JP2001354266A - Bottom film for carrier tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bottom film for a carrier tape which solves such a problem that an electronic part adheres to the tape and cannot be taken out. SOLUTION: This relates to a bottom film for a carrier tape for mounting an electronic part using a paper carrier base paper. The film is made of a resin composition mixed with a 0.05-1.0 pts.wt. antistatic agent of a polymeric charge transfer type bonded body relative to a 100 pts.wt. low density polyethylene whose density is 0.930 g/cm3 or less and melt flow index (MFR) (ASTM D-1238, 180 deg.C) is 5 (g/10 min) or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier tape which is widely used for mounting a tape mounter for electronic parts and the like. More specifically, the present invention relates to a method for preventing minute and lightweight electronic parts from remaining on a carrier due to static electricity or the like. The present invention relates to a bottom film for a carrier tape that can provide a carrier tape that can be stably mounted.

[0002]

2. Description of the Related Art For example, an efficient tape mounter has been frequently used for mounting electronic components. That is, the electronic components are set on a carrier tape and supplied. A relatively large electronic component is supplied by molding a space for inserting the electronic component into a continuous plastic film by vacuum molding or the like, and covering the space with a top film by heat sealing or the like. At the time of mounting, the electronic component is taken out by a robot while peeling off the top film, and mounted at a predetermined position on a substrate or the like.

In recent years, as electronic devices have become smaller and lighter,
Electronic components have become smaller and lighter in size. For example,
The size of the multilayer ceramic capacitor is 0.5mm x
It is about 0.5 mm x 1 mm. Carrier tapes for accommodating these small and lightweight electronic components cannot be used in molding plastic films from the viewpoint of accuracy. For this purpose, a space for mounting electronic components and a guide hole for driving a carrier tape are opened in a cardboard (homogeneous paperboard having a basis weight of about 600 g / m ² ; hereinafter, referred to as a paper carrier base paper). Are bonded together by heat sealing. Paper carrier tapes are widely used for micro and lightweight electronic components because of their excellent perforation accuracy and smoothness accuracy on paper carrier base paper.

[0004] However, as electronic components have been further miniaturized and lightened, the number of accidents in which electronic components cannot be removed from the bottom film by a mounting robot has increased, and serious damage has occurred due to line stoppage. It is believed that the cause is adhesion of electronic components to the bottom film due to static electricity, slight adhesion of the bottom film surface, and the like.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional disadvantages and to provide a bottom film to which minute and lightweight electronic components do not adhere.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have formulated a specific amount of a specific antistatic agent into a specific low-density polyethylene, and blended the blend with paper and / or plastic. The present inventors have found that by forming the bottom film by extrusion lamination coating on a film substrate, the small and lightweight electronic component hardly adheres to the bottom film, and the above-mentioned problem can be solved.

That is, the present invention relates to a bottom film for a carrier tape for mounting an electronic component using a paper carrier base paper, having a density of 0.930 g / cm ³ or less and a melt flow index (MFR) (ASTM D-1238,
180 ° C.) was mixed with 0.05 to 1.0 parts by weight of an antistatic agent for the polymer charge transfer type conjugate represented by the following general formula per 100 parts by weight of low-density polyethylene having 5 (g / 10 min) or more. A bottom film for a carrier tape, comprising a resin composition, is contained therein (claim 1).

[0008]

Embedded image

R, R1, R2: alkyl R3: polyethylene oxide P: a positive number of 1 or more

In a preferred embodiment, the bottom film is a carrier tape bottom film according to claim 1, wherein the bottom film is provided on a paper base material.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As a base material on which a bottom film is provided, which is used in the present invention, 20 base materials currently used are used.
A paper having a basis weight of about g / m ² or less, or a biaxially stretched polyethylene terephthalate film having a thickness of about 20 μm or less is used alone or as a laminate with paper after being subjected to anchor treatment or the like. On this base material, a bottom film for heat sealing with a paper carrier base paper is applied and formed by extrusion lamination. Among these substrates, a paper substrate is preferable from the viewpoint of adhesion to the resin composition to be used.

The bottom film layer used in the present invention must be firmly adhered to a substrate made of paper and / or plastic film during extrusion lamination. If the bonding is insufficient, the mounted electronic components may spill out. Further, the heat sealing property with the paper carrier base paper is also important. From this, low-density polyethylene is suitable as the resin for the bottom film used in the present invention. High-density polyethylene is unsuitable because of its low adhesion to thin paper or the like.

The low-density polyethylene is not limited to one composed solely of homopolymerized polyethylene, but may be a blend of two or more kinds of polyethylene. May be blended. However, the density must be 0.930 g / cm ³ or less, and the melt flow index (MFR) (ASTM D-1238, 180 ° C.) must be 5 (g / 10 min) or more. When these conditions are not satisfied, the resin composition of the present invention has insufficient extrusion adhesion to paper or the like as a base material due to the influence of an antistatic agent, and has poor heat sealability to a paper carrier base paper. Inferior. The lower limit of the density of the low-density polyethylene and the upper limit of the melt flow index are not particularly limited.
g / cm ³ and about 30 (g / 10 min).

When the antistatic agent of the present invention is kneaded with an antistatic agent such as glycerin fatty acid ester which is usually used in polyethylene, a thin film of the antistatic agent is formed on the surface of the antistatic agent. Cannot be used because it sticks. Furthermore, at low temperatures and low humidity, there is no antistatic effect, and micro / light-weight electronic components are also adhered by static electricity, and have no effect of preventing defects.

Therefore, the antistatic agent that can be used in the present invention is a polymer charge transfer conjugate represented by the following general formula. In the general formula, R, R1, and R2 are alkyl,
Preferably, alkyl having 8 to 18 carbon atoms is preferable. P is one or more positive numbers. The compounding amount is 0.05 to 1.0 part by weight based on the low density polyethylene.
If the amount is less than 0.05 part by weight, the antistatic effect is small, and the minute and light-weight electronic components are easily attached. On the other hand, if it exceeds 1.0 part by weight, the amount of the sticky substance increases on the surface, and the minute and light-weight electronic components also tend to adhere. In general, low-density polyethylene into which an antistatic agent has been kneaded has reduced adhesion during extrusion lamination to paper or the like. At the same time, the strength of heat sealing to the paper carrier base paper also decreases. From this point as well, the blending amount of the antistatic agent is set within the above range.

[0016]

Embedded image

R, R1, R2: alkyl R3: polyethylene oxide P: a positive number of 1 or more

Hereinafter, the present invention will be described with reference to the drawings showing embodiments of the present invention. However, it goes without saying that the present invention is not limited to this. FIG. 1 is a top view of a paper carrier tape using the bottom film of the present invention. FIG. 2 is a side view of the same. In the figure, 1 is a top film, 2 is a paper carrier (base paper), 3 is a space for mounting components, 4 is a hole for driving and positioning the paper carrier, 5 is a bottom film, and 6 is a base film base material.

Component mounting gap 3 of paper carrier (base paper) 2
The holes 4 for driving and positioning the paper carrier are punched in advance according to the shape of the electronic component to be mounted. Next, after the bottom film 5 is heat-sealed to the paper carrier (base paper) 2, electronic components are mounted in the component mounting gaps 3 of the paper carrier (base paper) 2. The component is enclosed in the gap 3. At the time of mounting, the electronic component is taken out of the gap 3 by a robot while peeling off the top film 1 and mounted at a predetermined position on a substrate or the like.

[0020]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples. In addition, in the following description, a part shows a weight part unless there is particular notice.

Example 1 As an adhesive layer, Mirason M-6 made of low density polyethylene was used.
7 (Mitsui Chemical Co., Ltd., density = 0.926 g / cm ³ , M
FR = 22) A mixture of 100 parts of 0.5 part of Hiboron ASA-400 (Boron International Co., Ltd.) as an antistatic agent for polymer charge transfer conjugate was mixed with an extruder of a laminating machine at a die temperature of 290 ° C. In, basis weight 1
Extrusion lamination at a thickness of 25 μm was performed on a paper substrate of 6 g / m ² to form a bottom film.

The performance required as the bottom film of the paper carrier tape was evaluated by the following method. The results are as shown in Table 1.
The adhesiveness to paper base material, heat sealability to paper carrier base paper, surface resistivity, and adhesion of small and lightweight electronic components were also excellent.

The evaluation method is as follows. Adhesion to paper substrate The bottom film is cut into a 20 mm strip, and the paper substrate and a part of the bottom film are forcibly peeled off. With both ends, the adhesion strength until all the layers were completely peeled was qualitatively evaluated in three steps according to the following criteria. ○ If the above evaluation is obtained, there is no practical problem. A: Strongly adhered, and if peeled off, the interlayer of the paper substrate is broken. ：: Adhesion is strong, and a part of the paper substrate is taken by the adhesive layer. ×: easily peeled off, and the paper substrate was not removed by the adhesive layer.

Heat Sealability to Paper Carrier Base Paper The above bottom film is cut into strips having a width of 15 mm × 150 mm, and the paper carrier base paper and the bottom film surface are combined, and the temperature is 120 ° C. and the pressure is 0.39 M with a heat sealer.
Pa (4 kg / cm ² ), 15 mm × 1 in 0.5 seconds
The area of 0 mm was heat-sealed at three places. The peeling force was measured by a conventional method using a tensile tester (180 ° peeling). The average value of three places is 98mN / 15mm (10g / 15mm)
Above, there is no practical problem.

Surface resistivity The surface resistivity of the bottom film was measured by allowing it to stand at 23 ° C. and 50% RH for 24 hours or more. In addition, the measuring device used Hewlett-Packard company, and the cell used 16008A type. Generally, 10 ¹² Ω or less is required.

Adhesiveness of micro / lightweight electronic parts Multilayer ceramic capacitors (dimensions: 0.5 mm × 0.5 mm × 1.0 mm rectangular parallelepiped) as micro / lightweight electronic parts
And arrange 20 pieces on the bottom film. This is heated in a high temperature bath at 70 ° C. for 10 minutes, cooled to room temperature, and gently turned over. The number of small and lightweight electronic components that did not fall and adhered to the adhesive layer was counted. The average was calculated three times. The smaller the value, the better the bottom film. This is a strict measurement method, and the adhesion is preferably 30% or less.

Examples 2-3 As shown in Table 1, a bottom film was prepared in the same manner as in Example 1 except that the composition was changed. The evaluation results are as shown in Table 1.

Comparative Example 1 A low density polyethylene Mirason M-16P (Mitsui Chemical Co., Ltd., density = 0.92) was placed on the paper base material used in Example 1.
3 g / cm ³ , MFR = 3.7) Only 100 parts were extruded from a laminating machine extruder at a die temperature of 310 ° C. and 25
Extrusion lamination with a thickness of μm produced a bottom film. As shown in Table 1, as shown in Table 1, the adhesion to the paper substrate is very excellent, but the adhesion rate of the small and lightweight electronic components is high.
The surface specific resistance is 10 ¹⁶ Ω, and there is no antistatic performance.

Comparative Examples 2 and 3 Bottom films of Comparative Examples 2 and 3 were prepared in the same manner as in Example 1 except that the composition was changed as shown in Table 1.
In Comparative Example 3, a glycerin fatty acid ester generally used as an antistatic agent for polyethylene was used. As shown in Table 1, two or more items are poor in the adhesion to the paper base material, the heat sealing property to the paper carrier base paper, the surface resistivity, and the adhesion of the micro and lightweight electronic components as shown in Table 1.

[0030]

[Table 1]

[0031]

As described above, the bottom film for a carrier tape of the present invention has good adhesiveness to a paper base material and good heat sealability to a paper carrier base paper, and adheres to minute and lightweight electronic parts. Is also good. Therefore, the bottom film of the present invention can provide a carrier tape free from troubles such as inability to take out electronic components and the like.

[Brief description of the drawings]

FIG. 1 is a top view of a paper carrier tape using a bottom film of the present invention.

FIG. 2 is a side view of FIG.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 top film 2 paper carrier (base paper) 3 gap for mounting components 4 hole for driving / positioning paper carrier 5 bottom film 6 base material for bottom film

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Toshiyasu So 4-13-18 Anritsu, Suminoe-ku, Osaka-shi, Osaka Go-Term Paper Co., Ltd. F-term (reference) 3E067 AA11 AB41 BB01A BB15A BB22A BC07A CA21 EB27 EE32 EE59 FA09 3E086 BA14 BA15 BA35 BB35 CA31

Claims (2)

[Claims] 1. A bottom film for a carrier tape for mounting electronic components using a paper carrier base paper, wherein the bottom film has a density of 0.
930 g / cm ³ or less, melt flow index (M
FR) (ASTM D-1238, 180 ° C) is 5 (g
/ 10 min) or more of low-density polyethylene of 100 parts by weight or more, and a resin composition in which 0.05 to 1.0 part by weight of an antistatic agent of a polymer charge transfer type conjugate represented by the following general formula is blended. Characteristic bottom film for carrier tape. Embedded image R, R1, R2: alkyl R3: polyethylene oxide P: a positive number of 1 or more 2. The bottom film for a carrier tape according to claim 1, wherein the bottom film is provided on a paper base material.