JP6930625B1 - Cover tape and electronic component packaging - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cover tape capable of obtaining a large peel strength. SOLUTION: A cover tape for packaging electronic parts. This cover tape includes a base material layer, an intermediate layer, and a sealant layer in this order. The intermediate layer and the sealant layer are provided in contact with each other. Further, the tack force T60 of the intermediate layer at 60 ° C. is 60 to 500 gf. [Selection diagram] Fig. 2

Description

The present invention relates to cover tapes and electronic component packaging. More specifically, the present invention relates to a cover tape for packaging electronic components and an electronic component package including the cover tape.

Carrier tapes and cover tapes are often used when transporting, storing, etc. electronic components.
Specifically, an electronic component (semiconductor chip or the like) is placed in a recess formed in the carrier tape for storing the electronic component, and then the cover tape is heat-sealed on the upper surface of the carrier tape to enclose the electronic component. .. Then, it is wound up in a reel shape and transported / stored. By doing so, it is possible to prevent contamination of electronic components during transportation / storage.

For example, Patent Document 1 describes a base material layer having a predetermined thickness and tensile elastic modulus, and a heat-sealing layer containing polystyrene resin, polyethylene resin, and fatty acid amide and having a predetermined thickness and tensile elastic modulus. A cover tape comprising the above is disclosed. According to Patent Document 1, the peel strength of this cover tape is not easily affected by the peel speed, and even in the conventional peel strength management method, the peel strength at the time of high-speed mounting does not increase abnormally.

Japanese Unexamined Patent Publication No. 2005-263257

The cover tape is required to have various performances, but for the purpose of the cover tape to "prevent contamination of electronic parts", the peel strength of the cover tape (strength when peeling the cover tape heat-sealed on the carrier tape). Is required to be large. If the peel strength is low, the cover tape may peel off during transportation / storage and the electronic components may be contaminated.

The present invention has been made in view of such circumstances. One of the objects of the present invention is to provide a cover tape capable of obtaining a large peel strength.

The present inventors have completed the inventions provided below and solved the above problems.

According to the present invention
Cover tape for packaging electronic components
The cover tape includes a base material layer, an intermediate layer, and a sealant layer in this order.
The intermediate layer and the sealant layer are provided in contact with each other.
The tackiness _{T 60} at 60 ° C. of the intermediate layer, Ri 110~491gf der,
The intermediate layer has a density of 0.890 to 0.912 g / cm ³ , polyethylene, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, and ethylene-vinyl acetate copolymer. A cover tape containing one or more resins (A) selected from the group consisting of coalesced saponified products and styrene copolymers is provided.

Further, according to the present invention.
A carrier tape in which electronic components are housed in a recess and the cover tape are provided.
An electronic component package in which the sealant layer is adhered to the carrier tape so as to seal the electronic component is provided.

According to the present invention, there is provided a cover tape capable of obtaining a large peel strength.

It is a figure for demonstrating the layer structure of a cover tape. It is a figure for demonstrating the layer structure of a cover tape. It is a perspective view which shows an example of the state which the cover tape is sealed with the carrier tape.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all drawings, similar components are designated by the same reference numerals, and description thereof will be omitted as appropriate.
All drawings are for illustration purposes only. The shape and dimensional ratio of each member in the drawing do not necessarily correspond to the actual article.

In the present specification, the term "abbreviation" means to include a range in consideration of manufacturing tolerances, assembly variations, etc., unless otherwise specified explicitly.
In the present specification, the notation "XY" in the description of the numerical range means X or more and Y or less unless otherwise specified. For example, "1 to 5% by mass" means "1% by mass or more and 5% by mass or less".
In the present specification, the unit "gf" represents a weight gram and "kgf" represents a weight kilogram. These values can be converted to SI units by multiplying them by the gravitational acceleration (9.8 m / s ^2).

In the notation of a group (atomic group) in the present specification, the notation that does not indicate whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
The notation "(meth) acrylic" herein represents a concept that includes both acrylic and methacryl. The same applies to similar notations such as "(meth) acrylate".
As used herein, "polyethylene" has only a homopolymer of ethylene, a copolymer of ethylene with 5 mol% or less of an α-olephyllene monomer, and ethylene with only carbon, oxygen, and hydrogen atoms as functional groups. Contains a copolymer with 1 mol% or less of a non-olefin monomer.

<Cover tape 10>
FIG. 1 schematically shows an example of a cover tape 10 (also simply referred to as “cover tape 10”) for packaging electronic components according to the present embodiment.
As shown in FIG. 1, the cover tape 10 includes a base material layer 1 and a sealant layer 3 provided on one side of the base material layer 1, and further, between the base material layer 1 and the sealant layer 3. There is at least one intermediate layer 2. The intermediate layer 2 and the sealant layer 3 are in contact with each other.
It can also be said that the cover tape 10 has the base material layer 1, the intermediate layer 2, and the sealant layer 3 laminated in this order, and at least the intermediate layer 2 and the sealant layer 3 are in contact with each other.
The sealant layer 3 is usually present on the outermost surface of the cover tape 10 and constitutes one surface of the cover tape 10. As a result, it can be brought into close contact with the carrier tape 20 described later.
The base material layer 1, the intermediate layer 2, and the sealant layer 3 usually have substantially the same width and length, and exist without breaks or divisions.

The cover tape 10 is typically used to seal the carrier tape 20 having pockets 21 for accommodating electronic components, as shown in FIG. That is, the sealant layer 3 in the cover tape 10 is heat-sealed so as to be in contact with the carrier tape 20.

In the cover tape 10, the tack force T ₆₀ of the intermediate layer 2 at 60 ° C. is 60 to 500 gf, preferably 100 to 400 gf, and more preferably 100 to 350 gf.
The "tacking force of the intermediate layer 2" is to measure the tacking force of the exposed surface of the intermediate layer 2 of the cover tape in which the intermediate layer 2 is exposed without providing the sealant layer 3 by using a tacking tester. Can be found at.
When only a cover tape having the sealant layer 3 and the intermediate layer 2 at the same time can be obtained by providing the sealant layer 3 and the intermediate layer 2 at the same time in the manufacturing process, for example, a carrier tape sheet (for example, a conductive polystyrene carrier) is provided on the sealant layer 3. The tape, Sumitomo Bakelite Co., Ltd. "CEL-E980A")) was heat-sealed, and then the heat-sealed carrier tape sheet was peeled off together with the sealant layer 3 to carefully remove the sealant layer 3, and then the intermediate layer. 2 is exposed. By exposing the intermediate layer 2 in this way, the tack force can be measured.

The cover tape 10 exhibits strong peel strength when heat-sealed to the carrier tape due to the above configuration. The reason for this is explained as follows. However, the following explanation includes speculation. Further, the present invention is not limited by the following description.
By the tackiness T ₆₀ at 60 ° C. of the intermediate layer 2 is large, heat applied during the manufacturing of the cover tape 10 (e.g., in the case of providing the sealant layer 3 by coating, heating during drying the coating solution) As a result, a part of the resin contained in the intermediate layer 2 easily flows into the sealant layer 3. In other words, it is considered that the intermediate layer 2 and the sealant layer 3 are "moderately mixed" at the interface during the production of the cover tape 10 due to the large _{T 60.} It is considered that this increases the peel strength between the intermediate layer 2 and the sealant layer 3.
(As a reminder, when the cover tape 10 is peeled off from the carrier tape, the cover tape 10 is peeled off between the intermediate layer 2 and the sealant layer 3.)

Incidentally, from the viewpoint of peel strength, the _{larger T 60} is, the more preferable it is. _{However, if the T 60 of the} intermediate layer 2 is too large, it cannot be peeled under normal peeling conditions, and there is a risk of breakage, for example. In addition, when the film is conveyed, it may be "stuck" and a coating defect such as wrinkles may occur. Therefore, _{the upper limit of T 60} is set to 500 gf.

The cover tape 10 has the effect of increasing the peeling strength and the effect of suppressing peeling due to vibration or the like when the cover tape 10 is transported in a warm state immediately after being heat-sealed to the carrier tape. Have. The cover tape 10 may be continuously heat-sealed on a carrier tape, wound on a reel with the heat remaining from the heat-sealing, and then conveyed. By packaging the electronic component with the cover tape 10, peeling in such a case can be suppressed.

The _{cover tape 10 having a T 60 of 60} to 500 gf can be manufactured by appropriately selecting a material and manufacturing conditions. From the viewpoint of the material, it is preferable to select the resin (A) described later as the material of the intermediate layer 2 (in particular, for the copolymer, select one having an appropriate copolymerization ratio). Further, although the production conditions are not limited, for example, an example in which the intermediate layer 2 is formed by an extrusion method using a T-die described later can be mentioned. Details of materials and manufacturing conditions will be explained later.

Hereinafter, aspects, materials, and the like of each layer of the cover tape 10 will be described.

[Base material layer 1]
The material constituting the base material layer 1 is not particularly limited. Typically, a material having sufficient mechanical strength to withstand when the cover tape 10 is manufactured, when the cover tape 10 is adhered to the carrier tape, when an external force is applied, or the like is preferable. Further, a material having heat resistance sufficient to withstand the heat when the cover tape 10 is adhered to the carrier tape is preferable.
The form of the material constituting the base material layer 1 is preferably in the form of a film in terms of ease of processing.

Specific examples of the material constituting the base material layer 1 include polyester resin, polyamide resin, polyolefin resin, polyacrylate resin, polymethacrylate resin, polyimide resin, polycarbonate resin, ABS resin and the like. Be done. Among them, a polyester resin is preferable, and a polyethylene terephthalate (PET) resin is more preferable, from the viewpoint of improving the mechanical strength of the cover tape 10 and the cost.
The base material layer 1 may contain an additive such as a lubricant.

The base material layer 1 may be only one layer or may have two or more layers (for example, the base material layer 1 may be formed of a multilayer film in which the above-mentioned materials are laminated).
The film used for forming the base material layer 1 may be an unstretched film, or may be a film stretched in the uniaxial direction or the biaxial direction. From the viewpoint of further improving the mechanical strength of the cover tape 10, a film stretched in the uniaxial direction or the biaxial direction is preferable.

The thickness of the base material layer 1 is not particularly limited. The thickness of the base material layer 1 is preferably 5 μm or more, more preferably 9 μm or more, and more preferably 12 μm or more. The thickness of the base material layer 1 is preferably 50 μm or less, more preferably 40 μm or less, and further preferably 30 μm or less.
When the thickness of the base material layer 1 is 50 μm or less, the rigidity of the cover tape 10 does not become too large. As a result, the cover tape 10 can easily follow the deformation of the carrier tape even when a torsional stress is applied to the carrier tape after sealing. Therefore, it is possible to prevent the cover tape 10 from being unintentionally peeled off from the carrier tape.
When the thickness of the base material layer 1 is 5 μm or more, the mechanical strength of the cover tape 10 can be sufficiently good. Therefore, for example, even when the cover tape 10 is peeled off from the carrier tape at high speed, it is possible to prevent the cover tape 10 from breaking.

The total light transmittance of the base material layer 1 is preferably 80% or more, more preferably 85% or more. By doing so, in the electronic component packaging body composed of the cover tape 10 and the carrier tape, it is possible to secure the necessary transparency to the extent that it can be inspected whether or not the electronic components are correctly housed. In other words, by setting the total light transmittance of the base material layer 1 to 80% or more, it becomes easy to visually confirm the electronic components housed inside the package composed of the cover tape 10 and the carrier tape from the outside. ..
The total light transmittance can be measured according to JIS-K-7361.

[Middle layer 2]
The intermediate layer 2 is located between the base material layer 1 and the sealant layer 3. Further, the intermediate layer 2 and the sealant layer 3 are in contact with each other. The presence of the intermediate layer 2 can enhance the cushioning property, impact resistance, and the like of the cover tape 10.
As described above, the tack force T60 of the intermediate layer 2 at 60 ° C. is ₆₀ to 500 gf.

The intermediate layer 2 is preferably polyethylene, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, ethylene-acetic acid having a density of 0.890 to 0.912 g / cm ^3. It contains one or more resins (A) selected from the group consisting of vinyl copolymer saponified products and styrene copolymers.

Polyethylene, which has a density of 0.890 to 0.912 g / cm ³ , has a relatively low density, which makes it easier to mix with other components (there are few crystal parts and the molecules move easily), or the solvent permeates. It is thought that it is easy to melt. As a result, it is considered that the peel strength between the intermediate layer 2 and the sealant layer 3 can be easily increased by the above-mentioned mechanism.

For ethylene- (meth) acrylic acid copolymers, ethylene- (meth) acrylic acid ester copolymers, and ethylene-vinyl acetate copolymer saponified products, these resins should have a relatively low melting point for good performance. It seems to be related. Further, it is considered that the intermediate layer 2 and the sealant layer 3 are more firmly adhered to each other due to the presence of polar structural units such as (meth) acrylic acid, (meth) acrylic acid ester or vinyl acetate. _{Regarding the styrene copolymer, it is considered that the T 60} can be easily designed to be large due to the appropriate polarity of the copolymer, and the intermediate layer 2 and the sealant layer 3 are more firmly adhered to each other.

The density of polyethylene preferably contained in the intermediate layer 2 and having a density of 0.890 to 0.912 g / cm ^{3 is more preferably 0.900 to 0.910 g / cm 3} , still more preferably 0.900 to 0.909 g. / Cm ³ . When a commercially available product is used as polyethylene, the catalog value can be adopted as the density. When using a commercially available polyethylene resin whose catalog value is unknown or a non-commercially available polyethylene resin, the density is defined / measured based on JIS K 7112.
Examples of polyethylene having a density of 0.890 to 0.912 g / cm ³ include those commercially available as ultra-low density polyethylene. More specifically, the metallocene plastomer "kernel" (trademark) of Japan Polyethylene Corporation can be mentioned.

The ethylene- (meth) acrylic acid copolymer, the ethylene- (meth) acrylic acid ester copolymer, and the ethylene-vinyl acetate copolymer saponified product preferably contained in the intermediate layer 2 are not particularly limited.
Examples of the "(meth) acrylate ester" in the ethylene- (meth) acrylate copolymer include methyl (meth) acrylate, ethyl (meth) acrylate and the like. "

For the ethylene- (meth) acrylic acid copolymer or the ethylene- (meth) acrylic acid ester copolymer, it is easy to design T60 to _{60 to 500 gf by using one having an appropriate copolymerization ratio.} ..
Specifically, the ratio of the structural unit derived from (meth) acrylic acid in the ethylene- (meth) acrylic acid copolymer is preferably 6 to 34% by mass, more preferably 8 to 30% by mass in the polymer. , More preferably 9 to 25% by mass.
Similarly, the proportion of structural units derived from (meth) acrylic acid ester in the ethylene- (meth) acrylic acid ester copolymer is preferably 6 to 34% by mass, more preferably 8 to 30% by mass in the polymer. , More preferably 9 to 25% by mass.

The ethylene-vinyl acetate copolymer saponified product may be a partially saponified product or a completely saponified product. Partially saponified products tend to have higher peel strength. It is considered that this is because a certain amount of polar vinyl acetate structure is contained in the copolymer.

Examples of the styrene copolymer preferably contained in the intermediate layer 2 include polystyrene, styrene / butadiene / styrene block copolymer (SBS), styrene / ethylene / butadiene / styrene block copolymer (SEBS), and styrene / isoprene / styrene block. Copolymer (SIS), Styrene / Ethylene / Styrene / Styrene Block Copolymer (SEPS), Styrene-Methyl Acrylate Copolymer, Hydrogenated Styrene Block Copolymer, High Impact Polystyrene (HIPS) Impact Polystyrene), general-purpose polystyrene resin (GPPS; General Purpose Styrene) and the like can be mentioned. Examples of commercially available styrene copolymers include the hydrogenated styrene-based thermoplastic elastomer "Tough Tech" (registered trademark) series sold by Asahi Kasei Co., Ltd.

As for the styrene copolymer, it is easy to design T60 to ₇₀ to 500 gf by using a styrene copolymer having an appropriate copolymerization ratio.
Specifically, the ratio of the structural unit derived from the styrene monomer in the styrene copolymer is preferably 10 to 60% by mass, more preferably 15 to 55% by mass, and further preferably 15 to 50% by mass in the copolymer. %.

The melting point of the resin (A) is, for example, 60 to 130 ° C., preferably 60 to 120 ° C., more preferably 60 to 105 ° C., and even more preferably 85 to 100 ° C.
By using the resin (A) having an appropriate melting point, it is considered that the resin (A) is likely to melt during the production of the cover tape 10 and / or during the heat sealing between the carrier tape and the cover tape 10. As a result, it is considered that the intermediate layer 2 and the sealant layer 3 are in close contact with each other more strongly, and the peel strength is further increased.
When a commercially available product is used as the resin (A), a catalog value can be adopted as the melting point. When a commercially available resin (A) whose catalog value is unknown or a non-commercially available resin (A) is used, the melting point can be measured using a DSC (Differential Scanning Calorimetry) by the method specified in JIS K 7121. be.

The resin (A) preferably has an appropriate melt flow rate (MFR).
The melt flow rate of the resin (A) is preferably 0.5 to 20 g / 10 min, more preferably 1 to 15 g / 10 min. By using the resin (A) having an appropriate melt flow rate, for example, the heat sealability can be further improved.
The melt flow rate is usually measured under the condition of 190 ° C./2.16 kg.

The intermediate layer 2 may have a single-layer structure or a multi-layer structure. In the case of a multi-layer structure, at least one layer preferably contains the above-mentioned resin (A).
As a preferred embodiment when the intermediate layer 2 has a multi-layer structure, the embodiment shown in FIG. 2 can be mentioned. In the cover tape 10 of FIG. 2, between the base material layer 1 and the sealant layer 3, the first intermediate layer 2A and the second intermediate layer different from the first intermediate layer 2A are formed from the side closest to the base material layer 1. There is 2B. The second intermediate layer 2B is in contact with the sealant layer 3. And preferably, the second intermediate layer 2B contains the above-mentioned resin (A).

The resin contained in the first intermediate layer 2A is not particularly limited, but the first intermediate layer 2A preferably contains polyethylene having a ^{density of more than 0.910 g / cm 3} and more preferably 0.913 to 0.938 g / cm ^3. include. Such polyethylene is available as low density polyethylene. Examples of commercially available products include the Petrosen (registered trademark) series manufactured by Tosoh Corporation.
The first intermediate layer 2A may or may not contain the above-mentioned resin (A). From the viewpoint of cost, it is preferable that the first intermediate layer 2A does not contain the resin (A).

As another viewpoint, the absolute value of the difference between the density of polyethylene contained in the first intermediate layer 2A and the density of the resin (A) contained in the second intermediate layer 2B is preferably 0.005 to 0.50 g / cm ³ , and more. It is preferably 0.010 to 0.25 g / cm ³ .

Since the density of the resin contained in the first intermediate layer 2A is higher than the density of the resin contained in the second intermediate layer 2B, the strength of the cover tape as a whole can be easily increased.
On the other hand, since the difference between the density of the resin contained in the first intermediate layer 2A and the density of the resin (A) contained in the second intermediate layer 2B is not too large, the intermediate layer 2 / the entire cover tape becomes "homogeneous", which is intended. There is a tendency for unpredictable breakage to be suppressed.
Normally, the density of the resin contained in the second intermediate layer 2B is lower than the density of the resin contained in the first intermediate layer 2A.

When the intermediate layer 2 is a single layer, the intermediate layer 2 may contain a resin other than the resin (A). This resin is not particularly limited, but preferred examples include polyethylene ^{having the above-mentioned density of more than 0.912 g / cm 3.} This makes it easy to increase the strength of the cover tape as a whole.
As a reminder, the intermediate layer 2 does not have to contain a resin other than the resin (A).
When the intermediate layer 2 is a single layer, the content of the resin (A) in the intermediate layer 2 is, for example, 50% by mass or more, more preferably 70% by mass or more, and further preferably 75% by mass or more. When the content of the resin (A) is large to some extent, the influence of other components is reduced, and it is easy to obtain sufficient peel strength.

When the intermediate layer 2 is multi-layered, the layer closest to the sealant layer 3 (second intermediate layer 2B in FIG. 2) may contain a resin other than the resin (A). Other resins are not particularly limited, but preferred examples include polyethylene ^{having the above-mentioned density of more than 0.912 g / cm 3.} As a reminder, the second intermediate layer 2B does not have to contain other resins, as a matter of course.
When the intermediate layer 2 is multi-layered, the content of the resin (A) in the layer closest to the sealant layer 3 is, for example, 50% by mass or more, more preferably 75% by mass or more, still more preferably 95% by mass or more. be. By using a large amount of the resin (A) to some extent, the peel strength can be sufficiently increased.

In FIG. 2, when the thickness of the first intermediate layer 2A is t ₁ and the thickness of the second intermediate layer 2B is t ₂ , _{the value of t 2} / t ₁ is preferably 0.05 to 5, more preferably. Is 0.0.1 to 3.
By _{designing t 2} / t ₁ to be 0.05 or more, a sufficient amount of the resin (A) can be used. Then, the peel strength can be sufficiently increased.
By _{designing t 2} / t _{1 to be 5 or less, the thickness t 2} of the second intermediate layer 2B, which has a relatively low density, becomes relatively small. As a result, the decrease in strength of the cover tape as a whole is suppressed, and the breakage at the time of peeling tends to be suppressed. Further, _{it is preferable to design t 2} / t ₁ to be 5 or less in terms of cost.

The intermediate layer 2, when the tackiness at 25 ° C. and _{T 25,} is preferably 25 ° C. and 60 ° C. The ratio _T 60 _{/ T 25} tack force more than a certain value in. Specifically, T ₆₀ / T ₂₅ is preferably 3.2 or more, more preferably 5.0 or more. When the tack force ratio T ₆₀ / T ₂₅ is within the above range, the peel strength can be increased. The upper limit of T ₆₀ / T ₂₅ is not particularly limited, but is, for example, 25 or less.

Further, regarding the intermediate layer 2, _{it is preferable that T 25} is within a certain numerical range in addition to _{T 60.} Specifically, T ₂₅ is 15 gf or more. When T ₂₅ is large to some extent, the peel strength can be further increased. The upper limit of T ₂₅ is, for example, 50 gf or less.

The intermediate layer 2 may contain various additives.
The thickness of the intermediate layer 2 (total thickness when the intermediate layer 2 is composed of a plurality of layers) is preferably 10 to 50 μm, more preferably 15 to 45 μm from the viewpoint of improving the cushioning property of the entire cover tape 10.

[Sealant layer 3]
The sealant layer 3 is not particularly limited as long as the cover tape 10 can be heat-sealed to the carrier tape by heat sealing (those that are appropriately melted by heat).
The sealant layer 3 preferably contains (a) a styrene resin and / or (b) a (meth) acrylic resin in terms of compatibility with the intermediate layer 2.
Hereinafter, these resins will be described.

(A) Styrene-based resin (a) The styrene content in the styrene-based resin is preferably 15% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more. On the other hand, the styrene content in the (a) styrene resin is preferably 90% by mass or less, more preferably 80% by mass or less, from the viewpoint of maintaining the adhesion of the sealant layer 3.
In the cover tape 10, by setting the styrene content of the sealant layer 3 to the above lower limit value or more, the adhesion between the intermediate layer 2 and the sealant layer 3 is further improved, and the peel strength is further improved. The details of the mechanism are not clear, but it is presumed that the affinity between the intermediate layer 2 and the sealant layer 3 is improved.
In the above, the styrene content refers to (a) the ratio (mass%) of the structural units derived from styrene contained in the styrene resin. When the (a) styrene resin contains two or more types of copolymers, the average value of the styrene content of each is the styrene content of the (a) styrene resin.

Examples of the styrene-based resin include (a-1) polystyrene, styrene- (meth) acrylate copolymer, styrene-olefin copolymer, hydrogenated styrene block copolymer, and impact-resistant polystyrene (HIPS; High Impact). Polystyrene), styrene-based polymers such as general-purpose polystyrene resin (GPPS; General Purple Polystylene), and (a-2) styrene-based polymers, α-methylstyrene-based polymers, styrene- (α-methylstyrene) -based copolymers. , Styrene-aliphatic hydrocarbon-based copolymers, styrene- (α-methylstyrene) -aliphatic hydrocarbon-based copolymers, styrene-based oligomers such as styrene-aromatic hydrocarbon-based copolymers, and the like. ..
One type of styrene resin may be used alone, or two or more types may be mixed and used.
Among them, a styrene- (meth) acrylate copolymer and / or a styrene-olefin copolymer is preferably used from the viewpoint of effectively improving the peel strength.

A styrene-olefin copolymer is a copolymer having a unit derived from olefin and a unit derived from styrene. Specific examples of the olefin include monoolefins such as α-olefins such as ethylene, propylene and butene; and diolefins (conjugated diene) such as butadiene and isoprene.
The polymerization mode of the styrene-olefin copolymer is not limited, but the styrene-olefin copolymer is preferably a block copolymer from the viewpoint of improving the peel strength between the cover tape 10 and the carrier tape 20.

Examples of the styrene-olefin copolymer include styrene / butadiene / styrene block copolymer (SBS), styrene / ethylene / butadiene / styrene block copolymer (SEBS), and styrene / isoprene / styrene block copolymer (SIS). ), Styrene / ethylene / propylene / styrene block copolymer (SEPS) and the like.

The styrene content in the styrene-olefin copolymer is preferably 15% by mass or more from the viewpoint of making the peel strength between the cover tape 10 and the carrier tape 20 more preferable with respect to the entire styrene-olefin copolymer. It is more than 20% by mass, more preferably 25% by mass or more. From the same viewpoint, the styrene content in the styrene-olefin copolymer is preferably 90% by mass or less, more preferably 85% by mass or less, based on the total styrene-olefin copolymer.

The content of the styrene resin (a) is preferably 5% by mass or more in the non-volatile components of the resin composition for forming the sealant layer 3 from the viewpoint of improving the peel strength between the cover tape 10 and the carrier tape 20. It is preferably 8% by mass or more. From the same viewpoint, the content of (a) the styrene resin is preferably 90% by mass or less, more preferably 80% by mass or less, still more preferably 80% by mass or less, in the non-volatile component of the resin composition for forming the sealant layer 3. It is 70% by mass or less.

When the styrene-based polymer of (a-1) is used among the styrene-based resins (a), the melt flow rate (MFR) at 200 ° C. and 5 kg is preferably 0.05 g / 10 min or more and 200 g / 10 min or less. Is 0.1 g / 10 min or more and 100 g / 10 min or less.
By setting the MFR to the above lower limit value or more, it becomes easy to improve the peel strength.
By setting the MFR to the above upper limit value or less, the solubility in a solvent becomes better, the viscosity can be easily adjusted, and a high peel strength can be stably obtained.
(A) The MFR of the styrene resin is measured according to JIS-K-7210 under the conditions of 200 ° C. and 5 kg.

When the styrene-based oligomer of (a-2) is used among the styrene-based resins (a), the number average molecular weight is, for example, 300 or more and 5000 or less, preferably 500 or more and 3000 or less.

(B) (Meta) Acrylic Resin The (meth) acrylic resin of the component (b) is a structural unit derived from (b-1) (meth) acrylic acid and / or (b-2) (meth). ) A polymer containing a structural unit derived from an acrylic acid ester.
Examples of the (meth) acrylic acid of the component (b-1) include acrylic acid and methacrylic acid.
Examples of the (meth) acrylic acid ester of the component (b-2) include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic. One or more selected from isobutyl acid acid, hexyl (meth) acrylate, ethylhexyl (meth) acrylate and the like can be mentioned.

(B) The (meth) acrylic resin may be a copolymer with another monomer as long as it does not correspond to the above-mentioned component (a). For example, (b) (meth) acrylic resin includes ethylene-methyl (meth) acrylate copolymer, ethylene-ethyl (meth) acrylate copolymer, ethylene- (meth) acrylate copolymer and ethylene-vinyl acetate copolymer. It may be a copolymer containing one kind or two or more kinds selected from the group consisting of polymers.
(B) The (meth) acrylic resin contains, for example, 5% by mass or more, preferably 10% by mass or more, and more preferably 15% by mass or more of structural units derived from the (meth) acrylic acid ester.

(B) The content of the (meth) acrylic resin is 1% by mass or more, preferably 10% by mass or more, and more preferably 20% by mass in the non-volatile component of the resin composition for forming the sealant layer 3. That is all. On the other hand, the content of the (b) (meth) acrylic resin may be 100% by mass or 98% by mass or less in the non-volatile component of the resin composition for forming the sealant layer 3. As a result, good adhesion resistance can be obtained.

When (a) a styrene resin and (b) (meth) acrylic resin are used in combination, the content [(a) / (b)] (mass ratio) of (a) with respect to the content of (b) is It is preferably 0.015 or more, and more preferably 0.02 or more. On the other hand, [(a) / (b)] (mass ratio) is preferably 5 or less, and more preferably 4 or less. By setting (a) / (b) to such a numerical range, the balance between peelability and adhesion can be further improved.

The sealant layer 3 may further contain the following components.

(C) Antistatic agent The sealant layer 3 may contain an antistatic agent. Thereby, the antistatic ability can be improved.
Examples of the antistatic agent include those containing lithium ions. A polymer-type antistatic agent in which lithium ions are present in the resin can be used. As a result, excellent antistatic performance is continuously and stably exhibited.
Lithium ions can be contained in the antistatic agent in the form of, for example, a lithium salt. Examples of this lithium salt include lithium chloride, lithium fluoride, lithium bromide, lithium iodide, lithium perchlorate, lithium acetate, lithium fluorosulfonate, lithium methanesulfonate, lithium trifluoromethanesulfonate, and pentafluoroethanesulfonic acid. Examples include lithium.

Lithium ions contained in the antistatic agent can be confirmed by measuring the amount of metal elements. The amount of lithium ions contained in the antistatic agent is preferably, for example, 50 μg / g or more (50 ppm or more).

Of course, as the antistatic agent, a known antistatic agent can be used in addition to the one containing lithium ions. In addition, those containing lithium ions and those not containing lithium ions can be used in combination.
Examples of the antistatic agent containing no lithium ion include the following.
-Polymer containing a polyether structure (for example, a polyamide copolymer such as a polyether ester amide, a block polymer of polyolefin and polyether, a polymer composed of polyethylene ether and glycol), a carboxylic acid base-containing polymer such as potassium ionomer, a fourth Grade ammonium base-containing copolymers, etc.
-Metal-containing fillers such as aluminum oxide, tin oxide, zinc oxide, indium oxide, and titanium oxide (metal oxide particles, etc.).
-Conductive polymers such as polyethylene dioxythiophene / polystyrene sulfonic acid (PEDOT / PSS), polyacetylene, and polyaniline.
-Conductive carbon.

Incidentally, by using, for example, a metal-containing filler (metal oxide particles, etc.), in addition to improving the antistatic ability, the tack force and the peel strength may be appropriately adjusted. Considering the viewpoint of adjusting the tack force and the peel strength, the primary particle size of the metal-containing filler (metal oxide particles or the like) is preferably 5 to 1000 nm, preferably 10 to 500 nm.
The primary particle size of the metal-containing filler (metal oxide particles, etc.) can be known from, for example, a microscope image.

When the sealant layer 3 contains an antistatic agent, the amount thereof (total amount when two or more kinds are contained) is, for example, 1% by mass or more, preferably 5% by mass or more, more preferably 5% by mass or more, based on the entire sealant layer 3. It is 8% by mass or more, more preferably 10% by mass or more. Thereby, an appropriate antistatic ability can be obtained.
The content of the antistatic agent is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 80% by mass or less, and particularly preferably 70% by mass or less, based on the entire sealant layer 3. .. Antistatic agents are often expensive. Therefore, setting the content of the antistatic agent in this way leads to a reduction in the cost of producing the cover tape 10.

-Adhesive-imparting agent The sealant layer 3 may contain a tackifier.
Examples of the tackifier include petroleum resin, rosin-based resin, terpene resin, styrene resin, and kumaron-inden resin. Among them, petroleum resin and styrene resin are preferable because of the difficulty of adhering electronic components, heat-sealing property to carrier tape, gas barrier property, and the like.
Examples of the petroleum resin-based tackifier include aliphatic petroleum resins, aromatic petroleum resins, and aliphatic aromatic copolymer petroleum resins. Commercially available products include hydrogenated petroleum resin manufactured by Arakawa Chemical Industry Co., Ltd. and the trade name "Arcon" series.

When a tackifier is used, one type may be used alone, or two or more types may be used in combination.
When the sealant layer 3 contains a pressure-sensitive adhesive, the lower limit of the content of the pressure-sensitive adhesive with respect to the entire sealant layer 3 is preferably 0.5% by mass or more from the viewpoint of making the sealing strength with the carrier tape suitable. More, more preferably 1% by mass or more.
Further, the upper limit of the content of the tackifier to the entire sealant layer is, for example, 5% by mass or less, specifically 4% by mass or less, from the viewpoint of difficulty in adhering electronic components and heat-sealing property to the carrier tape. Is.

-Other additive components In addition to the above components, the sealant layer 3 contains anti-blocking agents, slip agents, lubricants, plasticizers, antioxidants, UV absorbers, colorants, surfactants, and inorganic substances, as long as the characteristics are not impaired. It may contain any additive such as a filler. And / or, the surface of the sealant layer 3 may be subjected to these coating treatments.

Examples of the anti-blocking agent include silica, aluminosilicate (zeolite, etc.) and the like. By containing the anti-blocking agent in the sealant layer 3, blocking of the sealant layer 3 is alleviated.

Examples of slip agents include palmitate amide, stearate amide, behenic acid amide, oleic acid amide, erucic acid amide, oleyl palmido amide, stearyl palmido amide, methylene bisstearyl amide, methylene bisoleyl amide, ethylene bisoleyl amide, Examples thereof include various amides such as ethylene biserkaic acid amides, polyalkylene glycols such as polyethylene glycol and polypropylene glycol, and hydrogenated castor oil. When the sealant layer 3 contains a slip agent, processability such as extrusion processing, roll release property, film slip property and the like are improved.

The amount of other additive components in the sealant layer 3 may be appropriately adjusted according to the purpose of addition. Typically, it may be adjusted in the range of about 0.01 to 10% by mass with respect to the entire sealant layer 3.

The thickness of the sealant layer 3 is, for example, 0.005 to 5 μm, preferably 0.01 to 2 μm, and more preferably 0.015 to 1 μm.
When the thickness of the sealant layer 3 is 0.005 μm or more, sufficient sealing properties can be ensured. In addition, it is possible to prevent the seal layer from being cracked and falling off due to twisting.
When the thickness of the sealant layer 3 is 5 μm or less, the rigidity of the cover tape 10 does not become too high. As a result, the cover tape 10 can easily follow the deformation of the carrier tape even when a torsional stress is applied to the carrier tape after sealing. Therefore, it is possible to prevent the cover tape 10 from being unintentionally peeled off from the carrier tape.
Further, when the thickness of the sealant layer 3 is 5 μm or less, there is an advantage that “bleeding out” of the melted resin during heat sealing can be suppressed.

[Other layers]
The cover tape 10 may include any layer other than the base material layer 1, the intermediate layer 2 (single layer or multilayer) and the sealant layer 3.
For example, the cover tape 10 may have an adhesive layer between the base material layer 1 and the intermediate layer 2. By doing so, the mechanical strength of the cover tape can be improved.

The material for forming the adhesive layer usually contains a resin. Specific examples of the resin include urethane-based adhesive resin materials for dry lamination, adhesive resin materials for anchor coating, and the like. Examples of these adhesive resin materials include a combination of a polyol composition such as a polyester polyol or a polyether polyol and an isocyanate compound.

<Manufacturing method of cover tape 10>
The manufacturing method of the cover tape 10 is not limited. For example, the cover tape 10 can be manufactured by applying a known extrusion method, laminating method, coating method, or the like.

Specifically, the cover tape 10 can be manufactured by the following procedures (1) to (4).
(1) Prepare a film corresponding to the intermediate layer 2. When the intermediate layer 2 is multi-layered, the film is formed by, for example, a multi-layer extruder (T die).
(2) Prepare a film (PET film or the like) corresponding to the base material layer 1. This film may be subjected to surface treatment such as corona treatment.
(3) An adhesive material is applied to one side of the film corresponding to the base material layer 1 prepared in (2) (the treated side when corona treatment is applied), and the film corresponding to the base material layer 1 is attached. That is, a multilayer film including the base material layer 1 and the intermediate layer 2 is formed by the dry laminating method. Examples of the adhesive material at this time include the material for forming the above-mentioned adhesive layer.
(4) The coating liquid for forming the sealant layer 3 is applied to the surface of the multilayer film of (3) where the intermediate layer 2 is exposed, using a bar coater or the like. Then, the solvent in the applied coating liquid is dried. In this way, the sealant layer 3 can be provided. The coating liquid may be one in which the above-mentioned (A) styrene resin, (B) (meth) acrylic resin, or the like is dissolved or dispersed in some solvent. The concentration of the non-volatile component of the coating liquid may be appropriately adjusted according to the desired thickness of the sealant layer 3 and the like.
(5) If necessary, the obtained multilayer film is cut to an appropriate length and width.

<Electronic component packaging>
FIG. 3 is a diagram schematically showing the electronic component package 100.
The electronic component packaging body 100 is composed of the cover tape 10 described above and the carrier tape 20 in which electronic components are housed in pockets 21 (recesses).

In FIG. 3, the cover tape 10 is used as a cover material for a strip-shaped carrier tape 20 in which concave pockets 21 are continuously provided according to the shape of an electronic component. Specifically, the cover tape 10 is adhered (usually heat-sealed) to the surface of the carrier tape 20 so as to cover the entire opening of the pocket 21 of the carrier tape 20.

The electronic component package 100 can be manufactured, for example, by the following procedure.
First, the electronic components are housed in the pocket 21 of the carrier tape 20.
Next, the cover tape 10 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 is brought into contact with the carrier tape 20 (that is, the heat seal is performed so that the "back surface" of the cover tape 10 in FIG. 3 is the sealant layer 3). By doing so, a structure (electronic component package 100) in which the electronic component is hermetically sealed can be obtained.
The specific method and conditions of the heat seal are not particularly limited as long as the cover tape 10 adheres sufficiently strongly to the carrier tape 20. Typically, it can be carried out using a known taping machine at a temperature of 100 to 240 ° C., a load of 0.1 to 10 kgf (0.98 to 98 N), and a time of 0.0001 to 1 second.

The material of the carrier tape 20 is not particularly limited as long as the cover tape 10 can be adhered by heat sealing. The material may be made of resin such as a material containing polystyrene resin, a material containing polycarbonate resin, a material containing polyethylene terephthalate resin, or paper. Of these, resin is preferable from the viewpoint of effectively improving the peel strength.
High peel strength can be realized by heat-sealing the above-mentioned cover tape 10 to a carrier tape 20 made of these materials to form an electronic component package.

The electronic component package 100 is wound on a reel, for example, and then transported to a work area where electronic components are mounted on an electronic circuit board or the like. The material of the reel can be metal, paper, plastic, or the like.

After the electronic component package 100 is transported to the work area, the cover tape 10 is peeled off from the carrier tape 20 and the contained electronic component is taken out.

The electronic components housed in the electronic component packaging body 100 are not particularly limited. Examples of all parts used in the manufacture of electrical and electronic equipment such as semiconductor chips, transistors, diodes, capacitors, piezoelectric elements, optical elements, LED-related members, connectors, and electrodes can be mentioned.

Although the embodiments of the present invention have been described above, these are examples of the present invention, and various configurations other than the above can be adopted. Further, the present invention is not limited to the above-described embodiment, and modifications, improvements, and the like within the range in which the object of the present invention can be achieved are included in the present invention.
A reference form of the present invention will be added below.
1. 1.
Cover tape for packaging electronic components
The cover tape includes a base material layer, an intermediate layer, and a sealant layer in this order.
The intermediate layer and the sealant layer are provided in contact with each other.
A cover tape having a _{tack force T 60} of the intermediate layer at 60 ° C. of 60 to 500 gf.
2.
1. 1. The cover tape described in
The intermediate layer has a density of 0.890 to 0.912 g / cm ³ , polyethylene, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, and ethylene-vinyl acetate copolymer. A cover tape containing one or more resins (A) selected from the group consisting of coalesced saponified products and styrene copolymers.
3. 3.
2. The cover tape described in
Between the base material layer and the sealant layer, there is a first intermediate layer and a second intermediate layer different from the first intermediate layer from the side closer to the base material layer, and the second intermediate layer. The layer and the sealant layer are provided in contact with each other.
A cover tape in which the second intermediate layer contains the resin (A).
4.
3. 3. The cover tape described in
The first intermediate layer is a cover tape containing polyethylene having ^{a density of more than 0.910 g / cm 3.}
5.
3. 3. Or 4. The cover tape described in
A cover tape having a value of t ₂ / t ₁ of 0.05 to 5, when the thickness of the first intermediate layer is t ₁ and the thickness of the second intermediate layer is t _2.
6.
1. 1. ~ 5. The cover tape described in any one of the above.
The sealant layer is a cover tape containing a styrene resin and / or a (meth) acrylic resin.
7.
1. 1. ~ 6. The cover tape described in any one of the above.
The base material layer is a cover tape containing a polyester resin.
8.
1. 1. ~ 7. The cover tape described in any one of the above.
The sealant layer is a cover tape containing an antistatic agent.
9.
1. 1. ~ 8. The cover tape described in any one of the above.
A cover tape in which the ratio of styrene units in the styrene copolymer in the sealant layer is 15% by mass or more.
10.
1. 1. ~ 9. The cover tape described in any one of the above.
Wherein when the tackiness at 25 ° C. of the intermediate layer was changed to _{T 25,} is T 60 _{/ T 25} is 3.2 or more, the cover tape.
11.
Carrier tape with electronic components housed in recesses and 1. -10. With the cover tape described in any one of
An electronic component package in which the sealant layer is adhered to the carrier tape so as to seal the electronic component.

Embodiments of the present invention will be described in detail based on Examples and Comparative Examples. As a reminder, the invention is not limited to examples.

<Raw materials>
(Base layer)
Biaxially stretched polyester (PET) film with a film thickness of 12 μm (Toyobo Co., Ltd., trade name: 6140)

(Material for forming the intermediate layer)
Kernel KC573 (manufactured by Japan Polyethylene Corporation, polyethylene with a density of 0.910 g / cm ³ , melting point 102 ° C, MFR (190 ° C, 2.16 kg): 2 g / 10 minutes))
Ube-Maruzen 4540F (manufactured by Ube Maruzen Polyethylene, 0.913 g / cm ³ polyethylene, 99, 114 ° C, MFR (190 ° C, 2.16 kg): 4 g / 10 minutes))
Kernel KF260T (manufactured by Japan Polyethylene Corporation, polyethylene with a density of 0.901 g / cm ³ , melting point 93 ° C)
Petrosen 203 (manufactured by Tosoh, low density polyethylene (LDPE) with a density of 0.919 g / cm ^{3, melting point 87 ° C)}
Elvalois AC1820 (Mitsui / Dow Polychemical Co., Ltd., ethylene-methyl acrylate copolymer, ratio of methyl acrylate: 20% by mass)
Elvalois AC1609 (Mitsui / Dow Polychemical Co., Ltd., ethylene-methyl acrylate copolymer, ratio of methyl acrylate: 9% by mass)
Tough Tech H1052 (manufactured by Asahi Kasei Corporation, hydrogenated styrene-based thermoplastic elastomer, ratio of styrene: 20% by mass)
Tough Tech H1522 (manufactured by Asahi Kasei Corporation, hydrogenated styrene-based thermoplastic elastomer, ratio of styrene: 30% by mass)
Mercen H-6410M (manufactured by Tosoh Corporation, ethylene-vinyl acetate copolymer partially saponified product)
Mercen H-6051K (manufactured by Tosoh Co., Ltd., completely saponified ethylene-vinyl acetate copolymer)
Modic F515A (Adhesive resin manufactured by Mitsubishi Chemical Corporation, polyolefin with polar groups introduced)
Tough Tech M1913 (Asahi Kasei Co., Ltd., acid-modified type hydrogenated styrene-based thermoplastic elastomer)
Toyo Styrene MS-750 (manufactured by Toyo Styrene Co., Ltd., styrene / methacrylate copolymer resin)
H850N (manufactured by Toyo Styrene Co., Ltd., HIPS (high impact polystyrene))
Kernel KC452T (manufactured by Japan Polyethylene Corporation, polyethylene with a density of 0.888 g / cm ³ , melting point 55 ° C)
Tough Tech P2000 (manufactured by Asahi Kasei Corporation, hydrogenated styrene-based thermoplastic elastomer, ratio of styrene: 67% by mass)
DYNARON8300P (manufactured by JSR, hydrogenated styrene-based thermoplastic elastomer, ratio of styrene: 9% by mass)

(Material for forming a sealant layer (blended with coating liquid))
The following coating liquids for forming a sealant layer of Formulation A and Formulation B were prepared.
Formulation A:
Poly (meth) acrylic acid derivative ("A450A" manufactured by Dainippon Ink Co., Ltd.) 40% by mass
Antistatic agent (tin oxide, "T-1" manufactured by Mitsubishi Materials Corporation) 60% by mass
Formulation B:
Styrene-based resin (styrene-butadiene copolymer, tough tech H1517, styrene content 43% by mass) 13.3% by mass
Poly (meth) acrylic acid derivative ("A450A" manufactured by Dainippon Ink Co., Ltd.) 26.7% by mass
Antistatic agent (tin oxide, "T-1" manufactured by Mitsubishi Materials Corporation) 60% by mass

<Manufacturing of cover tape>
The cover tape was manufactured by the following procedure.
(1) A film corresponding to the intermediate layer was formed at 200 ° C. by the T-die method. When the intermediate layer was composed of two or more layers, the coextruded multilayer T-die method was adopted.
(2) One side of the polyester film corresponding to the base material layer was subjected to corona treatment, and the corona-treated surface was coated with an adhesive for dry lamination (Takelac A-520, manufactured by Mitsui Chemicals, Inc.).
(3) The film corresponding to the intermediate layer formed in (1) and the polyester film prepared in (2) were dry-laminated and joined. As a result, a multilayer film having an intermediate layer and a base material layer was obtained.
(4) The intermediate layer side of the multilayer film obtained in (3) was subjected to corona treatment.
(5) On the surface of the obtained laminated film on the intermediate layer side, a mixed solution obtained by mixing 50% by mass of the coating liquid for forming a sealant layer (formulation 1 or formulation 2) shown in Table 1 and 50% by mass of tetrahydrofuran is applied. A film was formed by a gravure coating method and dried at 70 ° C. to form a sealant layer. The coating amount was adjusted so that the final thickness of the sealant layer was the thickness shown in the table below.

As a reminder, in Examples 10 to 12, two kinds of resins were mixed and used for forming the second intermediate layer.

<Measurement of tack force (T ₂₅ , T ₆₀ ) in the middle layer>
First, the sealant layer side of the manufactured cover tape and the conductive polystyrene carrier tape (“CEL-E980A” manufactured by Sumitomo Bakelite Co., Ltd.) were heat-sealed under the conditions of 150 ° C., 0.5 MPa, and 1 second. Then, the heat-sealed carrier tape sheet was peeled off together with the sealant layer by hand peeling, and the sealant layer 3 was carefully removed. The intermediate layer was exposed in this way.

Using a tacking tester TAC-1000 (manufactured by Reska Co., Ltd.), a SUS (stainless steel) probe heated to 60 ° C. was pressed against the intermediate layer (exposed surface) exposed above with the following load and time. After that, the probe was peeled off vertically from the cover tape. The peak value of the load applied at the time of this peeling was taken as tackiness T _60.

The details of the measurement conditions are as follows.
・ Probe diameter: 5 mmφ
-Probe temperature: 60 ° C
-Load that the probe presses against the cover tape: 2500 gf
・ Time to continue pressing: 20 seconds ・ Speed to peel off the probe: 10 mm / s

_{Further, the tack force T 25} at 25 ° C. was obtained by the same measurement except that the probe temperature was changed from 60 ° C. to 25 ° C. Then, the ratio of tack force T ₆₀ / T ₂₅ was obtained.

<Evaluation: Measurement of peel strength>
(Sample creation)
First, the cover tape was cut to a width of 5.5 mm to prepare a sample for measurement.
The measurement sample was heat-sealed on an 8 mm wide sheet of conductive polystyrene carrier tape (“CEL-E980A” manufactured by Sumitomo Bakelite Co., Ltd.) under the following conditions. As a result, a test complex was obtained.
・ Equipment: ISMECA MBM4000 (taping machine)
-Iron shape at the time of sealing: Blade width 0.3 mm / Blade length 54 mm / Blade interval 1.95 mm
・ Seal temperature: 160 ℃
・ Sealing time: 0.1s
・ Seal pressure: 4kgf / cm ²

(measurement)
Using the obtained composite, the peel strength of the cover tape and the carrier tape was measured under the following conditions.
-Peeling device: 856VS (manufactured by General Production Devices)
-Peeling speed: 300 mm / min
・ Peeling angle: 180 °
-Standard: JIS K 0806-3

In addition to the above measurement of peel strength, the peel strength was measured by changing the type of carrier tape. Specifically, the same applies except that a polycarbonate-containing sheet (3M Co., Ltd., "No. 3000 (polycarbonate type)" is used instead of the conductive polystyrene carrier tape (Sumitomo Bakelite Co., Ltd., "CEL-E980A"). The peel strength was measured.

<Evaluation: Observation of peeling state>
The appearance of the sample after the measurement of the above peel strength was visually observed. What was peeled off cleanly between the sealant layer and the intermediate layer is 〇 (good), the appearance is dirty, stringing occurs, and the first intermediate layer and the second intermediate layer are not peeled off between the sealant layer and the intermediate layer. Those that had peeled off between them (those that had "derami") were evaluated as x (defective). In the table below, for items marked with x, what kind of defects occurred is also shown.

<Evaluation: Presence or absence of wrinkles during formation of sealant layer>
The sealant layer of each of the obtained cover tapes was observed. Then, those with no wrinkles confirmed are ○ (good), those with slight wrinkles but at a practically acceptable level are △ (acceptable), and the degree to which heat sealability and peelability are affected. Those with wrinkles were evaluated as x (bad).

<Evaluation: Difficulty of peeling while warm immediately after heat sealing>
First, a composite for testing was obtained as in <Evaluation: Measurement of peel strength> (Sample preparation). This was allowed to stand in an oven at 60 ° C. for 1 hour. The sample was then removed from the oven. Then, it was confirmed whether or not the heat seal portion was peeled off. The case where the heat seal part was not peeled off was evaluated as ◯ (good), and the case where the heat seal part was not peeled off was evaluated as × (poor).

Tables 1 to 3 summarize the raw materials, thickness, material properties and evaluation results of each layer of the cover tape.
In Tables 1 to 3, the measurement conditions for the melt flow rate are 190 ° C./2.16 kg unless otherwise specified. Further, when two kinds of resins are used in combination as the second intermediate layer, the melt flow rate of the combined resin (mixed resin) is shown.

As shown in Tables 1 and 2, the peel strength of the cover tapes of Examples 1 to 20 was good. In addition, the peeled state of the cover tapes of Examples 1 to 20 was good. That is, the cover tapes of Examples 1 to 20 in which _{T 60 was within a certain range performed well.}
On the other hand, as shown in Table 3, in the _{comparative example in which T 60} was small, only a small peel strength was obtained as compared with the example. Further, in _{Comparative Example 4 in which T 60} was too large, it was found that although a large peel strength was obtained, there was a problem as a cover tape in terms of the peeled state and the occurrence of wrinkles during the formation of the sealant layer.

1 Base material layer 2 Intermediate layer 2A First intermediate layer 2B Second intermediate layer 3 Sealant layer 10 Cover tape 20 Carrier tape 21 Pocket 100 Electronic component packaging

Claims (13)

Cover tape for packaging electronic components
The cover tape includes a base material layer, an intermediate layer, and a sealant layer in this order.
The intermediate layer and the sealant layer are provided in contact with each other.
The tackiness _{T 60} at 60 ° C. of the intermediate layer, Ri 110~491gf der,
The intermediate layer has a density of 0.890 to 0.912 g / cm ³ , polyethylene, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer, and ethylene-vinyl acetate copolymer. A cover tape containing one or more resins (A) selected from the group consisting of coalesced saponified products and styrene copolymers. The cover tape according to claim 1.
Between the base material layer and the sealant layer, there is a first intermediate layer and a second intermediate layer different from the first intermediate layer from the side closer to the base material layer, and the second intermediate layer. The layer and the sealant layer are provided in contact with each other.
A cover tape in which the second intermediate layer contains the resin (A). The cover tape according to claim 2.
The first intermediate layer is a cover tape containing polyethylene having ^{a density of more than 0.910 g / cm 3.} The cover tape according to claim 2 or 3.
A cover tape having a value of t ₂ / t ₁ of 0.05 to 5, when the thickness of the first intermediate layer is t ₁ and the thickness of the second intermediate layer is t _2. The cover tape according to any one of claims 1 to 4.
The sealant layer is a cover tape containing a styrene resin and / or a (meth) acrylic resin. The cover tape according to any one of claims 1 to 5.
The base material layer is a cover tape containing a polyester resin. The cover tape according to any one of claims 1 to 6.
The sealant layer is a cover tape containing an antistatic agent. The cover tape according to any one of claims 1 to 7.
A cover tape in which the ratio of styrene units in the styrene copolymer in the sealant layer is 15% by mass or more. The cover tape according to any one of claims 1 to 8.
Wherein when the tackiness at 25 ° C. of the intermediate layer was changed to _{T 25,} is T 60 _{/ T 25} is 3.2 or more, the cover tape. The cover tape according to any one of claims 2 to 4.
As a resin, the second intermediate layer contains polyethylene, an ethylene- (meth) acrylic acid copolymer, an ethylene- (meth) acrylic acid ester copolymer, and ethylene having a density of 0.890 to 0.912 g / cm ^3. -A cover tape containing only one resin (A) selected from the group consisting of a saponified vinyl acetate copolymer and a styrene copolymer. The cover tape according to any one of claims 2 to 4.
The second intermediate layer contains polyethylene, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester copolymer and ethylene-vinyl acetate having a density of 0.890 to 0.912 g / cm ^3. A cover tape containing two or more resins (A) selected from the group consisting of copolymer saponified products. The cover tape according to claim 1.
The intermediate layer is a cover tape which is a single layer. Comprising a carrier tape on which an electronic component is received in the recess, and a cover tape according to any one of claims 1 to 1 2,
An electronic component package in which the sealant layer is adhered to the carrier tape so as to seal the electronic component.

Images