Cover tape, electronic component package, and method for manufacturing cover tape

Abstract

This cover tape for electronic component packaging is provided with a base material layer and a sealant layer provided on at least one surface side of the base material layer. The sealant layer contains a conductive polymer. For a sample A obtained by heat-sealing the sealant layer-side surface of the cover tape and the polystyrene film in accordance with a predetermined step, the peel strength when the cover tape is peeled under predetermined conditions is set as FA. In addition, for a sample B obtained by placing the sample A in an environment with a temperature of 40 DEG C and a relative humidity of 90% for 7 days, the peel strength when peeled under predetermined conditions is set as FB. In this case, the value of FB / FA is 0.6-1.4.

Description

Technical Field

[0001] The present invention relates to a cover tape, an electronic component package, and a method for manufacturing the cover tape. More specifically, it relates to a cover tape for electronic component packaging, an electronic component package formed by packaging electronic components using the cover tape, and a method for manufacturing the cover tape for electronic component packaging. Background Art

[0002] To prevent damage, electronic components such as transistors, diodes, capacitors, piezoelectric elements, and resistors are sometimes shipped in "electronic component packages." These packages are placed in a carrier tape with a recessed area for accommodating the electronic components, and a cover tape is heat-sealed to the carrier tape to seal the electronic components within the recessed area. Electronic component packages are often imported and exported internationally by air or sea.

[0003] When the packaged electronic component is used, the cover tape in the electronic component package is peeled off and the electronic component is taken out from the recess.

[0004] Various studies have been conducted on the bonding and releasability of cover tapes. For example, Patent Document 1 discloses a technique for optimizing releasability by focusing on the peel resistance ratio α between the maximum and minimum peel resistances between the carrier tape and the cover tape.

[0005] Furthermore, in order to protect the electronic components to be packaged, it is preferred that the cover tape has the property of easily dissipating the generated static electricity. Therefore, attempts have been made to include a conductive material in a partial layer constituting the cover tape.

[0006] For example, Patent Document 2 describes a film for packaging electronic components comprising a base layer, an intermediate layer, and a heat-seal layer in this order. Furthermore, the disclosure states that the intermediate layer contains a conductive polymer, and an antistatic coating is provided on the surface of the base layer opposite to the intermediate layer.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2017-171393; Patent Document 2: International Publication No. 2012 / 079258. Summary of the Invention

[0010] Problems to be solved by the invention

[0011] As a preliminary study, the inventors have manufactured a cover tape. In order to improve the performance of the cover tape, especially to suppress static electricity, the cover tape comprises a base material layer and a sealant layer provided on at least one side of the base material layer, and the sealant layer contains a conductive substance.

[0012] However, preliminary studies have revealed that electronic component packages obtained by heat-sealing a cover tape and a carrier tape containing a conductive material in the sealant layer are susceptible to peeling between the cover tape and the carrier tape during or after ocean transportation.

[0013] The present invention has been made in view of such circumstances. One object of the present invention is to provide a cover tape that contains a conductive material in its sealant layer but is not easily peeled off from the carrier tape after heat-sealing with the carrier tape.

[0014] Means for solving problems

[0015] The present inventors have completed the invention provided below and solved the above-mentioned problems.

[0016] 1. A cover tape for electronic component packaging, comprising a base material layer and a sealant layer provided on at least one side of the base material layer, wherein: The sealant layer contains a conductive polymer, For Sample A obtained by heat-sealing the sealant layer side of the cover tape and the polystyrene film according to the steps described in the following [Heat Sealing Step], the peel strength when the cover tape is peeled off under the conditions described in the following [Peeling Conditions] is set as F A , The peel strength of the sample B obtained by leaving the sample A at a temperature of 40° C. and a relative humidity of 90% for 7 days was set as F when peeled under the conditions described in the following [Peeling Conditions]. B hour, F B / F A The value is 0.6~1.4, [Heat sealing step] (1) The sealant layer side of a cover tape cut to a width of 5.5 mm was laminated to the concave-convex surface side of a polystyrene film having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm to obtain a laminated body. (2) Heat sealing is performed by bringing a double-edged iron with a single-edged blade of 0.4 mm width and 28 mm length into contact with the cover tape side of the stacked body at a sealing temperature of 160°C, a load of 5 kgf, a sealing time of 60 milliseconds, and a carrier tape feed interval of 4 mm. [Peeling conditions] The measurement temperature was 25° C., the peeling speed was 300 mm / min, and the peeling angle was 170°.

[0017] 2. The cover tape according to 1., wherein: The conductive polymer contains polythiophenes.

[0018] 3. The cover tape according to 1. or 2., wherein: The sealant layer contains one or more resins selected from the group consisting of styrene-based resins and (meth)acrylic resins.

[0019] 4. The cover tape according to any one of 1. to 3., further comprising an intermediate layer between the base material layer and the sealant layer.

[0020] 5. The cover tape according to any one of 1. to 4., wherein: The haze value measured in accordance with JIS K 7105 is 5 to 25%.

[0021] 6. The cover tape according to any one of 1. to 5., wherein: F A The value is 0.2~0.7N.

[0022] 7. The cover tape according to any one of 1. to 6., wherein: The surface resistance of the exposed surface on the sealant layer side is 1×10 4 ~1×10 11 Ω / □.

[0023] 8. An electronic component package comprising a carrier tape containing an electronic component in a recessed portion and a cover tape according to any one of 1. to 7. The sealant layer is bonded to the carrier tape to seal the electronic component.

[0024] 9. The method for manufacturing a cover tape according to any one of 1. to 8., wherein: The sealant layer is provided by applying a sealant layer-forming coating liquid in which a conductive polymer soluble or dispersible in an organic solvent is dissolved or dispersed to the surface of the intermediate layer opposite to the base layer and drying the liquid.

[0025] Effects of the Invention

[0026] According to the present invention, there is provided a cover tape containing a conductive material in a sealant layer but which is not easily peeled from a carrier tape after heat-sealing with the carrier tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a diagram schematically showing an example of the layer structure of the cover tape.

[0028] Figure 2 This is a diagram showing an example of a state where the cover tape and the carrier tape are joined (heat-sealed). DETAILED DESCRIPTION

[0029] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0030] In all the drawings, the same components are denoted by the same reference numerals, and their descriptions are appropriately omitted.

[0031] To avoid redundancy, there are two cases: (i) when there are multiple identical components in the same drawing, only one of them is marked with a reference numeral instead of all of them; and (ii) especially in Figure 2 Later, Figure 1 The same components are not denoted by new reference numerals.

[0032] All drawings are for illustration purposes only. The shapes and dimensional ratios of the components in the drawings do not necessarily correspond to actual objects.

[0033] In this specification, unless otherwise specified, the expression "X to Y" in a numerical range description means greater than or equal to X and less than or equal to Y. For example, "1 to 5 mass %" means "1 mass % or more and 5 mass % or less."

[0034] The term "(meth)acrylic acid" in this specification is a concept encompassing both acrylic acid and methacrylic acid. The same applies to similar terms such as "(meth)acrylate".

[0035] <Cover tape>

[0036] Figure 1 This is a diagram schematically showing an example of the layer structure of the cover tape for electronic component packaging (cover tape 10 ) according to the present embodiment.

[0037] The cover tape 10 includes a base material layer 1 and a sealant layer 3 provided on at least one surface of the base material layer 1 .

[0038] The cover tape 10 preferably includes an intermediate layer 2 between the base material layer 1 and the sealant layer 3 .

[0039] The sealant layer 3 contains a conductive polymer.

[0040] The peel strength of the sample A obtained by heat-sealing the sealant layer 3 side of the cover tape 10 and the polystyrene film according to the steps described in the following [Heat Sealing Step] is determined by peeling under the conditions described in the following [Peeling Conditions] as F. A .

[0041] Furthermore, the peel strength of the sample obtained by leaving the sample A at a temperature of 40°C and a relative humidity of 90% for 7 days was determined by peeling it under the conditions described in the following [Peeling Conditions] as F. B .

[0042] At this time, F B / F AThe value of is 0.6 to 1.4, preferably 0.65 to 1.35, more preferably 0.7 to 1.3, particularly preferably 0.7 to 1.25, and particularly preferably 0.7 to 1.2. Incidentally, in practical applications, F B / F A The value of 1 is ideal, so as a result of the design of the sealant layer 3, F B / F A The value of can also exceed 1.

[0043] [Heat sealing step]

[0044] (1) The sealant layer side of a cover tape cut to a width of 5.5 mm was laminated to the concave-convex surface side of a polystyrene film having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm to obtain a laminate.

[0045] (2) A double-edged iron with a single-edged blade of 0.4 mm width and 28 mm length was brought into contact with the cover tape side of the stacked body for heat sealing at a sealing temperature of 160°C, a load of 5 kgf, a sealing time of 60 milliseconds, and a carrier tape feed interval of 4 mm.

[0046] [Peeling conditions]

[0047] The measurement temperature was 25° C., the peeling speed was 300 mm / min, and the peeling angle was 170°.

[0048] The present inventors have studied various aspects to understand the problem discovered in preliminary research: the reason why electronic component packages in which a cover tape containing a conductive material in its sealant layer is easily peeled off from the carrier tape during or after ocean transportation.

[0049] Research has led to the hypothesis that this phenomenon is caused by atmospheric moisture entering the sealant layer itself or between the sealant layer and the carrier tape during transportation under high-temperature and high-humidity conditions (e.g., transportation around Japan and Southeast Asia). This is because conductive materials, particularly some conductive polymers, are highly hygroscopic.

[0050] Based on the above speculation, the present inventors In (A), a sample A is prepared by heat-sealing a cover tape 10 containing a conductive material in a sealant layer 3 to a polystyrene film (polystyrene is a material frequently used for carrier tapes), and the peel strength when the cover tape is peeled off from the sample A under predetermined conditions is set as F. A , (B) Prepare sample B by placing sample A in an environment with a temperature of 40°C and a relative humidity of 90% for 7 days. The peel strength when the cover tape is peeled off from sample B under the specified conditions is set as F. B hour, FB / F A The value of the peel strength variation ratio under high temperature and high humidity conditions was used as one of the design indicators, and an attempt was made to create a new cover tape. B / F A A new cover tape having a value of 0.6 to 1.4 can suppress peeling between the cover tape and the carrier tape during or after ocean transportation.

[0051] By the way, F B / F A The value of F is too large. A Compared with F B When peeling off the carrier tape, the carrier tape may be pulled up when the cover tape is too large, making it difficult to remove the components and causing deformation of the carrier tape. B / F A The upper limit value of 1.4 is set in consideration of this situation.

[0052] The cover tape 10 can be manufactured by using appropriate materials and undergoing appropriate manufacturing processes. An example of "using appropriate materials" is using a conductive polymer that is dissolved or dispersed in an organic solvent, rather than a conductive polymer dispersed in water.

[0053] Details of the materials and manufacturing process for manufacturing the cover tape 10 will be described in detail later.

[0054] Next, the layer structure and various characteristics of the cover tape 10 will be described.

[0055] [Base material layer]

[0056] The material constituting the base material layer 1 is not particularly limited, and any film can be used as long as it has mechanical strength sufficient to withstand external forces applied to the cover tape 10 and heat resistance sufficient to withstand the heat during heat sealing.

[0057] Specific examples of the material constituting the substrate layer 1 include ester resins, amide resins, olefin resins, acrylate resins, methacrylate resins, imide resins, carbonate resins, and ABS resins. Among these, ester resins and olefin resins are preferred as materials constituting the substrate layer 1, with polyethylene terephthalate and polyethylene being particularly preferred as they can improve mechanical strength. The substrate layer 1 may contain only one resin or two or more resins.

[0058] The film used to form the base material layer 1 may be a stretched film, and may be a film stretched uniaxially or biaxially. From the viewpoint of improving the mechanical strength of the cover tape 10, a film stretched uniaxially or biaxially is preferred.

[0059] The base material layer 1 may be a single layer or a multilayer layer.

[0060] From the perspective of reducing the amount of charge generated by peeling of the carrier tape, the base layer 1 may contain an antistatic agent. Furthermore, an antistatic layer may be provided as one of the base layers on the surface of the base layer 1 opposite to the surface on which the intermediate layer 2 is provided.

[0061] The thickness of the base material layer 1 is, for example, 6 to 35 μm, preferably 7 to 33 μm, and more preferably 8 to 30 μm.

[0062] Since the thickness of the base material layer 1 is not too thick, the rigidity of the cover tape is not too high. Moreover, even if a torsional stress is applied to the sealed carrier tape, the cover tape 10 can follow the deformation of the carrier tape and reduce the possibility of peeling.

[0063] Since the thickness of the base material layer 1 is not too thin, it is easy to make the mechanical strength of the cover tape 10 appropriate. In addition, the possibility of the cover tape 10 being broken can be reduced even when the cover tape 10 is peeled off from the carrier tape at high speed.

[0064] [Middle layer]

[0065] The intermediate layer 2 is an optional layer, but is provided primarily to enhance the cushioning properties of the cover tape 10. Improving the cushioning properties of the cover tape 10 allows the pressure from the heat seal head to be more easily and securely transmitted to the cover tape 10 during heat sealing. This further improves the adhesion between the cover tape 10 and the carrier tape.

[0066] The material of the intermediate layer 2 is not particularly limited. Any material capable of imparting cushioning properties to the cover tape 10 can be used without particular limitation. Examples include polyacrylic acid derivatives, polyacrylate derivatives, polyvinyl acetate derivatives, styrene-based resins, olefin-based resins, cyclic olefin resins, and copolymers thereof. Of these, olefin-based resins are preferred, and ethylene-based resins can be used as appropriate. The intermediate layer 2 may contain only one resin or two or more resins.

[0067] When the intermediate layer 2 is provided, the intermediate layer 2 may be a single layer or multiple layers.

[0068] From the viewpoint of further improving the adhesion between the cover tape 10 and the carrier tape during heat sealing, the thickness of the intermediate layer 2 is usually 10 to 50 μm, preferably 15 to 45 μm.

[0069] [Sealing agent layer]

[0070] The sealant layer 3 is provided on at least one side of the base material layer 1. When the intermediate layer 2 is present, the sealant layer 3 is provided on the side of the intermediate layer 2 opposite to the side in contact with the base material layer 1. The sealant layer 3 is preferably in direct contact with the intermediate layer 2.

[0071] The sealant layer 3 comes into contact with the carrier tape when the cover tape 10 is heat-sealed to the carrier tape. The sealant layer 3 softens or melts due to the heat from the heat sealing head and is bonded to the carrier tape.

[0072] The sealant layer 3 preferably contains a thermoplastic resin. Specifically, the sealant layer 3 contains one or more resins selected from styrene resins, (meth)acrylic resins, olefin resins, urethane resins, and ester resins. Among these, styrene resins and (meth)acrylic resins are preferred from the perspectives of good heat sealing properties and good dissolution or dispersion of the conductive polymer. The sealant layer 3 may contain only one resin or two or more resins.

[0073] Specific examples of styrene-based resins include polystyrene, styrene / butadiene copolymers (SB), styrene / butadiene / styrene block copolymers (SBS), styrene / ethylene / butadiene / styrene block copolymers (SEBS), styrene / isoprene / styrene block copolymers (SIS), styrene / ethylene / propylene / styrene block copolymers (SEPS), styrene-methyl (meth)acrylate copolymers, hydrogenated styrene block copolymers, high-impact polystyrene (HIPS), and general-purpose polystyrene resins (GPPS). Among these, styrene / butadiene copolymers (SB) are preferred due to their balance of various properties.

[0074] Specific examples of (meth)acrylic resins include resins having structural units derived from monomers such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; methacrylic acid esters such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate; and acrylonitrile, methacrylonitrile, and acrylamide. (Meth)acrylic resins may contain structural units derived from one or more of these monomers. Of course, (meth)acrylic resins may further contain structural units derived from monomers other than these.

[0075] An ester resin generally consists of a structural unit derived from an alcohol component and a structural unit derived from a carboxylic acid component.

[0076] Specific examples of the alcohol component include chain or branched aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2,2-dimethyl-1,3-propanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol; alicyclic diols such as hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and alkylene oxide adducts of hydrogenated bisphenol A having 2 to 4 carbon atoms (average addition mole number of 2 to 12); and trivalent or higher polyols such as glycerol, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used alone or in combination.

[0077] Specific examples of the carboxylic acid component include chain or branched aliphatic dicarboxylic acids such as oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, azelaic acid, dodecanoic acid, dodecenylsuccinic acid, and octenylsuccinic acid; polycarboxylic acids having a valence of 3 or more such as trimellitic acid or its anhydride; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid; and the like. These carboxylic acid components may be used alone or in combination.

[0078] The sealant layer 3 contains a conductive polymer from the viewpoint of suppressing static electricity and charging by making the sealant layer 3 conductive. Specifically, the sealant layer 3 is composed of a mixture of a thermoplastic resin such as a styrene resin or a (meth)acrylic resin and a conductive polymer.

[0079] As conductive polymers, π-conjugated conductive polymers are preferred due to their excellent conductivity and availability. Specific conductive polymers include polypyrroles, polythiophenes, polyacetylenes, polyphenylenes, polyphenylenevinylenes, polyanilines, polyacenes, polythiophenevinylenes, and copolymers thereof. Polypyrroles, polythiophenes, and polyanilines are preferred due to their stability in air.

[0080] Specific examples of the π-conjugated conductive polymer include polypyrrole, poly(N-methylpyrrole), poly(3-methylpyrrole), poly(3-ethylpyrrole), poly(3-n-propylpyrrole), poly(3-butylpyrrole), poly(3-octylpyrrole), poly(3-decylpyrrole), poly(3-dodecylpyrrole), poly(3,4-dimethylpyrrole), poly(3,4-dibutylpyrrole), poly(3-carboxypyrrole), poly(3-methyl-4-carboxypyrrole), poly(3-methyl-4-carboxyethylpyrrole), and poly(3-methyl-4-carboxyethylpyrrole). ), poly(3-methyl-4-carboxybutylpyrrole), poly(3-hydroxypyrrole), poly(3-methoxypyrrole), poly(3-ethoxypyrrole), poly(3-butoxypyrrole), poly(3-methyl-4-hexyloxypyrrole), poly(thiophene), poly(3-methylthiophene), poly(3-ethylthiophene), poly(3-propylthiophene), poly(3-butylthiophene), poly(3-hexylthiophene), poly(3-heptylthiophene), poly(3-octylthiophene), poly(3-decylthiophene), poly(3-dodecylthiophene) , poly(3-octadecylthiophene), poly(3-bromothiophene), poly(3-chlorothiophene), poly(3-iodothiophene), poly(3-cyanothiophene), poly(3-phenylthiophene), poly(3,4-dimethylthiophene), poly(3,4-dibutylthiophene), poly(3-hydroxythiophene), poly(3-methoxythiophene), poly(3-ethoxythiophene), poly(3-butoxythiophene), poly(3-hexyloxythiophene), poly(3-heptyloxythiophene), poly(3-octyloxythiophene), poly(3-decyloxythiophene), poly( thiophene), poly(3-dodecyloxythiophene), poly(3-octadecyloxythiophene), poly(3-methyl-4-methoxythiophene), poly(3,4-ethylenedioxythiophene), poly(3-methyl-4-ethoxythiophene), poly(3-carboxythiophene), poly(3-methyl-4-carboxythiophene), poly(3-methyl-4-carboxyethylthiophene), poly(3-methyl-4-carboxybutylthiophene), polyaniline, poly(2-methylaniline), poly(3-isobutylaniline), poly(2-anilinesulfonic acid), poly(3-anilinesulfonic acid), and the like.

[0081] The sealant layer 3 may contain a dopant for improving the conductivity of the conductive polymer in addition to the conductive polymer. Preferred examples of the dopant include a polymer having an anionic functional group.

[0082] Specific examples of polymers having anionic functional groups include polyethylene sulfonic acid, polystyrene sulfonic acid, polyallyl sulfonic acid, polyacryloyl sulfonic acid, polymethacryloyl sulfonic acid, poly(2-acrylamide-2-methylpropane sulfonic acid), polyisoprene sulfonic acid, polyethylene carboxylic acid, polystyrene carboxylic acid, polyallyl carboxylic acid, polyacryloyl carboxylic acid, polymethacryloyl carboxylic acid, poly(2-acrylamide-2-methylpropane carboxylic acid), polyisoprene carboxylic acid, and polyacrylic acid. Among these, polystyrene sulfonic acid, polyacryloyl sulfonic acid, and polymethacryloyl sulfonic acid are preferred, and polystyrene sulfonic acid is particularly preferred.

[0083] Among conductive polymers, those containing structures derived from polythiophenes, i.e., thiophene or thiophene derivatives, are preferred from the perspectives of good conductivity and heat resistance during heat sealing. Poly(3,4-ethylenedioxythiophene) or its derivatives are particularly preferred as polythiophenes from the perspective of maintaining or improving various properties.

[0084] The ratio of the conductive polymer in the sealant layer 3 is, for example, 1 to 50 mass %, or preferably 2 to 45 mass %.

[0085] The sealant layer 3 may contain a leveling agent, a conductive auxiliary agent, and the like as other additives.

[0086] From the viewpoint of shortening the heat-sealing process and obtaining high sealing strength, the thickness of the sealant layer 3 is preferably 0.03 to 20 μm, more preferably 0.03 to 15 μm.

[0087] [Other layers]

[0088] The cover tape 10 may or may not include an additional layer different from the base material layer 1 , the intermediate layer 2 , and the sealant layer 3 .

[0089] For example, an anchor coat may be provided between the base layer 1 and the intermediate layer 2 to improve adhesion.

[0090] [Overall thickness]

[0091] From the viewpoint of ensuring a balance between strength and handling properties, the entire thickness of the cover tape 10 is preferably 40 to 65 μm, more preferably 45 to 60 μm.

[0092] [Haze and total light transmittance]

[0093] The haze value of the cover tape 10 measured in accordance with JIS K 7136 (2000) is preferably 5 to 25%, more preferably 5 to 20%. If the haze value is not excessively high, the visibility of the electronic components packaged with the cover tape 10 can be improved.

[0094] Furthermore, the total light transmittance of the cover tape 10 measured in accordance with JIS K 7361-1 (1997) is preferably 80 to 100%, and more preferably 85 to 95%.

[0095] To improve conductivity and antistatic properties, cover tape 10 contains a conductive polymer in sealant layer 3. However, cover tape 10 does not need to contain conductive "particles" such as metal particles. Therefore, cover tape 10 tends to have relatively low haze and relatively high total light transmittance.

[0096] [Surface resistance of the exposed surface on the sealant layer side]

[0097] The surface resistance of the exposed surface of the cover tape 10 on the sealant layer 3 side is preferably 1×10 4 ~-1×10 11 Ω / □, more preferably 1×10 5 ~-1×10 10 Ω / □.

[0098] Since the sealant layer 3 contains a conductive polymer, the surface resistance of the exposed surface of the cover tape 10 on the sealant layer 3 side becomes small.

[0099] [F A value of

[0100] Since in addition to F B / F A Except for the appropriate value of F A The value of F is large enough, so there is a tendency to further suppress the cover tape heat-sealed to the carrier tape from peeling off due to moisture. A The value of is not too large (and, accordingly, F B The value will not be too large), and the cover tape is easily peeled off from the carrier tape when taking out the packaged electronic components.

[0101] F A It is preferably 0.2 to 0.7N, more preferably 0.2 to 0.6N.

[0102] <Cover Tape Manufacturing Method>

[0103] The cover tape 10 can be manufactured by using appropriate materials and undergoing appropriate manufacturing processes. A suitable manufacturing method and the materials used in the manufacturing method will be described below.

[0104] First, the intermediate layer 2 is formed on the surface of the base layer 1. The base layer 1 is preferably a film formed of an ester resin, an olefin resin, etc. The intermediate layer 2 can be formed by, for example, extrusion lamination or dry lamination.

[0105] From the viewpoint of suppressing delamination between the base material layer 1 and the intermediate layer 2 , a layer based on, for example, an anchor coating agent may be present between the base material layer 1 and the intermediate layer 2 .

[0106] Next, a coating liquid for forming a sealant layer is applied to the surface of the intermediate layer 2 opposite to the base layer 1 and dried. As a coating method, for example, a gravure coating method can be used.

[0107] The coating liquid for forming the sealant layer can generally be obtained by thoroughly mixing a resin (preferably a thermoplastic resin such as the aforementioned styrene resin or (meth)acrylic resin), a conductive polymer, and a solvent in which these can be dissolved or dispersed.

[0108] Make F B / F A In terms of the cover tape 10 having a value of 0.6 to 1.4, it is preferable to select a conductive polymer that is soluble or dispersible in an organic solvent, and to select an organic solvent as the solvent. That is, it is preferable to apply a sealant layer-forming coating liquid in which a conductive polymer that is soluble or dispersible in an organic solvent is dissolved or dispersed to the surface of the intermediate layer 2 on the side opposite to the base material layer 1 and dry it, thereby providing the sealant layer 3. In particular, as the conductive polymer, it is preferable to use polythiophenes that are soluble or dispersible in an organic solvent. Incidentally, the fact that the conductive polymer is soluble in an organic solvent means, for example, that the conductive polymer dissolves without residue in the sealant layer-forming coating liquid described later.

[0109] Conductive polymers that are soluble or dispersible in organic solvents can be said to be lipophilic, i.e., hydrophobic. It is believed that the sealant layer 3 containing the hydrophobic conductive polymer is less likely to absorb moisture even in a high temperature / high humidity environment. Therefore, by using a conductive polymer that is soluble in an organic solvent, it is easy to manufacture the F B / F A The cover tape 10 has a value of 0.6 to 1.4.

[0110] Conductive polymers soluble or dispersible in an organic solvent can be purchased from, for example, Matsuo Sangyo Co., Ltd.

[0111] Incidentally, conventional cover tapes sometimes use a poly(3,4-ethylenedioxythiophene) / polystyrenesulfonic acid complex (so-called PEDOT / PSS). However, conventional PEDOT / PSS is often supplied as an aqueous dispersion (see: Chemistry and Education, Vol. 67, No. 2 (2019), pp. 86-89), and is not intended for use in organic solvents.

[0112] For the sake of caution, it is not impossible to use PEDOT / PSS supplied as an aqueous dispersion when providing the sealant layer 3. It is possible to adjust the F by taking various measures while using PEDOT / PSS supplied as an aqueous dispersion. B / FA However, in order to manufacture F B / F A For the cover tape 10 having a value of 0.6 to 1.4, it is preferable to use a conductive polymer soluble in an organic solvent.

[0113] <Electronic component packaging>

[0114] An electronic component package can be obtained by using the cover tape 10 described above and a carrier tape in which electronic components are accommodated in the recess. Figure 2 Provide explanation.

[0115] exist Figure 2 In the present invention, the cover tape 10 for electronic component packaging is used as a cover material of a strip-shaped carrier tape 20 on which concave pockets 21 are continuously provided in accordance with the shape of the electronic component.

[0116] Specifically, cover tape 10 for electronic component packaging is joined (typically heat-sealed) to the surface of carrier tape 20 so as to cover the entire opening of pocket 21 of carrier tape 20. Hereinafter, the structure formed by joining cover tape 10 for electronic component packaging to carrier tape 20 is referred to as electronic component package 100.

[0117] The electronic component package 100 can be produced, for example, according to the following steps.

[0118] First, electronic components are housed in pockets 21 of carrier tape 20 .

[0119] Then, the electronic component packaging cover tape 10 is bonded to the surface of the carrier tape 20 by heat sealing so as to cover the entire opening of the pocket 21 of the carrier tape 20. At this time, the sealant layer 3 in the electronic component packaging cover tape 10 is brought into contact with the carrier tape 20 (i.e., so that the sealant layer 3 is not formed on the carrier tape 20). Figure 2 Heat sealing is performed in such a way that the “back side” of the cover tape 10 for electronic component packaging becomes the sealant layer 3).

[0120] The specific heat sealing method and conditions are not particularly limited as long as the cover tape 10 for electronic component packaging is sufficiently firmly bonded to the carrier tape 20. Generally, a known heat sealer can be used, with a temperature of 100 to 240°C, a load of 0.1 to 10 kgf, and a time of 0.0001 to 1 second.

[0121] In this manner, a structure (electronic component package 100 ) in which an electronic component is sealed and accommodated can be obtained.

[0122] This structure (electronic component package 100) is wound on a reel and stored until the electronic component is used. Alternatively, the reel on which the electronic component package 100 is wound may be transported to a distant location by sea or air. As described above, in this embodiment, due to the F B / F A Since the value of is 0.6 to 1.4, even during ocean transportation, which may be subjected to high temperature and high humidity, it is possible to suppress the cover tape 10 from being peeled off from the carrier tape 20 .

[0123] The material of the reel can be metal, paper, plastic, etc.

[0124] When using the electronic components, the cover tape 10 for electronic component packaging is peeled off from the carrier tape 20 to take out the housed electronic components.

[0125] The electronic components housed in the electronic component package 100 are not particularly limited, and may include all components used in manufacturing electrical and electronic equipment, such as semiconductor chips, transistors, diodes, capacitors, piezoelectric elements, optical elements, LED-related components, connectors, and electrodes.

[0126] While the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be employed. Furthermore, the present invention is not limited to the above embodiments, and modifications and improvements within the scope of achieving the objectives of the present invention are included in the present invention.

[0127] Example

[0128] The embodiments of the present invention will be described in detail based on Examples and Comparative Examples. However, it should be noted that the present invention is not limited to the Examples.

[0129] In the following, the symbol "E" is sometimes used to represent an exponential notation. For example, 1.3E+06 means 1.3×10 6 .

[0130] <Manufacturing of Cover Tape>

[0131] The anchor coating agent was applied to an antistatic polyethylene terephthalate (PET) film (E7455 manufactured by Toyobo Co., Ltd.) having a thickness of 12 μm by gravure coating to a wet thickness of 4 μm, and then dried at 100°C.

[0132] Thereafter, low-density polyethylene (LDPE, “SUMIKATHENE L705” manufactured by Sumitomo Chemical Co., Ltd.) was extrusion laminated and cooled by passing through a cooling roll (surface temperature 20° C.) to provide an intermediate layer having a thickness of 37 μm.

[0133] In this manner, a laminated film composed of the base material layer and the intermediate layer was produced.

[0134] A sealant layer-forming coating solution (adjusted to a non-volatile component concentration of 12.5% ​​by mass) prepared by dissolving or dispersing the materials listed in the "Sealant Layer" column of Table 1 in methyl ethyl ketone was applied to the intermediate layer side of the resulting laminated film using a gravure coating method. This produced a dried film (sealant layer) with a thickness of 0.5 μm.

[0135] The obtained three-layer film was cut into a width of 5.5 mm to prepare a cover tape.

[0136] <F A and F B Determination of

[0137] First, the sealant layer side of the cover tape obtained in the above "Manufacturing of Cover Tape" was laminated to the concave-convex side of a polystyrene film ("CEL-E980A" manufactured by Sumitomo Bakelite Co., Ltd.) having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm on the concave-convex side to obtain a laminate.

[0138] This stack was heat-sealed using a heat sealer (Tokyo Weld Co., Ltd., "TWA-6621") using a double-edged iron with a single blade measuring 0.4 mm wide and 28 mm long. The conditions were: a sealing temperature of 180°C, a load of 5 kgf, a sealing time of 60 milliseconds, a carrier tape feed pitch of 4 mm, and 2 rows / 7 strikes. This yielded Sample A. Incidentally, to prepare Sample B below, at least two samples of Sample A were prepared in each of the Examples and Comparative Examples.

[0139] Using the obtained sample A, the peel strength (N) of the cover tape immediately after heat sealing to the polystyrene film was measured with reference to JIS C0806-3. Specifically, at 25°C, the peel was performed using a peel tester (EPI "PTS-5000") at a peel speed of 300 mm / min and a peel angle of 170°, and the peel strength was continuously recorded. Then, based on the relationship between the recorded time and the peel strength, the average peel strength within 10 seconds after the start of the peel was calculated. This average value was used as F A .

[0140] Incidentally, the surface roughness (Ra) of the polystyrene film used, which was bonded to the cover tape, was measured using a surface roughness meter (“SJ-210” manufactured by Mitutoyo Corporation) in accordance with JIS B 0601 (2001) before bonding to the cover tape.

[0141] Then, sample A was placed in an environment with a temperature of 40°C and a relative humidity of 90% for 7 days. This gave sample B. Sample B was also peeled under the same peeling conditions as sample A. The average value of the peel strength within 10 seconds after the start of peeling, calculated based on the relationship between the recorded time and the peel strength, was used as F. B .

[0142] According to the obtained F A and F B The value of F B / F A The value of .

[0143] <Surface resistance value on the sealant layer side>

[0144] The surface resistance (Ω / □) of the sealant layer surface of the obtained cover tape was measured using a surface resistance meter manufactured by SIMCO (“ST-3” manufactured by SIMCO) under an environment of 25° C. and 50% RH.

[0145] <Measurement of total light transmittance>

[0146] The total light transmittance (%) of the obtained cover tape was measured using a Haze Meter NDH2000 manufactured by Nippon Denshokku Industries Co., Ltd. under a light source of D65 in accordance with JIS K 7361-1 (1997).

[0147] <Haze measurement>

[0148] The haze (external haze, %) of the obtained cover tape was measured using a Haze Meter NDH2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. under a light source of D65 in accordance with JIS K 7136 (2000). The results are shown in Table 1.

[0149] <Evaluation: Ease of peeling under high temperature and high humidity environment (twist test)>

[0150] The evaluation was performed according to the following steps.

[0151] (1) The sealant layer side of the obtained cover tape was heat-sealed to a polystyrene film (CEL-E980A, manufactured by Sumitomo Bakelite Co., Ltd.) to obtain an evaluation sample. Specifically, a heat sealer (TWA-6621, manufactured by Tokyo Welding Co., Ltd.) equipped with a double-edged iron with a single-edged blade of 0.4 mm width and 28 mm length was used. The sealing was performed under the conditions of a sealing temperature of 180°C, a load of 5 kgf, a sealing time of 60 milliseconds, a carrier tape feed pitch of 4 mm, and 2 rows / 7 tapping. The sealing temperature was adjusted appropriately based on 180°C. Thus, the initial peel strength, measured at 25°C, a peel speed of 300 mm / min, and a peel angle of 170°, was 0.20 N.

[0152] (In this evaluation, the initial peel strength was set to a relatively low value of 0.20 N, intentionally facilitating peeling in a high-temperature / high-humidity environment to facilitate performance evaluation. Even if the initial peel strength is low, as long as peeling is not likely to occur, it can be said that the performance is very excellent in practical use.)

[0153] (2) The evaluation sample obtained in the above (1) was placed in an environment of a temperature of 40° C. and a relative humidity of 90% for 7 days.

[0154] (3) Cut the evaluation sample into 10 cm long strips. Twist one end of the sample 180° relative to the other end. Then, return it to its original shape, twist it 180° in the opposite direction, and return it to its original shape. Repeat this operation (one time in each of the forward and reverse directions) a total of five times.

[0155] (4) After performing the above (3), the evaluation samples were visually observed. Next, the presence of local seal lift was observed. In Table 1, "No" indicates no local seal lift, and "Yes" indicates a local seal lift.

[0156] Various information is summarized in Table 1.

[0157] The materials described in the column "Sealing agent layer" in Table 1 are as follows: The numerical values ​​described in the column "Sealing agent layer" represent the ratio of each component in the non-volatile component of the coating liquid for forming the sealant layer.

[0158] Resin 1: Acrylic resin, DIC Corporation bonding resin, product number: A450A

[0159] Resin 2: Styrene resin, manufactured by Asahi Kasei Corporation, product number: L7708

[0160] Resin 3…Acrylic resin, bonding resin from DAICEL-ALLNEX LTD., product number: VSC6274w

[0161] Resin 4…Polyester resin, Unitika Co., Ltd. bonding resin, product number: KA-5034

[0162] Conductive polymer 1... Conductive polymer soluble in organic solvents, polythiophene resin CPA-24 manufactured by Create Value Co., Ltd.

[0163] Conductive polymer 2…PEDOT:PSS dispersed in water (Clevios P1000 manufactured by Heraeus)

[0164] [Table 1]

[0165] As shown in Table 1, F B / F A The cover tapes of Examples 1 to 9, whose values ​​of F are 0.6 to 1.4, showed good results in the twisting test after a period of time under a high temperature and high humidity environment, despite containing a conductive material in the sealant layer. B / F A The cover tapes of Comparative Examples 1 and 3, in which the value of was less than 0.6, showed poor results in the twist test.

[0166] From this, we know that heat seal F B / F A An electronic component package obtained by combining a cover tape and a carrier tape having a value of 0.6 to 1.4 is unlikely to peel off during or after ocean transportation.

[0167] Incidentally, in Comparative Example 2, no local seal lifting was observed in the twist test. B / F A This value is much higher than 1.4. B Than F A When the cover tape is much larger than the carrier tape, the carrier tape may be pulled up when it is peeled off from the carrier tape, making it difficult to remove the components and causing deformation of the carrier tape. In other words, the cover tape of Comparative Example 2 is not preferred in terms of performance.

[0168] This application claims the benefit of priority based on Japanese patent application No. 2023-035462, filed on March 8, 2023, and incorporates herein the entire disclosure of that application.

[0169] Description of Reference Signs

[0170] 1- substrate layer, 2- Middle layer, 3- Sealant layer, 10-cover tape, 20-carrier tape, 21-bag, 100-Electronic component packaging.

Claims

1. A cover tape for electronic component packaging, comprising a base material layer and a sealant layer provided on at least one side of the base material layer, wherein: The sealant layer contains a conductive polymer, For Sample A obtained by heat-sealing the sealant layer side of the cover tape and the polystyrene film according to the following heat-sealing step, the peel strength when the cover tape is peeled off under the conditions described in the following peeling conditions is set as F A , The peel strength of the sample B obtained by leaving the sample A at a temperature of 40° C. and a relative humidity of 90% for 7 days was set as F when peeled under the following peeling conditions. B hour, F B / F A The value is 0.6~1.4, Heat sealing steps: (1) The sealant layer side of a cover tape cut to a width of 5.5 mm was laminated to the concave-convex surface side of a polystyrene film having a width of 8 mm and an average surface roughness Ra of 0.25 μm to obtain a laminated body. (2) Heat sealing is performed by bringing a double-edged iron with a single-edged blade of 0.4 mm width and 28 mm length into contact with the cover tape side of the stacked body at a sealing temperature of 160°C, a load of 5 kgf, a sealing time of 60 milliseconds, and a carrier tape feed interval of 4 mm. Stripping conditions: The measurement temperature was 25° C., the peeling speed was 300 mm / min, and the peeling angle was 170°.

2. The cover tape according to claim 1, wherein The conductive polymer contains polythiophenes.

3. The cover tape according to claim 1 or 2, wherein: The sealant layer contains one or more resins selected from the group consisting of styrene-based resins and (meth)acrylic resins.

4. The cover tape according to claim 1 or 2, wherein: An intermediate layer is further provided between the base material layer and the sealant layer.

5. The cover tape according to claim 1 or 2, wherein: The haze value measured in accordance with JIS K 7105 is 5 to 25%.

6. The cover tape according to claim 1 or 2, wherein: F A The value is 0.2~0.7N.

7. The cover tape according to claim 1 or 2, wherein: The surface resistance of the exposed surface on the sealant layer side is 1×10 4 ~1×10 11 Ω / □.

8. An electronic component package, wherein: The electronic component package comprises a carrier tape in which the electronic component is accommodated in a recessed portion and the cover tape according to claim 1 or 2. The sealant layer is bonded to the carrier tape to seal the electronic component.

9. A method for manufacturing a cover tape, which is the method for manufacturing a cover tape according to claim 1 or 2, wherein: The sealant layer is provided by applying a sealant layer-forming coating liquid in which a conductive polymer soluble or dispersible in an organic solvent is dissolved or dispersed on the surface of the intermediate layer opposite to the base layer and drying the liquid.

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