JPS6045586B2 - packaging film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packaging film, and more particularly to a film 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. . 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 have conventionally been used as packaging materials for electronic components.

However, since these are all opaque, it is impossible to confirm the existence and damage of the electronic components inside, or to identify the type.

On the other hand, there are plastic films mixed with antistatic agents, but these are simply... In addition, depending on the type of antistatic agent, it is easily affected by moisture and lacks stability.The present invention eliminates the above-mentioned drawbacks and the contents of the package An object of the present invention is to provide a film for packaging electronic parts that allows certain electronic parts to be seen through and at the same time is sufficient to protect the electronic parts from static electricity.

That is, the present invention provides a heat-sealing surface of a transparent plastic film having heat-sealing properties, on which a metal thin film has a light transmittance of 25% or more and an electric resistance per unit area of an IC.
It is a film for packaging electronic parts, which is provided under the conditions of PΩ or less and a film thickness of 20 to 250, and is used to form a package with a plastic film on the outside and a metal thin film on the inside. This will be explained below with reference to the drawings. 1 and 2 are partially enlarged sectional views showing one embodiment of the electronic component packaging film of the present invention, and FIG. 3 is a partially enlarged sectional view showing an example of the electronic component packaging film of FIG. It is a partially cutaway perspective view when the package is formed.

A transparent plastic film having heat-sealability can be obtained by providing a heat-sealable layer 2 on one side of a transparent plastic film 1, for example, as shown in FIG.

5 As the transparent plastic film 1, polyester film, acrylic film, vinyl chloride film,
Fluororesin films, styrene films, polypropylene films, polyethylene films, and any other material that can be used as packaging materials can be used.

The transparent plastic film 1 preferably has a thickness of 4μ to 100μ.

If the transparent plastic film 1 is thinner than 4p, it is extremely thin and extremely weak, and is therefore useless as a packaging material. If the transparent plastic film 1 is thicker than 100p, it is too stiff and has a strong repulsive force, making handling extremely inconvenient during heat sealing and after packaging is formed. The heat-sealable layer 2 can be provided on the transparent plastic film 1 by laminating a polyethylene or other heat-sealable film, extruding a resin such as polyethylene, laminating it, or coating it.

Usable resins include, for example, polyethylene, soft vinyl chloride, modified polyester, EVAl, and various other heat-fusible resins. When the transparent plastic film 1 is itself heat-sealable, the transparent plastic film 1 also serves as the heat-sealable layer 2, as illustrated in FIG. You can also do that.

In the case of the structure shown in FIG. 1, the heat-sealable layer 2 can also be provided only on the portion where heat sealing is actually performed, rather than over the entire surface. The metal thin film 3 can be provided on the heat-sealable layer 2 by a conventionally known thin film production method such as a vacuum evaporation method, a sputtering method, an ion blating method, an electron beam evaporation method, or the like.

The metal thin film 3 includes Cr, Al, Hj, Fe, In, Ag.
, Au, Su, Sn, Zn, Ti, Ni-Cr and other metals, alloys, and other metals that can be used to form thin films can all be used. Wear.

The metal thin film 3 needs to satisfy the following conditions: a light transmittance of 25% or more, an electrical resistance per unit area of 1 Cf3Ω or less, and a film thickness of 20A to 250A.

These conditions of light transmittance, electrical resistance, and film thickness achieve the purpose of this invention. It is essential to do so. That is, if the light transmittance is lower than 25%, it will be difficult to see through the electronic components inside the package.

Further, if the electrical resistance is higher than 10 3 Ω, the conductivity is poor and it is insufficient to protect electronic components from static electricity charging.
The film thickness indicates not only the relationship with light transmittance and electrical resistance, but also the relationship with the heat-sealable layer 2. If the film thickness is outside the range of 208 to 250A, the light transmittance will be 25% or more and the electrical resistance per unit area will be 1Cf3.
The condition of Ω or less cannot be met.

If the film thickness is less than 20 mm, the electrical resistance of some metals tends to be higher than 1Cf3Ω, resulting in insufficient protection of electronic components. If the film thickness is thicker than 250A, the light transmittance will be 2.
If it becomes lower than 5%, it becomes 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 3 are closely related to each other.
The metal thin film 3 must be formed so as to satisfy all of these three conditions.

The thickness of the metal thin film 3 is also of decisive importance when forming a package with the transparent plastic film 1 on the outside.

When the thickness of the metal thin film 3 is 250A or less, it is extremely thin and does not particularly affect the heat sealing of the heat-sealing layer 2 inside it, and is similar to the case where the metal thin film 3 is not present. Heat sealing is also possible. However, if the metal thin film 3 exceeds 250A, it is no longer possible to perform heat sealing sufficiently.This invention forms a package with the transparent plastic film 1 on the outside and the metal thin film 3 on the inside. Electronic components are packaged inside. 4 in the figure is a heat sealing part.

In this invention, since the metal thin film 3 is conductive with an electrical resistance per unit area of 1 Cf3Ω or less, electronic components can be sufficiently protected from static electricity generated inside and outside the package.

In particular, since the metal thin film 3 is present on the surface of the inside of the package,
The effects of static electricity can be completely eliminated. This invention is
A film containing an antistatic agent may be used as the transparent plastic film 1, or a layer containing an antistatic agent may be appropriately formed on one or both sides of the transparent plastic film 1.

The layer containing the antistatic agent can also be provided at other appropriate locations. In this invention, when the package is formed, the metal thin film 3 becomes the inside of the transparent plastic film 1, so the weather resistance is extremely good. ' Note that this invention can naturally be colored as appropriate.

Example A heat-sealable polyester film (Mellnex type #850 manufactured by ICI), which is a 25p thick polyester film with a modified polyester layer on one side, was used as a carrier sheet, and the degree of vacuum was 1 x 10-4T0 by vacuum evaporation method.
Under the conditions of RR, Cr was deposited at a deposition distance of approximately 25cm between 2cm and 2cm, and a Cr vapor-deposited film with a light transmittance of 75%, a resistance of 1 σΩ per unit area, and a film thickness of 50A was applied to the modified polyester layer of the carrier sheet. A film for packaging electronic components of the present invention was obtained by forming the film on top of the film.

Next, a comparison example with conventional products is shown.

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

Furthermore, using the electronic component packaging film of the present invention obtained in the Examples, a package was formed by heat sealing with the polyester film on the outside. A liquid crystal plate was enclosed in each of the above packages.

Next, 10C7! Ions of 1 and θ were irradiated from a distance of 8,000 V to 10,000 V using an electrostatic generator (ROSTAT) to examine whether or not the letters and numbers in the liquid crystal panel were distorted. We also compared the transparency of the packaging. The results are as follows.
As is clear from the results in the table, when the electronic component packaging film of this invention is used, there is no disturbance in the characters and numbers on the liquid crystal display, and compared to conventional products, the protection from static electricity is extremely significant. It has the following effects.

[Brief explanation of the drawing]

Both FIG. 1 and FIG. 2 are partially enlarged sectional views showing one embodiment of the electronic component packaging film of the present invention.
The figure is a partially cutaway perspective view of a package formed using the electronic component packaging film of FIG. 1. 1...Transparent plastic film, 2...
...Heat-sealable layer, 3...Metal thin film, 4
...Heat seal part.

Claims (1)

[Claims] 1. A thin metal film with a light transmittance of 25 on the heat sealing surface of a transparent plastic film having heat sealability.
% or more, electrical resistance per unit area of 10^8 Ω or less, and film thickness of 20 Å to 250 Å. For electronic component packaging, for forming a package with a plastic film on the outside and a metal thin film on the inside. film. 2. The film for packaging electronic components according to claim 1, wherein the transparent plastic film having heat sealability is provided with a layer containing an antistatic agent on one or both sides.