B.

[0033] The average thickness of each layer of base layer A is preferably 1.001 times or more the average thickness of each layer of base layer B. There are no particular limitations on the upper limit as long as the effects of the present invention are achieved, but from the viewpoint of film formability, it is preferably 20 times or less. In one aspect, the average thickness of each layer of base layer A is more preferably 1.001 to 20 times, even more preferably 1.01 to 15 times, even more preferably 1.05 to 12 times, even more preferably 1.2 to 10 times, and even more preferably 1.3 to 2 times the average thickness of each layer of base layer B. By setting the average thickness of each layer of base layer A within the above range, burrs and fluffing can be more effectively suppressed.

[0034] From the viewpoint of strength and formability when made into a carrier tape, the thickness of the base sheet is preferably 50 to 700 μm, more preferably 75 to 600 μm, even more preferably 90 to 450 μm, even more preferably 100 to 300 μm, even more preferably 150 to 200 μm, even more preferably 160 to 180 μm, and even more preferably 160 to 170 μm. The sheet for packaging electronic components according to this embodiment may be composed only of the above-mentioned base sheet. When the sheet for packaging electronic components according to this embodiment is a conductive sheet, a conductive layer may be formed on at least one surface of the base sheet. In addition, an optional layer (for example, an antifouling layer) may be provided on the base sheet.

[0035] (Conductive layer) The sheet for packaging electronic components according to this embodiment may include a conductive layer on at least one surface of the base sheet. The conductive layer is a layer made of a resin composition containing a conductive component. The resin composition constituting the conductive layer is not particularly limited as long as it has the effect of the present invention, and examples thereof include a resin composition containing 65 to 95 mass %, preferably 70 to 90 mass %, of the above-mentioned thermoplastic resin and 5 to 35 mass %, preferably 10 to 30 mass %, of a conductive agent such as carbon black, relative to the total mass of the resin composition. Examples of carbon black include furnace black, channel black, and acetylene black, and preferably those having a large specific surface area and capable of achieving high conductivity with a small amount added. Specifically, those having an average primary particle diameter of 20 to 100 nm are preferred, and those having an average primary particle diameter of 25 to 65 nm are more preferred. The average primary particle diameter refers to the average particle diameter measured using a transmission electron microscope. When a conductive layer is provided, its thickness is not particularly limited. From the viewpoint of easily improving the mechanical strength of the sheet for packaging electronic components, the thickness of the conductive layer is preferably 3 to 100 μm, more preferably 10 to 50 μm. When the thickness of the conductive layer is 10 to 50 μm, it may be 15 to 30 μm or 15 to 20 μm.

[0036] (Adhesion strength (interlayer adhesion)) The sheet for packaging electronic components according to this embodiment includes a base sheet in which base layers A and B are alternately laminated. When the electronic component packaging sheet is used after being formed into, for example, a carrier tape, the components are stored in a storage section of the carrier tape, a cover tape serving as a lid is attached to the carrier tape, and the components are packaged by peeling the cover tape off the carrier tape. Therefore, during the process of packaging and removing the components, it is preferable that the adhesive strength between the layers of the base material of the carrier tape and between the base material layer and the conductive layer is sufficient to prevent undesired peeling. In one embodiment, the adhesion strength between the base material layer A and the base material layer B of the sheet for packaging electronic components is preferably higher than 0.6 N, and more preferably 4 N or more. When the adhesion strength between the base material layer A and the base material layer B is 4 N or more, it may be 10 N or more, 20 N or more, or 30 N or more. When the base material layer A and the base material layer B have such an adhesion strength, undesired peeling can be easily suppressed in the normal use of the sheet for packaging electronic components, as described above, and stable packaging properties can be easily achieved.

[0037] Here, the adhesion strength can be measured, for example, by pressing and laminating the base material layer A and the base material layer B together, and then peeling the laminated sheets. In this case, the pressing pressure and the pulling speed for peeling are not limited as long as they are within ranges that allow appropriate measurement of the adhesion strength between the base material layer A and the base material layer B in the sheet for packaging electronic components. Specifically, for example, using a mini test press (manufactured by Toyo Seiki Seisakusho, catalog No. 519), resin pellets are sandwiched between the upper and lower press plates to produce evaluation sheets for base layer A and base layer B. The press pressure at this time can be 10 MPa. The temperatures of the upper and lower heat press plates can be set to a value 100°C higher than the heat distortion temperature of the resin pellets used. The thickness of each sheet of base layer A and base layer B can be 100 μm. Then, both sheets of base layer A and base layer B are bonded together using a mini test press manufactured by Toyo Seiki Seisakusho. The press pressure at this time can be 0.1 MPa, and the temperatures of the upper and lower heat press plates can be set to a value 100°C higher than the heat distortion temperature of base layer A. The size of the bonded sheet can be, for example, length x width = 150 mm x 20 mm. When laminating, to ensure smooth measurement of interlayer adhesion strength, a heat-resistant sheet may be sandwiched between the 20 mm x 20 mm portions at the ends of the laminated sheets to prevent base layer A and base layer B from being bonded together in that area. Next, the laminated sheets are peeled off, and the average adhesion strength N at this time can be taken as the adhesion strength N. For example, the laminated sheets can be peeled off using a Strograph VE1D manufactured by Toyo Seiki Seisakusho under conditions of a temperature of 23°C, humidity of 50%, a peeling speed of 300 mm / min, and a peeling angle of 180°, and the adhesion strength N can be measured.

[0038] [Method of manufacturing electronic component packaging sheets] The method for manufacturing the electronic component packaging sheet according to this embodiment can be the same as that for manufacturing a general multilayer sheet. For example, the method described in JP 2007-307893 A can be employed. Specifically, the resin composition for forming the base layer A and the resin composition for forming the base layer B are fed into separate extruders, melt-kneaded, and then fed to a feed block to laminate the base layer A and the base layer B alternately. The extrusion rate is adjusted so that the thickness of each layer of the base layer A is in the range of 10 to 60 μm, the thickness of each layer of the base layer B is in the range of 1 to 50 μm, and the average thickness of each layer of the base layer A exceeds the average thickness of each layer of the base layer B, and preferably 3 to 70 layers are laminated to form a multilayer base sheet. When the electronic component packaging sheet according to this embodiment is to be a conductive sheet, a resin composition for forming a conductive layer, melt-kneaded in a separate extruder, can be laminated on one or both surfaces of the base sheet to form the electronic component packaging sheet.

[0039] [Molded body] The molded article according to this embodiment comprises any one of the electronic component packaging sheets described above in the "Electronic component packaging sheet." The electronic component packaging sheet can be molded into a molded article by a known thermoforming method such as vacuum forming, pressure forming, vacuum pressure forming, press forming, or match mold forming. Preferred examples of molded articles from the electronic component packaging sheet include containers for storing electronic components, carrier tapes (embossed carrier tapes), and the like. The electronic component packaging sheet according to this embodiment can produce molded articles with extremely little burrs or fluff on the cross section when slitting the sheet or punching sprocket holes, etc. This is particularly effective in embossing carrier tape. By using these molding and secondary processing methods, it is possible to produce embossed carrier tapes with excellent dimensional accuracy, such as slit width and punched hole diameter, and with significantly reduced burr generation during punching.

[0040] More specifically, in the secondary processing steps of slitting and punching of the embossed carrier tape or the like, which is the molded product of the electronic component packaging sheet according to this embodiment, the punching conditions are a wide range of pin / die clearance (5 to 50 μm) on one side, and a wide range of punching speeds (10 to 300 mm / sec), which can produce sprocket holes with stable hole diameters and significantly reduced fuzz and burrs. Furthermore, even in the slitting process using a ring-shaped combination blade, it is possible to obtain sprocket holes with stable sheet width and minimal burrs and fuzz.

[0041] Furthermore, since the sheet for packaging electronic components according to this embodiment has good formability, pockets for storing electronic components can be formed into the desired shape. Specifically, pockets can be formed with the desired angle necessary for stably storing electronic components, and holes do not form in the bottom or wall of the pockets.

[0042] In particular, the electronic component packaging sheet according to this embodiment has good formability not only in forming methods that enable high-speed mass production, such as vacuum forming, pressure forming, and vacuum pressure forming, but also in forming methods that are suitable for manufacturing packaging containers that can accommodate parts with increasingly complex and diverse shapes, such as press forming and match mold forming. In the press molding method, the electronic component packaging sheet is heated and softened with radiant heat at 100 to 300°C, and then the electronic component packaging sheet is brought into contact with a pair of dies and molded by applying appropriate pressure. In the match mold molding method, the pair of dies is heated to 100 to 300°C, and then the electronic component packaging sheet is brought into contact with the dies and molded by applying appropriate pressure. Therefore, the press molding method and the match mold molding method enable molding that reproduces the details of the dies, and are suitable for producing packaging containers with complex and diverse shapes.

[0043] The container and embossed carrier tape according to this embodiment can be used for storing and transporting electronic components by storing electronic components in a storage section formed by the above-described molding method, and then covering the storage section with a cover tape and winding it up into a reel to form a carrier tape body.

[0044] A more preferred embodiment of the electronic component packaging sheet according to the present embodiment is a sheet for packaging electronic components, comprising a multilayer base sheet formed by alternately laminating base layers A containing an ABS resin as a main component and base layers B containing an AS resin as a main component, both surfaces of the base sheet being made of the base layer A, the difference in heat distortion temperature between the base layer A and the base layer B being greater than 0°C and less than 23°C, the thickness of each layer of the base layer A being 10 to 60 μm, the thickness of each layer of the base layer B being 1 to 50 μm, and the average thickness of each layer of the base layer A being greater than the average thickness of each layer of the base layer B. It is even more preferred that the number of layers formed by alternately laminating the base layer A and the base layer B is 3 to 9, the adhesive strength between the base layer A and the base layer B is 4 N or greater, and / or the average thickness of each layer of the base layer A is 1.001 to 10 times the average thickness of each layer of the base layer B. A more preferred embodiment of the molded article according to the present embodiment is a molded article comprising a sheet for packaging electronic components, comprising a multilayer base sheet formed by alternately laminating base layers A containing an ABS resin as a main component and base layers B containing an AS resin as a main component, both surfaces of the base sheet being made of the base layer A, the difference in heat distortion temperature between the base layer A and the base layer B being greater than 0°C and less than 23°C, the thickness of each layer of the base layer A being 10 to 60 μm, the thickness of each layer of the base layer B being 1 to 50 μm, and the average thickness of each layer of the base layer A being greater than the average thickness of each layer of the base layer B. It is even more preferred that the number of layers of the base layer A and the base layer B alternately laminated is 3 to 9, the adhesion strength between the base layer A and the base layer B is 4 N or greater, and / or the average thickness of each layer of the base layer A is 1.001 to 10 times the average thickness of each layer of the base layer B. [Example]

[0045] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0046] [Creating packaging sheets for electronic components] (Examples 1 to 8, Comparative Examples 1 to 10) For Examples 1 to 3, 6, and 7 and Comparative Examples 1 to 10, raw materials shown in the compositions of base layer A and base layer B in Tables 1 and 2 were prepared, and in Examples 4 and 5, 10 parts by mass and 30 parts by mass of b-4 (recycled material) were weighed out for 100 parts by mass of b-3, respectively. In Example 8, 15 parts by mass of b-4 (recycled material) was weighed out for a total of 100 parts by mass of b-1 and b-3, and the mixture was uniformly mixed using a high-speed mixer to form base layer B. The conductive layer was made of a resin composition obtained by kneading 80% by mass of polycarbonate resin (manufactured by Teijin Limited, product name: "Panlite (registered trademark) L-1225L") and 20% by mass of acetylene black (manufactured by Denka Co., Ltd., product name: "Denka Black (registered trademark) Granules", average primary particle diameter: 35 nm) using a φ30 mm vented twin-screw extruder and pelletizing the mixture using a strand cutting method. First, the resin compositions and conductive layer resin compositions shown in Tables 1 and 2 were extruded by a feed block method using a φ65 mm extruder (L / D=28), a φ50 mm extruder (L / D=28), a φ40 mm extruder (L / D=26) and a 500 mm wide T-die to form conductive layers on both sides of a base sheet in which base layers A and B were alternately laminated, thereby obtaining a sheet for packaging electronic components. The thicknesses and number of each layer of base layers A and B, the thickness of the conductive layer, the thickness of the base sheet, and the total thickness of the sheet for packaging electronic components obtained were as shown in Tables 1 and 2.

[0047] Example 2 Example 2 is an example of a sheet for packaging electronic parts that does not have a conductive layer. The resin compositions shown in Table 1 were laminated alternately as base material layers A and B by a feed block method using a φ65 mm extruder (L / D=28), a φ50 mm extruder (L / D=28) and a 500 mm wide T-die, to produce a base sheet, thereby obtaining a sheet for packaging electronic components. The thickness and number of each layer of base layers A and B, the thickness of the base sheet, and the total thickness of the sheet for packaging electronic components obtained were as shown in Table 1.

[0048] Details of the raw materials shown in Tables 1 and 2 are as follows. a-1: Acrylonitrile-butadiene-styrene copolymer (ABS): Manufactured by Denka Co., Ltd., product name "SE-10". Heat distortion temperature: 100°C. a-2: Polycarbonate resin (PC): Teijin Limited, product name "Panlite L-1225L". Heat distortion temperature: 150°C. a-3: High impact polystyrene resin (HIPS): Toyo Styrene Co., Ltd., product name "E640N". Heat distortion temperature 100°C. b-1: Polycarbonate resin (PC): Teijin Limited, product name "Panlite L-1225L". Heat distortion temperature: 150°C. b-2: Acrylonitrile-butadiene-styrene copolymer (ABS): Denka Co., Ltd., product name "SE-10". Heat distortion temperature: 100°C. b-3: Acrylonitrile-styrene copolymer (AS): manufactured by Denka Co., Ltd., product name "AS-EXS". Heat distortion temperature: 105°C. b-4: Recycled material: A material made by crushing and re-pelletizing parts that cannot be used in products when manufacturing a laminated sheet by extrusion molding, such as both ends (edges) of the sheet extruded from a mold (T-die) or the starting end when the sheet is wound up. The recycled materials used in Examples 4, 5, and 8 were recycled materials obtained in the manufacture of electronic component packaging sheets in Examples 4, 5, and 8.

[0049] The average primary particle size of the acetylene black in the conductive layer is a value determined by the following method. First, a dispersion sample was prepared by dispersing acetylene black in chloroform for 10 minutes using an ultrasonic disperser at 150 kHz and 0.4 kW. This dispersion sample was sprinkled and fixed on a carbon-reinforced support film, and then photographed using a transmission electron microscope (JEOL Ltd., JEM-2100). The particle diameters of 1,000 or more inorganic filler particles (maximum diameter for shapes other than spherical) were measured randomly from images magnified 50,000 to 200,000 times using an Endter device, and the average value was taken as the average primary particle diameter.

[0050] [Evaluation of electronic component packaging sheets] The electronic component packaging sheet obtained in each example was cut in the extrusion direction to prepare sheet samples, which were then left for 24 hours in an atmosphere at a temperature of 23°C and a relative humidity of 50%. Thereafter, the formability and punching burr characteristics were evaluated under the following conditions.

[0051] (1) Measurement of layer thickness (thickness of individual layers, total thickness of electronic component packaging sheet) The thickness of each layer constituting the substrate sheet can be measured by observation using a microscope or the like, as described above in "Layer Thickness." In this measurement, a shape analysis laser microscope (Keyence Corporation, model: VK-X100) was used to measure the thickness of the layer by cutting out the cross section of the substrate sheet with a single-edged knife. The thickness was measured at both ends and the center of the cross section in the direction perpendicular to the sheet flow direction (TD), and the average value was used for evaluation.

[0052] (2) Layer thickness accuracy The layer thickness was measured in the same manner as in (1). As described above in "Layer Thickness Accuracy," the layer thickness accuracy was calculated based on the difference between the target thickness during production of the electronic component packaging sheet and the actually measured thickness. When the difference between the target thickness of the surface layer and each base material layer of the sheet during sheet formation was between ±10% and 20%, it was expressed as "good," when it was less than ±10%, it was expressed as "excellent," and when it was more than ±20%, it was expressed as "poor." The layer thickness accuracy of each of the surface layer and each base material layer constituting one electronic component packaging sheet was evaluated, and the layer thickness accuracy of the electronic component packaging sheet was evaluated based on the average value, i.e., "excellent," "good," or "poor."

[0053] (3) Moldability using the vacuum molding method (hot air heating-vacuum molding) A sheet sample slit to a width of 8 mm was molded using a vacuum rotary molding machine (manufactured by Muehlbauer, product name: "CT8 / 24") at a heater temperature of 450°C under an atmosphere of 23°C and 50% relative humidity to produce an 8 mm-wide carrier tape. The pocket size of the carrier tape was 3 mm in the machine direction, 3 mm in the width direction, and 1 mm in the depth direction. The pockets of the obtained molded product were observed under a microscope, and the sharpness of the pocket corners (periphery of the bottom wall) was evaluated on a 5-point scale according to the evaluation criteria shown in Figure 1. That is, in the molded product (carrier tape) 10, the sharpness of the pocket corners 11 of the pocket 20 was visually confirmed and evaluated as falling under any of evaluation criteria 1 to 5. The presence or absence of holes in the pocket 20 was also visually confirmed. Based on these results, moldability was evaluated according to the following criteria. A rating of good or better was considered to be acceptable (good moldability). <Judgment criteria> Excellent: The sharpness of the pocket corners was rated 4 or higher, and there were no holes. Good: The sharpness of the pocket corners was rated at 3 or more and less than 4, and there were no holes. Unacceptable: There was a hole, or there was no hole, but the sharpness of the pocket corners was 2 or less.

[0054] (4) Formability using the press molding method (radiant heating-press molding) A sheet sample slit to a width of 24 mm was molded into a 24 mm-wide carrier tape using a press molding machine manufactured by our company under conditions of 23°C and 50% relative humidity, with a top and bottom heater temperature of 280°C, a mold temperature of 40°C, a heating time, pressing time, and mold cooling time of 4 seconds each, and a press pressure of 0.5 MPa. The pocket size of the carrier tape was 12 mm in the machine direction, 13 mm in the width direction, and 4 mm in the depth direction. The pockets in the resulting molded product were observed under a microscope, and the sharpness of the pocket corners (the periphery of the bottom wall) was evaluated on a 5-point scale according to the evaluation criteria shown in Figure 1. Specifically, the sharpness of the pocket corners 11 of the pocket 20 in the molded product (carrier tape) 10 was visually confirmed and evaluated according to evaluation criteria 1 to 5. The presence or absence of holes in the pocket 20 was also visually confirmed. Based on these results, moldability was evaluated according to the following criteria. A rating of good or better was considered pass (good moldability). <Judgment criteria> Excellent: The sharpness of the pocket corners was rated 4 or higher, and there were no holes. Good: The sharpness of the pocket corners was rated at 3 or more and less than 4, and there were no holes. Unacceptable: There was a hole, or there was no hole, but the sharpness of the pocket corners was 2 or less.

[0055] (5) Punching burr characteristics Sheet samples slit to a width of 8 mm were punched out using a vacuum rotary molding machine (manufactured by Muehlbauer, product name: "CT8 / 24") in an atmosphere of 23°C and 50% relative humidity, and the burrs and fuzz in the punched holes were evaluated. Punching was carried out at a speed of 240 m / h using a punching device equipped with a cylindrical punching pin with a sprocket hole pin tip diameter of 1.5 mm and a die hole with a diameter of 1.58 mm. The punched holes in the sheet formed above were photographed using a microscopic measuring instrument (Mitutoyo Corporation, product name "MF-A1720H (Image Unit 6D)") under a light source environment with 0% incident light, 40% transmitted light, and 0% ring light. Ten holes with a diameter of 1.5 mm were observed, and the number of burrs and fluffs 0.15 mm or longer was counted. The results were evaluated according to the following criteria, with a score of good or better being considered pass (burr and fluff generation suppressed). <Judgment criteria> Excellent: The number of burrs and fluffs was less than 6. Good: The number of burrs and fluffs was 6 or more but less than 10. Unacceptable: There were 10 or more burrs or fluffs.

[0056] (6) Interlayer adhesion strength (interlayer adhesion) Using a mini test press (manufactured by Toyo Seiki Co., Ltd., catalog No. 519), resin pellets were sandwiched between the upper and lower press plates to produce evaluation sheets for base layer A and base layer B. The press pressure was 10 MPa, and the temperatures of the upper and lower heat press plates were set to a value 100°C higher than the heat distortion temperature of the resin pellets used. The thickness of each sheet of base layer A and base layer B was 100 μm. The sheets of base material layer A and base material layer B were then bonded together using a mini test press manufactured by Toyo Seiki Co., Ltd. The press pressure was 0.1 MPa, and the temperatures of the upper and lower plates of the heat press were set to a value 100°C higher than the heat distortion temperature of base material layer A. The size of the bonded sheet was 150 mm x 20 mm. During bonding, to ensure smooth measurement of interlayer adhesion strength, a heat-resistant sheet was sandwiched between the sheets in a 20 mm x 20 mm section at the end of the bonded sheet, preventing the bonding of base material layer A and base material layer B in that section, thereby producing a bonded sheet. Using a Strograph VE1D manufactured by Toyo Seiki Co., Ltd., the laminated sheets were peeled at a peel speed of 300 mm / min and a peel angle of 180° in an environment of 23°C and 50% humidity, and the average strength N at that time was taken as the adhesion strength N.

[0057] The evaluation results of the sheets produced in each of the Examples and Comparative Examples are summarized in Tables 1 and 2, respectively. [Table 1]

[0058] [Table 2]

[0059] As shown in Table 1, the sheets for packaging electronic components of Examples 1 to 8, which satisfy the constitution of the present invention, have good formability when formed by a press forming method (radiant heating-press forming), and furthermore, it was found that the occurrence of burrs and fluff during sheet punching can be sufficiently effectively suppressed. The press forming method is a forming method suitable for producing packaging containers that can accommodate parts with complex and diverse shapes. On the other hand, as shown in Table 2, the sheets for packaging electronic components of Comparative Examples 1 to 10, which do not satisfy the constitution of the present invention, had poor formability in the press molding method (radiant heating-press molding). From the above results, it was confirmed that the sheet for packaging electronic components according to the present invention maintains good formability when molded by press molding, and can effectively suppress the occurrence of burrs and fluff. [Explanation of symbols]

[0060] 10 Molded products 11 Pocket corner 20 pockets

Claims

1. A sheet for packaging electronic components comprising a base sheet in which base layer A and base layer B are alternately laminated, a difference in heat distortion temperature between the base material layer A and the base material layer B is higher than 0°C and lower than 23°C; the thickness of each layer of the base layer A is 10 to 60 μm, the thickness of each layer of the base layer B is 1 to 50 μm, and the average value of the thickness of each layer of the base layer A is greater than the average value of the thickness of each layer of the base layer B; The sheet for packaging electronic components, wherein the base material layer A and the base material layer B contain different thermoplastic resins as main components.

2. 2. The sheet for packaging electronic components according to claim 1, wherein the number of layers obtained by alternately laminating the base material layer A and the base material layer B is 3 to 9.

3. 3. The sheet for packaging electronic components according to claim 1, wherein the adhesive strength between the base material layer A and the base material layer B is 4N or more.

4. 3. The sheet for packaging electronic components according to claim 1, wherein an average thickness of each layer of the base material layer A is 1.001 times or more the average thickness of each layer of the base material layer B.

5. The sheet for packaging electronic components according to claim 1 or 2, wherein the base layer A contains an ABS resin as a main component.

6. The sheet for packaging electronic components according to claim 1 or 2, wherein the base layer B contains a thermoplastic resin other than a PC-based resin as a main component.

7. A molded article comprising the sheet for packaging electronic parts according to claim 1 or 2.

8. The molded article according to claim 7, which is a container.

9. The molded article according to claim 7, which is a carrier tape.

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