JP2002337975A - Electronic component packaging cover tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent cover tape which prevents troubles in mounting such as jumping when mounting, an electronic component coming out during transportation due to a change with time in peeling resistance, a cover tape which cannot be peeled smoothly or broken at mounting, and which has appropriate peeling resistance. SOLUTION: The electronic component packaging cover tape 1 can be heat- sealed to a plastic carrier tape formed with a continuum of storage pockets for housing electronic components. The cover tape comprises a film (referred to as a base layer hereafter) either of a polyester or a nylon and an adhesive layer 4 made of a thermoplastic resin. The adhesive layer comprises two or more kinds of ethylene-α olefin copolymers different in weight ratio of the ethylene and α olefin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the storage of electronic components,
A package having a function of protecting electronic components from contamination during transportation and mounting, aligning and mounting for mounting on an electronic circuit board, and a cover tape which can be sealed with a plastic carrier tape having a storage pocket formed therein. It is.

[0002]

2. Description of the Related Art Surface mounting electronic components such as ICs, transistors, diodes, capacitors, piezoelectric element registers, etc., continuously form embossed pockets that can be accommodated according to the shape of the electronic components. It is packaged and supplied by a plastic carrier tape and a cover tape that can be sealed to the carrier tape. After the cover tape of the package is peeled off, the electronic components of the contents are automatically taken out and surface-mounted on the electronic circuit board. In recent years, electronic components have become smaller, lighter and thinner. On the other hand, the surface mounting speed is increasing, and the speed at which the cover tape is peeled off from the carrier tape is also increasing. As a result, the pulsation phenomenon that the strength at the time of peeling (hereinafter referred to as peeling strength) becomes stronger or weaker appears remarkably, and the so-called jumping trouble that the packaged electronic component jumps out of the carrier tape increases. are doing. In order to prevent such troubles, the peel strength is often set to a low value in advance. Has also occurred. When the electronic components to be packaged are relatively large, the peel strength is often set in advance to prevent the electronic components from jumping out of the carrier tape during transportation. However, in this case, if the peel strength changes with time and the peel strength becomes too strong, there may be a problem that the cover tape cannot be peeled off smoothly during mounting, the electronic components cannot be taken out, or the cover tape breaks.

[0003]

SUMMARY OF THE INVENTION According to the present invention, the above-mentioned jumping trouble at the time of mounting, the jump of the electronic component at the time of transportation due to the temporal change of the peeling strength, the cover tape at the time of mounting cannot be peeled off smoothly or breaks. Provided is a transparent cover tape which prevents mounting troubles such as accidental mounting and has an appropriate peel strength and is transparent.

[0004]

SUMMARY OF THE INVENTION The present invention is a cover tape which can be heat-sealed to a plastic carrier tape in which storage pockets for storing electronic components are continuously formed, the cover tape being made of polyester, nylon or the like. (Hereinafter, a substrate layer) and an adhesive layer made of a thermoplastic resin, the adhesive layer comprising ethylene and α ·
Two or more types of ethylene-α having different olefin weight ratios
-A cover tape for packaging electronic parts, characterized by being made of an olefin copolymer. Further, in the present invention, the α-olefin is vinyl acetate, acrylic acid, methyl acrylate, ethyl acrylate, methacrylic acid, methyl methacrylate, and an ionomer.
It is a cover tape for packaging electronic parts having a haze of 0% or more and 60% or less.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One example of components of a cover tape 1 of the present invention will be described with reference to FIG. In a first aspect of the present invention,
Although it does not have the antistatic agent layer 2 on the surface of the base material layer 3, it preferably has the antistatic agent layer 2. First
The antistatic agent layer 2, which is a layer, is made of a surfactant, a polypyrrole-based, polyaniline-based, polythiophene-based π-electron conjugated conductive polymer, or tin oxide, indium oxide, zinc oxide, titanium oxide, carbon black, or Si-based. Organic compounds, composed of conductive fillers such as a complex of polyalkylene glycol and perchlorate such as lithium perchlorate, and using a conductive filler doped with antimony or the like to increase antistatic properties Is also good. In the case where the antistatic agent layer 2 is not provided, the above-mentioned antistatic agent or a surfactant such as an alkylammonium salt is previously kneaded into the base material layer to impart antistatic properties.

[0006] The second layer is either a polyester film or a nylon film, but it is preferable to use a stretched film to impart rigidity. The thickness is 6-10
0 μm transparent film.

The third layer is made of a thermoplastic resin, is an adhesive layer 4 having a thickness of 0.5 to 100 μm, and is a transparent layer. In order to increase the bonding strength between the second layer and the third layer, the bonding surface of the second layer may be subjected to corona treatment, or a thermosetting resin layer 5 such as isocyanate may be provided between the layers. FIG. 1A shows a case where a thermosetting resin layer is not provided between the second layer and the third layer,
FIG. 1B shows a case where a thermosetting resin layer 5 is provided between the second layer and the third layer. In addition, a polyolefin layer may be provided between the thermosetting resin layer 5 and the adhesive layer 4 for providing cushioning properties as a film or for cost reduction.

[0008] The adhesive layer 4 is composed of ethylene-α-olefin in which α-olefin is vinyl acetate, acrylic acid, methyl acrylate, ethyl acrylate, methacrylic acid, methyl methacrylate, and ionomer, and the weight ratio of ethylene and α-olefin is different. It consists of a mixture of two or more olefin copolymers. The surface of the adhesive layer may be coated or kneaded with an antistatic agent such as a conductive polymer, a conductive filler, or a surfactant in order to impart antistatic properties. Lamination is performed by extrusion coating, a die coater, or a gravure coater.

The cover tape must be laminated so that the total light transmittance is 70% or more and the haze is 60% or less. If the total light transmittance is less than 70% or the haze is 60% or more, it will be difficult to inspect whether the contents are correctly inserted after packaging the electronic component with a cover tape, depending on the inspector.

[0010]

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited by these examples. The adhesive layer 4 is exemplified by vinyl acetate as an example of α-olefin. However, this is because the other α-olefin described above is very similar to vinyl acetate in properties as an adhesive for a cover tape. To represent. Regarding the base material layer, the peel strength and the transparency, which are listed as characteristics, were unified with polyester since no significant difference was observed even when both polyester and nylon were substituted.

<< Comparative Examples 1 to 3 and Examples 1 and 2
>> An antistatic layer (first layer) on one side of a biaxially stretched polyethylene terephthalate film (second layer) having a thickness of 25 μm
Is laminated by a gravure coating method, and then the other surface of the second layer is coated with a polyurethane-based thermosetting resin. The layers were laminated by a method to obtain a cover tape having a layer configuration shown in FIG. The adhesive layer was prepared by previously mixing a mixture of ethylene-vinyl acetate copolymers having different weight ratios of ethylene and vinyl acetate shown in Table 1 with a twin-screw extruder. Total light transmittance,
The haze was measured according to JIS K7105.

[0012]

[Table 1]

As Comparative Example 4, VA = 10% and VA = 2
An 8% ethylene-vinyl acetate copolymer was mixed to form a mixture ratio of 50:50, and an attempt was made to form a film. Did not reach. Regarding the transparency, the light transmittance varied in the range of 65% to 85% and the haze varied in the range of 20% to 65%, and it was difficult to correctly recognize the characters written on the surface of the electronic component. After slitting the cover tape obtained in Table 1 to a width of 5.5 mm, sealing was performed at 180 ° C. with a carrier tape made of polystyrene having a width of 8 mm, and after sealing, the peel strength was measured 5 minutes later. The initial values are shown. Further, they are stored at room temperature 23 ° C., humidity 50% (hereinafter abbreviated as 23 ° C. × 50% RH), 40 ° C. × 90%, 60%
The values measured for the peel strength after storage at 30 ° C and -15 ° C for 30 days are shown in the corresponding columns in the table.

As shown in Table 2, 40 ° C. × 90% of Comparative Example 1
The measured values after storage at RH, 60 ° C. and 60 ° C. in Comparative Example 2 were observed to have a decrease in peel strength of 10 cN or more compared to the initial value. In Comparative Example 3, the measured values after storage at 60 ° C. and −15 ° C. were higher than the initial value by 30 cN or more in peel strength, and the pulse width was also observed to be 30 cN or more. However, in Examples 1 and 2 obtained by mixing the adhesives used in Comparative Examples 1 to 3, it was confirmed that both the displacement from the initial value and the pulse width were within 10 cN.

[0015]

[Table 2]

[0016]

According to the present invention, it is possible to obtain a transparent cover tape having an appropriate peel strength and to prevent various mounting troubles.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a layer structure of a cover tape of the present invention.

FIG. 2 is a cross-sectional view illustrating a layer configuration of a cover tape manufactured in an example.

[Explanation of symbols]

 1: cover tape 2: antistatic agent layer (first layer) 3: biaxially stretched film (second layer) 4: adhesive layer (third layer) 5: thermosetting resin layer 6: polyethylene layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09J 131/04 C09J 133/02 133/02 133/04 133/04 B65D 85/38 PF term (Reference) 3E067 AA11 AB41 AC04 BA34A BB14A CA11 CA24 EA06 EA13 EA32 FA01 FC01 GD08 3E096 AA06 BA08 CA15 DA17 DB06 DC02 EA02 FA12 FA27 GA07 4F100 AK04B AK41A AK46A AK68B AK70B AL01B AL01B03C02 BA02 BA02 BA02 BA02 BA02 BA02 BA02A AA09 AA10 AB01 CA06 CB03 CC05 CE02 FA04 FA08 FA10 4J040 DA051 DA061 DA071 DE031 DF011 DF031 JA09 JB09 LA10 MA09 MA10 NA06 NA20

Claims (3)

[Claims] 1. A cover tape which can be heat-sealed to a plastic carrier tape in which storage pockets for storing electronic components are continuously formed, wherein the cover tape is made of a film made of either polyester or nylon and heat-sealed. A cover tape for packaging electronic parts, comprising an adhesive layer made of a plastic resin, wherein the adhesive layer is made of two or more ethylene-α-olefin copolymers having different weight ratios of ethylene and α-olefin. . 2. The electronic component packaging according to claim 1, wherein the α-olefin according to claim 1 is any one of vinyl acetate, acrylic acid, methyl acrylate, ethyl acrylate, methacrylic acid, methyl methacrylate, and an ionomer. Cover tape. 3. The cover tape according to claim 1, wherein the cover tape has a total light transmittance of 70% or more and a haze of 60% or less.