TWI841722B - Covering tape for packing elecronic component and package - Google Patents

Abstract

The present disclosure provides a covering tape for packing electronic component, the covering tape comprising: a base material layer, a heat seal layer that is disposed at one surface side of the base material layer and includes an ethylene-vinyl acetate copolymer and a polyethylene resin, and an antistatic layer that is disposed at the opposite surface side to the heat seal layer side of the base material layer.

Description

Cover tape and packaging body for electronic parts packaging

The present invention relates to a covering tape for packaging electronic components and a packaging body using the covering tape for packaging electronic components.

In recent years, electronic components such as ICs, resistors, transistors, diodes, capacitors, and piezoelectric components are packaged in tape for surface mounting. In tape packaging, electronic components are stored in a carrier tape having multiple storage sections for storing electronic components, and then the carrier tape is heat-sealed with a cover tape to obtain a package for storing and transporting electronic components. When installing electronic components, the cover tape is peeled off from the carrier tape, and the electronic components are automatically taken out and surface mounted on the substrate. Furthermore, the cover tape is also called the top tape.

In addition, in the case of braided packaging, in addition to the static electricity generated by friction or contact between electronic components and carrier tape or cover tape, static electricity is also generated by peeling the cover tape off the carrier tape during installation.

Therefore, in order to suppress the generation of static electricity, various cover tapes with anti-static properties have been proposed (for example, refer to patent documents 1~3).

[Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 4162961

[Patent document 2] Japanese Patent Publication No. 10-95448

[Patent Document 3] Japanese Patent No. 4061136

However, the inventors of the present invention have found that even when using a cover tape with antistatic properties, there is still a possibility that electronic components adhere to the cover tape.

The present invention is made in view of the above-mentioned problems, and its purpose is to provide a covering tape for packaging electronic components that can suppress abnormal behavior of electronic components when peeling off the carrier tape.

One embodiment of the present invention provides a covering tape for packaging electronic components, which comprises: a substrate layer; a heat-sealing layer disposed on one side of the substrate layer, comprising ethylene-vinyl acetate copolymer and polyethylene resin; and an antistatic layer disposed on the side of the substrate layer opposite to the side of the heat-sealing layer.

One embodiment of the present invention provides a packaging body, which comprises: a carrier tape having a plurality of storage portions for storing electronic components; and the above-mentioned electronic component packaging covering tape, which is arranged in a manner to cover the above-mentioned storage portions.

According to the electronic component packaging cover tape of the present invention, a packaging body can be obtained that can suppress abnormal behavior of electronic components generated when the cover tape is peeled off from the carrier tape even in a humid and hot environment. Therefore, by using the electronic component packaging cover tape or packaging body of the present invention, the installation of electronic components can be improved.

1: Covering tape

2: Base material layer

3: Heat sealing layer

3h: Heat sealing part

4: Anti-static layer

5: Middle layer

10:Packaging body

11: Carrier tape

12: Storage Department

13: Electronic parts

14: Feed hole

FIG1 is a schematic cross-sectional view showing an example of the cover tape for electronic component packaging of the present invention.

Figures 2(a) and 2(b) are schematic top and cross-sectional views of the packaging body of the present invention.

FIG3 is a schematic cross-sectional view showing an example of the cover tape for electronic component packaging of the present invention.

The following describes the implementation form of the present invention with reference to the drawings, etc. However, the present invention can be implemented in a variety of different forms, and should not be interpreted as limited to the contents described in the implementation forms illustrated below. In addition, in order to make the description clearer, there are cases where the width, thickness, shape, etc. of each part are schematically represented relative to the actual form, but this is only an example and does not limit the interpretation of the present invention. In addition, in this specification and each figure, the same symbol is attached to the same components as those described in the already presented figures, and there are cases where detailed descriptions are appropriately omitted.

In this specification, when expressing the configuration of other components on a component, when it is only described as "above" or "below", unless otherwise specified, it includes the following two situations: the configuration of other components directly above or below in a manner of connecting with a component; and the configuration of other components above or below a component through another component. In addition, in this specification, when expressing the configuration of other components on the surface of a component, when it is only described as "side" or "face", unless otherwise specified, it includes the following two situations: the configuration of other components directly above or below in a manner of connecting with a component; and the configuration of other components above or below a component through another component.

The following is a detailed description of the cover tape and packaging body for electronic component packaging of the present invention.

A. Covering tape for electronic parts packaging

The electronic component packaging cover tape of the present invention is a cover tape for electronic component packaging having a base layer, a heat seal layer disposed on one side of the base layer and comprising ethylene-vinyl acetate copolymer and polyethylene resin, and an antistatic layer disposed on the side of the base layer opposite to the side of the heat seal layer. In addition, in this specification, "electronic component packaging cover tape" is sometimes referred to as "cover tape".

The cover tape of the present invention is described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the cover tape of the present invention. As shown in FIG. 1 , the cover tape 1 of the present invention comprises: a substrate layer 2; a heat-sealing layer 3, which is disposed on one side of the substrate layer 2 and comprises an ethylene-vinyl acetate copolymer and a polyethylene resin; and an antistatic layer 4, which is disposed on the side of the substrate layer 2 opposite to the side of the heat-sealing layer 3.

Figures 2(a) and 2(b) are schematic top and cross-sectional views of an example of a package body using the cover tape for electronic component packaging of the present invention, and Figure 2(b) is a cross-sectional view along the A-A line of Figure 2(a). As shown in Figures 2(a) and 2(b), the package body 10 has: a carrier tape 11 having a plurality of storage portions 12 for storing electronic components 13; electronic components 13 stored in the storage portions 12; and a cover tape 1 arranged to cover the storage portions 12. The cover tape 1 is heat-sealed to the carrier tape 11, and heat-sealed portions 3h are provided linearly at both ends of the heat-sealed layer 3 of the cover tape 1 with a specific width. In addition, in the package body 10, the carrier tape 11 may have a feed hole 14.

The inventors of the present invention have found that when using a cover tape having a heat-sealing layer containing ethylene-vinyl acetate copolymer, the initial surface tackiness is relatively high, so when a plurality of electronic components are attached, and further, when the package is placed in a high-humidity and heat environment during storage or transportation, the heat-sealing layer is easily degraded, and the electronic components attached to the cover tape are more difficult to fall off. The reason for this can be inferred that the cover tape having a heat-sealing layer containing ethylene-vinyl acetate copolymer has a high MFR (melt flow rate) and low viscosity due to the characteristics of ethylene-vinyl acetate copolymer, so it has good heat sealing properties, but on the other hand, the surface tackiness is relatively high, and it is easy to degrade in a high-humidity and heat environment. In particular, since the packaging is usually in a rolled-up state during storage or transportation, it is difficult for such electronic components to fall off.

Therefore, the inventors of the present invention have conducted intensive research and found that in order to suppress the adhesion of electronic components to the cover tape, in addition to suppressing static electricity, it is also necessary to reduce the initial surface tackiness of the heat sealing layer of the cover tape and suppress the deterioration after placing it in a high humidity and heat environment. In addition, the inventors of the present invention have repeatedly studied and found that in addition to ethylene-vinyl acetate copolymer, by making the heat sealing layer of the cover tape also contain polyethylene resin, the surface tackiness can be reduced and the deterioration after placing it in a high humidity and heat environment can be suppressed.

Thus, in the present invention, by using a cover tape having a heat-sealing layer comprising ethylene-vinyl acetate copolymer and polyethylene resin, a packaging body using the cover tape of the present invention can be obtained, which can suppress abnormal behavior of electronic components such as electronic components jumping out, protruding, and standing up from the storage portion of the carrier tape due to the electronic components adhering to the cover tape when the cover tape is peeled off from the carrier tape.

As described above, the covering tape for electronic component packaging according to the present invention can normally remove electronic components and improve installation efficiency.

The following describes the various structures of the covering belt of the present invention.

1. Heat sealing layer

The heat sealing layer of the present invention is disposed on one side of the base material layer and includes a layer of ethylene-vinyl acetate copolymer and polyethylene resin. When the cover tape of the present invention is used to manufacture a package, the heat sealing layer is used to bond the cover tape to the carrier tape by heat sealing the carrier tape.

(a) Ethylene-vinyl acetate copolymers

The heat sealing layer includes ethylene-vinyl acetate copolymer. By making the heat sealing layer include ethylene-vinyl acetate copolymer, the heat sealing property to the carrier can be improved. Generally, it is difficult to heat-seal the cover tape to the paper carrier, but the cover tape having the heat sealing layer including ethylene-vinyl acetate copolymer can also obtain good heat sealing property to the paper carrier. Therefore, the cover tape of the present invention can suppress accidental peeling during transportation and storage.

The ethylene-vinyl acetate copolymer of the present invention is a copolymer containing at least ethylene monomer units and vinyl acetate monomer units. The ethylene monomer units refer to structural units derived from ethylene monomers, and the vinyl acetate monomer units refer to structural units derived from vinyl acetate monomers.

The ethylene content in the ethylene-vinyl acetate copolymer is not particularly limited, but is preferably 60% by mass to 97% by mass, and particularly preferably 80% by mass to 95% by mass.

The content of vinyl acetate in the ethylene-vinyl acetate copolymer is not particularly limited, but is preferably 3% by mass or more and 40% by mass or less, and particularly preferably 5% by mass or more and 20% by mass or less.

The ethylene-vinyl acetate copolymer of the present invention may also contain a third monomer unit in addition to the ethylene monomer unit and the vinyl acetate monomer unit. As the third monomer unit, styrene; (meth) acrylic acid such as saturated carboxylic acid or unsaturated carboxylic acid ester; (meth) acrylate methyl; methyl acrylate; ethyl acrylate; butyl acrylate; propylene; 1-butene; 4-methyl-1-pentene; 1-hexene; 1-octene, 1-decene; 1,3-butadiene, 2-methyl-1,3-butadiene and other conjugated dienes; 1,4-pentadiene, 1,5-hexadiene and other non-conjugated dienes, etc.

The content of the ethylene-vinyl acetate copolymer in the heat-sealing layer is not particularly limited, and may be greater than 0 mass % and less than 100 mass %, preferably greater than 50 mass % and less than 90 mass %, and more preferably greater than 60 mass % and less than 80 mass %.

If it is above the above value, better sealing strength can be obtained, so it is better. If it is below the above value, the initial tackiness can be reduced, and even after exposure to a high humidity and heat environment, the deterioration of the heat sealing layer can be suppressed, so it is better.

(b) Polyethylene resin

The heat sealing layer of the present invention is characterized by containing polyethylene resin. In addition to ethylene-vinyl acetate copolymer, polyethylene resin is formulated in the heat sealing layer, thereby reducing surface tackiness while maintaining good heat sealing properties and inhibiting deterioration caused by being placed in a high humidity and heat environment.

As polyethylene resins, various polyethylenes can be listed, such as low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, and high-density polyethylene. However, due to their advantages in terms of dispersibility, low-density polyethylene (LDPE, density less than 0.910~0.930) and linear low-density polyethylene (LLDPE, density 0.910~0.925) are suitable.

In addition, in the present invention, the classification of various polyethylenes refers to those defined in the old JIS K6748:1995 or JIS K6899-1:2000.

The content of polyethylene resin in the heat sealing layer may be, for example, greater than 0 mass % and less than 100 mass %, preferably greater than 10 mass % and less than 50 mass %, and more preferably greater than 20 mass % and less than 40 mass %.

If it is below the above value, the sealing strength after heat sealing will not be affected, so it can suppress the abnormal risk of peeling when packaging electronic parts, or the risk of accidental peeling of the covering tape during storage or transportation, so it is better. If it is above the above value, the initial surface contact of the heat sealing layer can be suppressed, and the deterioration caused by being placed in a humid and hot environment can also be suppressed, so it is better. In addition, if it is within the range of the above value, it has the above effects, so it is even better.

In the present invention, as described above, the content of the polyethylene resin in the heat sealing layer is preferably 10% by mass or more and 50% by mass or less, and particularly preferably 20% by mass or more and 40% by mass or less, for the following reasons.

That is, as mentioned above, in order to prevent the deterioration caused by being placed in a humid and hot environment and to suppress the abnormal behavior of electronic components such as jumping out, protruding, and standing up from the storage part of the carrier, it is better to have a high content of polyethylene resin in the above-mentioned heat sealing layer. On the other hand, when using a paper carrier, it is usually difficult to increase the sealing strength after heat sealing, so it is necessary to increase the content of ethylene-vinyl acetate copolymer in the heat sealing layer.

From this point of view, in order to suppress the risk of abnormalities such as peeling when packaging electronic parts, or the risk of accidental peeling of the covering tape during storage or transportation, specifically, a sealing strength of about 5~50gf, preferably about 15~40gf, is given, so the range of the polyethylene resin content in the heat sealing layer is set as mentioned above.

Furthermore, the above-mentioned sealing strength is the value obtained by measuring the method used in the [heat sealing strength evaluation] in the embodiment described later.

The heat sealing layer only needs to contain ethylene-vinyl acetate copolymer and polyethylene resin, and may also contain other resins. Examples of other resins include polyolefins such as polypropylene; polyesters; acrylic acids such as polyacrylates or polymethacrylates, etc. These resins may also be modified.

If necessary, the heat sealing layer may also contain additives such as adhesion agents, antistatic agents, anti-adhesive agents, dispersants, fillers, plasticizers, colorants, etc.

The thickness of the heat sealing layer can be, for example, 5 μm to 60 μm. In the case of a paper carrier, the thickness of the heat sealing layer can be, for example, 10 μm to 60 μm. In the case of a plastic carrier, the thickness of the heat sealing layer can be, for example, 5 μm to 60 μm. If the thickness of the heat sealing layer is too thin, a uniform film may not be obtained. In addition, if the thickness of the heat sealing layer is too thick, the transparency of the covering tape may be reduced.

As a method for forming a heat sealing layer, for example, there can be cited a method of using a heat sealing layer composition in which ethylene-vinyl acetate copolymer, polyethylene resin, and the above-mentioned other resins or additives as needed are dispersed or dissolved in a solvent, and applying the above-mentioned heat sealing layer composition on one side of the substrate layer and drying it. As the coating method of the above-mentioned heat sealing layer composition, for example, well-known coating methods such as roller coating, reverse coating, gravure coating, gravure reverse coating, comma coating, rod coating, wire rod coating, rod coating, contact coating, scraping coating, die nozzle coating, flow coating, dipping coating, and spray coating can be listed.

In addition, a film can be used as a heat-sealing layer. In this case, the lamination method of the substrate layer and the heat-sealing layer is not particularly limited, and a known method can be used. For example, a method of laminating a pre-made film with a substrate layer by an adhesive, or a method of extruding a hot-melted raw material into a substrate layer by a T-die head to obtain a laminated body can be listed. As an adhesive, for example, a polyester adhesive, a polyurethane adhesive, an acrylic adhesive, etc. can be used.

2. Anti-static layer

The antistatic layer of the present invention is a layer that is disposed on the surface of the substrate layer opposite to the heat sealing layer side and is used to prevent the cover tape from being charged. By having an antistatic layer, it is possible to prevent the electronic parts from being closely attached to the cover tape due to static electricity, or to prevent dirt or dust from being attached to the surface of the cover tape. In addition, it is possible to prevent static electricity from being generated due to contact with other surfaces.

The antistatic layer is formed by applying an antistatic agent to the substrate layer. As the antistatic agent, conductive polymers can be listed, such as polythiophene, polyaniline, polypyrrole, polyacetylene, polyparaphenylene, polyphenylene vinylene, polyvinyl carbazole, etc. Among them, the conductive polymer is preferably selected from the group consisting of polythiophene, polyaniline and polypyrrole. The reason is that sufficient antistatic properties and transparency that do not depend on humidity can be obtained. As polythiophene, for example, PEDOT/PSS (poly (3,4-ethylenedioxythiophene/polystyrene sulfonic acid) is suitable. As polyaniline, for example, sulfide polyaniline is suitable.

Furthermore, the antistatic layer of the present invention can exhibit antistatic properties by including an antistatic agent other than a conductive polymer. Examples of antistatic agents other than a conductive polymer include polymer surfactants and low molecular surfactants. Surfactants include non-ionic, cationic and anionic surfactants. From the perspective of antistatic performance and coating properties, cationic polymer surfactants are preferred. The counter anions of the quaternary ammonium salt are not particularly limited. For example, halogen ions, sulfide ions, etc. can be used, and aromatic groups and alkyl groups can be included at the 1st to 3rd positions of the ammonium, but are not particularly limited. From the perspective of solubility, the carbon number is preferably 6 or less. From the perspective of transparency and substrate adhesion, it is preferred to use an acrylic acid main chain as the main chain of the polymer-type quaternary ammonium salt.

Furthermore, the antistatic layer may also contain resin.

As a method for forming an antistatic layer, for example, an antistatic layer composition in which an antistatic agent is dispersed or dissolved in a solvent is used, and the antistatic layer composition is applied to the other side of the substrate layer and dried. As a method for applying the antistatic layer composition, for example, well-known coating methods such as air knife, scraper coating, scraper coating, rod coating, rod coating, direct roll coating, reverse coating, gravure coating, and inclined plate coating can be listed.

The thickness of the antistatic layer can be, for example, 0.02 μm to 3 μm. By making the antistatic layer have such a thickness, the cover tape can be endowed with antistatic properties.

3. Substrate layer

The substrate layer of the present invention is a layer that supports the above-mentioned heat sealing layer or antistatic layer.

As the base material layer, various materials can be used as long as they have mechanical strength to withstand external forces during storage and transportation, and heat resistance to withstand manufacturing and braid packaging. For example, polyesters such as polyethylene terephthalate, polyethylene butylene terephthalate, polyethylene naphthalate, polyethylene terephthalate-isophthalate copolymer, terephthalic acid-cyclohexanedimethanol-ethylene glycol copolymer; polyamides such as nylon 6, nylon 66, nylon 610; polyolefins such as polyethylene, polypropylene, polymethylpentene, etc. Among them, polyesters such as polyethylene terephthalate and polyethylene naphthalate are suitable for use because of their good cost and mechanical strength.

Furthermore, if necessary, the base layer may also contain additives such as fillers, plasticizers, colorants, antistatic agents, etc.

The substrate layer can be a single layer or a laminate of multiple layers of the same or different types. In addition, the substrate layer can be a stretched film or an unstretched film. In order to increase the strength, the substrate layer can also be a film stretched in a uniaxial direction or a biaxial direction.

The thickness of the substrate layer can be, for example, 2.5 μm to 300 μm, 6 μm to 100 μm, or 12 μm to 50 μm. If the thickness of the substrate layer is too thick, the rigidity will increase during the braid packaging, which will be disadvantageous in terms of handling and cost. In addition, if the thickness of the substrate layer is too thin, the mechanical strength will be insufficient.

The substrate layer may also be subjected to easy-to-attach treatments such as corona discharge treatment, plasma treatment, ozone treatment, membrane treatment, preheating treatment, dust removal treatment, evaporation treatment, alkaline treatment, sandblasting treatment, etc.

4. Middle layer

In the present invention, for example, as shown in FIG3 , an intermediate layer 5 may be arranged between the substrate layer 2 and the heat sealing layer 3 as needed. The intermediate layer can improve the adhesion between the substrate layer and the heat sealing layer. In addition, when the cover tape of the present invention is heat-sealed to the carrier tape by the intermediate layer, the cushioning property can be improved, thereby applying heat to the heat sealing layer more evenly.

The material of the middle layer is appropriately selected according to the materials of the base layer and the heat sealing layer, and examples thereof include polyolefins such as polyethylene or polypropylene, polyurethane, and polyester.

The thickness of the intermediate layer can be, for example, greater than 5μm and less than 50μm.

A film can be used as an intermediate layer. In this case, the lamination method of the substrate layer and the intermediate layer is not particularly limited, and a known method can be used. For example, a method of laminating a pre-made film to a substrate layer by means of an adhesive, or a method of obtaining a laminate by extruding the raw material of the hot-melted film to the substrate layer by means of a T-die, etc., can be cited. Furthermore, the adhesive is the same as the adhesive described in the above-mentioned heat sealing layer.

5. Adhesion layer

Furthermore, there may be an adhesion layer between the substrate layer and the intermediate layer. By forming the adhesion layer on the substrate layer, the adhesion between the substrate layer and the intermediate layer can be improved even when the substrate layer lacks adhesion. As the adhesion layer, it can be appropriately selected according to the materials used in the substrate layer and the intermediate layer, and there is no particular limitation. The adhesion layer can be formed by a resin with good adhesion, such as an acrylic, isocyanate, urethane, or ester adhesive.

B.Packaging

The packaging body of the present invention comprises: a carrier tape having a plurality of storage portions for storing electronic components; electronic components stored in the storage portions; and the covering tape configured to cover the storage portions.

In the present invention, by providing a cover tape having a heat-sealing layer comprising ethylene-vinyl acetate copolymer and polyethylene resin, a packaging body using the cover tape of the present invention can be obtained, which can suppress abnormal behavior of electronic components such as electronic components jumping out, protruding, and standing up from the storage portion of the carrier tape due to the electronic components adhering to the cover tape when the cover tape is peeled off from the carrier tape.

Figure 2 (a) and (b) are schematic top view and cross-sectional view of an example of the packaging body of the present invention. In addition, as Figure 2 (a) and (b) have been described in the above-mentioned "A. Cover tape for packaging electronic components", they will not be described here in detail.

The following describes the various structures of the packaging body of the present invention.

1. Covering tape

As the cover tape of the present invention has been described in the above-mentioned "A. Cover tape for packaging electronic components", it will not be described here in detail.

In the packaging body of the present invention, the heat-sealing layer of the covering tape and the carrier tape are connected by a heat-sealing portion. The heat-sealing portion can be arranged, for example, at a portion where the heat-sealing layer of the covering tape and the carrier tape are connected. That is, the heat-sealing layer can have a heat-sealing portion and a non-heat-sealing portion. In this way, the peeling property of the covering tape to the carrier tape can be improved.

2. Carrier tape

The carrier of the present invention is a component having a plurality of storage portions for storing electronic components.

As a carrier tape, any tape having multiple storage parts may be used, for example, any of embossed carrier tape (also called embossed tape), punched carrier tape (also called punched tape), and stamped carrier tape (also called stamped tape) may be used. Among them, embossed carrier tape is more suitable from the perspectives of cost, formability, dimensional accuracy, etc.

As the material of the carrier, for example, plastics such as polyvinyl chloride, polystyrene, polyester, polypropylene, polycarbonate, polyacrylonitrile, ABS resin, or paper can be listed. Among them, the material of the carrier is preferably paper. That is, it is preferably a paper carrier made of paper. The paper of the present invention refers to a paper with cellulose as the main component, and may further contain a resin component. The reason is that the paper carrier is excellent in terms of cost and environmental load, and can show appropriate adhesion with the cover tape of the present invention.

The thickness of the carrier is appropriately selected according to the material of the carrier or the thickness of the electronic components. For example, the thickness of the carrier can be between 30μm and 1500μm. If the thickness of the carrier is too thick, the formability will deteriorate, and if the thickness of the carrier is too thin, the strength will be insufficient.

The carrier tape has multiple storage sections. Usually, the storage sections are arranged at specific intervals in the length direction of the carrier tape. The size, depth, and spacing of the storage sections are appropriately adjusted according to the size and thickness of the electronic components.

As a method for forming a carrier tape having a storage portion, a commonly used carrier tape forming method can be used, and it can be appropriately selected according to the type or material of the carrier tape. For example, pressure forming, vacuum forming, air compression forming, punching processing, compression processing, etc. can be listed.

3. Electronic parts

The electronic components used in the package of the present invention are not particularly limited, and examples thereof include IC, resistor, capacitor, inductor, transistor, diode, LED (light emitting diode), liquid crystal, piezoelectric element register, filter, crystal oscillator, crystal resonator, connector, switch, potentiometer, relay, etc. The form of IC is also not particularly limited.

4.Packaging body

The packaging body of the present invention is used for storing and transporting electronic components. The electronic components are stored and transported in the packaging body for installation. During installation, the covering tape is peeled off, and the electronic components stored in the storage portion of the carrier tape are taken out and installed on a substrate, etc.

Furthermore, the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are illustrative only, and those having substantially the same structure and exerting the same effects as the technical ideas described in the scope of the patent application of the present invention are all included in the technical scope of the present invention.

[Implementation example]

The following describes embodiments and comparative examples and explains the present invention in more detail.

[Implementation Example 1]

As the substrate layer, a biaxially stretched polyethylene terephthalate film (FE2002 manufactured by FUTAMURA CHEMICAL, hereinafter referred to as PET film) with a thickness of 25 μm and corona treated on both sides was prepared. An antistatic layer was formed by coating one side of the PET film with an antistatic coating (ARACOAT AS601D/CL910 (mass ratio) = 10/1 containing PEDOT as a conductive polymer and aziridine as a curing agent, manufactured by Arakawa Chemical Industries, Ltd.). A urethane-based tackifier coating (Takenate A-3075/Takelac A-3210 (mass ratio) = 3/1 diluted with 5% ethyl acetate) was applied to the PET film on the side opposite to the side on which the antistatic layer was formed to form a tackifier layer. Then, a polyethylene resin (CE4009 manufactured by Sumitomo Chemical Industries, Ltd.) and a polyethylene resin (Sumikathene L705 manufactured by Sumitomo Chemical Industries, Ltd.) and an ethylene-vinyl acetate copolymer (Melthene (registered trademark) M (MX53C) manufactured by Tosoh Corporation) mixed at a ratio of 40/60 (mass ratio) were laminated to a thickness of 20 μm by melt extrusion to form an intermediate layer and a heat seal layer, respectively. Thus, a cover tape 1 having a structure including an antistatic layer (less than 1μ)/base material layer (25μm)/adhesive layer/intermediate layer (20μm)/heat sealing layer (20μm) is produced.

[Example 2]

Except that the heat sealing layer material (mixed material of ethylene-vinyl acetate copolymer and polyethylene resin) of Example 1 is changed to a mixed material of polyethylene resin (Sumikasen L705 manufactured by Sumitomo Chemical Industries) and ethylene-vinyl acetate copolymer (Merusen (registered trademark) M (MX53C) manufactured by Tosoh Corporation) with a mass ratio of 20/80, a cover tape 2 having a structure including an antistatic layer (less than 1μ)/base material layer (25μm)/adhesive layer/intermediate layer (20μm)/heat sealing layer (20μm) is prepared by the same method as Example 1.

[Implementation Example 3]

Except that the heat sealing layer material (mixed material of ethylene-vinyl acetate copolymer and polyethylene resin) of Example 1 is changed to a 60/40 mixed material of polyethylene resin (Sumikasen L705 manufactured by Sumitomo Chemical Industries) and ethylene-vinyl acetate copolymer (Merusen (registered trademark) M (MX53C) manufactured by Tosoh Corporation), a cover tape 3 having a structure including an antistatic layer (less than 1μ)/base material layer (25μm)/adhesive layer/intermediate layer (20μm)/heat sealing layer (20μm) is prepared by the same method as Example 1.

[Comparison Example 1]

Except that the heat sealing layer material (mixed material of ethylene-vinyl acetate copolymer and polyethylene resin) of Example 1 is changed to ethylene-vinyl acetate copolymer (Merusen (registered trademark) M (MX53C) manufactured by Tosoh Corporation), a cover tape 4 having a structure including an antistatic layer (less than 1μ)/base material layer (25μm)/adhesive layer/intermediate layer (20μm)/heat sealing layer (20μm) is prepared by the same method as Example 1.

[Comparison Example 2]

Except that the heat sealing layer material (mixed material of ethylene-vinyl acetate copolymer and polyethylene resin) of Example 1 is changed to polyethylene resin (Sumikasen L705 manufactured by Sumitomo Chemical Industries, Ltd.), a cover tape 5 having a structure including an antistatic layer (less than 1μ)/base material layer (25μm)/adhesive layer/intermediate layer (20μm)/heat sealing layer (20μm) is prepared by the same method as Example 1.

[Evaluation of initial adhesion]

The tactile adhesion of the heat-sealing layers of the covering tapes 1 to 4 obtained above was measured in the following manner.

(Measurement method)

Place the heat-sealed surface of the sample facing upwards, and attach the four corners of the sample to a glass slide (76×26mm, 0.8~1.0mmt) in a flat manner. Place the sample on the stage of the following measuring device, make the probe contact the sample from the top under the following conditions, and make the probe separate from the sample under the following conditions, and obtain the load value borne by the probe at this time. The results are shown in Table 1.

(Measuring device)

Adhesion tester TAC-2 (made by RHESCA)

(Measurement conditions)

Compression speed: 30mm/min

Pressurizing load: 200gf

Pressurization time: 10s

Measuring (detachment) speed: 30mm/min

Measuring contact part (probe): cylindrical diameter 5mm, SUS304

Temperature conditions: Probe temperature 60℃, sample table temperature 60℃ (sample temperature 60℃)

[Abnormal behavior quantity assessment]

Using the above-mentioned covering tapes 1 to 4, sample packaging bodies were prepared as follows, and the number of abnormal behaviors of electronic components when the covering tapes were peeled off from the packaging bodies was measured.

(Sample production)

The sample of the package body was prepared according to the following conditions. The following 500 electronic components were continuously arranged in the cavity of the following paper carrier tape, and the paper carrier tape and the cover tape were heat-sealed and rolled up using the following taping machine according to the following conditions to obtain a sample of the package body in a roll shape.

(Sample production conditions)

Taping machine NST-35 (made by Nitto Industry Co., Ltd.)

Paper carrier: HOCTO 0.31mmt (virgin paper) produced by Hokuetsu Kishu Paper Co., Ltd.

Tape temperature: 180℃

Taping speed: 3500 takt

Sealing width: 0.6mm×2

Electronic parts: 0402 size capacitors

(Abnormal behavior quantity measurement)

The package roll was stored in a constant temperature and humidity test room at 60℃ and 95%RH for 24 hours. The cover tape was peeled off from the stored roll-shaped package at a speed of 100mm/sec using a cover tape stripping device (W08f intelligent feeder, manufactured by FUJI). The stripping was performed in an environment of 25±3℃ and 30±5%RH and completed within 10 seconds. The behavior of the electronic components during the stripping was observed by a high-speed camera. During the peeling process, the situation where more than half of the crystals jumped out of the paper carrier cavity (including the situation where the electronic components adhered to the cover tape, the situation where the electronic components rotated 90 degrees and stood up, and the situation where the electronic components jumped out of the paper carrier cavity) was considered abnormal behavior. The images taken by the high-speed camera were played back in slow motion, and the number of abnormal behaviors was counted visually.

Similarly, after storage at room temperature (24 hours), the behavior of the electronic components during peeling was observed by the above-mentioned high-speed camera. The images taken by the high-speed camera were played back at a slow speed, and the number of abnormal behaviors was visually counted. The results are shown in Table 1.

[Evaluation of heat seal strength]

Regarding the sample in which the paper carrier tape and the above-mentioned covering tapes 1 to 5 are sealed according to the following taping conditions, the peeling strength is measured by the sealing strength tester under the following conditions. The average value of the measured length of 15 cm is taken as the measured value. The results are shown in Table 2.

(Heat sealing device and heat sealing conditions)

Taping machine NST-35 (made by Nitto Industry Co., Ltd.)

Paper carrier: HOCTO 0.31mmt (virgin paper) produced by Hokuetsu Kishu Paper Co., Ltd.

Tape temperature: 180℃

Taping speed: 3500 production distance

Sealing width: 0.6mm×2

(Seal strength test conditions)

Device: Vanguard Systems peel back tester VG-20

Peeling speed: 300mm/min

Stripping temperature: 25±3℃

Peeling angle: 165~175°

According to Table 1 and Table 2, the surface tackiness of the cover tape (Examples 1 to 3) of the present invention, in which the heat sealing layer includes ethylene-vinyl acetate copolymer and polyethylene resin, is suppressed, the number of abnormal behaviors when the package body is peeled off the cover tape after being placed in a high humidity and heat environment is suppressed, and the sealing strength is sufficient. On the other hand, in Comparative Example 1 in which the heat sealing layer does not include polyethylene resin, the surface tackiness is stronger, and the number of abnormal behaviors when the package body is peeled off the cover tape after being placed in a high humidity and heat environment is more. In addition, in Comparative Example 2 in which the heat sealing layer does not include ethylene-vinyl acetate copolymer, the heat sealing strength is weaker.

1: Covering tape

2: Base material layer

3: Heat sealing layer

4: Anti-static layer

Claims (3)

A covering tape for packaging electronic components, comprising: a substrate layer; a heat-sealing layer disposed on one side of the substrate layer, comprising ethylene-vinyl acetate copolymer and polyethylene resin; and an antistatic layer disposed on the side of the substrate layer opposite to the side of the heat-sealing layer, wherein the heat-sealing layer comprises more than 20% by mass and less than 40% by mass of the polyethylene resin. A packaging body, comprising: a carrier tape having a plurality of storage portions for storing electronic components; electronic components stored in the storage portions; and a covering tape for packaging electronic components as in claim 1, which is arranged to cover the storage portions. For example, the packaging body of claim 2, wherein the carrier tape is a paper carrier tape made of paper.