JP2004115094A - Cover tape for packaging electronic part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cover tape capable of preventing an electrostatic trouble, particularly an electrostatic trouble even under low humidity circumstances showing 12% of relative humidity. <P>SOLUTION: The cover tape can be heat-sealed to a plastic-made carrier tape having continuously formed housing pockets each housing an electronic part wherein the cover tape comprises at least 3 layers of a heat seal material layer (layer B), a base material layer (layer A) and a surface layer (layer C). The layer C is made of an amino-modified poly(meth)acrylic acid-poly(meth)acrylic acid copolymer and surface resistivity of the layer C kept under 50% relative humidity at 23 °C for 24 hours is not more than 1×10<SP>12</SP>Ω/surface area. <P>COPYRIGHT: (C)2004,JPO

Description

【００１４】
表１中の記号は以下の通りである。
ＰＥＴ　　：ポリエチレンテレフタレート
ＰＰ　　　：ポリプロピレン
Ｎｙ　　　：ナイロン
ＰＣ　　　：ポリカーボネート
Ｏ−　　　：二軸延伸の意味。
ＬＤＰＥ　：低密度ポリエチレン
ＭＬＤＰＥ：メタロセン系触媒を使用して合成した低密度ポリエチレン
ＥＶＡ　　：エチレン−酢酸ビニル共重合体
ＥＥＡ　　：エチレン−エチルアクリレート共重合体
ＥＭＭＡ　：エチレン−メチルメタクリレート共重合体
ＩＯＮ　　：アイオノマー
【００１５】
【発明の効果】
本発明に従うと、実装工程における静電気トラブルを防止し更に、相対湿度１２％といった低湿度の環境下においても該静電気トラブルを防止できる。
全光線透過率が８０％以上、曇度が７０％以下になる様、積層されている為、電子部品包装後の内容物の確認が容易になる。
【図面の簡単な説明】
【図１】本発明のカバーテープの層構成を示す断面図である。
【図２】本発明の実施例にあげたカバーテープの層構成を示す断面図である。
【図３】本発明のカバーテープをキャリアテープに接着し、その使用状態を示す断面図である。
【符号の説明】
１：カバーテープ
２：層Ａ
３：層Ｂ
４：層Ｄ
５：ポリウレタン系接着剤層
６：シールされる部分
７：キャリアテープ
８：層Ｃ[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a plastic carrier in which a storage pocket is formed in a package having a function of protecting electronic components from contamination, aligning and mounting the electronic components on an electronic circuit board when storing, transporting, and mounting the electronic components. The present invention relates to a cover tape that can be sealed to a tape.
[0002]
[Prior art]
In recent years, electronic components for surface mounting, such as ICs, transistors, diodes, capacitors, piezoelectric element registers, etc., are made of plastic in which embossed pockets that can be accommodated are continuously formed according to the shape of the electronic components. It is supplied by being packaged in a package consisting of a carrier tape and a cover tape that can be sealed to the carrier tape. After peeling off the cover tape of the package, the electronic components of the contents are automatically taken out and surface-mounted on the electronic circuit board.
The carrier tape in which the electronic components are wrapped is usually wound on a paper or plastic reel, and the state is maintained until the mounting process.
At the time of mounting, the reel is stored in a feeder cassette provided in the mounting machine, but the feeder cassette is moved to a predetermined position before the cover tape is peeled off from the carrier tape. Repeated movements, that is, static electricity generated by friction accumulates on the surface of the reel and the cover tape, and when the cover tape is peeled off, the static electricity flows into the electronic components as contents, causing a trouble that an internal circuit is broken. .
The trouble is unlikely to occur in an environment where the relative humidity is controlled to 60% or more, but is very high in a dry environment of 50% or less and a dry environment of 12% or less. Patent Literatures 1 to 3 describe that a surfactant is added to a cover tape in order to cope with such a phenomenon. However, when the cover tape is stored for several days, the surfactant layer is peeled off. In some cases, the surface resistivity may be 1 × 10 ¹² Ω / □ or more, and the fundamental solution has not been reached.
[0003]
[Patent Document 1]
Japanese Patent Application Laid-Open No. 10-17015 [Patent Document 2]
JP 2000-128117 A [Patent Document 3]
Japanese Patent Application Laid-Open No. 2000-142786
[Problems to be solved by the invention]
The present invention provides a cover tape that can prevent the above-described electrostatic trouble and can prevent the electrostatic trouble even in a low humidity environment such as a relative humidity of 12%.
[0005]
[Means for Solving the Problems]
The present invention relates to [1] a cover tape that can be heat-sealed to a plastic carrier tape in which storage pockets for housing electronic components are continuously formed, wherein the cover tape is at least heat-sealed from the side that is heat-sealed to the carrier tape. It comprises three layers: a sealing material layer (hereinafter abbreviated as layer B), a base material layer (hereinafter abbreviated as layer A), and a surface layer (hereinafter abbreviated as layer C). The layer C is composed of a (meth) acrylic acid-poly (meth) acrylic acid copolymer, and has a surface resistivity of 1 × 10 ¹² Ω / □ or less after being left at 23 ° C. and 50% RH for 24 hours. Electronic parts packaging cover tape,
[2] The cover tape for packaging electronic components according to [1], wherein the layer C has a surface resistivity of 1 × 10 ¹² Ω / □ or less after being left at 23 ° C. and 12% RH for 24 hours.
[3] One or more layers selected from the group consisting of a polyester layer, a nylon layer, a polypropylene layer, a polyethylene layer, and an ethylene copolymer layer (hereinafter abbreviated as layer D) between layer A and layer B. 3. The cover tape for packaging electronic parts according to claim 1, wherein the cover tape is laminated.
(4) The main component of the layer B is an ethylene copolymer, and the copolymer component is one selected from the group consisting of vinyl acetate, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester and ionomer. (1) The cover tape for packaging electronic components according to any one of (1) to (3),
(5) The cover tape for packaging electronic parts according to any one of (1) to (4), wherein the total light transmittance is 80% or more and the haze is 70% or less.
It is.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
One example of the components of the cover tape 1 of the present invention will be described with reference to FIG. It is preferable that the layer A is a base material layer and is a transparent and highly rigid film having a thickness of 6 to 100 μm. As the thermoplastic resin used for the layer A, a thermoplastic resin having a deflection temperature under load (ASTM D-648) of 60 ° C. or more at a load of 1.82 MPa, such as polycarbonate, polyether sulfone, polyether imide, polyimide, nylon or polyester, is used. Preferably it is.
To increase the mechanical strength of the cover tape, two or more films may be laminated.
[0007]
The layer B is not particularly limited as long as it is a resin that can be heat-sealed to the corresponding carrier tape and always obtains a stable peel strength. After the heat-sealing with the carrier tape, the peel strength when the cover tape is peeled from the carrier tape is removed. In order to make the difference between the maximum value and the minimum value 0.01 to 0.4 N per 1 mm width, the main component of the layer B is an ethylene copolymer, and the copolymer component is vinyl acetate, acrylic acid, acrylate, Methacrylic acid, one selected from the group consisting of methacrylic acid esters and ionomers, wherein the subcomponent of layer B is polystyrene, styrene-methacrylic acid ester copolymer, styrene-butadiene copolymer, styrene-hydrogenated butadiene copolymer. Thermoplastic resin which is a polymer, styrene-isoprene copolymer, styrene-hydrogenated isoprene copolymer, polyethylene It is preferably a mixture of.
A polyester layer, a nylon layer or a polypropylene layer may be provided between layer A and layer B to increase the mechanical strength of the substrate, and between layer A and layer B to increase the adhesion strength with the substrate. A polyethylene layer and a polyethylene copolymer layer may be provided. In the present invention, these layers are referred to as layer D. Further, a polyurethane-based adhesive layer or an epoxy-based adhesive layer may be provided between the layers A and B or between the layers A and D.
[0008]
The layer C, which is a surface layer disposed on the surface of the layer A, is composed of an amino-modified poly (meth) acrylic acid-poly (meth) acrylic acid copolymer. Examples of the amino-modified poly (meth) acrylic acid-poly (meth) acrylic acid copolymer include amino-modified polymethyl methacrylate butyl methacrylate copolymer, amino-modified polymethyl methacrylate hexyl methacrylate copolymer, and amino-modified polymethyl acrylate Examples thereof include butyl methacrylate copolymer and amino-modified polymethyl acrylate hexyl methacrylate copolymer. The surface resistivity of the surface of the layer C is, 23 ° C., and a 1 × ^{10 12} Ω / □ or less at 24 hours after standing in RH 50%, 23 ℃, 1 × 10 12 even 24 hours after standing in 12% RH It is preferably Ω / □ or less.
[0009]
The cover tape of the present invention prevents troubles such as the electronic components to be packaged being destroyed by static electricity and the electronic components being small in size and being attached to the cover tape by static electricity when the cover tape is peeled off during the mounting process. For this purpose, the layer B may be subjected to an antistatic treatment.
Typical antistatic formulations include a method of mixing an antistatic agent in layer B and a method of providing an antistatic layer on the surface.
Examples of the antistatic agent used as these antistatic formulations include a conductive fine powder and / or a surfactant and / or an amino-modified polyacrylic acid or polymethacrylic acid copolymer described in the claims of the present invention. . Examples of the conductive fine powder include tin oxide, zinc oxide, titanium oxide, and carbon black. The effect can be obtained by using these alone, but they can be used in combination of two or more. Further, a surfactant may be added to these. Further, the surfactant may be used alone.
[0010]
The cover tape must be laminated so that the total light transmittance is 80% or more and the haze is 70% or less. When the total light transmittance is less than 80% and the haze is 70% or more, it becomes difficult to inspect whether the contents are correctly inserted after packaging the electronic component with a cover tape, depending on the inspector.
[0011]
【Example】
Examples of the present invention are shown below, but the present invention is not limited by these examples.
<< Examples 1-4 and Comparative Examples 1-3 >>
The first layer (= corresponding to the layer C of the present invention) shown in Table 1 is provided on the surface of the second layer (= corresponding to the layer A of the present invention) by gravure coating so as to have a thickness of 1 μm. On the opposite side, a polyurethane adhesive layer, a third layer (= corresponding to layer D of the present invention) and a fourth layer (= corresponding to layer B of the present invention) were provided by an extrusion lamination method, and shown in FIG. A layered cover tape was obtained. The polyurethane-based adhesive layer is provided to increase the adhesive strength between the second layer and the third layer.
The thickness of each layer was 12 μm for the second layer, 1 μm for the polyurethane adhesive layer, 15 μm for the third layer, and 10 μm for the fourth layer.
[0012]
The surface resistivity was measured according to JIS K6911, and the total light transmittance and the haze were measured according to JIS K7105.
The surface resistivity of the layer C was measured after leaving the sample in a room at room temperature of 23 ° C. and relative humidity of 50% in the state of a cover tape for 24 hours. Then, the sample was left in a room at a room temperature of 23 ° C. and a relative humidity of 12% for 24 hours, and the surface of the layer C was measured again.
Next, after the sample was left in a room at room temperature of 60 ° C. and a relative humidity of 10% or less for 24 hours, and further left in a room at room temperature of 23 ° C. and a relative humidity of 50% for 24 hours, the surface of the layer C was measured. , “After storage” are shown in Table 1.
[0013]
[Table 1]

[0014]
The symbols in Table 1 are as follows.
PET: Polyethylene terephthalate PP: Polypropylene Ny: Nylon PC: Polycarbonate O-: Meaning of biaxial stretching.
LDPE: low-density polyethylene MLDPE: low-density polyethylene EVA synthesized using a metallocene-based catalyst EVA: ethylene-vinyl acetate copolymer EEA: ethylene-ethyl acrylate copolymer EMMA: ethylene-methyl methacrylate copolymer ION: ionomer [ 0015
【The invention's effect】
According to the present invention, it is possible to prevent an electrostatic trouble in a mounting process and further to prevent the electrostatic trouble even in a low humidity environment such as a relative humidity of 12%.
Since the layers are laminated so that the total light transmittance is 80% or more and the haze is 70% or less, it is easy to confirm the contents after packaging the electronic parts.
[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 sectional view showing a layer structure of a cover tape according to an embodiment of the present invention.
FIG. 3 is a cross-sectional view showing a state in which the cover tape of the present invention is adhered to a carrier tape and used.
[Explanation of symbols]
1: Cover tape 2: Layer A
3: Layer B
4: Layer D
5: Polyurethane adhesive layer 6: Sealed part 7: Carrier tape 8: Layer C

Claims (5)

A cover tape that can be heat-sealed to a plastic carrier tape in which storage pockets for housing electronic components are continuously formed, wherein the cover tape is at least a heat-sealing material layer (hereinafter, referred to as a heat-sealing material layer from the side that is heat-sealed to the carrier tape. Layer B), a base layer (hereinafter abbreviated as Layer A) and a surface layer (hereinafter abbreviated as Layer C), and Layer C is amino-modified poly (meth) acrylic acid-poly. A cover for electronic parts packaging, comprising a (meth) acrylic acid copolymer, wherein the layer C has a surface resistivity of 1 × 10 ¹² Ω / □ or less after standing at 23 ° C. and 50% RH for 24 hours. tape. The cover tape for packaging electronic parts according to claim 1, wherein the surface resistivity of the layer C after being left at 23 ° C and 12% RH for 24 hours is 1 × 10 ¹² Ω / □ or less. One or more layers (hereinafter abbreviated as layer D) selected from the group consisting of a polyester layer, a nylon layer, a polypropylene layer, a polyethylene layer, and an ethylene copolymer layer are laminated between the layer A and the layer B. The cover tape for packaging electronic parts according to claim 1 or 2, which is formed. The main component of the layer B is an ethylene copolymer, and the copolymer component is one selected from the group consisting of vinyl acetate, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, and ionomer. 4. The cover tape for packaging electronic parts according to 2, 3 or 4. The cover tape for packaging electronic parts according to any one of claims 1 to 4, wherein the total light transmittance is 80% or more and the haze is 70% or less.

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