JP6400880B2 - Cover tape - Google Patents

Description

  The present invention relates to a cover tape, and more particularly to a cover tape that is attached to a carrier tape having a large number of electronic component storage cavities.

  In recent years, in order to store and transport electronic components such as IC chips, surface mount components such as transistors, diodes, capacitors, and piezo-resistors, pockets that have been processed into a concave shape are continuously used according to the shape of the electronic components. A specially provided carrier tape is widely used. After the electronic components are stored in the concave pocket of the carrier tape, a heat-sealable cover tape is used to prevent the electronic components from falling during transport and to prevent contamination of the electronic components until they are provided to the mounting process. Used to seal the concave pocket. Therefore, many cover tapes have been conventionally proposed.

  In Patent Document 1, the cover tape does not peel off or curl due to the heat shrinkage of the base film even after the baking process, and the storage component adheres to the cover tape or is stained, In addition, the peel strength does not increase significantly, and the sealing speed of the cover tape can be increased faster than before. In addition, as a heat-resistant cover tape with extremely small variations in peel strength, it is adhesive at room temperature on one side of the transparent base film. A heat-resistant cover tape is disclosed in which a resin layer is formed, and a transparent mask film wider than the width of the cavity and narrower than the width of the transparent base film is attached to the surface of the adhesive resin layer. In addition, in order to give the heat resistant cover tape antistatic properties, there is provided a heat resistant cover tape provided with an antistatic film by coating the surface of the transparent base film and the transparent mask film with a transparent antistatic agent or a transparent conductive paint. It is disclosed.

  However, in the heat-resistant cover tape described in Patent Document 1, since the antistatic film is provided in a bare state on the surfaces of the transparent base film and the transparent mask film, the peeled antistatic film is dusted or the like. There is a risk of adhering to electronic components housed in the concave pocket portion of the carrier tape as contaminants or contaminants. In addition, the transparent antistatic agent or the transparent conductive paint used when the antistatic film is provided may come into contact with the electronic component, and the electronic component may be corroded. Therefore, in the heat-resistant cover tape provided with the antistatic film described in Patent Document 1, it is necessary to protect the electronic component from the antistatic film. However, in this document, there is a specific example for solving such a problem. No means are described or suggested.

JP-A-5-51053

  The present invention has been made on the basis of the above circumstances, and the problem to be solved is that the peeled antistatic film is stored in the concave pocket portion of the carrier tape as contaminants and contaminants such as dust generation. Cover tape that prevents the electronic parts from being corroded by contact with the transparent antistatic agent or transparent conductive paint used when the antistatic film is provided and preventing the electronic parts from adhering to the electronic parts Is to provide.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have provided a topcoat layer on the antistatic layer of the cover tape, so that dust and other contaminants / contaminants generated from the antistatic layer are provided. And the movement of ions generated from the antistatic layer can be suppressed, and the present invention has been completed.

That is, the present invention
1. Ions generated from the antistatic layer in a cover tape in which a pressure-sensitive adhesive layer is formed on the base material 1 and the base material 2 narrower than the base material 1 and the antistatic layer are laminated on the pressure-sensitive adhesive layer. A cover tape, wherein a top coat layer for suppressing movement of the antistatic layer is further laminated on the antistatic layer,
2. 1. The total amount of ions extracted from the cover tape with pure water at 121 ° C. for 24 hours, measured according to an ion chromatography method, is 1 to 20 ng / cm ² . Cover tape as described,
3. The top coat layer is a coating layer of an aqueous coating solution. Or 2. Cover tape as described in the
It is about.

The cover tape of the present invention can prevent foreign matters and contaminants such as dust generated from the antistatic layer by the topcoat layer laminated on the antistatic layer, and the topcoat layer is worn out. Because of its excellent properties, the cover tape is difficult to peel off even when it comes into contact with electronic components.
Since the cover tape of the present invention can suppress the movement of ions generated from the antistatic layer by the topcoat layer laminated on the antistatic layer, the electronic component housed in the concave pocket portion of the carrier tape is Corrosion can be prevented.
Since the cover tape of the present invention has a surface resistance value of 10 ^{6 to} 10 ¹¹ Ω, even if the cover tape comes into contact with the electronic component, the electronic component is hardly damaged by static electricity.
Since the cover tape of the present invention is excellent in transparency, it is possible to check the state of the electronic component stored in the cavity of the carrier tape, such as the storage direction.

  The present invention relates to a cover tape in which a pressure-sensitive adhesive layer is formed on a base material 1 and a base material 2 narrower than the base material 1 and an antistatic layer are laminated on the pressure-sensitive adhesive layer. A cover tape, further comprising a topcoat layer for suppressing movement of ions generated from the antistatic layer.

[Substrate 1]
Although the base material 1 used by this invention is not specifically limited, What is excellent in transparency and smoothness is good, for example, polyester resins, such as a polyethylene terephthalate; Acrylic resins, such as a polymethylmethacrylate; Polypropylene resin; Polycarbonate resin; Examples thereof include films formed from polystyrene resin; polyvinyl chloride resin; polyamide resin; polyimide resin and the like.
The thickness of the film is preferably in the range of 5 to 200 μm, more preferably in the range of 10 to 80 μm.

[Adhesive layer]
Since the pressure-sensitive adhesive layer used in the present invention is required to confirm the state of the electronic component stored in the cavity of the carrier tape as in the case of the base material, the transparency of the cover tape of the present invention is required. If it is not impaired, it will not specifically limit. Examples of the pressure-sensitive adhesive include acrylic pressure-sensitive adhesives, rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and two or more kinds of mixed pressure-sensitive adhesives. Various fillers are used for the purpose of adjusting the adhesive force and improving the heat resistance. Or a curing agent may be added to these pressure-sensitive adhesives.
The thickness of the pressure-sensitive adhesive layer is preferably in the range of 1 to 50 μm, and more preferably in the range of 10 to 40 μm.

[Substrate 2]
The base material 2 used in the present invention is wider than the width of the cavity for housing the electronic component in the carrier tape and narrower than the width of the base material 1 on which the adhesive layer is formed.
In general, the base material 2 is set thinner than the base material 1.
The material of the base material 2 is basically the same as that of the base material 1, that is, it should be excellent in transparency and smoothness. For example, a polyester resin such as polyethylene terephthalate; an acrylic resin such as polymethyl methacrylate; a polypropylene resin A film formed from polycarbonate resin; polystyrene resin; polyvinyl chloride resin; polyamide resin;
The thickness of the film is preferably in the range of 2 to 100 μm, more preferably in the range of 4 to 40 μm.

[Antistatic layer]
The antistatic layer used in the present invention is not particularly limited as long as it is a conductive layer, but a layer having transparency is preferable.
Specific examples of the antistatic layer having transparency include a layer containing a conductive polymer or an ionic surfactant.
As the conductive polymer, for example, known conductive polymers can be used, and specific examples include conductive polymers produced by polymerizing the monomers shown below. For example, pyrrole, N-methylpyrrole, N-ethylpyrrole, N-phenylpyrrole, N-naphthylpyrrole, N-methyl-3-methylpyrrole, N-methyl-3-ethylpyrrole, N-phenyl-3-methylpyrrole N-phenyl-3-ethylpyrrole, 3-methylpyrrole, 3-ethylpyrrole, 3-n-butylpyrrole, 3-methoxypyrrole, 3-ethoxypyrrole, 3-n-propoxypyrrole, 3-n-butoxypyrrole 3-phenylpyrrole, 3-toluylpyrrole, 3-naphthylpyrrole, 3-phenoxypyrrole, 3-methylphenoxypyrrole, 3-aminopyrrole, 3-dimethylaminopyrrole, 3-diethylaminopyrrole, 3-diphenylaminopyrrole, 3 -Methylphenylaminopyrrole and 3-Fe Pyrrole derivatives such as naphthylaminopyrrole; aniline, o-chloroaniline, m-chloroaniline, p-chloroaniline, o-methoxyaniline, m-methoxyaniline, p-methoxyaniline, o-ethoxyaniline, m-ethoxyaniline , Aniline derivatives such as p-ethoxyaniline, o-methylaniline, m-methylaniline and p-methylaniline; thiophene, 3-methylthiophene, 3-n-butylthiophene, 3-n-pentylthiophene, 3-n- Hexylthiophene, 3-n-heptylthiophene, 3-n-octylthiophene, 3-n-nonylthiophene, 3-n-decylthiophene, 3-n-undecylthiophene, 3-n-dodecylthiophene, 3-methoxythiophene , 3-naphthoxythiophene and 3, - thiophene derivatives such as ethylene dioxy thiophene. Among these, Preferably, pyrrole, aniline, thiophene, 3,4-ethylenedioxythiophene, etc. are mentioned, More preferably, pyrrole is mentioned.

When a layer containing a conductive polymer is used as the antistatic layer, it is preferable to use a binder resin in order to improve the adhesion between the substrate 2 and the topcoat layer.
The binder resin is preferably soluble in an organic solvent, and is preferably a thermosetting resin.
In particular, it is preferable to employ a crosslinked type binder resin capable of forming a three-dimensional network structure from the viewpoint of preventing migration of ions from the antistatic layer.
Examples of the binder resin include melamine resin, acrylic resin, urethane resin, polyester resin, epoxy resin, and alkyd resin.
The amount of the binder resin used is in the range of 0.1 to 10 parts by mass with respect to 1 part by mass of the conductive polymer.

As described above, the antistatic layer used in the present invention is preferably a layer containing polypyrrole and at least one binder resin selected from the group consisting of melamine resin, acrylic resin, urethane resin and polyester resin. .
The thickness of the antistatic layer is preferably in the range of 0.02 to 0.5 μm, and more preferably in the range of 0.05 to 0.4 μm.
The antistatic layer can be formed, for example, by applying a coating material containing the conductive polymer and the binder resin on the substrate 2 and heating and drying as necessary.
Examples of the solvent that can be used for the paint include organic solvents that can disperse the conductive polymer without damaging the conductive polymer, and preferably aromatic hydrocarbons such as benzene, toluene, and xylene. And the like.
Furthermore, it is also possible to add a resin such as a dispersion stabilizer, a thickener, and an ink binder to the paint as necessary.
The coating method of the coating material onto the substrate 2 is not particularly limited, and printing or coating can be performed using, for example, a gravure printing machine, an ink jet printing machine, dipping, a spin coater, a roll coater, or the like.

[Topcoat layer]
The topcoat layer used in the present invention is required to be able to maintain the high conductivity of the antistatic layer and to prevent ion migration from the antistatic layer.
Therefore, as the resin for forming the topcoat layer, it is preferable to employ a cross-linked binder resin that can form a three-dimensional network structure that has a high effect of preventing ion migration from the antistatic layer.
Moreover, as said resin, what is necessary is just to be soluble in a water solvent or an organic solvent, and a thermosetting resin is preferable.
Examples of the resin include melamine resin, acrylic resin, polyester resin, polyvinyl alcohol resin, urethane resin, epoxy resin, alkyd resin, and silicon resin.

The resin for forming the topcoat layer is preferably the same resin as the binder resin contained in the antistatic layer.
By making the resin for forming the topcoat layer and the binder resin contained in the antistatic layer the same resin, the compatibility and bonding between the antistatic layer and the topcoat layer are improved. Can more effectively suppress the movement of ions generated from the antistatic layer.
Specifically, the ions from the antistatic layer are ions that can corrode the copper plate and may be contained in the antistatic layer.
Specific examples of the ions include SO ₃ ⁻ , SO ₄ ²⁻ , COO ⁻ , Cl ^{− and the} like.
The thickness of the top coat layer is preferably in the range of 0.01 to 0.3 μm, and more preferably in the range of 0.05 to 0.2 μm.
If the thickness is less than 0.01 μm, it may be difficult to prevent migration of ions from the antistatic layer, and if the thickness exceeds 0.3 μm, the high conductivity of the antistatic layer may be maintained. It can be difficult.
The surface resistance value of the topcoat layer is usually in the range of 10 ^{6 to} 10 ¹¹ Ω.

The topcoat layer can be formed, for example, by applying an aqueous solution containing a resin for forming the topcoat layer on the antistatic layer and, if necessary, heating and drying.
As described above, it is preferable to employ an aqueous system as the coating liquid for forming the topcoat layer because it has an effect of washing the ionic components of the antistatic layer when the coating liquid is applied.
The method for applying the aqueous solution is not particularly limited, and printing or coating can be performed using, for example, a gravure printer, an inkjet printer, dipping, a spin coater, a roll coater, or the like.

The cover tape of the present invention can be easily manufactured by sticking a base material 2 in which an antistatic layer and a topcoat layer are sequentially laminated on a base material 1 on which an adhesive layer is formed.
The cover tape of the present invention is used by sticking to a carrier tape in which a storage component such as an electronic component is stored in a cavity, but the surface that can come into contact with the storage component is not an antistatic layer but an antistatic layer. Since the top coat layer can maintain the high conductivity of the layer and prevent the migration of ions from the antistatic layer, the antistatic agent peels off and adheres to the storage components as dust and other contaminants and contaminants. In other words, the ionic substance generated from the antistatic layer is prevented from being corroded by contacting the housing component.
Further, since the top coat layer is excellent in wearability, the possibility of peeling off even if the top coat layer itself contacts the storage component is low.

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

<Example 1>
[Preparation of polypyrrole paint]
1.5 mmol of di-2-ethylhexyl sodium sulfosuccinate was dissolved in 50 mL of toluene, and 100 mL of ion-exchanged water was further added, followed by stirring until emulsification was maintained at 20 ° C. To the obtained emulsion, 21.2 mmol of pyrrole monomer was added and stirred for 30 minutes, and then 50 mL (corresponding to 6 mmol) of a 0.12M aqueous ammonium persulfate solution was added dropwise little by little and reacted for 4 hours. After completion of the reaction, the organic phase was recovered and washed several times with ion exchange water to obtain a polypyrrole dispersion (solid content 5%) in which black conductive fine particles were dispersed in toluene.
10 parts by mass of a melamine resin (manufactured by DIC, Super Becamine J820) was mixed with 100 parts by mass of the obtained polypyrrole dispersion to obtain a polypyrrole paint.

[Preparation of topcoat layer forming coating solution]
PVA (manufactured by Kuraray Co., Poval 217) is mixed with an aqueous melamine resin (manufactured by DIC, Watersol S-695) so that the solid content ratio is 1: 1, and a coating solution for forming a topcoat layer is prepared. Obtained.

[Preparation of antistatic layer (4)]
The obtained polypyrrole-based paint was coated on one side of a substrate (3): PET film (thickness 12 μm, width 11 mm) with a bar coater # 4, dried at 100 ° C. for 1 minute, and 0. A 2 μm antistatic layer was obtained.

[Preparation of Topcoat Layer (5)]
The obtained topcoat layer-forming coating solution was coated on the antistatic layer (4) with a bar coater # 4, dried at 100 ° C. for 1 minute, and a 0.1 μm topcoat layer Got.

[Manufacture of cover tape]
First, a pressure-sensitive adhesive made of an acrylic resin is used as a base material (1): PET film (thickness 25 μm,
It was coated with an applicator on one side having a width of 13 mm and dried under conditions of 100 ° C. for 5 minutes to obtain an adhesive layer (2) having a thickness of 5 μm and a width of 13 mm.
Subsequently, the film of 11 mm width composed of the base material (3) / antistatic layer (4) / topcoat layer (5) is laminated while being positioned so as to be in the center of the adhesive layer (2) having a width of 13 mm. A cover tape was obtained by sticking using

< Reference Example 2>
A cover tape was obtained in the same manner as in Example 1 except that an acrylic resin (manufactured by DIC, Burnock WE-304) was used as the top coat layer.

< Reference Example 3>
A cover tape was obtained in the same manner as in Example 1, except that a polyester resin (Plus Coat Z-565, manufactured by Kyoyo Chemical Co., Ltd.) was used as the top coat layer.

<Comparative Example 1>
A cover tape was obtained in the same manner as in Example 1 except that the top coat layer was not provided.

For the cover tapes of Example 1, Reference Example 2, Reference Example 3 and Comparative Example 1, the surface resistance value, transparency, wear resistance, ion extraction amount, and copper plate corrosivity were evaluated. The results are shown in Table 1.
Each characteristic was tested and evaluated as follows.

[Surface resistance (Ω)]
For the cover tapes of Example 1, Reference Example 2 and Reference Example 3 using a Hiresta manufactured by Mitsubishi Chemical Corporation, the surface resistance value on the topcoat layer (5) was measured, and the cover tape of Comparative Example 1 Measured the surface resistance value on the antistatic layer (4).

[transparency]
Based on JIS K 7105, it measured with the haze meter.
○: The transmittance is 50% or more.
X: The transmittance is less than 50%.

[Abrasion]
Put a ceramic piece that assumes storage parts (electronic parts) into a carrier tape with cavities (recesses), seal the opening with cover tape, apply vibration shock, and visually observe the surface condition of the cover tape did.
○: The antistatic layer of the cover tape is not dropped.
X: A part of the antistatic layer of the cover tape was peeled off.

[Ion extraction amount]
The obtained cover tape was cut to 1 g to prepare a sample. Then, this sample was put in a clean Teflon (registered trademark) pressure vessel, poured with 20 mL of pure water and sealed, and heated and extracted at 121 ° C. for 24 hours. After cooling to room temperature, the ions of SO ₃ ⁻ and SO ₄ ²⁻ eluted in pure water were quantified by ion chromatography.

[Copper plate corrosion]
For Example 1, Reference Example 2 and Reference Example 3, the topcoat layer (5) and the copper plate were bonded, and for Comparative Example 1, the antistatic layer (4) and the copper plate were bonded to each other at 70 ° C., 95% RH, 5 After the lapse of days, it was visually observed.
○: No discoloration.
×: Discolored.

Since the cover tape of the present invention can suppress the movement of ions generated from the antistatic layer by laminating the topcoat layer on the antistatic layer, it is possible to prevent corrosion of electronic components. Is clear (Example 1, Reference Example 2 and Reference Example 3).
Moreover, it is clear that the cover tape of this invention is excellent in abrasion property and transparency (
Example 1, Reference Example 2 and Reference Example 3).
On the other hand, in the cover tape in which the topcoat layer is not laminated on the antistatic layer, the movement of ions generated from the antistatic layer cannot be suppressed, so that the corrosion of the copper plate could not be prevented ( Comparative Example 1).

Claims (2)

Ions generated from the antistatic layer in a cover tape in which a pressure-sensitive adhesive layer is formed on the base material 1 and the base material 2 narrower than the base material 1 and the antistatic layer are laminated on the pressure-sensitive adhesive layer. A top coat layer that suppresses movement of the antistatic layer is further laminated on the antistatic layer, and the top coat layer has a thickness of 0.01 to 0.3 μm and a binder resin for forming the top coat layer is three-dimensional. A cover tape comprising a cross-linked melamine resin capable of forming a network structure and the antistatic layer using a melamine resin as a binder resin . The cover tape according to claim 1, wherein the total amount of ions extracted from the cover tape with pure water at 121 ° C for 24 hours, measured according to an ion chromatography method, is 1 to 20 ng / cm ² .