JP7796067B2 - Cover tape for packaging electronic components and electronic component packaging - Google Patents

Description

The present invention relates to a cover tape for packaging electronic components and an electronic component package. More specifically, it relates to a cover tape for packaging electronic components and an electronic component package in which electronic components are packaged using the cover tape.

2. Description of the Related Art When transporting, storing, etc. electronic components, carrier tapes and cover tapes are often used.
Specifically, electronic components (such as semiconductor chips) are placed in recesses formed in the carrier tape for storing electronic components, and then a cover tape is heat-sealed to the top surface of the carrier tape to enclose the electronic components. The carrier tape is then wound into a reel for transportation and storage. This prevents contamination of the electronic components during transportation and storage.

Prior art for cover tapes can be found in, for example, Patent Document 1. Patent Document 1 describes a cover tape for an embossed carrier tape for surface mounting, which includes the following outer layer, intermediate layer, and adhesive layer.
Outer layer: Biaxially stretched film of either polyester or polypropylene. Middle layer: Ethylene-α-olefin copolymer with tear strength (JIS K 7128) of 100 kg/cm or more, tensile impact strength (ASTM D1822) of 100 kg-cm/ ^cm2 or more, and haze (JIS K 7105) of 15% or less. Adhesive layer: An adhesive made of one of polyurethane resin, acrylic resin, polyvinyl chloride resin, ethylene vinyl acetate resin, polyester resin, butadiene resin, styrene resin, or a combination thereof, which can be heat-sealed to a plastic carrier tape, and in which conductive fine powder of either tin oxide or zinc oxide is dispersed.

Japanese Patent Application Publication No. 8-258888

From the viewpoint of "protecting electronic components," which is one of the original purposes of cover tapes for packaging electronic components, it is important that the cover tape has sufficient strength.
There are various viewpoints for "strength." For example, considering the definition of the "intermediate layer" in Patent Document 1, the cover tape in Patent Document 1 is understood to be a cover tape that has high strength against "tear" and "tensile."

In the course of investigating ways to further improve the strength of the cover tape, the inventors recently discovered that conventional cover tapes need improvement in that they are prone to being punctured by a sharp object. The inventors also discovered that conventional cover tapes need improvement in that they are prone to being damaged when bent.

In light of the above points requiring improvement, the inventors have set as one of their objectives the provision of a cover tape for packaging electronic components that is resistant to damage even when pierced or bent.

As a result of their investigations, the inventors have completed the invention provided below, which has solved the above-mentioned problems.

The present invention is as follows:

1.
a substrate layer;
a polyamide-containing layer provided on one surface of the base material layer;
a sealant layer provided on the surface of the polyamide-containing layer opposite to the substrate layer;
A cover tape for packaging electronic components, comprising:
A cover tape in which F _MD /F _TD is 0.95 to 1.05, where F _MD is the tear strength in the MD direction of the cover tape and F _TD is the tear strength in the TD direction of the cover tape, as measured in accordance with JIS K 7128-3.
2.
1. The cover tape according to claim 1,
A cover tape having an F _MD of 550 to 1400 N/cm and an F _TD of 600 to 1400 N/cm.
3.
The cover tape according to 1. or 2.,
The polyamide-containing layer of the cover tape comprises at least one resin selected from the group consisting of nylon 6, nylon 66, nylon 11, and nylon 12.
4.
The cover tape according to any one of 1. to 3.,
The polyamide-containing layer has a thickness of 5 to 30 μm.
5.
The cover tape according to any one of 1. to 4.,
The polyamide-containing layer is a bar tape made of a biaxially oriented polyamide film.
6.
The cover tape according to any one of 1. to 5.,
The cover tape further comprises an intermediate layer provided between the polyamide-containing layer and the sealant layer.
7.
6. The cover tape according to item 6,
The intermediate layer of the cover tape comprises a polyethylene-based resin.
8.
The cover tape according to any one of 1. to 7.,
The cover tape includes a base layer containing a polyester resin.
9.
1. The cover tape according to any one of 1. to 8.,
The cover tape, wherein the sealant layer contains a (meth)acrylic resin.
10.
The cover tape according to any one of 1. to 9.,
A cover tape having a tensile modulus of elasticity measured in accordance with JIS K 7161 of 1500 to 2000 MPa.
11.
A carrier tape having an electronic component housed in a recess, and the cover tape according to any one of 1. to 10.
An electronic component package in which the sealant layer is adhered to the carrier tape so as to seal the electronic component.

The present invention provides a cover tape for packaging electronic components that is resistant to damage even when pierced or bent.

FIG. 2 is a diagram schematically illustrating the layer structure of a cover tape. FIG. 2 is a diagram schematically illustrating an electronic component package. FIG. 1 is a diagram for supplementing the method for measuring "tear strength" in the examples.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In all the drawings, similar components are denoted by similar reference numerals and descriptions thereof will be omitted where appropriate.
To avoid complexity, (i) when there are multiple identical components in the same drawing, only one of them will be given a reference number, and not all of them will be given a reference number, or (ii) particularly in Figure 2 and subsequent figures, components similar to those in Figure 1 will not be given a reference number again.
All drawings are for illustrative purposes only, and the shapes and dimensional ratios of the components in the drawings do not necessarily correspond to the actual products.

In this specification, the notation "X to Y" in the description of a numerical range means at least X and at most Y, unless otherwise specified. For example, "1 to 5% by mass" means "at least 1% by mass and at most 5% by mass."

In the description of groups (atomic groups) in this specification, when a notation does not specify whether the group is substituted or unsubstituted, it encompasses both unsubstituted and substituted groups. For example, the term "alkyl group" encompasses not only alkyl groups without a substituent (unsubstituted alkyl groups) but also alkyl groups with a substituent (substituted alkyl groups).
In this specification, the term "(meth)acrylic" represents a concept that encompasses both acrylic and methacrylic. The same applies to similar terms such as "(meth)acrylate."
In this specification, the terms "MD direction" and "TD direction" are used in the same sense as they are commonly used in the field of resin films. Just to be clear, the "MD" in "MD direction" is an abbreviation for machine direction. The MD direction is sometimes referred to as the flow direction. Furthermore, the "TD" in "TD direction" is an abbreviation for transverse direction, and is sometimes referred to as the vertical direction. In a long cover tape, the long direction is usually the MD direction, and the width direction is the TD direction.

<Cover tape>
FIG. 1 is a schematic diagram showing the layer structure of a cover tape 10 for packaging electronic components (also simply referred to as "cover tape 10") according to this embodiment.
1 , the cover tape 10 comprises a substrate layer 1, a polyamide-containing layer 2 provided on one side of the substrate layer 1, and a sealant layer 3 provided on the side of the polyamide-containing layer 2 opposite the substrate layer 1. In other words, the cover tape 10 comprises, in this order, the substrate layer 1, the polyamide-containing layer 2, and the sealant layer 3. There may or may not be additional layers between these layers.
The cover tape 10 also preferably includes an intermediate layer 2B between the polyamide-containing layer 2 and the sealant layer 3.

The sealant layer 3 is usually present on the outermost surface of the cover tape 10 and constitutes one side of the cover tape 10. This allows the cover tape 10 to adhere closely to the carrier tape 20 described below.
Typically, the substrate layer 1, the polyamide-containing layer 2, and the sealant layer 3 all have substantially the same width and length and exist without any breaks or divisions. When an intermediate layer 2B is present, it is preferable that the intermediate layer 2B also has substantially the same width and length as the substrate layer 1, the polyamide-containing layer 2, and the sealant layer 3 and exists without any breaks or divisions.

As shown in Figure 2, the cover tape 10 is typically used to seal a carrier tape 20 having a pocket 21 for accommodating electronic components. That is, the cover tape 10 is heat-sealed so that the sealant layer 3 of the cover tape 10 contacts the carrier tape 20.

When the tear strength of the cover tape 10 in the MD direction measured in accordance with JIS K 7128-3 is F _MD and the tear strength of the cover tape 10 in the TD direction is F _TD , F _MD /F _TD is 0.95 to 1.05, preferably 0.97 to 1.03, and more preferably 0.97 to 1.01.

Based on past findings and preliminary studies, the inventors have discovered that the reason conventional cover tapes are vulnerable to punctures and bending is likely due to the weakness of the material that makes up the cover tape itself, as well as the difference in strength between the MD and TD directions of the cover tape. Cover tapes with a difference in strength between the MD and TD directions cannot absorb external impacts "evenly" across the entire cover tape, and it is believed that this leads to their vulnerability to punctures and bending.

In light of the above, the inventors decided to use a polyamide-containing layer 2, whose material has a relatively high strength, as one of the layers constituting the cover tape 10. Furthermore, the tear strength F _MD of the cover tape 10 in the MD direction and the tear strength F _TD of the cover tape 10 in the TD direction were made the same or substantially the same (F _MD /F _TD was 0.95 to 1.05). In other words, a cover tape 10 was manufactured in which the tear strength required in the MD direction was the same or nearly the same in the TD direction. This enabled the production of a cover tape 10 with good resistance to punctures and bending.

A cover tape 10 having an F _MD /F _TD of 0.95 to 1.05 can only be manufactured by selecting appropriate materials and employing an appropriate manufacturing method. In particular, by using a "custom-made" polyamide (nylon) film in which the longitudinal and transverse stretching ratios are highly controlled, it is easy to manufacture a cover tape 10 having an F _MD /F _TD of 0.95 to 1.05. To the best of the inventor's knowledge, it is difficult to manufacture a cover tape 10 having an F _MD /F _TD of 0.95 to 1.05 using a conventional polyamide (nylon) film.

Continuing with the explanation of the cover tape 10.

[Base material layer 1]
There are no particular limitations on the material constituting the base material layer 1. Typically, a material that provides sufficient mechanical strength to withstand external forces when producing the cover tape 10, adhering the cover tape 10 to the carrier tape, etc. is preferred. Also, a material that has sufficient heat resistance to withstand the heat generated when adhering the cover tape 10 to the carrier tape is preferred.
The material constituting the base layer 1 is preferably in the form of a film from the viewpoint of ease of processing.

Specific examples of materials constituting the base material layer 1 include polyester-based resins, polyamide-based resins, polyolefin-based resins, polyacrylate-based resins, polymethacrylate-based resins, polyimide-based resins, polycarbonate-based resins, ABS resins, etc. Among these, polyester-based resins are preferred from the viewpoint of improving the mechanical strength of the cover tape 10 and from the viewpoint of cost, and polyethylene terephthalate (PET)-based resins are more preferred.
The base layer 1 may or may not contain additives such as lubricants.
In order to protect the electronic components from static electricity, the base layer 1 is preferably subjected to an antistatic treatment.

The base layer 1 may be a single layer or may be composed of two or more layers. For example, the base layer 1 may be formed of a multilayer film in which the above-mentioned materials are laminated.
The film used to form the base layer 1 may be an unstretched film or a uniaxially or biaxially stretched film. From the viewpoint of further improving the mechanical strength of the cover tape 10, a uniaxially or biaxially stretched film is preferred.

The thickness of the substrate layer 1 is not particularly limited. The thickness of the substrate layer 1 is preferably 5 μm or more, more preferably 8 μm or more, and more preferably 10 μm or more. The thickness of the substrate layer 1 is preferably 50 μm or less, more preferably 40 μm or less, even more preferably 30 μm or less, and particularly preferably 20 μm or less.
By setting the thickness of the base layer 1 to 50 μm or less, the rigidity of the cover tape 10 is not too high. As a result, even if a torsional stress is applied to the carrier tape after sealing, the cover tape 10 can easily follow the deformation of the carrier tape. Therefore, it is possible to prevent the cover tape 10 from unintentionally peeling off from the carrier tape.
The thickness of the base material layer 1 is 5 μm or more, which ensures sufficient mechanical strength of the cover tape 10. Therefore, even when the cover tape 10 is peeled off from the carrier tape at high speed, for example, the cover tape 10 can be prevented from breaking.

The total light transmittance of the base material layer 1 is preferably 80% or more, and more preferably 85% or more. This ensures the transparency necessary to enable inspection of whether the electronic components are properly housed in the electronic component package consisting of the cover tape 10 and the carrier tape. In other words, by making the total light transmittance of the base material layer 1 80% or more, it becomes easier to visually check the electronic components housed inside the package consisting of the cover tape 10 and the carrier tape from the outside.
The total light transmittance can be measured in accordance with JIS-K-7361.

[Polyamide-containing layer 2]
The polyamide-containing layer 2 is not particularly limited as long as it contains polyamide. From the viewpoint of further suppressing damage to the cover tape 10 due to "piercing" or "bending," the polyamide content in the polyamide-containing layer 2 is preferably 50% by mass or more, more preferably 75% by mass or more, even more preferably 90% by mass or more, and particularly preferably 95% by mass or more.

From the standpoint of good strength and easy material availability, the polyamide-containing layer 2 preferably contains at least one resin selected from the group consisting of 6-nylon, 6,6-nylon, and nylon 12. Of course, other polyamides can also be used, and any polyamide that can be molded into a film can be used without particular restrictions.

From the viewpoint of particularly increasing the strength of the cover tape 10 against "puncture" and "bending" and from the viewpoint of precisely controlling the value of F _MD /F _TD , the polyamide-containing layer 2 is preferably composed of a biaxially oriented polyamide film.
The biaxially oriented polyamide film is preferably a simultaneously biaxially oriented polyamide film.
The stretching ratio of the biaxially oriented polyamide film is not particularly limited, but is, for example, 2 to 7 times, preferably 3 to 6 times, and more preferably 4 to 6 times. The stretching ratio in the MD direction and the stretching ratio in the TD direction are usually approximately the same. However, as long as the F _MD /F _{TD ratio} of the cover tape 10 is 0.95 to 1.05, the stretching ratios in the longitudinal and transverse directions of the biaxially oriented polyamide film may be different.

The polyamide-containing layer 2 may have a single layer structure or a multi-layer structure.
The thickness of the polyamide-containing layer 2 is preferably 5 to 30 μm, more preferably 10 to 20 μm, from the viewpoint of particularly increasing the strength of the cover tape 10 against punctures and bending, and from the viewpoint of making the cover tape 10 thinner to improve handling.

[Middle layer 2B]
The cover tape 10 preferably includes an intermediate layer 2B between the polyamide-containing layer 2 and the sealant layer 3. The presence of the intermediate layer 2B can further enhance the cushioning properties and impact resistance of the cover tape 10.

Examples of materials for forming the intermediate layer include olefin-based resins, styrene-based resins, cyclic olefin-based resins, etc. Among these, olefin-based resins are preferred from the viewpoint of improving the cushioning properties of the entire cover tape 10.
Examples of olefin-based resins include polyethylene-based resins and polypropylene-based resins, with polyethylene-based resins being preferred. In particular, from the viewpoint of cushioning properties, low-density polyethylene (LDPE) or linear low-density polyethylene (L-LDPE) is more preferred. Furthermore, from the viewpoint of achieving both cushioning properties and strength, high-density polyethylene (HDPE) is also preferred.
The intermediate layer 2B may or may not contain various additives, examples of which include those listed for the other layers.

When the intermediate layer 2B is provided, the intermediate layer 2B may have a single layer structure or a multi-layer structure.
When the intermediate layer 2B is provided, its thickness is preferably 10 to 45 μm, more preferably 15 to 40 μm, from the viewpoint of improving the cushioning properties of the entire cover tape 10 without excessively impairing other performances.

[Sealant layer 3]
The sealant layer 3 can contain any resin as long as it softens or melts appropriately under normal heat sealing conditions and can be heat-sealed to the carrier tape 20 .

The sealant layer 3 typically contains a thermoplastic resin, such as an ionomer resin, a polyester resin, a vinyl chloride-vinyl acetate copolymer, a (meth)acrylic resin, a polyurethane resin, an ethylene-vinyl acetate copolymer, an ethylene-(meth)acrylic acid copolymer, an ethylene-(meth)acrylic acid ester copolymer, or a maleic acid resin.
In particular, (meth)acrylic resins and ethylene-vinyl acetate copolymers are preferably used because they can be heat-sealed to a wide variety of carrier tapes and there is little variation in heat seal strength due to changes in heat seal conditions.

The sealant layer 3 preferably contains inorganic particles in addition to the resin. The inorganic particles may contribute to optimizing the peel strength and improving the antistatic properties.
Examples of inorganic particles include sulfide particles such as zinc sulfide, copper sulfide, cadmium sulfide, nickel sulfide, and palladium sulfide, metal oxides such as aluminum oxide, tin oxide, zinc oxide, indium oxide, and titanium oxide, carbon fine particles, and silica. Metal oxides are preferred as inorganic particles because of their availability and ease of adjusting the peel strength.
In order to improve antistatic properties, it is preferable to use tin-doped indium oxide (ITO) or antimony-doped tin oxide (ATO) as the inorganic particles. These inorganic particles are transparent, and are therefore preferable in that they maintain the light transmittance of the cover tape 10 and ensure the visibility of the electronic components.

The average particle size of the inorganic particles is preferably 10 to 1000 nm, more preferably 50 to 500 nm.
When the sealant layer 3 contains inorganic particles, the amount thereof is, for example, 1 to 20 parts by mass, preferably 1 to 10 parts by mass, per 100 parts by mass of the resin (thermoplastic resin).

To impart antistatic properties to the sealant layer 3, the sealant layer 3 may contain conductive fillers such as metal oxides, polymeric copolymer-type antistatic agents, etc. (The inorganic particles mentioned above may also serve as conductive fillers.) The sealant layer 3 may further contain additives such as dispersants, fillers, and plasticizers as needed.

The thickness of the sealant layer 3 is preferably 0.1 to 5 μm, more preferably 0.5 to 3 μm, from the viewpoint of achieving sufficient heat-sealing properties without excessively impairing other performance properties.

[Other layers]
The cover tape 10 may or may not include layers other than those described above.
For example, an adhesive layer may be present between the base layer 1 and the polyamide-containing layer 2. In other words, an adhesive layer may be provided for bonding the film constituting the base layer 1 and the film constituting the polyamide-containing layer 2 together.

As a material for forming the adhesive layer, a combination of a polyol such as polyester polyol or polyether polyol with an isocyanate compound can generally be used.
The adhesive layer can be formed from a known solvent-based or water-based anchor coating agent, such as an isocyanate-based, polyurethane-based, polyester-based, polyethyleneimine-based, polybutadiene-based, polyolefin-based, or alkyl titanate-based anchor coating agent.
Furthermore, examples of materials for forming the adhesive layer include urethane-based adhesive resin materials for dry lamination.

By the way, adhesion can be further improved by subjecting the adhesive surface to corona treatment. The corona treatment conditions can be adjusted as appropriate.

If an adhesive layer is present, its thickness is preferably 0.001 to 10 μm, and more preferably 0.01 to 5 μm. By selecting an appropriate thickness, sufficient adhesion can be achieved while minimizing reductions in visibility.

An adhesive layer may also be present between the polyamide-containing layer 2 and the intermediate layer 2B. Specific embodiments of the adhesive layer in this case may be similar to those of the adhesive layer that may be present between the substrate layer 1 and the polyamide-containing layer 2, as described above.

[Regarding _FMD and _FTD ]
In addition to the F _MD /F _TD value being 0.95 to 1.05, appropriate values for each of F _MD and F _TD tend to make the cover tape 10 more resistant to "puncture" and "bending." Also, appropriate values for each of F _MD and F _TD tend to make the cover tape 10 more resistant to "tear."

From the viewpoint of further increasing the strength of the cover tape 10 and from the viewpoint of material availability and manufacturability, the preferred ranges of F _MD and F _TD are as follows:
F _MD : preferably 550 to 1900 N/cm, more preferably 650 to 1800 N/cm, and even more preferably 750 to 1700 N/cm
F _TD : preferably 600 to 2000 N/cm, more preferably 700 to 1900 N/cm, and even more preferably 800 to 1800 N/cm

Incidentally, F _MD /F _TD is preferably 0.97 to 1.03, more preferably 0.99 to 1.01.

Other Characteristics of Cover Tape 10
The tensile modulus of elasticity measured in accordance with IS K 7161 is preferably 1500 to 2000 MPa. By having an appropriate tensile modulus of elasticity for the bar tape 10, the cover tape 10 also tends to be strong against "tension."

[Method of manufacturing the cover tape 10]
As described above, the cover tape 10 having an F _MD /F _{TD ratio} of 0.95 to 1.05 can be manufactured by selecting an appropriate material and employing an appropriate manufacturing method.

In particular, the key to obtaining the cover tape 10 is to use a polyamide (nylon) film whose longitudinal and transverse stretching ratios are highly controlled, so that the tear strength in the MD direction and the tear strength in the TD direction, and the ratio between these, are appropriate values.
Specifically, the value of (tear strength in MD)/(tear strength in TD) of the film for forming the polyamide-containing layer is preferably about 0.80 to 1.80. Furthermore, the tear strength in MD of the film for forming the polyamide-containing layer is preferably about 3000 to 5000 N/cm. Furthermore, the tear strength in TD of the film for forming the polyamide-containing layer is preferably about 1900 to 4000 N/cm. Such films can be obtained, for example, by "custom-ordering" them from a film manufacturer.
Just to be clear, it is not difficult to produce a polyamide (nylon) film with the same level of tear strength in the MD and TD directions as described above. By starting from the production conditions of an existing polyamide (nylon) film and conducting several "trial experiments" in which the stretching conditions and other conditions are changed, and understanding the relationship (trend) between the changed conditions and the tear strength in the MD/TD directions, it is entirely possible to produce a polyamide (nylon) film with the same level of tear strength in the MD and TD directions.

For reference, let us consider conventional "non-custom" polyamide (nylon) film.
Among commercially available polyamide (nylon) films, some have the same longitudinal and transverse stretch ratios listed in their catalogs. At first glance, the MD and TD strengths of such films appear to be comparable. However, according to the inventor's findings and research, for example, the longitudinal and transverse stretch ratios may not be strictly controlled due to production costs, or factors other than stretching may exist in process conditions that cause differences in MD and TD strengths. Furthermore, even in biaxial stretching, sequential biaxial stretching tends to result in differences in MD and TD strengths in the resulting film. Furthermore, depending on the resin structure and physical properties of the polyamide (nylon), it may not always be possible to produce films with substantially the same MD and TD strengths, even when the longitudinal and transverse stretch ratios are the same.
In other words, it is possible that polyamide (nylon) films with the same or nearly the same tear strength in the MD and TD directions have not been common up until now. Furthermore, it has not been known to apply such polyamide (nylon) films to cover tapes.

Incidentally, although the cover tape 10 has a multilayer structure, to the best of the inventor's knowledge, the MD strength and TD strength of the polyamide-containing film constituting the polyamide-containing layer 2 particularly contribute to the value of F _MD /F _TD of the cover tape 10. The contribution of the films and materials constituting the base material layer 1, intermediate layer 2B, and sealant layer 3 to the value of F _MD /F _TD is smaller than the contribution of the polyamide-containing layer 2.
(Of course, depending on the materials constituting the base layer 1, intermediate layer 2B, and sealant layer 3, the F _MD /F _TD value of the cover tape 10 may be less than 0.95 or 1.05 or greater.)

<Electronic component packaging>
FIG. 2 is a diagram schematically illustrating the electronic component packaging body 100. As shown in FIG.
The electronic component packaging body 100 is composed of the above-mentioned cover tape 10 and the carrier tape 20 in which the electronic components are accommodated in the pockets 21 (recesses).

In Figure 2, the cover tape 10 is used as a lid for a strip-shaped carrier tape 20 that has a continuous series of recessed pockets 21 formed to fit the shapes of electronic components. Specifically, the cover tape 10 is adhered (usually heat-sealed) to the surface of the carrier tape 20 so as to completely cover the openings of the pockets 21 on the carrier tape 20.

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 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 in contact with the carrier tape 20 (that is, the heat sealing is performed so that the "back surface" of the cover tape 10 in FIG. 2 becomes the sealant layer 3). In this way, a structure (electronic component packaging body 100) in which electronic components are hermetically housed is obtained.

The specific method and conditions for heat sealing are not particularly limited, as long as the cover tape 10 adheres sufficiently strongly to the carrier tape 20. Typically, a known taping machine is used, and heat sealing can be performed at a heating temperature of 100 to 240°C, a load of 0.1 to 10 kgf (0.98 to 98 N), and a heating time of 0.0001 to 1 second.

The material of the carrier tape 20 is not particularly limited as long as it can adhere the cover tape 10 by heat sealing. The material can be a resin such as a material containing polystyrene resin, a material containing polycarbonate resin, or a material containing polyethylene terephthalate resin, or paper. Of these, resin is preferred from the perspective of effectively improving peel strength.

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

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 housed electronic components are removed.

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

The above describes embodiments of the present invention, but these are merely examples of the present invention, and various other configurations may be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements that achieve the objectives of the present invention are included in the present invention.

Embodiments of the present invention will be described in detail based on examples and comparative examples. It should be noted that the present invention is not limited to the examples.

<Preparation of polyamide film>
We requested a film manufacturer to prepare the following polyamide films.

[Substances used in Example 1]
Nylon 6, thickness: 20 μm, stretch ratio: 5 times vertically and 5 times horizontally (Note 1), tear strength in MD direction of film alone: 3580 N/cm, tear strength in TD direction of film alone: 2580 N/cm (Note 2)
(Note 1: The stretching ratio was adjusted to 5 times vertically and 5 times horizontally as standard, and the tear strength in the MD direction and the tear strength in the TD direction of the film alone were adjusted to the above values.)
(Note 2: The tear strength was measured in accordance with the method described below in <Measurement of MD tear strength F _MD and TD tear strength F _TD of cover tape>. However, in this case, the measurement was performed three times, and the MD tear strength and TD tear strength were reported above as the average of the three measurements.)

[Substances used in Example 2]
Nylon 6, thickness: 20 μm, stretch ratio: 6 times vertically and 6 times horizontally (Note 3), tear strength in MD direction of film alone: 4400 N/cm, tear strength in TD direction of film alone: 5020 N/cm (Note 4)
(Note 3: The stretching ratio was adjusted to 6 times vertically and 6 times horizontally as a standard, and the tear strength in the MD direction and the tear strength in the TD direction of the film alone were adjusted to the above values.)
(Note 4: The tear strength was measured using the same method as in Example 1 above.)

[Substances used in Example 3]
Nylon 6, thickness: 30 μm, stretch ratio: 5 times vertically and 5 times horizontally (Note 5), tear strength in MD direction of film alone: 3500 N/cm, tear strength in TD direction of film alone: 2000 N/cm (Note 6)
(Note 5: The stretching ratio was adjusted to 5 times vertically and 5 times horizontally as standard, and the tear strength in the MD direction and the tear strength in the TD direction of the film alone were adjusted to the values specified above.)
(Note 6: The tear strength was measured using the same method as in Example 1 above.)

[Substances used in Comparative Example 1]
Nylon 6, thickness: 20 μm, tear strength in MD direction of film alone: 4300 N/cm, tear strength in TD direction of film alone: 2100 N/cm
(This film is also a stretched film, but the "fine adjustment" of the stretch ratio as described above has not been performed.)

<Cover tape manufacturing>
The films (cover tapes) of Examples 1 to 3 and Comparative Example 1 were produced according to the following procedure.
(1) As a substrate layer, a 9 μm thick polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., Espet (registered trademark) E5100) that had been subjected to an antistatic treatment was prepared.
(2) The polyamide film was laminated on the corona-treated surface of the substrate layer by dry lamination using a urethane adhesive, thereby providing a polyamide-containing layer.
(3) After subjecting the exposed surface of the polyamide-containing layer to a corona treatment, a polyethylene film (Sumitomo Chemical Co., Ltd.'s "Sumikathen L705" film thickness 25 μm) was laminated thereon by dry lamination using a urethane adhesive in Examples 1 and 2 and Comparative Example 1, and a polyethylene film (Sumitomo Chemical Co., Ltd.'s "Sumikathen L705" film thickness 15 μm) was laminated thereon in Example 3.
(4) A coating solution containing 30% by mass of an acrylic sealant resin (A450A, manufactured by DIC Corporation), 2% by mass of aluminum oxide having an average particle size of 100 nm, and 68% by mass of toluene was applied and dried at 70° C. to provide a sealant layer. The amount of coating was adjusted so that the film thickness after drying would be 2 μm.

Furthermore, a film of Comparative Example 2 was produced in the same manner as above, except that (2) was not performed and in (3) a 45 μm thick polyethylene film (Sumitomo Chemical Co., Ltd.'s "Sumikathen L705," 45 μm thick) was laminated using the dry lamination method.

Furthermore, the film of Comparative Example 3 was produced in the same manner as above, except that (2) was not performed and in (3) a 15 μm thick polyethylene film (Sumitomo Chemical Co., Ltd.'s "Sumikathen L705", 15 μm thick) was laminated using the dry lamination method.

<Measurement of tear strength F _MD in MD direction and tear strength F _TD in TD direction of cover tape>
Measurement was performed according to the "Right-Angle Tear Method" of JIS K 7128-3. Specifically, the manufactured cover tape was first cut out to prepare test pieces with right-angled portions having the shape and size shown in Figure 3. For each cover tape, two test pieces were prepared: one in which the direction indicated by arrow a in Figure 3 was the MD direction, and the other in which the direction indicated by arrow a in Figure 3 was the TD direction.
Next, the prepared test pieces were torn at a test speed of 200 mm/min using a tensile tester RTH-1225 manufactured by A&D Co., Ltd. The maximum load at this time was taken as the tear strength (F _MD or F _TD ).
Incidentally, the measurements were carried out three times in each direction, and the average value of the three measurements was used.

<Measurement of tensile modulus of cover tape>
The test was carried out in accordance with the method described in JIS K 7161. Specifically, the test was carried out as follows.
First, the produced cover tape was cut into a No. 1 dumbbell-shaped test piece.
Next, the prepared test piece was set in an A&D tensile testing machine "RTH-1225." Then, it was pulled at a test speed of 1 mm/min. The pulling direction was the longitudinal direction of the cover tape, i.e., the MD direction. The maximum stress at this time was taken as the tensile strength.

<Evaluation of puncture strength>
The tip of a needle with a tip radius of curvature of 0.5 mm was thrust into the resulting cover tape (laminated film) from its base layer side (polyethylene terephthalate side) and pushed perpendicularly into the cover tape at a speed of 500 mm/min. The load applied to the needle was then read at the moment the needle penetrated the cover tape. This reading was used as the "piercing strength."

<Evaluation of resistance to bending>
The resulting cover tape (laminated film) was bent using a Gelbo flex tester at a temperature of 23° C. and 500 flexes in accordance with ASTM F392.
After the test, the cover tape was visually inspected and the number of pinholes was counted.

The above is summarized in Table 1.

From the above table, it can be seen that the cover tapes of Examples 1 to 3, in which the value of F _MD /F _TD is close to 1, are strong against "puncture" and "bending" and are less susceptible to damage.

1 Base material layer 2 Polyamide-containing layer 2B Intermediate layer 3 Sealant layer 10 Cover tape (cover tape for packaging electronic components)
20 Carrier tape 21 Pocket 100 Electronic component package

Claims (12)

a substrate layer;
a polyamide-containing layer provided on one surface of the base material layer;
a sealant layer provided on the surface of the polyamide-containing layer opposite to the substrate layer;
A cover tape for packaging electronic components, comprising:
A cover tape in which F _MD /F _TD is 0.95 to 1.05, where F _MD is the tear strength in the MD direction of the cover tape and F _TD is the tear strength in the TD direction of the cover tape, as measured in accordance with JIS K 7128-3. 2. The cover tape of claim 1,
A cover tape having an F _MD of 550 to 1900 N/cm and an F _TD of 600 to 2000 N/cm. The cover tape according to claim 1 or 2,
The polyamide-containing layer of the cover tape comprises at least one resin selected from the group consisting of nylon 6, nylon 66, nylon 11, and nylon 12. The cover tape according to claim 1 or 2,
The polyamide-containing layer has a thickness of 5 to 30 μm. The cover tape according to claim 1 or 2,
The polyamide-containing layer of the cover tape is composed of a biaxially oriented polyamide film. The cover tape according to claim 1 or 2,
The cover tape further comprises an intermediate layer provided between the polyamide-containing layer and the sealant layer. 7. The cover tape according to claim 6,
The intermediate layer of the cover tape comprises a polyethylene-based resin. The cover tape according to claim 1 or 2,
The cover tape includes a base layer containing a polyester resin. The cover tape according to claim 1 or 2,
The cover tape, wherein the sealant layer contains a (meth)acrylic resin. The cover tape according to claim 1 or 2,
A cover tape having a tensile modulus of elasticity measured in accordance with JIS K 7161 of 1500 to 2000 MPa. 7. The cover tape according to claim 6,
The cover tape wherein the intermediate layer comprises low density polyethylene (LDPE) or linear low density polyethylene (L-LDPE). A carrier tape having electronic components housed in recesses and the cover tape according to claim 1 or 2,
An electronic component package in which the sealant layer is adhered to the carrier tape so as to seal the electronic component.