Sheet for electronic component packaging

Abstract

The present invention provides an electronic component packaging sheet capable of effectively suppressing the generation of fuzz and burrs, the electronic component packaging sheet comprising a base sheet having at least one base layer, the base layer comprising a thermoplastic resin (I), and a resin (II) comprising at least one copolymer selected from the group consisting of a (meth)alkyl acrylate copolymer (A) having a weight average molecular weight of 700000 to 4300000 and a styrene-acrylonitrile copolymer (B).

Description

Technical Field

[0001] This invention relates to sheets for packaging electronic components. Background Technology

[0002] As packaging containers for semiconductors, electronic components, especially integrated circuits (ICs) and electronic components containing ICs, trays (injection trays, vacuum-formed trays, etc.), magazines, and carrier tapes (embossed carrier tapes) are used. The thermoplastic resins used as the components of these packaging containers 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 viewpoint of preventing IC malfunctions and damage caused by static electricity, for example, packaging containers have been proposed that have a conductive layer containing a resin incorporating conductive agents such as conductive carbon black on the surface of a substrate layer containing ABS-based resin (Patent Documents 1, 2, etc.).

[0003] The aforementioned trays and carriers are formed from sheets of material used for packaging electronic components using known methods. During the forming process, especially when cutting the original sheet and punching sprocket holes, burrs and rough edges may occur. If these burrs and rough edges fall into the storage compartment (bag-like object) and adhere to the electronic components, it can cause defects in the electronic components. In recent years, with the miniaturization of electronic components, there is an even stronger demand to reduce defects caused by the adhesion of burrs and rough edges.

[0004] For this problem, it has been proposed to incorporate polyolefins, styrene-butadiene-styrene block copolymers, or styrene-ethylene-butene-styrene block copolymers into the substrate layer and conductive layer to reduce burrs and fuzzing (e.g., patent documents 3 and 4). However, the previous methods have not been sufficient to suppress burrs and fuzzing.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 9-174769

[0008] Patent Document 2: Japanese Patent Application Publication No. 2002-292805

[0009] Patent Document 3: International Publication No. 2006 / 030871

[0010] Patent Document 4: Japanese Patent Application Publication No. 2003-170547 Summary of the Invention

[0011] The problem the invention aims to solve

[0012] Therefore, the object of the present invention is to provide a sheet for packaging electronic components that can effectively suppress the generation of fuzz and burrs, and a molded body comprising the above-mentioned sheet.

[0013] Solution for solving the problem

[0014] The inventors of this application have diligently explored the above-mentioned problems and discovered that as long as the electronic component packaging sheet has a substrate sheet having one or more substrate layers, and the substrate layer is composed of a resin (II) containing at least one copolymer selected from high molecular weight (meth) acrylate copolymer and styrene-acrylonitrile copolymer and a thermoplastic resin (I), the above-mentioned problems can be solved, and the present invention is thus completed.

[0015] That is, the present invention has the following solution.

[0016] [1] A sheet for packaging electronic components, comprising a substrate sheet having at least one substrate layer, the substrate layer comprising: a thermoplastic resin (I), and a resin (II) comprising at least one copolymer selected from alkyl methacrylate copolymer (A) and styrene-acrylonitrile copolymer (B) having a weight average molecular weight of 700,000 to 4,300,000.

[0017] [2] The electronic component packaging sheet as described in [1], wherein the substrate sheet has at least one substrate layer comprising 70 to 99% by mass of the thermoplastic resin (I) and 1 to 30% by mass of the resin (II).

[0018] [3] Sheets for packaging electronic components as described in [1] or [2], wherein the (meth)acrylate copolymer (A) comprises alkyl acrylate monomer units (a1) having alkyl groups having 4 to 8 carbon atoms.

[0019] [4] The sheet for packaging electronic components as described in any one of [1] to [3], wherein the thermoplastic resin (I) comprises at least one thermoplastic resin selected from ABS resins and PC resins.

[0020] [5] The electronic component packaging sheet as described in any one of [1] to [4], wherein the thermoplastic resin (I) comprises 70 to 100% by mass of ABS resin relative to the total mass of the thermoplastic resin (I).

[0021] [6] A sheet for packaging electronic components as described in any one of [1] to [5], wherein the substrate sheet has at least one separating layer that divides the substrate layer.

[0022] [7] The sheet for packaging electronic components as described in [6], wherein the average thickness of each layer of the substrate layer is greater than or equal to the average thickness of each layer of the separator layer.

[0023] [8] A molded body comprising any one of [1] to [7] a sheet for packaging electronic components.

[0024] [9] The molded body as described in [8] is a container.

[0025]

[10] The molded body as described in [8] is a carrier tape.

[0026] The effects of the invention

[0027] According to the present invention, it is possible to provide a sheet for packaging electronic components that can effectively suppress the generation of fuzz and burrs, and a molded body comprising the sheet. Detailed Implementation

[0028] The present invention will be described in detail below, but the present invention is not limited to the following solutions.

[0029] [Sheets for Packaging Electronic Components]

[0030] The electronic component packaging sheet (hereinafter referred to simply as "sheet") of the present invention comprises a substrate sheet having at least one substrate layer, the substrate layer comprising a thermoplastic resin (I) and a resin (II) comprising at least one copolymer selected from (meth)acrylate copolymer (A) and styrene-acrylonitrile copolymer (B) having a weight average molecular weight of 700,000 to 4,300,000. The electronic component packaging sheet of the present invention having this configuration can effectively suppress the generation of fuzz and rough edges.

[0031] (Substrate sheet)

[0032] The electronic component packaging sheet of the present invention comprises a substrate sheet. The substrate sheet has at least one substrate layer comprising a thermoplastic resin (I) and a resin (II) comprising at least one copolymer selected from alkyl methacrylate copolymer (A) and styrene-acrylonitrile copolymer (B) having a weight average molecular weight of 700,000 to 4,300,000.

[0033] <Substrate Layer>

[0034] The substrate layer comprises a thermoplastic resin (I) and a resin (II) comprising at least one copolymer selected from alkyl methacrylate copolymer (A) and styrene-acrylonitrile copolymer (B) with a weight average molecular weight of 700,000 to 4,300,000.

[0035] The proportion of thermoplastic resin (I) contained in the substrate layer relative to the total mass of the resin composition constituting the substrate layer is preferably 70-99% by mass, more preferably 75-98% by mass, and particularly preferably 80-96% by mass. Furthermore, the proportion of resin (II) contained in the substrate layer relative to the total mass of the resin composition constituting the substrate layer is preferably 1-30% by mass, more preferably 2-25% by mass, and particularly preferably 4-20% by mass. By having at least one substrate layer containing thermoplastic resin (I) and resin (II) within the above range, it becomes easier and more effective to suppress the generation of burrs and frayed edges during sheet molding.

[0036] The mass ratio of thermoplastic resin (I) to resin (II) in the substrate layer (thermoplastic resin (I) / resin (II)) is preferably 99 / 1 to 70 / 30, more preferably 98 / 4 to 75 / 25. As long as the mass ratio of thermoplastic resin (I) to resin (II) is within the above range, the film-forming properties of the substrate sheet are difficult to reduce, and the generation of burrs and frayed edges becomes easier to effectively suppress.

[0037] (Thermoplastic resin (I))

[0038] Examples of thermoplastic resins (I) include polystyrene resins (PS resins), ABS resins, polyester resins, and polycarbonate resins (PC resins). These thermoplastic resins can be used alone or in combination of two or more.

[0039] Examples of PS-based resins include polystyrene resins, rubber-modified styrene resins (rubber-g-styrene resins (GPPS) or impact-resistant styrene resins (HIPS)). A single PS-based resin can be used alone, or two or more can be used in combination.

[0040] Aromatic vinyl monomers used to form PS-based resins include, for example, styrene, alkyl-substituted styrene (e.g., vinyltoluene, vinylxylene, p-ethylstyrene, p-isopropylstyrene, butylstyrene, p-tert-butylstyrene, etc.), halogen-substituted styrene (e.g., chlorostyrene, bromostyrene, etc.), and α-alkyl-substituted styrene with alkyl substitution at the α-position (e.g., α-methylstyrene, etc.). These aromatic vinyl monomers can be used alone or in combination of two or more. Among these monomers, styrene, vinyltoluene, and α-methylstyrene are generally preferred, with styrene being particularly preferred.

[0041] The preferred MFR of PS resin, as determined according to ISO 1133, is 1 to 30 g / 10 minutes, more preferably 2 to 25 g / 10 minutes.

[0042] ABS-based resins are those in which a terpolymer of diene-based rubber, aromatic vinyl monomer, and vinyl cyanide monomer is used as the main component, typically referring to resins or resin compositions in which acrylonitrile-butadiene-styrene terpolymer is used as the main component. Specific examples include acrylonitrile-butadiene-styrene terpolymers, mixtures of acrylonitrile-butadiene-styrene terpolymers and acrylonitrile-styrene binary copolymers. Among these, acrylonitrile-butadiene-styrene terpolymers are preferred as ABS-based resins, and even more preferably, mixtures of acrylonitrile-butadiene-styrene terpolymers and acrylonitrile-styrene binary copolymers are used. In addition to the monomer units mentioned above, these polymers also contain trace amounts of monomers such as α-methylstyrene, vinyltoluene, dimethylstyrene, chlorostyrene, and vinylnaphthalene as styrene monomers. Furthermore, they also contain trace amounts of monomers such as methacrylonitrile, ethylacrylonitrile, and fumaronitrile as vinyl cyanide monomers. Descriptions of trace components are omitted in the following description, but include those components without impairing the effects of the present invention. ABS resins can be used alone or in combination with two or more types.

[0043] The MFR of ABS resin, as measured according to ISO 1133, is preferably 1 to 30 g / 10 minutes, more preferably 2 to 25 g / 10 minutes.

[0044] Examples of polyester resins include polyester resins derived from aromatic polyfunctional carboxylic acids, aliphatic polyfunctional carboxylic acids, and polyfunctional diols, as well as hydroxycarboxylic acid-based polyester resins. Examples of polyester resins derived from aromatic polyfunctional carboxylic acids, aliphatic polyfunctional carboxylic acids, and polyfunctional diols include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene adipate, polybutylene adipate, and other copolymers thereof. Examples of other copolymers include polyester resins copolymerized with polyalkylene glycols, polycaprolactone, etc. Examples of hydroxycarboxylic acid-based polyester resins include polylactic acid, polyglycolic acid, and polycaprolactone. In this invention, copolymers of the polyester resins exemplified above may also be used. One type of polyester resin may be used alone, or two or more may be used in combination.

[0045] The MFR of the polyester resin, as determined according to ISO 1133, is preferably 1 to 30 g / 10 minutes, more preferably 2 to 25 g / 10 minutes.

[0046] PC-based resins are resins derived from dihydroxy compounds, preferably resins derived from aromatic dihydroxy compounds, and particularly preferably aromatic dihydroxy compounds (bisphenols) in which two aromatic dihydroxy compounds are bonded together by a bonding group. These can be manufactured using known methods, which are not particularly limited. Alternatively, commercially available resins can also be used. One type of PC-based resin can be used alone, or two or more types can be used in combination.

[0047] The MFR of PC resin, as measured according to ISO 1133, is preferably 1 to 30 g / 10 minutes, more preferably 2 to 25 g / 10 minutes.

[0048] The thermoplastic resin (I) preferably includes at least one thermoplastic resin selected from ABS-based resins and PC-based resins, and more preferably includes an ABS-based resin. By including at least one thermoplastic resin selected from ABS-based resins and PC-based resins, and particularly preferably including an ABS-based resin, the number of entanglement points between the molecular chains of the resins increases when combined with the resin (II), making it easier to effectively suppress burrs and fraying during punching.

[0049] When the thermoplastic resin (I) includes ABS-based resin, the proportion of ABS-based resin relative to the total mass of the thermoplastic resin (I) is preferably 70 to 100% by mass, more preferably 75 to 100% by mass, and particularly preferably 77 to 100% by mass. As long as the proportion of ABS-based resin is within the above range, the formation of burrs and fuzz can be effectively suppressed, and the moldability is easy to improve.

[0050] In addition, when the thermoplastic resin (I) includes ABS-based resin, the proportion of ABS-based resin in the substrate layer relative to the total mass of the resin composition constituting the substrate layer is preferably 70 to 99% by mass, more preferably 80 to 98% by mass.

[0051] (Resin(II))

[0052] Resin (II) is a resin composition comprising at least one copolymer selected from alkyl methacrylate copolymer (A) and styrene-acrylonitrile copolymer (B) with a weight average molecular weight of 700,000 to 4,300,000. The electronic component packaging sheet of the present invention effectively suppresses the generation of burrs and frayed edges by having a substrate layer comprising a thermoplastic resin (I) and a high molecular weight resin (II).

[0053] The Mw of the copolymers (A) and (B) contained in the resin (II) is 700,000 to 4,300,000, preferably 800,000 to 4,000,000, more preferably 900,000 to 3,800,000, and particularly preferably 1,000,000 to 3,500,000. As long as the Mw of the copolymers (A) and (B) is 700,000 to 4,300,000, the generation of flash and fluff can be effectively suppressed, and the film-forming property is also difficult to decrease. It should be noted that the Mw of the copolymers (A) and (B) is calculated as the molecular weight in terms of polystyrene by using gel permeation chromatography (GPC) to calculate the molecular weight at each elution time through the elution curve of monodisperse polystyrene.

[0054] <Mw measurement conditions>

[0055] Model: manufactured by Showa Denko K.K., product name "Shodex GPC-101"

[0056] Column: manufactured by Polymer Laboratories, product name "PLgel 10μm MIXED-B"

[0057] Mobile phase: tetrahydrofuran

[0058] Sample concentration: 0.2% by mass

[0059] Temperature: oven 40°C, injection port 35°C, detector 35°C

[0060] Detector: differential refractometer

[0061] <Copolymer (A)>

[0062] Copolymer (A) is an alkyl (meth)acrylate copolymer with an Mw of 700,000 to 4,300,000. In this specification, "(meth)acrylate" means acrylate and methacrylate. Copolymer (A) can be obtained by polymerizing at least two kinds of (meth)acrylates.

[0063] Examples of the (meth)acrylate constituting copolymer (A) include (meth)acrylates having a linear or branched alkyl group with 1 to 12 carbon atoms.

[0064] The copolymer (A) preferably contains alkyl acrylate monomer units (a1) having a straight-chain or branched alkyl group having 4 to 8 carbon atoms (hereinafter referred to as "monomer unit (a1)"). By including monomer units (a1) in the copolymer (A), the moldability becomes easier to improve. Examples of monomers constituting such monomer units (a1) include n-butyl acrylate, tert-butyl acrylate, isobutyl acrylate, amyl acrylate, hexyl acrylate, cyclohexyl acrylate, heptyl acrylate, octyl acrylate, and 2-ethylhexyl acrylate. These can be used alone or in combination of two or more. Among them, n-butyl acrylate and 2-ethylhexyl acrylate are preferred as monomer units (a1), and n-butyl acrylate monomer units are more preferred.

[0065] The proportion of monomer units (a1) in copolymer (A) relative to all monomer units constituting copolymer (A) (100% by mass) is preferably 10 to 50% by mass, more preferably 15 to 40% by mass, and particularly preferably 20 to 30% by mass.

[0066] The copolymer (A) more preferably comprises the aforementioned monomer unit (a1) and an alkyl methacrylate monomer unit (a2) having a straight-chain or branched alkyl group having 1 to 12 carbon atoms. Examples of monomers constituting such a monomer unit (a2) include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, 2-ethylhexyl methacrylate, and cyclohexyl methacrylate. These may be used individually or in combination of two or more. Preferably, the monomer unit (a2) comprises a methyl methacrylate or ethyl methacrylate monomer unit, and more preferably, a methyl methacrylate monomer unit.

[0067] The mass ratio of monomer units (a1) to monomer units (a2) in copolymer (a1 / a2) is preferably 15 / 85 to 40 / 60, more preferably 20 / 80 to 30 / 70, and particularly preferably 22 / 78 to 28 / 72. As long as the ratio of monomer units (a1) to monomer units (a2) is within the above range, the film-forming and molding properties are easily improved.

[0068] The copolymer (A) may also contain other monomer units besides the monomer units (a1) and (a2) mentioned above.

[0069] <Copolymer(B)>

[0070] Copolymer (B) is a styrene-acrylonitrile copolymer with a Mw of 700,000 to 4,300,000. Copolymer (B) can be obtained by copolymerizing styrene and acrylonitrile. The copolymerization ratio of styrene to acrylonitrile in copolymer (B) is not particularly limited as long as it has the effect of the present invention, and can be appropriately varied according to the desired physical properties. From the viewpoint of suppressing burrs, the copolymerization ratio of styrene to acrylonitrile, in terms of mass ratio (styrene / acrylonitrile), is preferably 90 / 10 to 20 / 80, more preferably 80 / 20 to 30 / 70, and particularly preferably 70 / 30 to 40 / 60.

[0071] Styrene, as a styrene monomer unit constituting copolymer (B), can include, for example, styrene, alkyl-substituted styrene (e.g., vinyltoluene, vinylxylene, p-ethylstyrene, p-isopropylstyrene, butylstyrene, p-tert-butylstyrene, etc.), halogen-substituted styrene (e.g., chlorostyrene, bromostyrene, etc.), and α-alkyl-substituted styrene with alkyl substitution at the α-position (e.g., α-methylstyrene, etc.). One of these can be used alone, or two or more can be used in combination. Styrene and vinyltoluene are preferred, and styrene is more preferred.

[0072] Resin (II) comprises at least one copolymer selected from copolymer (A) and copolymer (B) described above. Preferably, it comprises copolymer (A) or copolymer (B), more preferably copolymer (A). In a preferred embodiment, resin (II) may also consist solely of copolymer (A).

[0073] When resin (II) contains copolymer (A), its proportion relative to the total mass of resin (II) is preferably 50 to 100% by mass, more preferably 60 to 100% by mass, and particularly preferably 70 to 100% by mass. Furthermore, the proportion of copolymer (A) in the substrate sheet is preferably 0.5 to 30% by mass, more preferably 2 to 25% by mass, relative to the total mass of the resin composition constituting the substrate sheet.

[0074] When resin (II) contains copolymer (B), its proportion relative to the total mass of resin (II) is preferably 30 to 100% by mass, more preferably 40 to 100% by mass, and particularly preferably 50 to 100% by mass. Furthermore, the proportion of copolymer (B) in the substrate sheet relative to the total mass of the resin composition constituting the substrate sheet is preferably 0.3 to 30% by mass, more preferably 1 to 25% by mass.

[0075] The sheet material of the present invention comprises a thermoplastic resin (I) and a resin (II) in the resin composition constituting the substrate layer, thereby increasing the strength of the sheet and suppressing resin stretching during sheet die-cutting. As a result, fuzzing and burr formation are effectively suppressed. The substrate layer may also be composed of a resin composition containing only thermoplastic resin (I) and resin (II).

[0076] The substrate sheet comprises at least one substrate layer, or more than two layers. When there are two or more substrate layers, the proportions of thermoplastic resin (I) and resin (II) in each layer of the substrate layer may be the same or different. From the viewpoint that the sheet is less prone to curling defects and its formability is easily improved, it is preferable that each layer of the substrate layer has the same composition.

[0077] The substrate sheet may also consist of only a substrate layer. In this case, the thickness of the substrate layer becomes the thickness of the substrate sheet. When the substrate sheet consists of a single substrate layer, from the viewpoint of film-forming properties and moldability of the sheet for packaging electronic components, the thickness of the substrate layer is preferably 50–700 μm, and more preferably 100–500 μm.

[0078] When the substrate sheet is a multilayer substrate sheet formed by stacking two or more substrate layers, the number of substrate layers included in the substrate sheet is preferably 2 to 70, more preferably 3 to 50. In this case, the average thickness of each substrate layer is preferably 2 to 200 μm, more preferably 3 to 100 μm, and particularly preferably 5 to 50 μm. Furthermore, "average thickness of each substrate layer" refers to the value calculated by dividing the total thickness of the substrate layers included in the substrate sheet by the total number of substrate layers. That is, it refers to the value calculated by (x1 + x2 + x3 + ... + xn) / n when the thickness of one substrate layer is set as "x1". Here, "n" refers to the total number of substrate layers in the substrate sheet.

[0079] When the substrate sheet has two or more substrate layers, it may also have a separating layer that divides the substrate layers from each other.

[0080] <Separator Layer>

[0081] The substrate sheet for packaging electronic components according to the present invention may include a separator layer. The separator layer is a layer that divides two or more substrate layers, preferably disposed between the substrate layers. In one embodiment, the substrate sheet may have a configuration in which substrate layers and separator layers are alternately stacked.

[0082] The separator layer preferably comprises a thermoplastic resin different from the thermoplastic resin (I) comprised in the substrate layer as its main component. Here, "comprises...as a main component" means that, relative to the total mass of the resin composition constituting the separator layer, it comprises 50% by mass or more of thermoplastic resin. Furthermore, "thermoplastic resin different from thermoplastic resin (I)" includes thermoplastic resins that are not only different in type but also different in physical properties. That is, the separator layer may comprise a thermoplastic resin different in type from thermoplastic resin (I) as its main component, or it may comprise the same thermoplastic resin with different physical properties as its main component. From the viewpoint of suppressing burrs, the thermoplastic resin comprised in the separator layer preferably comprises a thermoplastic resin different in type from thermoplastic resin (I) as its main component.

[0083] The thermoplastic resin included in the separator layer can be, for example, the same as the thermoplastic resin (I) described above. When the thermoplastic resin (I) includes an ABS-based resin, the thermoplastic resin included in the separator layer is preferably at least one thermoplastic resin selected from PC-based resins and polyester-based resins, and more preferably includes a PC-based resin. In addition, when the thermoplastic resin (I) includes an ABS resin, the thermoplastic resin included in the separator layer may also be a copolymer of acrylonitrile and styrene.

[0084] Styrene, as a styrene monomer unit constituting an acrylonitrile-styrene binary copolymer, can be exemplified by copolymers (B) described above.

[0085] In one embodiment, when the separator layer comprises a PC-based resin, its proportion relative to the total mass of the resin composition constituting the separator layer is preferably 50-100% by mass, more preferably 60-100% by mass, and particularly preferably 70-100% by mass. Furthermore, as the aforementioned PC-based resin, it is more preferable to have an MFR of 1-30 g / 10 minutes as measured according to ISO 1133.

[0086] When the substrate sheet has a separator layer, the number of layers can be adjusted by the number of substrate layers stacked. That is, when the number of substrate layers is 2 to 35, the number of separator layers is preferably 1 to 34.

[0087] When the number of separator layers is two or more, the resin composition of each separator layer can be different or the same. From the viewpoint of film formation, it is preferable that the resin composition of each separator layer is the same.

[0088] Furthermore, when the number of separator layers is two or more, the thickness of each separator layer can be the same or different. In one embodiment, the average thickness of each separator layer is preferably less than or equal to the average thickness of each substrate layer (i.e., the average thickness of each substrate layer is preferably greater than or equal to the average thickness of each separator layer). When the average thicknesses of both the separator layer and the substrate layer satisfy the above relationship, it becomes easier to more effectively suppress the generation of burrs and fuzz. Furthermore, "the average thickness of each separator layer" is the same as that of the substrate layer described above. That is, it refers to the value obtained by dividing the total thickness of the separator layers included in the substrate sheet by the number of separator layer layers. In one embodiment, the average thickness of each separator layer is preferably 2 to 200 μm, more preferably 3 to 100 μm, and particularly preferably 5 to 50 μm.

[0089] The upper limit of the average thickness of each layer of the substrate layer is not particularly limited relative to the average thickness of each layer of the separator layer, but from the viewpoint of film formation, it is preferably less than 10 times.

[0090] It is presumed that burrs and fuzzing generated during sheet forming are caused by resin stretching during sheet punching and cutting. The inventors of this application have discovered that by providing a substrate layer composed of a thermoplastic resin (I) and a high molecular weight resin (II), the entanglement points of the thermoplastic resin (I) molecular chains increase, suppressing resin elongation during forming and effectively suppressing burr and fuzzing. Furthermore, the aforementioned substrate layer also exhibits excellent sheet strength, thus suppressing resin stretching during sheet punching. It has also been found that by creating a multilayer substrate sheet with multiple layers of this structure, further comprising separator layers between the substrate layers, it becomes even easier to effectively suppress burr and fuzzing.

[0091] The sheet material involved in this invention preferably has a yield stress of 30 to 80 MPa, determined by tensile testing according to JIS K 7127 at a speed of 67 mm / s.

[0092] When the substrate sheet has two or more substrate layers and separator layers, the total number of layers of these substrate layers and separator layers is preferably 3 to 70, more preferably 3 to 50, and even more preferably 5 to 40.

[0093] From the viewpoint of strength and formability when making the carrier tape, the thickness of the substrate sheet is preferably 50 to 700 μm, more preferably 75 to 600 μm, and particularly preferably 90 to 450 μm.

[0094] The packaging sheet for electronic components according to the present invention may also be composed solely of the aforementioned substrate sheet. When the packaging sheet for electronic components according to the present invention is made into a conductive sheet, a conductive layer may be formed on at least one surface of the aforementioned substrate sheet. Furthermore, any layer (e.g., an anti-fouling layer) may be provided on the aforementioned substrate sheet.

[0095] (Conductive layer)

[0096] The electronic component packaging sheet of the present invention may also have a conductive layer on at least one surface of the aforementioned substrate sheet. The conductive layer is a layer composed of a resin composition containing conductive components.

[0097] The resin composition constituting the conductive layer is not particularly limited as long as it has the effects of the present invention. For example, examples include a resin composition containing 65 to 95% by mass of the above-mentioned thermoplastic resin, preferably 70 to 90% by mass, and 5 to 35% by mass of a conductive agent such as carbon black, preferably 10 to 30% by mass, relative to the total mass of the resin composition.

[0098] Examples of carbon black include furnace black, channel black, and acetylene black, with a preference for those having a large specific surface area and achieving high conductivity with a small addition amount. Specifically, an average primary particle size of 20–100 nm is preferred, and 20–65 nm is more preferred. The aforementioned average primary particle size refers to the average diameter of the particles as measured using a transmission electron microscope.

[0099] The thickness of the conductive layer is not particularly limited. From the viewpoint of easily improving the mechanical strength of the sheet material for packaging electronic components, the thickness of the conductive layer is preferably 3 to 100 μm, and more preferably 10 to 50 μm.

[0100] [Manufacturing Method of Sheets for Packaging Electronic Components]

[0101] The method for manufacturing the electronic component packaging sheet according to the present invention can employ conventionally known manufacturing methods. Examples include: mixing a resin composition comprising thermoplastic resin (I) and resin (II) in a desired proportion using a mixer to prepare a resin composition for forming a substrate layer; feeding this resin composition to an extruder and performing melt mixing; and forming a substrate layer by using a feed block method or similar methods to achieve a predetermined film thickness. When two or more substrate layers are provided, a multi-layer substrate sheet can be formed by forming a film on the first substrate layer using the same method and then stacking them. Alternatively, when a separator layer is provided between the substrate layers, a resin composition for the separator layer is prepared in advance, fed to another extruder, and melt-mixed. Subsequently, by stacking the substrate layers and separator layers alternately, a multi-layer substrate sheet with substrate layers and separator layers can be obtained. When the electronic component packaging sheet of the present invention is made into a conductive sheet, a resin composition for forming a conductive layer, which is melt-blended using another extruder, can be laminated on one or both surfaces of the above-mentioned substrate sheet to make the electronic component packaging sheet.

[0102] [Molded body]

[0103] The sheet material for packaging electronic components involved in this invention can be molded into a molded body using known methods such as vacuum forming, air forming, and pressure forming. Examples of molded bodies for packaging electronic components include containers for holding electronic components and carrier tapes (embossed carrier tapes). The sheet material for packaging electronic components involved in this invention produces molded bodies with minimal burrs or rough edges on its cross-section during sheet cutting and punching of sprocket holes, etc. This is particularly advantageous in embossing carrier tapes. Furthermore, through these molding and secondary processing methods, embossed carrier tapes with excellent dimensional accuracy in cutting width, punching hole diameter, etc., and significantly suppressed burr formation during punching can be manufactured.

[0104] More specifically, in the secondary processing steps of cutting and punching the embossed carrier tape and the like of the formed body of the electronic component packaging sheet according to the present invention, punching conditions can be used within a certain wide range of 5 to 50 μm single-sided clearance of the pin / die head, and a wide range of punching speeds of 10 to 300 mm / s, to obtain sprocket holes with stable hole diameters and significantly suppressed burr and edge formation. Furthermore, in the cutting process using a ring-shaped combined blade, a cut end face with less burr, fewer edges, and stable sheet width can also be obtained.

[0105] The container and embossed carrier tape of the present invention can store electronic components in the storage part formed by the above molding method, cover it with a cover tape, and make it into a carrier tape body wound into a reel shape for storage and transportation of electronic components.

[0106] A more preferred embodiment of the electronic component packaging sheet of the present invention is an electronic component packaging sheet comprising a substrate sheet having at least one substrate layer. This substrate layer contains a thermoplastic resin (I) comprising an ABS-based resin and a resin (II) comprising an alkyl methacrylate copolymer (A) with a Mw of 700,000 to 4,300,000. The mass ratio (resin (I) / resin (II)) of the thermoplastic resin (I) to the resin (II) in the substrate layer is 98 / 2 to 75 / 25. The substrate sheet may also have two or more substrate layers, with a separator layer provided between the substrate layers. The separator layer preferably comprises a PC-based resin as its main component. The copolymer (A) preferably comprises monomer units (a1) and monomer units (a2).

[0107] Example

[0108] The present invention is described in detail below with reference to embodiments, but the present invention is not limited by the following description.

[0109] Fabrication of Sheets for Electronic Component Packaging

[0110] (Examples 1-9, Comparative Examples 1-5)

[0111] The raw materials shown in Tables 1 and 2 for the composition of the substrate layer are measured separately in the proportions (mass%) shown in the tables, and then uniformly mixed using a high-speed mixer. The resin composition for forming the substrate layer is obtained by mixing in a vented twin-screw extruder and granulating by wire cutting. Additionally, as the conductive layer, a resin composition as follows is used: 80% by mass of polycarbonate resin (manufactured by Teijin, product name "Panlite (registered trademark) L-1225L") and 20% by mass of acetylene black (manufactured by Denka, product name "Denka Black (registered trademark) granular, average primary particle size: 35 nm) is used. A resin composition is compounded by a vented twin-screw extruder and granulated by a strand cutting method.

[0112] Using these resin compositions, by using Extruder (L / D=28) A feed block method using an extruder (L / D=26) and a 500mm wide T-die forms conductive layers on both sides of a substrate layer to obtain a sheet for packaging electronic components. Furthermore, the substrate sheet has a thickness of 160μm, and each layer of the conductive layer has a thickness of 20μm.

[0113] (Example 10)

[0114] The raw materials shown in Table 1 for the composition of the substrate layer were measured separately in the proportions (mass %) shown in the table, and a resin composition for forming the substrate layer was obtained using the same method as in Example 1. Using this composition, by using... A single-layer substrate sheet is produced using an extruder (L / D=28) and a 500mm wide T-die feed block method. Furthermore, the thickness of the substrate sheet is 200μm.

[0115] (Examples 11-13)

[0116] Examples 11-13 are examples in which a separator layer is provided between the substrate layers.

[0117] First, the raw materials shown in Table 1 for the composition of the substrate layer were measured in the proportions (mass%) shown in the table, and resin compositions for forming the substrate layer were obtained using the same method as in Example 1. Additionally, a conductive layer resin composition with the same composition as in Example 1 was prepared as the conductive layer. Furthermore, a polycarbonate resin (manufactured by Teijin Co., Ltd., product name "Panlite L-1225L") was prepared as a separating layer for dividing the substrate layer. Using these resin compositions, by... Extruder (L / D=28) Extruder (L / D=28) Using an extruder (L / D = 26) and a 500mm wide T-die feed block method, conductive layers are formed on both sides of a substrate sheet formed by laminating a substrate layer and a separator layer to the thicknesses listed in Table 1, resulting in a sheet for packaging electronic components. Furthermore, the thickness of the substrate sheet is 160μm, and the thickness of each conductive layer is 20μm. The structures of the electronic component packaging sheets in various examples are as follows.

[0118] <Composition of Packaging Sheets for Electronic Components in Various Examples>

[0119] Examples 11, 13, 14: Conductive layer / (substrate layer / separator layer / substrate layer) / conductive layer

[0120] Example 12: Conductive layer / (substrate layer / separator layer / substrate layer / separator layer / substrate layer / separator layer / substrate layer) / conductive layer

[0121] (Example 14)

[0122] The raw materials shown in Table 1 for the composition of the substrate layer were measured separately in the proportions (mass %) shown in the table, and a resin composition for forming the substrate layer was obtained using the same method as in Example 1. Additionally, a resin composition for a separator layer with the same composition as in Example 11 was prepared as a separator layer. Using these compositions, by... Extruder (L / D=28) A substrate sheet with a substrate layer / separator / substrate layer stack structure is produced using an extruder (L / D = 26) and a 500mm wide T-die feed block method. This structure consists of a substrate layer / separator / substrate layer with separator layers between substrate layers. Furthermore, the substrate sheet thickness is 200μm, and the thicknesses of the segmented substrate layers and separator layers are shown in Table 1.

[0123] The details of the raw materials shown in Table 1 are as follows.

[0124] (Thermoplastic resin (I))

[0125] • Acrylonitrile-butadiene-styrene copolymer (ABS): Manufactured by Denka Corporation, product name "SE-10".

[0126] • Polycarbonate resin (PC): Manufactured by Teijin Co., Ltd., product name "Panlite L-1225L".

[0127] • Impact-resistant polystyrene resin (HIPS): Manufactured by Toyo Styrene Co., Ltd., product name "E640N".

[0128] (Resin(II))

[0129] <Copolymer(A)>

[0130] a-1: Copolymer of methyl methacrylate and n-butyl acrylate: Manufactured by Mitsubishi Chemical Co., Ltd., product name "Metablen (registered trademark) P-551A" (Mw: 3000000).

[0131] a-2: Copolymer of methyl methacrylate and n-butyl acrylate: Manufactured by Mitsubishi Chemical Co., Ltd., product name "Metablen P-530A" (Mw: 1500000).

[0132] a-3: Copolymer of methyl methacrylate and ethyl acrylate (mass ratio: 60 / 40): Our company's polymer (Mw: 3,000,000).

[0133] <Copolymer(A')>

[0134] a-4: Copolymer of methyl methacrylate and n-butyl acrylate (mass ratio: 60 / 40): Our company's polymer (Mw: 400000).

[0135] a-5: Copolymer of methyl methacrylate and n-butyl acrylate: manufactured by Mitsubishi Chemical Corporation, product name "Metablen P-531A" (Mw: 4500000).

[0136] <Copolymer (B)>

[0137] b-1: Styrene-acrylonitrile copolymer: manufactured by Mitsubishi Chemical Corporation, product name "Metablen P-1500" (Mw: 4000000).

[0138] <Copolymer (B’)>

[0139] b-2: Styrene-acrylonitrile copolymer: manufactured by Denka Company Limited, product name "AS-C-800" (Mw: 180000).

[0140] b-3: Styrene-acrylonitrile copolymer (mass ratio: 75 / 25): polymerized product of our company (Mw: 6000000).

[0141] Furthermore, the Mw of the above resin (II) is calculated as the molecular weight in terms of polystyrene by calculating the molecular weight at each elution time from the elution curve of monodisperse polystyrene using gel permeation chromatography (GPC).

[0142] <Measurement conditions of Mw>

[0143] Model: manufactured by Showa Denko K.K., product name "Shodex GPC-101"

[0144] Column: manufactured by Polymer Laboratories, product name "PLgel 10μm MIXED-B"

[0145] Mobile phase: tetrahydrofuran

[0146] Sample concentration: 0.2 mass%

[0147] Temperature: oven 40°C, injection port 35°C, detector 35°C

[0148] Detector: differential refractometer

[0149] In addition, the average primary particle diameter of acetylene black in the conductive layer is a value obtained by the following method.

[0150] First, acetylene black was 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 was then sprinkled onto a carbon-reinforced support membrane and fixed. The membrane was then photographed using a transmission electron microscope (JEM-2100, Nippon Electron Ltd.). The particle size (maximum diameter for shapes other than spherical) of more than 1000 inorganic fillers was randomly measured using an Ender apparatus from images magnified 50,000 to 200,000 times, and the average value was taken as the average primary particle size.

[0151] [Evaluation of Sheets for Packaging Electronic Components]

[0152] The electronic component packaging sheets obtained in each example were cut along the extrusion direction to prepare sheet samples, which were then placed in an environment of 23°C and 50% relative humidity for 24 hours. Subsequently, the film-forming properties and die-cutting burr characteristics were evaluated under the following conditions.

[0153] (1) Film-forming properties

[0154] As an evaluation of the sheet's film-forming properties, the uniformity of the sheet's characteristics was assessed. Sheet samples were tested at 23°C and 50% relative humidity using a tensile testing machine (manufactured by Toyo Seiki Co., Ltd., product name "Strograph VE-1D") according to JIS-K-7127 (1999). The flow direction of the sheet was set to the length direction, and the test sheet type was sampled at three points: the left end, the center, and the right end in the width direction (perpendicular to the length direction). The elastic modulus was measured at a speed of 5 mm / min. The larger of the difference between the average and the maximum value of the three elastic moduli (maximum value - average value), or the difference between the average and the minimum value (average value - minimum value), was divided by the average value, and the resulting value was defined as the tolerance (%). The following judgment criteria were used for evaluation. In the following judgment criteria, "good" or above was defined as acceptable (high sheet uniformity and good film-forming properties).

[0155] <Judgment Criteria>

[0156] Advantages: Sheets with a thickness and elastic modulus tolerance of less than 10% (very high sheet uniformity).

[0157] Good: The thickness and elastic modulus tolerance is 10% or more but less than 20% (high uniformity of sheet material).

[0158] Not allowed: Sheets with a thickness and elastic modulus tolerance of more than 20% (uneven sheet material).

[0159] (2) Characteristics of punching burrs

[0160] Samples cut into 8mm wide sheets were punched using a vacuum rotational forming machine (manufactured by Muehlbauer, product name "CT8 / 24") at 23°C and 50% relative humidity to evaluate the burrs and roughness of the punched holes. Furthermore, punching was performed at a speed of 240m / h using a punching device equipped with a cylindrical punching pin with a 1.5mm diameter tip and a die hole with a 1.58mm diameter tip.

[0161] The punched holes in the sheet material were photographed using a microscopic measuring machine (Mitutoyo Co., Ltd., product name "MF-A1720H (Image Unit 6D)") under a light source environment of 0% incident light, 40% transmittance, and 0% annular light. Ten holes with a diameter of 1.5 mm were observed, and the number of burrs and frayed areas with a length of 0.15 mm or more was counted. Furthermore, the material was evaluated according to the following criteria, with "Good" or above being considered acceptable (suppression of burr and frayed areas).

[0162] <Judgment Criteria>

[0163] Excellent: The number of rough edges and fuzz is less than 6.

[0164] Good: The number of rough edges and fuzz is more than 6 but less than 10.

[0165] Not allowed: More than 10 frayed or fuzzy edges.

[0166] [Table 1]

[0167]

[0168] [Table 2]

[0169]

[0170] As shown in Table 1, it can be seen that the electronic component packaging sheets of Examples 1 to 14, which satisfy the configuration of the present invention, can effectively suppress the generation of fuzz and burrs during sheet die-cutting. On the other hand, as shown in Table 2, the electronic component packaging sheets of Comparative Examples 1, 2, and 4, which do not satisfy the configuration of the present invention, have a high number of fuzz and burrs. In addition, Comparative Examples 3 and 5, which contain copolymers with a Mw greater than 4,300,000, have poor film-forming properties and cannot obtain uniform sheets. From the above results, it is confirmed that the electronic component packaging sheet of the present invention can effectively suppress the generation of fuzz and burrs.

Claims

1. A sheet for packaging electronic components, comprising a substrate sheet having at least one substrate layer, the substrate layer comprising: a thermoplastic resin (I), and a resin (II) comprising at least one copolymer selected from alkyl methacrylate copolymer (A) and styrene-acrylonitrile copolymer (B) having a weight average molecular weight of 700,000 to 4,300,000. The proportion of thermoplastic resin (I) and resin (II) contained in the substrate layer is 70-99% by mass relative to the total mass of the resin composition constituting the substrate layer.

2. The sheet for packaging electronic components according to claim 1, wherein, The (meth)acrylate alkyl copolymer (A) comprises alkyl acrylate monomer units (a1) having alkyl groups having 4 to 8 carbon atoms.

3. The sheet for packaging electronic components according to claim 1 or 2, wherein, The thermoplastic resin (I) comprises at least one thermoplastic resin selected from ABS resins and PC resins.

4. The sheet for packaging electronic components according to claim 1 or 2, wherein, The thermoplastic resin (I) comprises 70-100% by mass of ABS resin relative to the total mass of the thermoplastic resin (I).

5. The sheet for packaging electronic components according to claim 1 or 2, wherein, The substrate sheet has at least one separating layer that divides the substrate layer.

6. The sheet for packaging electronic components according to claim 5, wherein, The average thickness of each layer of the substrate layer is greater than or equal to the average thickness of each layer of the separator layer.

7. A molded body comprising the sheet for packaging electronic components according to any one of claims 1 to 6.

8. The molded body according to claim 7, wherein it is a container.

9. The molded body according to claim 7, wherein it is a carrier tape.

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