JPS6046016B2 - Electronic parts packaging sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packaging sheet, and more particularly to a sheet for packaging electronic components.

Electronic components that are sensitive to static electricity, such as semiconductors, are easily damaged by static electricity before they are attached to electronic circuits, and even after they are attached to electronic circuits, which poses a major problem. ing.

Therefore, in order to protect electronic components from static electricity,
Plastic films and metal foils mixed with conductive substances such as carphones and metal powder are used as packaging materials for electronic components.

However, since all of these are opaque, there is no possibility of the presence or loss of the electronic components inside. L゛-T- Bushipu
■I--J-On the other hand, there are plastic films mixed with antistatic agents, but these have considerably high electrical resistance per unit area and are completely inadequate for protecting electronic components. Depending on the type of agent, it is easily affected by moisture and lacks stability.

The present invention eliminates the above-mentioned drawbacks, and provides a sheet for packaging electronic components that is sufficient to allow the electronic components contained in the package to be seen through and at the same time protect the electronic components from static electricity. Furthermore, the present invention is an extremely convenient, useful, and novel sheet for packaging electronic components that can be heat-sealed on both the front and back sides.

That is, in this invention, metal thin films are provided on both the front and back surfaces of a transparent plastic film that has heat sealability on both the front and back surfaces.

(B) The light transmittance of the metal thin film is 25% or more when light passes through the metal thin films on both the front and back surfaces.

- (C) The electrical resistance per unit area of the metal thin film is about Ω or less.

(old) The thickness of the metal thin film is 108 to 2508.

(E) A transparent protective layer containing an antistatic agent or not containing an antistatic agent is provided on the metal thin film to a thickness of 1 μm or less, if necessary. This is an electronic component packaging sheet that is heat-sealable on both the front and back sides, and is characterized by meeting the requirements (E) above.

Next, the present invention will be explained with reference to the drawings.

Both Fig. 1 and Fig. 2 are partially enlarged sectional views showing one embodiment of the electronic component packaging sheet of the present invention, and Fig. 3 is a partially enlarged sectional view showing an embodiment of the electronic component packaging sheet of the present invention. This is a partially cutaway perspective view of the package being formed. In the figure, 1 is a transparent plastic film having heat sealability on both the front and back sides, 2 is a metal thin film, 3 is a transparent protective layer, and 4 is a heat sealing part.

The transparent plastic film 1, which has heat-sealability on both the front and back sides, is a plastic film itself that is heat-sealable, such as polyethylene film, ionomer resin film, ethylene-vinyl acetate copolymer film, end-oriented polyethylene film, vinyl chloride film, etc. If it is sealable, it can be used as is.

The transparent plastic film 1, which has heat-sealing properties on both the front and back sides, may also include polyester film, acrylic film, vinyl chloride film, fluororesin film,
It can also be obtained by providing a transparent heat-sealable layer on both the front and back sides of a styrene film, polypropylene film, polyethylene film, or other transparent plastic film that can be used as a packaging material.

This heat-sealable layer can be provided by laminating polyethylene or other heat-sealable films on the plastic film, extruding a resin such as polyethylene, laminating it, or coating it. Examples of resins that can be used for the heat-sealing layer include polyethylene, soft vinyl chloride, modified polyester,
EVAl and other types of heat. Examples include fusible ones.
The heat-sealing layer can also be provided not over the entire surface, but only in the areas where heat-sealing is actually performed. The metal thin film 2 is provided on both the front and back surfaces of the transparent plastic film 1 having heat sealability by a conventionally known thin film production method such as a vacuum evaporation method, a sputtering method, an ion blating method, or an electron beam evaporation method. ing.

In this specification, the term "metal thin film" includes any of thin films made of simple metals, thin films made of alloys, and thin films made of metal oxides, as long as they have conductivity. The metal thin film 2 contains Cr. ．． Ni. ．． Al, Fe, . In.
．． AglAu. ．． CulSn. sZnlTi. sNi-
Cr,. Any material capable of forming a thin film, such as In2O3, can be used.

The metal thin film 2 must satisfy the following conditions: a light transmittance of 25% or more when light passes through the metal thin films on both the front and back surfaces, an electrical resistance of 1σΩ or less per unit area, and a film thickness of 10A to 250A.

These conditions of light transmittance and electrical resistance film thickness are essential for achieving the object of the present invention. That is, if the light transmittance in the above case is lower than 25%, it will be difficult to see through the electronic components inside the package.

Further, if the electrical resistance of the metal thin film is higher than 10 3 Ω, the conductivity will be poor and it will be insufficient to protect electronic components from static electricity charging. The film thickness shows the relationship with light transmittance and electrical resistance, and at the same time shows the relationship with heat sealing.

If the film thickness is outside the range of 10 to 250 A, the conditions of light transmittance of 25% or more and electric resistance per unit area of 1σΩ or less cannot be met.

If the film thickness is thinner than 10A, the electrical resistance of the metal tends to be generally higher than 1Cf3Ω, resulting in insufficient protection of electronic components. If the film thickness is thicker than 250A, the light transmittance will be lower than 25% depending on the metal, making it difficult to see through the electronic components inside. In this way, the light transmittance, electrical resistance per unit area, and film thickness of the metal thin film 2 in the above case are as follows:
These three conditions are closely related to each other, and the metal thin film 2 must be formed so as to satisfy all of these three conditions.

The thickness of the metal thin film 2 is also of critical importance when forming the package by heat sealing.

When the thickness of the metal thin film 2 is 250A or less, it is extremely thin and does not particularly affect heat sealing, and heat sealing is possible in the same way as in the case where the metal thin film 2 does not exist. However, when the metal thin film 2 exceeds 250A,
It is no longer possible to perform heat sealing satisfactorily. In this invention, a package is formed by heat-sealing both the front and back sides, and electronic components are packaged in the package.

In this invention, the electrical resistance per unit area of the metal thin film 2 is 1.
Since it has a conductivity of σΩ or less, it can sufficiently protect electronic components from static electricity generated inside and outside the packaging.

In particular, since the metal thin film 2 is present on the surface of both the inside and outside of the package, the influence of static electricity can be almost completely eliminated. Furthermore, since both the front and back surfaces of the present invention can be heat-sealed, it has the following extremely convenient and beneficial effects in addition to the above-mentioned effects and advantages.

1 Conventional products can be heat-sealed on only one side, so it is necessary to check in advance to confirm which side can be heat-sealed when heat-sealing. No need to check the heat seal surface.

2. There is no possibility of errors in setting the front and back sides during automatic bag making.

Therefore, work efficiency is greatly improved. 3. Regardless of the type of heat sealing, such as spine pasting, envelope pasting, or side sealing,
Heat sealing can be done with both the same sides and opposite sides.

4. Since heat sealing can be performed in any combination on the front and back sides, it is extremely easy to increase the width of the sheet by heat sealing.

By overlapping and heat-sealing 5 sheets, the sheets can be assembled firmly.

In the present invention, a film containing an antistatic agent can also be used as the transparent plastic film 1 having heat sealability. Further, in the present invention, a transparent protective layer 3 made of a suitable resin can be provided on the metal thin film 2, and in this case, the protective layer 3 can also contain an antistatic agent.

However, the protective layer 3 needs to be extremely thin, with a thickness of 1 μm or less. This is because if the thickness of the protective layer 3 exceeds 1 μm, since it exists on the surface, it will have some influence on the removal of static electricity and heat sealing. Protective layer 3
If the thickness is 1μ or less, it is extremely thin, so it has almost no effect on static electricity removal or heat sealing, and even if it does, it is negligible for electronic component packaging. This is because it is small. Note that this invention naturally allows for coloring or printing as appropriate, and this invention also includes those that are colored or printed at appropriate locations.

Example 1 A Cr vapor-deposited film having a light transmittance of 78%, an electrical resistance of 6 σΩ per unit area, and a film thickness of 50 μm was formed on one side of a transparent plastic film with a thickness of 40 μm by vacuum deposition.

Next, on the other side of the polyethylene film, a Cr vapor deposited film having a light transmittance of 80%, an electrical resistance per unit area of 1.5×1 Cf'Ω, and a film thickness of 40A(7) was formed by the same vacuum deposition method. The light transmittance of the entire sheet-like material thus obtained was about 61%. Next, using the sheet-like material thus obtained, a package A with the 50A Cr film thickness on the outside and a package B with the Cr film thickness of 40A on the outside were both formed by heat sealing. Example 2 Ni vapor-deposited films having a light transmittance of 75%, an electrical resistance per unit area of 4×1 CPΩ, and a film thickness of 50 A were formed on both sides of a transparent ionomer resin film with a thickness of 40 μm by vacuum evaporation.

Next, a protective layer with a thickness of 0.2 μm was formed on the Ni vapor-deposited films on both sides using a transparent resin paint containing 0.1% of an antistatic agent. The light transmittance of the entire sheet-like material thus obtained was about 50%. Next, the sheet-like product thus obtained was used to form a package C by heat sealing.

Example 3 A heat-sealable polyester film, in which a transparent modified polyester layer was provided on both sides of a transparent plastic film with a thickness of 25μ, was coated with a light transmittance of 50% and an electrical resistance per unit area of 4× by electron beam evaporation on one side. 1C) 3Ω
, a Cr vapor deposition film was formed to a thickness of 120 mm.

Next, the other side of the heat-sealable polyester film was coated with a light transmittance of 60% using the same electron beam evaporation method.
, electrical resistance per unit area 2X1σΩ, film thickness 60A (7
) A Cr vapor deposited film was formed. The light transmittance of the entire sheet-like material thus obtained was about 30%. 7 Next, using the sheet-like material obtained in this way, a Cr film thickness of 120A was obtained.
Packaging D with the side facing outward and Packaging E having the side with the Cr film thickness of 60A facing the outside were both formed by heat sealing.

Next, a comparison example with conventional products is shown.

As a comparative example, sample 1 is a conventionally commercially available heat-sealable non-static polyethylene packaging (pink plastic bag manufactured by Tokyo Denki Kagaku Kogyo Co., Ltd.), which is made by laminating a 25μ thick polyester film and a polyethylene film. This was used as a package and was adopted as Sample 2.

A liquid crystal plate was enclosed in each of the packages of Samples 1 and 2 of Package A obtained in Examples 1 to 3.

Next, 10C7T!
A static electricity generator of 8000V to 10000V from a distance of (
1 and θ ions were irradiated using the pressure ROSTAT to check for irregularities in the characters on the liquid crystal panel. We also compared the transparency of the packaging. The results are shown in the table below. In addition, O...no disturbance at all.

×...Very disturbed.

As is clear from the results in the table, when the electronic component packaging sheet of the present invention is used, there is no disturbance of characters on the liquid crystal display, and compared to conventional products, it is extremely effective in protecting against static electricity. It has the following.

[Brief explanation of drawings]

Both FIG. 1 and FIG. 2 are partially enlarged cross-sectional views showing one embodiment of the electronic component packaging sheet of the present invention, and FIG. 3 shows the electronic component packaging sheet of FIG. It is a partially cutaway perspective view when the package is formed. 1...Transparent plastic film having heat sealability on both front and back sides, 2...Metal thin film,
3...Transparent protective layer, 4...Heat seal portion.

Claims (1)

[Scope of Claims] 1 (A) Metal thin films are provided on both the front and back surfaces of a transparent plastic film that has heat sealability on both sides. (B) The light transmittance of the metal thin film is 25% or more when light passes through the metal thin films on both the front and back surfaces. (C) Electrical resistance per unit area of metal thin film is 10^8Ω
It is as follows. (D) The thickness of the metal thin film is 10 Å to 250 Å. (E) A transparent protective layer containing an antistatic agent or not containing an antistatic agent is provided on the metal thin film to a thickness of 1 μm or less, if necessary. A sheet for packaging electronic components that is heat-sealable on both the front and back sides, and is characterized by meeting the requirements (A) to (E) above.