JPH0986589A - Electrically conductive carrier tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep peeling strength of a top tape to a carrier tape const. and to prevent a part from being stained by providing an electrically conductive layer with a specified compounding ratio of a synthetic resin binder, an electrically conductive carbon black and a synthetic resin bead at least on the face of the storing side of an electronic part of a thermoplastic synthetic resin base material. SOLUTION: An electrically conductive layer 5 prepd. by compounding 10-50 pts.wt. electrically conductive carbon black and 10-20 pts.wt. synthetic resin bead to 100 pts.wt. synthetic resin binder is provided at least on the face of the storing side of an electronic part of a thermoplastic synthetic resin base material for an electrically conductive carrier tape 1 for storing electronic parts. When a top tape 6 is heat-sealed on the face of the carrier tape 1 through this electrically conductive layer 5, even if there exists a little fluctuation on the seal condition of a heat seal machine, peeling strength of the top tape 6 to the carrier tape 1 is always kept const. without fluctuation and mounting of electronic parts can be efficiently performed and the electronic parts can be prevented from being stained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive carrier tape useful for accommodating and transporting and storing a large number of electronic parts.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a carrier tape a in which electronic parts are housed is heat-sealed with a top tape d having an adhesive layer c on the surface of a flange portion b, and a reel (not shown). The tape was peeled off and the electronic component was taken out at the time of mounting after the tape was wound up in (1) and transported and stored, but in order to efficiently carry out the work while keeping the peeled state constant. It was necessary to maintain the sealed condition by adjusting the temperature and pressure of the heat sealing machine. Further, since the carrier tape is usually wound on a reel, it tends to have a curling tendency, loses the flatness of the flange portion of the carrier tape, and has a peel strength from the top tape at the flange portion between the electronic component storage portions. The variation of the peeling strength was increased such that the peeling strength decreased and periodic pulsation of the peeling strength occurred. For these reasons, it is difficult to maintain and manage the peel strength, and this variation causes the top tape to break when electronic components are taken out from the carrier tape and mounted, often requiring the mounting machine to be stopped. It was On the other hand, in a carrier tape that houses electronic components, a method of applying a conductive coating material to the surface of a synthetic resin base material has been used in order to protect the electronic components from contamination due to adhesion of dust and the like due to electrification.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to separate a top tape from a conductive carrier tape (hereinafter simply referred to as a carrier tape) even if the sealing conditions of a heat sealing machine are slightly changed. It is an object of the present invention to provide a carrier tape which can keep the strength constant without any variation, can efficiently mount electronic parts, and can prevent the electronic parts from being contaminated.

[0004]

In order to solve the above-mentioned problems, the present inventor sets the peel strength of the conductive layer to the carrier tape to 10 to 50 g / mm width and heat seals the carrier tape and the top tape. Even if there are some fluctuations in the conditions, when peeling the top tape from the carrier tape,
Focusing on the fact that the adhesive layer is transferred from the carrier tape to the top tape side so that both tapes are smoothly peeled off, and as a result of earnest research on the conditions for obtaining this peeling strength and conductivity, the present invention has been reached. It is a thing. That is, the present invention is, as a carrier tape for storing electronic components, a conductive carbon black (hereinafter, simply referred to as 100 parts by weight of the synthetic resin binder on the surface of the thermoplastic synthetic resin base material on which at least the electronic components are stored. Carbon black) 10
The present invention is characterized in that a conductive layer formed by mixing ˜50 parts by weight and 10˜20 parts by weight of synthetic resin beads is provided. Further, the peel strength of the conductive layer to the thermoplastic synthetic resin substrate is 10 ~ 50 g / mm width, after heat sealing the top tape to the thermoplastic synthetic resin substrate through this conductive layer, both It is preferable that the conductive tape is a carrier tape which is transferred to the top tape when peeled off.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A carrier tape of the present invention will be described below with reference to FIG. FIG. 1A is a vertical cross-sectional view showing a state in which the top tape is peeled off from the carrier tape of the present invention, and FIG. 1B is a perspective view of FIG. 1A. In the figure, 1 is a carrier tape for storing electronic components, which is obtained by slitting a thermoplastic synthetic resin base material to a predetermined width and then embossing the same. It has a continuous structure. Reference numeral 4 is a feed hole for winding the carrier tape on a reel (not shown). Reference numeral 5 denotes a conductive layer which is coated / formed in advance on at least a surface of the base material made of a thermoplastic synthetic resin for the carrier tape 1 on which electronic parts are stored, and 6 denotes the carrier tape 1.
Similarly to the above, the top tape is provided with an adhesive layer 7 obtained by slitting a thermoplastic synthetic resin substrate into a predetermined width.
Reference numeral 8 is a seal mark when the top tape 6 is heat-sealed to the surface of the carrier tape 1 through the conductive layer 5. The conductive layer 5 shows that only this portion is heated and melted and fused to the top tape 6. There is. Further, the conductive layer 5 in the peeled portion in the figure shows that only this fused portion was transferred to the top tape 6, and 9 is a trace thereof.

The thermoplastic synthetic resin base material used for forming the carrier tape 1 and the top tape 6 is made of a thermoplastic synthetic resin such as polyvinyl chloride, A (amorphous) -PET, ABS or polycarbonate. Sheet or film is used. The conductive layer 5 is prepared by diluting a composition obtained by adding and mixing 100 to 50 parts by weight of a synthetic resin binder, 10 to 50 parts by weight of carbon black and 10 to 20 parts by weight of synthetic resin beads to an organic solvent and applying a gravure coating method or the like. , Thermoplastic synthetic resin substrate surface with dry thickness 1-10
It is coated and formed to a thickness of μm. An acrylic resin, a polyester resin, or the like is used as the synthetic resin binder. The amount of carbon black added is the amount required to make the surface specific resistance of the conductive layer 5 10 ⁴ to 10 ¹⁰ Ω.
Synthetic resin beads are added as a dispersant for carbon black, and silicone beads and polyethylene beads are preferable, and the peel strength of the conductive layer 5 from the base material surface is set to 10 to 50 g / mm width by the above-mentioned addition amount. You can
If the amount added is less than 10 parts by weight, the peel strength will be too strong, and if it exceeds 20 parts by weight, the peel strength will be too weak, and the conductive film will be rubbed during carrier tape molding or when storing chip type electronic components. Easy to peel off. The particle size of the synthetic resin beads is 1 to 20 μm, especially 4 to 7 μm.
Is preferred.

The carrier tape for accommodating electronic parts according to the present invention has a conductive layer having a surface resistivity of 10 ⁴ to 10 ¹⁰ Ω on at least the surface of the thermoplastic synthetic resin base on which the electronic parts are accommodated.
Since it is formed with a peel strength of 10 to 50 g / mm width, when the top tape is heat-sealed on the carrier tape surface via this conductive layer and then the top tape is peeled off, the heat-sealed part of the top tape side Since the conductive layer is in a transferred state, there is no variation and stable peel strength, and the presence of the conductive layer does not cause contamination due to charging.

[0008]

EXAMPLES Specific embodiments of the present invention will be described below with reference to Examples and Comparative Examples. Examples 1-2. 0.3mm thick A-PET resin sheet is used as the base material, and acrylic resin binder is applied on both sides.
100 parts by weight of carbon black 25 parts by weight and an average particle size of 5μ
m silicone or polyethylene beads 15
By coating and forming a conductive layer having a thickness of 2 to 3 μm with the gravure coating method, two types of conductive compositions mixed with 1 part by weight were obtained, and the surface specific resistance was 10 ⁶ Ω, and the base material surface and the conductive layer were formed. Two types of sheets having a peel strength of 25 to 30 g / mm width were obtained. After slitting these two types of sheets to a width of 24 mm, a carrier tape was formed by embossing. The top tape provided with the EVA adhesive layer was heat-sealed (the width of the sealing trowel was 0.6 mm on one side, 1.2 mm in total), and then the top tape was peeled off, and the top tape was heat-sealed. Peeling was performed with the conductive layer on the part transferred, and the peel strength at this time was measured.
It was stable at g / mm width.

Comparative Examples 1-4. 0.3 mm thick as a base material
-Using a PET resin sheet, a conductive composition in which 100 parts by weight of an acrylic resin binder and the amount of carbon black shown in Table 1 and silicone beads having an average particle size of 5 µm are mixed on both sides of the sheet are gravure coated. To form a conductive layer having a thickness of 2 to 3 μm, and the surface specific resistance thereof was measured. This was slit in the same manner as in the example and then embossed to obtain a carrier tape. The same top tape was heat-sealed and then peeled off, and the peeling strength between the substrate surface and the conductive layer (in the table, peeling strength) was measured and the transfer state of the conductive layer was observed. Table 1 shows the above results.

[0010]

[Table 1]

[0011]

According to the carrier tape of the present invention, it is easy to manage the conditions when the top tape is heat-sealed, the peel strength of the flange portion between the electronic component accommodating portions of the carrier tape decreases, and the carrier tape pulsates periodically. It becomes possible to always have a stable peel strength and prevent contamination of electronic parts.

[Brief description of drawings]

FIG. 1 shows a state in which a top tape is peeled off from a carrier tape of the present invention, (a) is a longitudinal sectional view and (b) is a perspective view.

FIG. 2 is a vertical cross-sectional view showing a state in which a top tape is peeled from a conventional carrier tape.

[Explanation of symbols]

1, a ... Carrier tape, 2 ... Electronic component storage section, 3, b ... Flange section, 4 ...
Feed holes, 5 ... Conductive layer, 6, d ... Top tape, 7, c ... Adhesive layer, 8
… Trace of heat seal, 9… Trace of transferred conductive layer.

Claims (2)

[Claims] 1. A conductive carrier tape for accommodating electronic parts, wherein at least a surface of a base material made of a thermoplastic synthetic resin for accommodating electronic parts has 100 parts by weight of a synthetic resin binder and 10 to 50 parts of conductive carbon black. A conductive carrier tape comprising a conductive layer formed by mixing 10 parts by weight with 10 parts by weight of synthetic resin beads. 2. The peel strength of the conductive layer from the thermoplastic synthetic resin base material is 10 to 50 g / mm width, and after the top tape is heat-sealed to the thermoplastic synthetic resin base material via the conductive layer, The conductive carrier tape according to claim 1, wherein the conductive layer is transferred to the top tape when both are peeled off.