JP7683282B2 - Cover tape for packaging electronic components, electronic component package, and method for producing cover tape for packaging electronic components - Google Patents

Description

The present invention relates to a cover tape for packaging electronic components, an electronic component package, and a method for manufacturing a cover tape for packaging electronic components.

Conventionally, at electronic equipment manufacturing sites, electronic components such as transistors, diodes, capacitors, and piezoelectric resistors are stored in a package consisting of a carrier tape with continuous pockets formed therein in which the electronic components can be stored, and a cover tape that is sealed to the carrier tape, and then heat-sealed. The electronic components are then transported in a state where they are wound on a paper or plastic reel to a work area where they are surface-mounted on electronic circuit boards, etc. Then, after the cover tape of the package is peeled off in the above-mentioned work area, the electronic components are taken out of the pockets formed in the carrier tape and surface-mounted on electronic circuit boards, etc.

For example, Patent Document 1 discloses that the peelability is optimized by focusing on the peel resistance ratio α between the maximum and minimum values of the peel resistance between the carrier tape and the cover tape.

JP 2017-171393 A

When a package consisting of carrier tape and cover tape is transported to the work area where surface mounting is performed, the environment can become hot and humid. In addition, because the tape is wound on a reel, a certain amount of pressure is applied to the carrier tape and cover tape, causing the carrier tape and cover tape to adhere even to the non-heat-sealed parts, which causes the carrier tape and cover tape to not peel off smoothly during the mounting process. In other words, conventional cover tapes have the problem that when pressure is applied in a high-temperature, high-humidity environment, the non-heat-sealed parts adhere to the carrier tape.

In consideration of the above problems, one of the objects of the present invention is to provide a cover tape that prevents the portions that are not heat sealed to the carrier tape from adhering to the carrier tape (unintended adhesion) even when pressure is applied in a high-temperature, high-humidity environment.

The inventors discovered that the above objectives could be achieved by using a resin with a glass transition temperature in a specific range for the sealant layer of the cover tape, and thus completed the present invention.

According to the present invention, the following cover tape for packaging electronic components is provided:

A base layer;
The middle class,
A sealant layer;
A cover tape for packaging electronic components, comprising, in this order:
The cover tape for packaging electronic components, wherein the sealant layer contains one or more resins (A1) having a glass transition temperature of more than 60° C. and not more than 120° C., as measured in accordance with the <Method for Measuring Glass Transition Temperature> described below.
<Method of measuring glass transition temperature>
The glass transition temperature (° C.) of the resin (A1) is measured using a differential scanning calorimeter (DSC) by increasing the temperature from 0° C. to 200° C. at a temperature increase rate of 10° C./min in a nitrogen atmosphere.

Further, according to the present invention,
a carrier tape having electronic components housed in recesses;
The cover tape for packaging electronic components described above,
An electronic component package is provided having a sealant layer side adhered to a carrier tape so as to encapsulate the electronic component.

Further, according to the present invention,
A base layer;
The middle class,
A sealant layer;
A method for producing a cover tape for packaging electronic components, comprising the steps of:
a step of preparing a composition for forming a sealant layer, the composition including a resin (A1) having a glass transition temperature of more than 60° C. and not more than 120° C., the glass transition temperature being measured according to the following <Method for measuring glass transition temperature>;
forming the sealant layer using the sealant layer-forming composition;
having
A method for manufacturing cover tape for packaging electronic components.
<Method of measuring glass transition temperature>
The glass transition temperature (° C.) of the resin (A1) is measured using a differential scanning calorimeter (DSC) by increasing the temperature from 0° C. to 200° C. at a temperature increase rate of 10° C./min in a nitrogen atmosphere.

The present invention provides a cover tape that prevents the non-heat-sealed portion from adhering to the carrier tape (unintended adhesion) even when pressure is applied in a high-temperature, high-humidity environment.

1 is a schematic diagram showing an example of a cover tape for packaging electronic components according to an embodiment of the present invention; FIG. 2 is a diagram showing an example of a state in which a cover tape for packaging electronic components is bonded (heat sealed) to a carrier tape.

The following describes an embodiment of the present invention with reference to the drawings. Note that in all drawings, similar components are given similar reference symbols and descriptions are omitted where appropriate. Also, the drawings are schematic and do not necessarily correspond to the actual dimensional ratios.

In this specification, the term "acrylic" refers to a concept that includes both acrylic and methacrylic. The same applies to similar terms such as "acrylate."

<Cover tape for packaging electronic components>
FIG. 1 is a schematic diagram showing an example of a cover tape for packaging electronic components according to the present embodiment.
The cover tape for packaging electronic components of this embodiment is a cover tape for packaging electronic components that includes a base layer 1, an intermediate layer 2, and a sealant layer 3 in this order.
In the cover tape 10 for packaging electronic devices, the sealant layer 3 is usually bonded to the carrier tape. In other words, the upper surface side in FIG.
Moreover, each layer may be composed of a plurality of layers.
The sealant layer 3 also contains one or more resins (A1) having a glass transition temperature, measured by a predetermined method, of more than 60° C. and not more than 120° C. The resin (A1) is preferably at least one selected from the group consisting of styrene-based resins, acrylic-based resins, and ester-based resins.
Furthermore, the sealant layer 3 has a peel strength against a polystyrene film measured by a predetermined method of preferably 0.3 N to 0.9 N, and a tack strength against a polystyrene film measured by a predetermined method of preferably 0 N/cm ² to 5.0 N/cm ^2. This allows the cover tape for packaging electronic components to have a good balance between adhesion to the carrier tape and peelability, while also having good adhesion resistance.

The cover tape 10 for packaging electronic components of the present embodiment has a good balance between adhesiveness and peelability, and also has excellent adhesion resistance.
Although the details of the mechanism by which the electronic component packaging cover tape 10 has excellent adhesion resistance while maintaining a good balance between adhesion and peelability are not clear, by using a resin (A1) having a glass transition temperature (hereinafter also referred to as Tg) of more than 60° C. and less than 120° C., preferably at least one resin (A1) selected from the group consisting of styrene-based resins, acrylic-based resins, and ester-based resins, the cover tape and the carrier tape are bonded together to form a package, and since the resin is in a glass state even in a room temperature environment or a transport environment, it is possible to suppress adhesion while maintaining good adhesion resistance. Furthermore, it is thought that the peelability when peeling the cover tape from the carrier tape at room temperature can be improved.

<Other demographics>
An adhesive layer (not shown) may be provided between each layer of the cover tape for packaging electronic components 10. The adhesive layer can improve the adhesion between each layer.
Materials for forming the adhesive layer include urethane-based adhesive resins for dry lamination or adhesive resins for anchor coats, and generally include a combination of a polyester composition such as polyester polyol or polyether polyol with an isocyanate compound.
Furthermore, layers other than the adhesive layer may be provided, such as a layer for improving the strength of the entire film, a water vapor barrier layer, etc.

<Base material layer>
The base material layer 1 can be a film made from various materials, so long as it has the mechanical strength to withstand the external forces applied during processing of the cover tape 10 for packaging electronic components, heat sealing to the carrier tape, and use, and the heat resistance to withstand the heat generated during heat sealing.

Specific examples of materials constituting the base layer 1 include polyester resins, polyamide resins, polyolefin resins, polyacrylate resins, polymethacrylate resins, polyimide resins, polycarbonate resins, and ABS resins. Among these, polyester resins and polyolefin resins are preferred as materials constituting the base layer 1, and polyethylene terephthalate and polyethylene, which can improve mechanical strength, are particularly preferred. In addition, when selecting polyamide resins as the material constituting the base layer 1, it is preferable to use nylon, which can improve mechanical strength and flexibility.

The form of the film used to form the base layer 1 may be a stretched film or a film stretched uniaxially or biaxially, but from the viewpoint of improving the mechanical strength of the cover tape for packaging electronic components, a film stretched uniaxially or biaxially is preferred.

The base layer 1 may be formed of a single layer film containing the above-mentioned materials, or may be formed of a multilayer film containing the above-mentioned materials in each layer.
From the viewpoint of reducing the amount of static electricity generated by peeling off the carrier tape, the base layer 1 may contain an antistatic agent, or an antistatic layer may be provided as one layer of the base layer on the surface of the base layer 1 opposite to the surface on which the intermediate layer 2 is provided. When electronic components are contained in a package consisting of the carrier tape and the cover tape 10 for packaging electronic components and transported, if multiple packages are stacked and transported, the surface of the base layer 1 or the antistatic layer containing such an antistatic agent may come into contact with the bottom surface of the carrier tape of the package stacked on top.

The thickness of the base layer 1 is, for example, 6 μm or more, preferably 7 μm or more, and more preferably 8 μm or more. The thickness of the base layer 1 is, for example, 35 μm or less, preferably 33 μm or less, and more preferably 30 μm or less. If the thickness of the base layer 1 is equal to or less than the above upper limit, the rigidity of the cover tape for packaging electronic components is not too high, and even if a torsional stress is applied to the carrier tape after sealing, the cover tape for packaging electronic components 10 follows the deformation of the carrier tape, and the possibility of peeling off can be reduced. Furthermore, if the thickness of the base layer 1 is equal to or more than the above lower limit, the mechanical strength of the cover tape for packaging electronic components 10 becomes suitable, and even when the cover tape for packaging electronic components 10 is peeled off from the carrier tape at high speed, the possibility of the cover tape for packaging electronic components 10 breaking can be reduced.
The substrate layer 1 may have a two-layer structure of a first substrate layer and a second substrate layer, or a three-layer structure having an additional layer. In this case, the material may be, for example, the same as that used for the substrate layer 1. The thickness is preferably the total thickness of the first substrate layer, the second substrate layer, etc., which is the "thickness of substrate layer 1."

<Middle class>
The intermediate layer 2 is a layer provided for the purpose of imparting cushioning properties to the cover tape 10 for packaging electronic components according to this embodiment, thereby improving the adhesion between the cover tape 10 for packaging electronic components and the carrier tape during sealing.

The intermediate layer 2 may be made of any material that can provide cushioning properties to the electronic component packaging cover tape 10, but examples of such materials include one or more selected from polyacrylic acid derivatives, polyacrylic acid ester derivatives, polyvinyl acetate derivatives, styrene-based resins, olefin-based resins, and cyclic olefin resins, as well as copolymers thereof. Among these, olefin-based resins are preferred, and ethylene-based resins are more preferred.

The thickness of the intermediate layer 2 is typically 10 μm or more and 50 μm or less, preferably 15 μm or more and 45 μm or less, from the viewpoint of improving the adhesion between the electronic component packaging cover tape 10 and the carrier tape during sealing.

<Sealant Layer>
The sealant layer 3 is a layer provided on the side opposite to the side of the intermediate layer 2 that contacts the base material layer 1, and is a layer that comes into contact with the carrier tape when the cover tape 10 for packaging electronic components is sealed (e.g., heat sealed) to the carrier tape.
The sealant layer 3 has heat sealability and can be adhered to a carrier tape, and exhibits easy peelability so that it can be easily peeled off when in use.
The sealant layer 3 may be formed by laminating an adhesive resin layer and an antistatic layer in this order on the side opposite to the surface in contact with the intermediate layer 2.

The sealant layer 3 contains a resin (A1) having a glass transition temperature (°C) of more than 60°C and not more than 120°C, as measured by a differential scanning calorimeter (DSC) under a nitrogen atmosphere at a temperature rise rate of 10°C/min from 0°C to 200°C. The resin (A1) preferably contains at least one resin (A1) selected from the group consisting of styrene-based resins, acrylic-based resins, and ester-based resins. The glass transition temperature (°C) of the resin (A1) is more than 60°C and not more than 120°C, preferably not more than 118°C, more preferably not more than 116°C, and even more preferably not more than 114°C.
By considering not only the lower limit but also the upper limit of the glass transition temperature of the resin (A1), it becomes easier to achieve, for example, both improved adhesion of the cover tape to the carrier tape (improved peel strength) and ease of peeling during peeling (peelability).

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), general purpose polystyrene resins (GPPS), and the like, which may be used alone or in combination of two or more.
Among these, it is preferable to use polystyrene and styrene-butadiene copolymer (SB) from the viewpoint of high transparency and well-balanced improvement of adhesion resistance and peel strength.

Specific examples of acrylic resins include resins composed of 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. The constituent monomers of the acrylic resin include one or more of these examples. The constituent monomers of the acrylic resin may further include monomers other than these examples. The monomers may also be derivatives of these monomers.

The ester resin is composed of an alcohol component and a carboxylic acid component. Specific examples of the alcohol component include, for example, aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 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 hydrogenated bisphenol A with alkylene oxide having 2 to 4 carbon atoms (average molar addition number of 2 to 12), and trivalent or higher polyhydric alcohols such as glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohol components may be used alone or in combination of two or more.
Examples of the carboxylic acid component include 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, dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid, polyvalent carboxylic acids having three or more valences such as trimellitic acid or its anhydride, aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, and terephthalic acid, and aromatic dicarboxylic acids such as naphthalenedicarboxylic acid, etc. These carboxylic acid components may be used alone or in combination.

An example of a commercially available styrene-based resin having a glass transition temperature of more than 60° C. and not more than 120° C. is L8900 (Tg: 100° C.) manufactured by Asahi Kasei Corporation.
Examples of commercially available acrylic resins having a glass transition temperature of more than 60° C. and not more than 120° C. include VSC6254w (Tg: 84° C.) manufactured by Daicel Allnex Corporation.
Commercially available ester resins having a glass transition temperature of more than 60° C. and not more than 120° C. include ELITEL KT-8803 (Tg: 65° C.) manufactured by Unitika Ltd., ELITEL KA-5034 (Tg: 67° C.) manufactured by Unitika Ltd., ELITEL KA-3556 (Tg: 80° C.) and ELITEL KA-5034 (Tg: 67° C.) manufactured by Unitika Ltd.

When the total amount of materials constituting the sealant layer 3 is taken as 100% by mass, the content of resin (A1) relative to the total amount of materials constituting the sealant layer 3 is preferably 10% by mass or more, more preferably 20% by mass or more, and also preferably 98% by mass or less, more preferably 95% by mass or less. By having the content of resin (A1) within the above range, for example, unintended adhesion can be further suppressed, and the balance between the adhesion and peelability of the cover tape for packaging electronic components to the carrier tape can be improved.

The sealant layer 3 preferably further contains a resin (A2) having a glass transition temperature of 60° C. or less, as measured in a nitrogen atmosphere using a differential scanning calorimeter (DSC) at a temperature rise rate of 10° C./min from 0° C. to 200° C. The resin (A2) is preferably at least one selected from the group consisting of styrene-based resins, acrylic-based resins, and ester-based resins.
The glass transition temperature of the resin (A2) is preferably 60° C. or less, more preferably 55° C. or less, and even more preferably 50° C. or less. There is no lower limit to the glass transition temperature of the resin (A2), but it is, for example, 20° C. or more. By using the resin (A2), for example, it is possible to improve the balance between the adhesiveness and peelability of the cover tape for packaging electronic components to the carrier tape.

Examples of commercially available styrene-based resins having a glass transition temperature of 60° C. or lower include Asahi Kasei Corporation's L-7708 (Tg: 38° C.), Asahi Kasei Corporation's A-7755 (Tg: 36° C.), Asahi Kasei Corporation's L-2301 (Tg: 24° C.), and Asahi Kasei Corporation's L-7532 (Tg: 17° C.).
Commercially available acrylic resins having a glass transition temperature of 60° C. or less include VSC6828w (Tg: 42° C.) manufactured by Daicel Allnex Corporation.
Commercially available ester resins having a glass transition temperature of 60° C. or less include Elitel KA-0134 (Tg: 40° C.) manufactured by Unitika Ltd., Elitel KT-9204 (Tg: 18° C.) manufactured by Unitika Ltd., and the like.

When the total amount of resin (A1) and resin (A2) in the sealant layer 3 is taken as 100, the ratio by mass of (A1):(A2) is preferably 10:90 to 90:10, more preferably 15:85 to 85:15, and even more preferably 20:80 to 80:20.

The resins used for resin (A1) and resin (A2) may be a combination of resins of the same type or a combination of resins of different types. This means that, for example, a combination of a styrene-based resin having a glass transition temperature of more than 60°C and less than 120°C and a styrene-based resin having a glass transition temperature of less than 60°C may be used, or a combination of a styrene-based resin having a glass transition temperature of more than 60°C and less than 120°C and a resin other than a styrene-based resin having a glass transition temperature of less than 60°C (acrylic resin or ester resin), etc.

The sealant layer 3 may contain other resins in addition to the above resin (A1) and resin (A2). Specific examples of other resins include one or more resins selected from the group consisting of olefin-based resins and urethane-based resins, and copolymers thereof.

The sealant layer 3 may further contain (B) an antistatic agent from the viewpoints of reducing the surface resistance value of the sealant layer 3 to suppress the generation of static electricity associated with peeling and maintaining the sealing properties.
Specific examples of the (B) antistatic agent include antimony-doped tin, polythiophene or a polythiophene derivative, phosphorus-doped tin, fluorine-doped tin, carbon nanotubes, etc. From the viewpoint of obtaining good compatibility with the above (A1) alone or with the above (A1) and (A2) and more reliably obtaining the effect of suppressing static electricity during peeling, it is preferable that the (B) antistatic agent is polythiophene, a polythiophene derivative, or antimony-doped tin.

Examples of the polythiophene or polythiophene derivatives include polythiophene, poly(3,4)-ethylenedioxythiophene, and poly(3-thiophene-β-ethanesulfonic acid). Among these, poly3,4-ethylenedioxythiophene or its derivatives are preferred from the viewpoint of maintaining better antistatic properties and sealing properties.

The sealant layer 3 may contain other additives such as a dispersant to improve the dispersibility of the antistatic agent, silica sol, a leveling agent, a conductive assistant, etc.

From the viewpoint of performing sealing and peeling operations smoothly, the thickness of the sealant layer 3 is typically preferably 0.02 μm or more and 20 μm or less, and more preferably 0.03 μm or more and 15 μm or less.

From the viewpoint of ensuring film strength, the thickness of the cover tape for packaging electronic components according to this embodiment is preferably 40 μm or more and 65 μm or less, and more preferably 45 μm or more and 60 μm or less.

The characteristics of the cover tape for packaging electronic components according to this embodiment are described below.

In the cover tape for packaging electronic components according to this embodiment, the tack strength of the sealant layer 3 is considered to be an index closely related to unintended adhesion of the cover tape to the carrier tape (described above).
Here, a stainless steel material with a contact area of 20 ^mm2 is pressed against the sealant layer 3 of a cover tape for packaging electronic components at a contact speed of 30 mm/min, and after holding at a measurement temperature of 60°C and a contact load of 25 N for 20 seconds, the load per unit area when peeled off at a speed of 600 mm/min is defined as the tack force at 60°C.
In this case, the tack strength of the sealant layer 3 at 60°C is preferably 5.0 N/ ^cm2 or less, more preferably 4.5 N/cm2 or less, and even more preferably 4.0 N/ ^cm2 or ^less , from the viewpoint of further suppressing unintended adhesion of the cover tape to the carrier tape.
In addition, there is no lower limit for the tack strength at 60° C., but it is, for example, 0 N/cm ² or more, specifically 0.01 N/cm ² or more.

The cover tape for packaging electronic components according to this embodiment can achieve a better balance between adhesion and peelability to the polystyrene carrier tape by devising the composition of the sealant layer, etc. Specific indicators for this include the following:

A cover tape for packaging electronic components is made to have a width of 5.5 mm, and the sealant layer side of the cover tape for packaging electronic components is bonded to the uneven surface side of a polystyrene film having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm. The sample is heat sealed using a two-blade iron with a width of 0.4 mm and a length of 28 mm under the conditions of a sealing temperature of 180°C, a load of 5 kgf, a sealing time of 60 milliseconds, and a carrier tape feed pitch of 4 mm. In the sample, the lower limit of the peel strength of the cover tape for packaging electronic components against the polystyrene film under the conditions of a peel speed of 300 mm/min, a measurement temperature of 25°C, and a peel angle of 170° is preferably 0.20 N or more, more preferably 0.21 N or more, and even more preferably 0.22 N or more. In addition, the upper limit of the 170° peel strength of the cover tape for packaging electronic components against the polystyrene film is preferably 0.9 N or less, more preferably 0.8 N or less, and even more preferably 0.7 N or less. By setting the 170° peel strength of the cover tape for packaging electronic components against the polystyrene film within the above range, the balance between adhesion and peelability to the polystyrene carrier tape can be further improved.

In addition, the cover tape for packaging electronic components according to this embodiment can achieve a better balance between adhesion to the polycarbonate carrier tape and peelability by devising the composition of the sealant layer, etc. Specific indicators for this include the following:

A cover tape for packaging electronic components is made to have a width of 5.5 mm, and the sealant layer side of the cover tape for packaging electronic components is bonded to the uneven surface side of a polycarbonate film having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm on the uneven surface. A sample is obtained by heat sealing the cover tape for packaging electronic components to the polycarbonate film at a sealing temperature of 180° C., a load of 5 kgf, a sealing time of 60 milliseconds, and a carrier tape feed pitch of 4 mm using a two-blade iron with a width of 0.4 mm and a length of 28 mm. In the sample, the lower limit of the peel strength of the cover tape for packaging electronic components to the polycarbonate film under the conditions of a peel speed of 300 mm/min, a measurement temperature of 25° C., and a peel angle of 170° is preferably 0.2 N or more, more preferably 0.21 N or more, and even more preferably 0.22 N or more. In addition, the upper limit of the 170° peel strength of the cover tape for packaging electronic components against the polycarbonate film is preferably 0.9 N or less, more preferably 0.8 N or less, and even more preferably 0.7 N or less. By setting the 170° peel strength of the cover tape for packaging electronic components against the polycarbonate film within the above range, the balance between adhesion and peelability to the polycarbonate carrier tape can be further improved.

As described above, the cover tape for packaging electronic components according to this embodiment prevents the portions that are not heat sealed to the carrier tape from adhering to the carrier tape (unintended adhesion) even when pressure is applied in a high-temperature, high-humidity environment. Specific indicators for this include the following:

A cover tape for packaging electronic components is made to have a width of 10 mm, and the sealant layer side of the cover tape is bonded to the uneven surface of a polystyrene film having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm to obtain a sample. A seal iron having a width of 0.5 mm, a length of 32.0 mm, and a weight of 46.0 g is placed on the upper surface of the cover tape of the sample, and the sample is left standing under conditions of 60° C. and 90% RH for 24 hours. After standing, whether the polystyrene film and the cover tape for packaging electronic components are adhered to each other is evaluated based on the adhesion marks on the polystyrene film. Specifically, the dimension of the adhesion marks on the polystyrene film in the length direction is measured as the length of the adhesion marks on the polystyrene film. The length of the adhesion marks on the polystyrene film is preferably 15 mm or less, more preferably 13 mm or less, and even more preferably 11 mm or less. There is no lower limit to the length of the adhesive mark on the polystyrene film, but it is, for example, 0 mm or more.
By designing the cover tape so that the length of the adhesion mark is shortened, when the cover tape and carrier tape are bonded together to form a package and then wound on a reel for storage, adhesion between the cover tape and carrier tape can be further suppressed in areas other than those bonded by heat sealing.

The surface resistance value of the surface of the above-mentioned base material layer of the cover tape for packaging electronic components according to this embodiment, measured at 25°C and 50% RH, is preferably 1.0 x ¹⁰³ Ω or more, more preferably 1.0 x ¹⁰⁴ Ω or more, even more preferably 1.0 x ¹⁰⁵ Ω or more, preferably 1.0 x ¹⁰¹³ Ω or less, more preferably 1.0 x ¹⁰¹² Ω or less, and even more preferably 1.0 x ¹⁰¹¹ Ω or less. By setting the surface resistance value of the above-mentioned base material layer of the cover tape for packaging electronic components within the above range, static electricity generated due to various factors can be efficiently discharged to the outside.
The surface of the base material layer refers to the exposed surface side of the base material layer in the cover tape for packaging electronic components (that is, the surface of the base material layer that is not in contact with the intermediate layer).

The surface resistance value of the sealant layer of the cover tape for packaging electronic components according to this embodiment, measured at 25° C. and 50% RH, is preferably 1.0×10 ³ Ω or more, more preferably 1.0×10 ⁴ Ω or more, even more preferably 1.0×10 ⁵ Ω or more, preferably 1.0×10 ¹² Ω or less, more preferably 1.0×10 ¹¹ Ω or less, and even more preferably 1.0×10 ¹⁰ Ω or less. By setting the surface resistance value of the sealant layer of the cover tape for packaging electronic components, measured at 25° C. and 50% RH, within the above range, the cover tape for packaging electronic components can be made to have even better antistatic properties associated with peeling of the carrier tape.
The surface of the sealant layer refers to the exposed surface side of the sealant layer in the cover tape for packaging electronic components (that is, the surface of the sealant layer that is not in contact with the intermediate layer).

The total light transmittance of the electronic component packaging cover tape according to this embodiment, measured with a light source D65 in accordance with JIS K7361-1 (1997), is preferably 70% or more, more preferably 75% or more, even more preferably 80% or more, preferably 95% or less, more preferably 94% or less, and even more preferably 93% or less. In this way, the package 100 consisting of the electronic component packaging cover tape 10 and the carrier tape can be given a degree of transparency that allows inspection of whether or not electronic components are properly accommodated in the pockets of the carrier tape. In other words, by setting the total light transmittance of the electronic component packaging cover tape to the above-mentioned lower limit value or more, it becomes possible to visually confirm the electronic components accommodated inside the package 100 consisting of the electronic component packaging cover tape 10 and the carrier tape from the outside of the package 100.

The external haze of the electronic component packaging cover tape according to this embodiment, measured with light source D65 in accordance with JIS K7136 (2000), is preferably 5% or more, more preferably 6% or more, and most preferably 7% or more, and is preferably 50% or less, more preferably 45% or less, and most preferably 40% or less. By making the external haze of the electronic component packaging cover tape equal to or less than the upper limit value, it is possible to impart transparency to a degree that allows inspection of whether electronic components are properly housed in the pockets of the carrier tape in a package consisting of the electronic component packaging cover tape 10 and the carrier tape.

In this embodiment, by appropriately selecting conditions such as the type, properties and amounts of each component contained in the base layer 1, intermediate layer 2, and sealant layer 3 that constitute the cover tape for packaging electronic components, and the manufacturing method of the cover tape for packaging electronic components, it is possible to prevent the non-heat-sealed parts from adhering to the carrier tape (unintended adhesion) even when pressure is applied in a high-temperature, high-humidity environment.
In the present embodiment, in addition to using the resin (A1) having a glass transition temperature in a specific range for the sealant layer 3, by further adjusting other conditions, it is possible to achieve a good balance between adhesion to a carrier tape and peelability, for example.

<Method of manufacturing cover tape for packaging electronic components>
An example of a method for producing the cover tape for packaging electronic components according to this embodiment will be described.
First, the intermediate layer 2 is formed on the surface of the base layer 1. The intermediate layer 2 can be formed by, for example, an extrusion lamination method or a dry lamination method.
The method for producing a cover tape for packaging electronic components according to this embodiment includes the steps of preparing a composition for forming a sealant layer containing the resin (A1) and forming a sealant layer using the composition for forming a sealant layer.
In the step of forming the sealant layer, the sealant layer forming composition obtained above, i.e., the sealant layer coating liquid, is applied onto the intermediate layer 2 by a coating method and dried, or laminated by an extrusion lamination method, to form the sealant layer 3.

When forming the above-mentioned adhesive layer, the material for the adhesive layer may be applied to the surface of the target layer by a conventionally known application method.

The cover tape for packaging electronic components according to the present embodiment can be attached to a carrier tape to be used as a package. That is, it is preferable to use a package that includes a carrier tape having a plurality of storage compartments for storing electronic components, the electronic components stored in the storage compartments, and the cover tape for packaging electronic components arranged to cover the storage compartments.
Such a package can suppress the generation of static electricity, and can more reliably protect the electronic components stored in the storage section from static electricity.

<Electronic component packaging>
An electronic component package can be obtained from the cover tape for packaging electronic components of this embodiment described above and a carrier tape having electronic components housed in recesses. This will be described with reference to FIG.

In FIG. 2, a cover tape 10 for packaging electronic components is used as a lid material for a strip-shaped carrier tape 20 having a continuous series of recessed pockets 21 formed to match the shapes of electronic components.
Specifically, the cover tape 10 for packaging electronic components is adhered (usually by heat sealing) to the surface of the carrier tape 20 so as to cover the entire opening of the pocket 21 of the carrier tape 20. Hereinafter, the structure obtained by adhering the cover tape 10 for packaging electronic components and the carrier tape 20 together will be referred to as the electronic component package 100.

The electronic component packaging body 100 can be produced, for example, by the following procedure.
First, electronic components are placed in the pockets 21 of the carrier tape 20 .
Next, the cover tape 10 for packaging electronic components is adhered to the surface of the carrier tape 20 by a heat sealing method so as to cover the entire opening of the pocket 21 of the carrier tape 20. At this time, the sealant layer 3 of the cover tape 10 for packaging electronic components is in contact with the carrier tape 20 (i.e., the heat sealing is performed so that the "back surface" of the cover tape 10 for packaging electronic components in FIG. 2 becomes the sealant layer 3).
The specific method and conditions of heat sealing are not particularly limited as long as the cover tape 10 for packaging electronic components is sufficiently strongly adhered to the carrier tape 20. Typically, a known heat sealing machine can be used, and the heat sealing can be performed at a temperature of 100 to 240° C., a load of 0.1 to 10 kgf, and a time of 0.0001 to 1 second.

In this manner, a structure (electronic component packaging body 100) in which electronic components are hermetically housed is obtained.
This structure (electronic component packaging body 100) is, for example, wound on a reel and then transported to a work area where the electronic components are mounted on an electronic circuit board, etc. The reel may be made of metal, paper, plastic, or the like.

After the electronic component packaging body 100 is transported to the work area, the electronic component packaging cover tape 10 is peeled off from the carrier tape 20, and the contained electronic components are removed.

The electronic components housed in the electronic component packaging body 100 are not particularly limited. Examples include semiconductor chips, transistors, diodes, capacitors, piezoelectric elements, optical elements, LED-related parts, connectors, electrodes, and other components generally used in the manufacture of electrical and electronic devices.

The above describes in detail the embodiments of the present invention, but these are merely examples of the present invention. In addition, various configurations other than those described above can be adopted. In addition, the present invention is not limited to the above-described embodiments.

The embodiments of the present invention will be described in detail based on examples and comparative examples, but the present invention is not limited to these.

The constituent materials of the sealant layer shown in Table 1 are as follows.
(Resin (A1) having a glass transition temperature of more than 60° C. and not more than 120° C., specifically, a styrene-based resin, an acrylic-based resin, or an ester-based resin)
Resin 1: Styrene-based resin ("L8900" manufactured by Asahi Kasei Corporation, Tg: 100°C)
Resin 2: Ester resin ("Elite KT-8803" manufactured by Unitika Ltd., Tg: 65°C)
Resin 3: Acrylic resin (Daicel Allnex "VSC6254w", Tg: 84°C)
Resin 4: Ester resin ("Z-687" manufactured by GOO Chemical Industry Co., Ltd., Tg: 110°C)

(Resin (A2) having a glass transition temperature of 60° C. or less, specifically, a styrene-based resin, an acrylic-based resin, or an ester-based resin)
Resin 5: Styrene-based resin ("L7708" manufactured by Asahi Kasei Corporation, Tg: 38°C)
Resin 6: Ester resin ("Elite KA-0134" manufactured by Unitika Ltd., Tg: 40°C)
Resin 7: Acrylic resin (DAICEL-ALLNEX "VIACRYL VSC6828w" Tg: 42°C)

(Resin with a glass transition temperature of over 120°C (for comparison), specifically, acrylic resin)
Resin 8: Acrylic resin ("TE-1048" manufactured by Seiko PMC, Tg: 123°C)

(Antistatic Agent)
Antistatic agent 1: Polythiophene derivative (PEDOT:PSS) ("Clevios P1000" manufactured by Heraeus)

Example 1
[Preparation of Base Layer and Intermediate Layer]
An anchor coating agent was applied to a 12 μm thick antistatic polyethylene terephthalate (PET) film ("E7455" manufactured by Toyobo Co., Ltd.) to a wet thickness of 4 μm by gravure coating, and after drying at 100° C., low-density polyethylene ("Sumikathene L705" manufactured by Sumitomo Chemical Co., Ltd., 37 μm thick) was extrusion laminated thereon, and cooled with a cooling roll (surface temperature 20° C.) to produce a laminated film consisting of a base layer and an intermediate layer.

A sealant layer having a thickness of 0.5 μm and composed of the components shown in Table 1 was formed on the intermediate layer side of the obtained laminated film by gravure coating.
The total thickness of the cover tape is shown in Table 1.

<Examples 2 to 10 and Comparative Examples 1 to 4>
According to the formulation shown in Table 1, a cover tape for packaging electronic devices was prepared in the same manner as in Example 1.

<Glass transition temperature>
For the at least one resin (A1) selected from the group consisting of a styrene-based resin, an acrylic-based resin, and an ester-based resin, and the at least one resin (A2) selected from the group consisting of a styrene-based resin, an acrylic-based resin, and an ester-based resin used in the examples and comparative examples, the glass transition temperature (°C) was measured under a nitrogen atmosphere condition by increasing the temperature from 0°C to 200°C at a temperature increase rate of 10°C/min using a differential scanning calorimeter (DSC) ("DSC7000X" manufactured by Hitachi High-Tech Science Corporation).

<Tack strength at 60°C>
A stainless steel material (SUS304) with a contact area of 20 ^mm2 was pressed against the sealant layer of the cover tape at a contact speed of 30 mm/min, and after holding for 20 seconds at a measurement temperature of 60°C and a contact load of 25 N, the load per unit area when peeled off at a speed of 600 mm/min was measured using a tack tester TAC0-1000 manufactured by RHESCA, and this was recorded as the tack force (N/ ^cm2 ) at 60°C. The stainless steel material was included with the tack tester.

<170° peel strength against polystyrene film>
Each electronic component packaging cover tape obtained above was made to have a width of 5.5 mm, and the sealant layer side of the electronic component packaging cover tape was bonded to the uneven surface side of a polystyrene film (manufactured by Sumitomo Bakelite Co., Ltd., "CEL-E980A") having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm. The bonded product was heat-sealed using a heat sealer (manufactured by Tokyo Wells Co., Ltd., "TWA-6621") with a two-blade iron having a width of 0.4 mm and a length of 28 mm 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 and 7 times of hitting, to obtain a sample. Using the obtained sample, the peel strength (N) of the electronic component packaging cover tape immediately after heat sealing to the polystyrene film was measured. The peel strength was measured using a peel tester (EPI "PTS-5000") under conditions of a peel speed of 300 mm/min, a peel angle of 170°, and a measurement temperature of 25° C. The results are shown in Table 1.
The surface roughness (Ra) of the polystyrene film was measured in accordance with JIS B 0601 (2001) using a surface roughness measuring device (Mitutoyo's "SJ-210") for the portion of the polystyrene film used above that was to be bonded to the cover tape for packaging electronic components before bonding to the cover tape for packaging electronic components. The unit is μm.

<170° peel strength against polycarbonate film>
Each of the electronic component packaging cover tapes obtained above was made to have a width of 5.5 mm, and the sealant layer side of the electronic component packaging cover tape was bonded to the uneven surface side of a polycarbonate film (3M "No. 3000") having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm. The bonded product was heat-sealed using a heat sealer (Tokyo Wells "TWA-6621") with a two-blade iron having a width of 0.4 mm and a length of 28 mm 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 and 7 times of hitting, to obtain a sample. Using the obtained sample, the peel strength (N) of the electronic component packaging cover tape immediately after heat sealing to the polycarbonate film was measured. The peel strength was measured using a peel tester (EPI "PTS-5000") under conditions of a peel speed of 300 mm/min, a peel angle of 170°, and a measurement temperature of 25° C. The results are shown in Table 1.
The surface roughness (Ra) of the polycarbonate film was measured in accordance with JIS B 0601 (2001) using a surface roughness measuring device (Mitutoyo Corporation's "SJ-210") for the portion of the polycarbonate film used above that was to be bonded to the cover tape for packaging electronic components before bonding to the cover tape for packaging electronic components. The unit is μm.

<Measurement of adhesion marks (evaluation of unintentional adhesion)>
The cover tape for packaging electronic components obtained above was made to have a width of 10.0 mm, and the sealant layer side of the cover tape was bonded to the uneven surface side of a polystyrene film (manufactured by Sumitomo Bakelite Co., Ltd., "CEL-E980A") having a width of 8.0 mm and an average surface roughness (Ra) of 0.25 μm on the uneven surface to prepare a sample. A seal iron having a width of 0.5 mm, a length of 32.0 mm, and a weight of 46.0 g was placed on the upper surface of the cover tape and left under conditions of 60 ° C. and 90% RH for 24 hours. After that, the dimension in the length direction of the polystyrene film in the adhesion marks (glossy) on the polystyrene film was measured as the length of the adhesion marks on the polystyrene film. Incidentally, the "length of the adhesion marks" means the total length of each adhesion mark when the adhesion marks are observed intermittently (discontinuously).
It can be said that the shorter the adhesion mark is, the more the portions of the cover tape that are not heat sealed to the carrier tape are prevented from adhering to the carrier tape (unintentional adhesion).

<Surface Resistance Value of Base Material Layer>
The surface resistance (Ω) of the substrate layer surface of the cover tape for packaging electronic components obtained above was measured in an environment of 25° C. and 50% RH using a surface resistance measuring device manufactured by SIMCO (manufactured by SIMCO, “ST-3”). The results are shown in Table 1.
In addition, for example, "5.E+09" in Example 1 shown in Table 1 represents "5×10 ⁹ ".

<Surface Resistance Value of Sealant Layer>
The surface resistance (Ω) of the sealant layer surface of the cover tape for packaging electronic components obtained above was measured in an environment of 25° C. and 50% RH using a surface resistance measuring device manufactured by SIMCO (manufactured by SIMCO, “ST-3”). The results are shown in Table 1.
In addition, for example, "1.E+07" in Example 1 shown in Table 1 represents "1×10 ⁷ ".

<Total light transmittance>
The total light transmittance (%) of the cover tape for packaging electronic components obtained above was measured in accordance with JIS K7361-1 (1997) using a Haze Meter NDH 2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. under a light source of D65. The results are shown in Table 1.

<External haze>
The external haze (%) of the cover tape for packaging electronic components obtained above was measured in accordance with JIS K7136 (2000) using a Haze Meter NDH 2000 manufactured by Nippon Denshoku Kogyo Co., Ltd. under a light source of D65. The results are shown in Table 1.

In Examples 1 to 10, the resin (A1) had a glass transition temperature of more than 60° C. and less than 120° C., and therefore the tack strength at 60° C. was relatively small, and the length of the adhesion mark on the polystyrene film was relatively short. This shows that by using the cover tapes of Examples 1 to 10, it is possible to prevent the part of the cover tape that is not heat-sealed to the carrier tape from adhering to the carrier tape (unintended adhesion).
Furthermore, in Examples 1 to 10, the evaluation results of various peel strengths, the surface resistance value of the sealant layer, the surface resistance value of the base layer, the total light transmittance, the external haze, and the like were good.

REFERENCE SIGNS LIST 1: Base material layer 2: Intermediate layer 3: Sealant layer 10: Cover tape 20: Carrier tape 21: Pocket 100: Electronic component package

Claims (13)

A base layer;
The middle class,
a sealant layer (excluding a heat seal layer containing a random copolymer of 60% by mass of butyl methacrylate and 40% by mass of methyl methacrylate (manufactured by Mitsubishi Rayon, "Dianal BR-106", glass transition temperature 52°C, acid value 7 mgKOH/g) and SEBS (manufactured by Asahi Kasei Chemicals, "Tuftec H1141", styrene content 30% by mass, hydrogenated butadiene content 70% by mass, MFR = 22 g/10 min. (JIS K7210, temperature 190°C x load 2.16 kg)),
a cover tape for packaging electronic components, comprising in this order at least (A) a base layer, (B) an intermediate layer, (C) an adhesive layer, and (D) a heat seal layer having a heat sealable resin, wherein the thermoplastic resin constituting the heat seal layer (D) is a mixture of two types of (meth)acrylic acid ester copolymers having different glass transition temperatures and a hydrazide compound, one of the (meth)acrylic acid ester copolymer mixtures having a glass transition temperature of -20 to 10°C and the other (meth)acrylic acid ester copolymer having a glass transition temperature of 40 to 80°C,
The sealant layer comprises one or more resins (A1) having a glass transition temperature of more than 60° C. and not more than 120° C., as measured in accordance with the following <Method for Measuring Glass Transition Temperature> (excluding hydrogenated resins (a) of block copolymers of aromatic vinyl compounds and conjugated diene hydrocarbon compounds, in which the aromatic vinyl compound is contained in the resin (a) in an amount of 20% by mass or more and 45% by mass or less);
the resin (A1) contains at least one resin selected from the group consisting of a styrene-based resin, an acrylic-based resin, and an ester-based resin,
The sealant layer further comprises (B) an antistatic agent,
When evaluated in the <Adhesion Test> below, the length of the adhesion mark on the polystyrene film is 0 mm or more and 11 mm or less,
The cover tape for packaging electronic components, wherein the content of the resin (A1) relative to all of the materials constituting the sealant layer is 10 mass% or more and 95 mass% or less, when the all of the materials constituting the sealant layer are taken as 100 mass% .
<Method of measuring glass transition temperature>
The glass transition temperature (° C.) of the resin (A1) is measured using a differential scanning calorimeter (DSC) by increasing the temperature from 0° C. to 200° C. at a temperature increase rate of 10° C./min in a nitrogen atmosphere.
<Adhesion test>
The cover tape for packaging electronic components is made to have a width of 10.0 mm, and the sealant layer side of the cover tape is bonded to the uneven surface side of a polystyrene film having a width of 8.0 mm and an average surface roughness (Ra) of 0.25 μm, to obtain a sample. A sealing iron having a width of 0.5 mm, a length of 32.0 mm, and a weight of 46.0 g is placed on the upper surface of the cover tape of the sample and left to stand for 24 hours under conditions of 60° C. and 90% RH. After standing, the dimension of the adhesive mark on the polystyrene film in the length direction of the polystyrene film is measured as the length of the adhesive mark on the polystyrene film. 2. The cover tape for packaging electronic components according to claim 1,
The cover tape for packaging electronic components, wherein the sealant layer further contains one or more resins (A2) having a glass transition temperature of 60° C. or lower, as measured in accordance with the above-mentioned <Method for measuring glass transition temperature>. 3. The cover tape for packaging electronic components according to claim 2,
The cover tape for packaging electronic components, wherein the resin (A2) comprises at least one resin selected from the group consisting of styrene-based resins, acrylic-based resins, and ester-based resins. The cover tape for packaging electronic components according to any one of claims 1 to 3,
A cover tape for packaging electronic components, wherein the (B) antistatic agent is polythiophene or a polythiophene derivative. The cover tape for packaging electronic components according to any one of claims 1 to 4,
A cover tape for packaging electronic components, having a peel strength against a polystyrene film of 0.2 N or more and 0.9 N or less, as measured by the <Method for measuring peel strength against polystyrene film> described below.
<Method for measuring peel strength against polystyrene film>
The electronic component packaging cover tape is made to have a width of 5.5 mm, and the sealant layer side of the electronic component packaging cover tape is bonded to the uneven surface side of a polystyrene film having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm, and a sample is obtained by heat sealing the sample with a two-blade iron having a width of 0.4 mm and a length of 28 mm under the conditions of a sealing temperature of 180° C., a load of 5 kgf, a sealing time of 60 milliseconds, and a carrier tape feed pitch of 4 mm. In the sample, the peel strength (N) of the electronic component packaging cover tape against the polystyrene film is measured under the conditions of a peel speed of 300 mm/min, a measurement temperature of 25° C., and a peel angle of 170°. The cover tape for packaging electronic components according to any one of claims 1 to 5,
A cover tape for packaging electronic components, having a peel strength against a polycarbonate film of 0.2 N or more and 0.9 N or less, as measured in accordance with the method described below in "Measurement of Peel Strength Against Polycarbonate Film."
<Measurement of peel strength against polycarbonate film>
The electronic component packaging cover tape is made to have a width of 5.5 mm, and the sealant layer side of the electronic component packaging cover tape is bonded to the uneven surface side of a polycarbonate film having a width of 8 mm and an average surface roughness (Ra) of 0.25 μm, and a sample is obtained by heat sealing using a two-blade iron with a width of 0.4 mm and a length of 28 mm under the conditions of a sealing temperature of 180° C., a load of 5 kgf, a sealing time of 60 milliseconds, and a carrier tape feed pitch of 4 mm. In the sample, the peel strength (N) of the electronic component packaging cover tape against the polycarbonate film is measured under the conditions of a peel speed of 300 mm/min, a measurement temperature of 25° C., and a peel angle of 170°. The cover tape for packaging electronic components according to any one of claims 1 to 6 ,
A cover tape for packaging electronic components, wherein the tack strength of the sealant layer, as measured by the <Method for measuring tack strength> described below, is 0 N/ ^cm2 or more and 5.0 N/cm2 or ^less .
<Method of measuring tack strength>
A stainless steel material with a contact area of 20 ^mm2 is pressed against the sealant layer of the cover tape at a contact speed of 30 mm/min, and the measurement temperature is 60°C, a contact load of 25 N is held for 20 seconds, and then the load per unit area is peeled off at a speed of 600 mm/min. The measured value of the load is the tack force (N/ ^cm2 ) at 60°C. The cover tape for packaging electronic components according to any one of claims 1 to 7 ,
A cover tape for packaging electronic components, wherein the surface resistance value of the surface of the base layer measured at 25° C. and 50% RH is 1.0×10 ³ Ω or more and 1.0×10 ¹³ Ω or less. The cover tape for packaging electronic components according to any one of claims 1 to 8 ,
A cover tape for packaging electronic components, wherein the surface resistance value of the surface of the sealant layer measured at 25° C. and 50% RH is 1.0×10 ³ Ω or more and 1.0×10 ¹² Ω or less. The cover tape for packaging electronic components according to any one of claims 1 to 9 ,
A cover tape for packaging electronic components, which has a total light transmittance of 70% or more and 95% or less as measured with a light source D65 in accordance with JIS K7361-1 (1997). The cover tape for packaging electronic components according to any one of claims 1 to 10 ,
A cover tape for packaging electronic components, having an external haze of 5% or more and 50% or less as measured with a light source D65 in accordance with JIS K7136 (2000). a carrier tape having electronic components housed in recesses;
A cover tape for packaging electronic components according to any one of claims 1 to 11 ,
An electronic component package in which the sealant layer side is adhered to the carrier tape so as to seal the electronic component. A base layer;
The middle class,
a sealant layer (excluding a heat seal layer containing a random copolymer of 60% by mass of butyl methacrylate and 40% by mass of methyl methacrylate (manufactured by Mitsubishi Rayon, "Dianal BR-106", glass transition temperature 52°C, acid value 7 mgKOH/g) and SEBS (manufactured by Asahi Kasei Chemicals, "Tuftec H1141", styrene content 30% by mass, hydrogenated butadiene content 70% by mass, MFR = 22 g/10 min. (JIS K7210, temperature 190°C x load 2.16 kg)),
a heat seal layer (D) having a heat sealable resin, and the thermoplastic resin constituting the heat seal layer (D) is a mixture of two types of (meth)acrylic acid ester copolymers having different glass transition temperatures and a hydrazide compound, one of the (meth)acrylic acid ester copolymer mixtures having a glass transition temperature of -20 to 10°C and the other (meth)acrylic acid ester copolymer having a glass transition temperature of 40 to 80°C), comprising:
a step of preparing a composition for forming a sealant layer, comprising a resin (A1) having a glass transition temperature of more than 60° C. and not more than 120° C., as measured in accordance with the following <Method for Measuring Glass Transition Temperature> (excluding a hydrogenated resin (a) of a block copolymer of an aromatic vinyl compound and a conjugated diene hydrocarbon compound, in which the aromatic vinyl compound is contained in the resin (a) in an amount of 20% by mass or more and 45% by mass or less);
forming the sealant layer using the sealant layer-forming composition;
Including,
the resin (A1) contains at least one resin selected from the group consisting of a styrene-based resin, an acrylic-based resin, and an ester-based resin,
The sealant layer further comprises (B) an antistatic agent.
When evaluated in the <Adhesion Test> below, the length of the adhesion mark on the polystyrene film is 0 mm or more and 11 mm or less,
a content of the resin (A1) relative to all materials constituting the sealant layer is 10% by mass or more and 95% by mass or less, when all materials constituting the sealant layer are taken as 100% by mass .
<Method of measuring glass transition temperature>
The glass transition temperature (° C.) of the resin (A1) is measured using a differential scanning calorimeter (DSC) by increasing the temperature from 0° C. to 200° C. at a temperature increase rate of 10° C./min in a nitrogen atmosphere.
<Adhesion test>
The cover tape for packaging electronic components is made to have a width of 10.0 mm, and the sealant layer side of the cover tape is bonded to the uneven surface side of a polystyrene film having a width of 8.0 mm and an average surface roughness (Ra) of 0.25 μm, to obtain a sample. A sealing iron having a width of 0.5 mm, a length of 32.0 mm, and a weight of 46.0 g is placed on the upper surface of the cover tape of the sample and left to stand for 24 hours under conditions of 60° C. and 90% RH. After standing, the dimension of the adhesive mark on the polystyrene film in the length direction of the polystyrene film is measured as the length of the adhesive mark on the polystyrene film.

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