JP2003300582A - Cover tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cover tape with good transparency, adhesion and peelability and excellent in resistance to humidity. <P>SOLUTION: The cover tape comprises a base layer 31 made of a polyethylene terephthalate, an intermediate layer 32 made of a low-density polyethylene, an adhesion reinforcing layer 41 stacked thereon formed of a polyurethane based resin with polyethylene wax added and an adhesive layer 42 formed of an acrylic resin with the polyethylene wax added. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cover tape which constitutes a tape-shaped packaging material for packaging chip type electronic components such as semiconductor integrated circuits.

[0002]

2. Description of the Related Art Chip-type electronic components such as semiconductor integrated circuits are stored as a package hermetically wrapped with a packaging material to prevent contamination after the manufacturing process and before being provided in a mounting process. , Will be transported. The packaging of this electronic component, in order to support the mounting process on the board by the automatic mounting device,
A tape-shaped packaging material is used, and the packaging material is composed of a carrier tape in which a plurality of recesses are formed in a long sheet at predetermined intervals, and a cover tape which is heat-sealed to the carrier tape. To be done.

FIG. 1 shows an example of the structure of a tape-shaped packaging material. FIG. 1 is a perspective view showing a packaging process of electronic components,
In the figure, 1 is a cover tape and 2 is a carrier tape, which is composed of a flange portion 3 and a concave portion 4. Reference numeral 5 denotes a sprocket provided on the flange portion of the carrier tape 2, which is used for carrying the carrier tape 2. 6 is a seal part, and 7 is a packaged electronic component. Further, FIG. 2 shows a cross-sectional view taken along the line AB of FIG.

As shown in FIGS. 1 and 2, the manufactured electronic component 7 is housed in a concave portion 4 of a carrier tape 2 and is covered with a cover tape 1, and the cover tape 1 is heated and melted into a rail shape at a flange portion 3. The seal portion 6 is formed by attaching (heat sealing) and fixed. The wrapped package is sequentially wound on a reel, stored and transported in a roll.

When mounting the electronic component 7 packaged with the carrier tape 2 and the cover tape 1 on the substrate as described above, the packaging body wound into a roll is pulled out, and the reverse of the packaging step. Then, while peeling off the cover tape 1 from the carrier tape 2, the electronic component 7 is taken out and provided for mounting.

Usually, as the carrier tape 2, a tape-shaped plastic sheet having a recess 4 formed by embossing is used. In addition, as the cover tape 1, so that the electronic components 7 inside can be visually recognized after packaging,
A transparent plastic sheet laminated with a heat-sensitive adhesive layer is used.

FIG. 3 schematically shows a cross section of a structural example of the cover tape 1. In the figure, 31 is a base material layer, 32 is an intermediate layer,
Reference numeral 33 denotes an adhesive layer, a polyethylene terephthalate (PET) film is used for the base material layer 31, a polyethylene (PE) film is used for the intermediate layer 32, and an ethylene / vinyl acetate copolymer (EVA) or polystyrene is used for the adhesive layer 33. (P
S) is used.

Further, as shown in FIG.
There is proposed a cover tape 1 which has a two-layer structure of an adhesion strengthening layer 41 and an adhesive layer 42 from the base material layer side, and is peeled off between the adhesion strengthening layer 41 and the adhesive layer 42. As a combination of such an adhesion strengthening layer 41 and an adhesive layer 42, for example, a combination of polyester resin and acrylic resin has been proposed.

[0009]

The tape-like packaging material for packaging electronic parts is required to have a sufficient adhesive strength at the seal portion so that the electronic parts after packaging are not contaminated. Therefore, it is also required that the cover tape 1 be smoothly peeled from the carrier tape 2 in the mounting process.

However, in the conventional adhesive layer,
Although the adhesive state was good immediately after heat sealing, when the package was stored under high temperature and high humidity, the adhesive strength was lowered and the seal part 6 was partially peeled in some cases. Therefore, before mounting, the internal electronic component 7 is partially contaminated from the peeled portion, or the adhesive strength of the seal portion 6 becomes uneven, and smooth continuous peeling cannot be performed by the peeling operation in the mounting process. There was a risk of problems.

An object of the present invention is to solve the above-mentioned problems and to provide a cover tape having excellent moisture resistance, and the adhesive strength of the seal portion can be maintained well even under high temperature and high humidity in the package, It is an object of the present invention to provide a cover tape that does not cause a decrease in adhesive strength or partial peeling.

[0012]

SUMMARY OF THE INVENTION A cover tape of the present invention is a cover tape in which a plurality of recesses for accommodating electronic parts are provided in a long sheet at predetermined intervals in the lengthwise direction. A cover tape which is heat-sealed to cover the recess after housing the parts, and is formed by laminating at least a base material layer, an intermediate layer, an adhesion strengthening layer, and an adhesive layer, and the base material layer is made of polyethylene terephthalate. The intermediate layer is made of low density polyethylene, the adhesion-strengthening layer is made of a polyurethane resin containing polyethylene wax, and the adhesive layer is made of an acrylic resin containing polyethylene wax.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 4, a cover tape of the present invention comprises a base material layer 31, an intermediate layer 32, and an adhesion strengthening layer 4.
1, the adhesive layer 42, the base material layer 31 is made of PET, and the intermediate layer 32 is made of low density polyethylene (LDPE). According to the present invention, the adhesion-strengthening layer 41 is formed of a polyurethane-based resin containing polyethylene wax, and the adhesive layer 42 is made of an acrylic-based resin containing polyethylene wax, so that sufficient adhesive strength and good peelability can be obtained. In addition to the above, it is characterized in that it has improved moisture resistance. As a result, the package using the cover tape of the present invention does not cause peeling of the adhesive layer or reduction in peel strength even when stored under high temperature and high humidity.

In the present invention, as the polyurethane resin constituting the adhesion strengthening layer 41, a generally used polyurethane resin adhesive is preferably used. In the present invention, polyethylene wax is added to the polyurethane resin for use. The amount of polyethylene wax added is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the polyurethane resin. A commercially available polyethylene wax is preferably used as the wax, and an oxidized polyethylene wax is particularly preferably used.

In the present invention, the acrylic resin used for the adhesive layer 42 includes an acrylic polymer made of an acrylic monomer such as (meth) acrylic acid or its derivative, or an acrylic polymer and other monomers. Is preferably used. For example, when combined with a polystyrene carrier tape, a styrene-acrylic resin containing styrene as a monomer component is preferably used. In the present invention, polyethylene wax is added to the acrylic resin to be used, and the addition amount of the polyethylene wax is preferably 0. 0 based on 100 parts by weight of the acrylic resin.
It is 1 to 10 parts by weight. A commercially available polyethylene wax is preferably used as the wax, and an oxidized polyethylene wax is particularly preferably used.

The total thickness of the cover tape of the present invention is preferably about 25 to 75 μm, of which the base layer 31 is 9 to 25 μm, the intermediate layer 32 is 15 to 50 μm, and the adhesion strengthening layer 41 is 0.1 to 0.1 μm. 2 μm, the adhesive layer 42 is 0.1 to 3 μm
It is selected in the range of m.

As the method for producing the cover tape of the present invention, the conventional method for producing a cover tape can be applied as it is, and specifically, the extrusion laminating method and the dry laminating method can be mentioned. By forming the intermediate layer by extrusion laminating, a thin intermediate layer can be formed, and the thickness of the entire cover tape can be 50 μm or less. As described above, the cover tape is used by being wound on a reel, but by reducing the total thickness, it is possible to reduce the bulk when wound and to increase the number of windings accordingly.

As the carrier tape used in combination with the cover tape of the present invention, those conventionally used can be used as they are, for example, polystyrene, polypropylene, polyvinyl chloride, polyester, polycarbonate, acrylic resin, etc. It is preferable to use a sheet having a concave portion formed by embossing, but a polystyrene carrier tape is preferably combined in consideration of adhesiveness.

[0019]

[Example] A cover tape having the following layer structure was prepared, and the moisture resistance was evaluated by the evaluation method shown below.

[Layer constitution] Base material layer: "AS-PET" manufactured by Toyobo Co., Ltd. (thickness: 16 µ
m) Intermediate layer (two-layer structure of LDPE having different densities): "L1850K" manufactured by Asahi Kasei (thickness: 15 µm) "PT1450" manufactured by Dow Chemical Japan (thickness: 15)
μm)

Example 1 Adhesion-strengthening layer: Two-component urethane AC agent ["EL-510" manufactured by Toyo Morton Co., Ltd .: "CAT-RT80" = 5: 1 (weight ratio)] 100 parts by weight of polyethylene wax ( 5 parts by weight of an oxidized polyethylene wax "Hi-Flat 8514" manufactured by Gifu Shellac Co., Ltd. was used. Thickness is 1μ
m. Adhesive layer: Methyl methacrylate-butyl methacrylate resin (“SZ1529” manufactured by Nippon Carbide Industry Co., Ltd.) 1
5 parts by weight of the polyethylene wax used for the above-mentioned adhesion-strengthening layer was added to 100 parts by weight. The thickness was 1 μm.

Example 2 Adhesion Strengthening Layer: Same as in Example 1. Adhesive layer: Styrene-acrylic acid ester copolymer ("Newcoat MK-005" manufactured by Shin-Nakamura Chemical Co., Ltd.) 10
5 parts by weight of the polyethylene wax used in Example 1 was added to 0 parts by weight. The thickness was 1 μm.

(Comparative Example 1) Adhesion-strengthening layer: Only the AC agent used in Example 1. Adhesive layer: same as in Example 1.

(Comparative Example 2) Adhesion-strengthening layer: Only the AC agent used in Example 1. Adhesive layer: same as in Example 2.

Comparative Example 3 Adhesion Strengthening Layer: 100 parts by weight of the AC agent used in Example 1,
Silica (Dainippon Ink and Co., Ltd., anti-blocking agent "C-
2 parts by weight of "blocking agent") was added and used. The thickness was 1 μm. Adhesive layer: To 100 parts by weight of the methylmethacrylate-butylmethacrylate resin used in Example 1, 2 parts by weight of the silica used in the adhesion-strengthening layer was added and used. Thickness is 1μ
m.

[Evaluation Method] The cover tape of each example was set to a seal portion: 0.5 mm × 100 mm, and a heating temperature: 150
° C., a pressure: 120 kg / cm ^2, a heat sealing conditions of 0.2 seconds, a polystyrene sheet (Denka Co. "CST
2401 "), and immediately after sealing and at the temperature:
The peel strength was measured after storage in an environment of 50 ° C. and relative humidity: 95% for 168 hours. PALMEC for measurement
"PET-50S" manufactured by the company was used, and the temperature was 23 ° C and the condition was 300 mm / min.

As a result, the haze value was 20% or less immediately after the sealing and the transparency was exhibited, and in Examples 1 and 2 and Comparative Example 3, uniform peeling strength was exhibited in the entire sealing portion.
In Comparative Examples 1 and 2, the peel strength was non-uniform and smooth peeling could not be performed.

After storage at 50 ° C./95%×168 hours, in Examples 1 and 2, as in the case before storage, uniform peel strength was exhibited in the entire seal portion. Further, in Comparative Examples 1 and 2, the peel strength was non-uniform, but there was no change to that extent as compared with before storage. Further, in Comparative Example 3, peeling was observed in 44% of the area within the seal portion.

[0029]

INDUSTRIAL APPLICABILITY The cover tape of the present invention has good transparency, good adhesiveness to a carrier tape and good peelability, and further has excellent moisture resistance, so that it can be used as a package. Even when stored in a high temperature and high humidity environment, since the adhesive strength does not deteriorate, the electronic parts are not contaminated due to partial peeling of the seal portion, and can be smoothly peeled in the mounting process.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a packaging process of electronic components using a tape-shaped packaging material for packaging electronic components.

FIG. 2 is a schematic cross-sectional view of the package shown in FIG.

FIG. 3 is a schematic cross-sectional view showing the layer structure of the cover tape shown in FIG.

FIG. 4 is a schematic sectional view showing the layer structure of the cover tape of the present invention.

[Explanation of symbols]

1 cover tape 2 carrier tape 3 Flange part 4 recess 5 sprockets 6 Heat seal part 7 electronic components 31 base material layer 32 Middle class 33 Adhesive layer 41 Adhesion Strengthening Layer 42 Adhesive layer

Continued front page    (72) Inventor Masahiro Yagi             2102 Hiratsuka, Ageo City, Saitama Prefecture Asahi Kasei Pax Co., Ltd.             Inside the company F-term (reference) 3E067 AA11 AB41 AC18 BA26A                       BB14A BB25A BC07A CA07                       EA04 EA29 EB27 FA01 FC01                       GD06                 3E086 AB02 BA04 BA15 BA24 BB52                       BB71 CA31                 3E096 AA05 AA06 BA08 CA13 CA14                       CA15 CC01 DA04 DA14 EA02X                       EA02Y EA11X EA11Y FA02                       FA09 FA27 FA30 FA31 GA07

Claims (2)

[Claims] 1. A carrier tape having a plurality of recesses for accommodating electronic components on a long sheet at predetermined intervals in the longitudinal direction, after accommodating the electronic components in the recesses, covering the recesses. A heat-sealable cover tape, which is formed by laminating at least a base material layer, an intermediate layer, an adhesion-strengthening layer, and an adhesive layer, the base material layer is made of polyethylene terephthalate, and the intermediate layer is made of low-density polyethylene. A cover tape in which the reinforcing layer is made of a polyurethane resin containing polyethylene wax and the adhesive layer is made of an acrylic resin containing polyethylene wax. 2. The cover tape according to claim 1, wherein the intermediate layer is laminated by extrusion lamination of low density polyethylene.