JP2003273573A - Electromagnetic wave shielding member for display, film board of the same, and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic wave shielding member for a display which possesses electromagnetic wave shielding properties, superior transparency, and non-visibility; its film board; and its manufacturing method. <P>SOLUTION: The electromagnetic shielding wave shielding film board for a display comprises a polyester film base with an adhesive layer and a copper foil. The surface of the copper foil bonded to the adhesive layer has an average surface roughness of 0.40 μm or below. The copper foil is an electrolytic copper foil that is 12 μm or below in thickness and has a thickness variation of ±0.8 μm or below. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shielding member for a display, a film substrate for the same, and a method for producing the same, and in particular, it comprises a polyester film base material having an adhesive layer and a copper foil of mesh, and the copper foil is etched The present invention relates to an electromagnetic wave shielding film substrate for a display that is manufactured.

[0002]

2. Description of the Related Art With the recent increase in the use of various electric equipments and electronic equipments, electromagnetic noise interference is also increasing. Noise is roughly divided into conducted noise and radiated noise.
There is a method of using a noise filter or the like. On the other hand, as a measure against radiated noise, it is necessary to electromagnetically insulate the space, so the housing is made of a metal body or a highly conductive body, a metal plate is inserted between the circuit boards, or a cable is used. The method such as wrapping with a metal foil is taken. These methods can be expected to have an electromagnetic wave shielding effect for circuits and power supply blocks, but they cannot be applied to electromagnetic wave shielding applications such as CRTs and PDPs that are generated from the front surface of a display because they are opaque.

As a method for achieving both electromagnetic wave shielding properties and transparency, a method of depositing a metal or a metal oxide on a transparent substrate to form a thin film conductive layer (JP-A-1-278800).
Japanese Patent Laid-Open Publication No. 5-323101). On the other hand, an electromagnetic wave shielding material (see JP-A-5-327274 and JP-A-5-269912) in which good conductive fibers are embedded in a transparent substrate, or a conductive resin containing metal powder or the like is directly printed on a transparent substrate. Electromagnetic wave shielding material (Japanese Patent Laid-Open No. 62-57297, Japanese Patent Laid-Open No. 2-52)
In addition, a transparent resin layer is formed on a transparent substrate such as polycarbonate having a thickness of about 2 mm,
An electromagnetic wave shielding material having a copper mesh pattern formed thereon by electroless plating (Japanese Patent Laid-Open No. 5-2883889).
(See Japanese Patent Publication).

As a method for achieving both the electromagnetic wave shielding property and the transparency, JP-A-1-278800 and JP-A-5-78800 are available.
The method of forming a thin film conductive layer by vapor-depositing a metal or a metal oxide on a transparent substrate disclosed in Japanese Patent No. 323101 is a film thickness (several hundred Å to 2, which can achieve transparency).
If it is set to 000Å), the surface resistance of the conductive layer becomes too large, so that a shielding effect of 30 dB or more required at 30 MHz to 1 GHz is required, but it is insufficient at 20 dB or less.

In the electromagnetic wave shield material (Japanese Patent Laid-Open No. 5-327274 and Japanese Patent Laid-Open No. 5-269912) in which a highly conductive fiber is embedded in a transparent substrate, 30 MHz to 1 GHz is used.
Electromagnetic wave shielding effect of 40 to 50 dB is sufficiently large, but in order to regularly arrange the conductive fibers so as to prevent electromagnetic wave leakage, the fiber diameter must be 35 μm or more, and the fibers are visible to the naked eye. (Hereinafter, “visibility”
Therefore, it was not suitable for display applications.

Further, in the case of the electromagnetic wave shielding material in which a conductive resin containing a metal powder or the like is directly printed on a transparent substrate as disclosed in JP-A-62-57297 and JP-A-2-52499, the printing accuracy is similarly improved. From the limit, the minimum line width is
The thickness was around 100 μm and visibility was exhibited, which was not suitable.

Further, a shield having a thickness of about 2 mm, which is described in JP-A-5-283889, is formed on a transparent substrate such as polycarbonate and a transparent resin layer is formed thereon, and a copper mesh pattern is formed thereon by electroless plating. In the material,
In order to secure the adhesion of electroless plating, it is necessary to roughen the surface of the transparent substrate. As the roughening means, generally, a highly toxic oxidizing agent such as chromic acid or permanganic acid must be used, and this method makes it difficult to perform satisfactory roughening with a resin other than ABS. Further, even if the electromagnetic wave shielding property and the transparency can be achieved by this method, it is difficult to reduce the thickness of the transparent substrate,
It was not suitable as a film forming method. Furthermore, if the transparent substrate is thick, it cannot be closely attached to the display, and electromagnetic waves leak from there. Also,
In this method, there is a drawback in that the shield material is bulky because it cannot be made into a scroll or the like in terms of manufacturing, and the manufacturing cost is high because it is not suitable for automation. Regarding the shielding property of electromagnetic waves generated from the front surface of the display, in addition to the electromagnetic wave shielding function of 30 dB or more at 30 MHz to 1 GHz, good visible light transmittance,
In addition to having a high visible light transmittance, it is also necessary to have adhesiveness that can be attached in close contact with the display surface to prevent leakage of electromagnetic waves, and non-visibility that is a characteristic that the presence of a shield material cannot be visually confirmed. To be done.

Regarding the adhesiveness of the shield material, it is necessary that it be easily attached to glass or a general-purpose plastic plate at a relatively low temperature and have good adhesiveness for a long period of time. However, until now, a satisfactory adhesive film has not been obtained as an adhesive film that sufficiently satisfies the properties of electromagnetic wave shielding property, infrared ray shielding property, transparency / non-visibility and adhesiveness.

It is proposed that the copper foil of the electromagnetic wave shielding film substrate consisting of a polyester film base having an adhesive layer and a copper foil is etched to form a mesh and then overcoated to form an electromagnetic wave shielding member for a display. However, since the surface roughness of the adhesive layer of the copper foil portion removed by etching is large, overcoating tends to cause bubbles, dust, etc., resulting in poor transparency and visibility. Was there.

[0010]

In view of the above points, the present invention provides an electromagnetic wave shielding member for a display having an electromagnetic wave shielding property and good transparency and non-visibility, a film substrate thereof, and a manufacturing method thereof. To aim.

[0011]

The present invention is an electromagnetic wave shielding film substrate for a display comprising a polyester film-based substrate having an adhesive layer and a mesh copper foil, wherein the copper foil is an adhesive agent. It is an electromagnetic wave shielding film substrate for a display having an average surface roughness of 0.40 μm or less on a bonding surface with a layer.

In the present invention, the copper foil has a thickness of 12 μm.
An electromagnetic wave shielding film substrate for a display, which is an electrolytic copper foil having a thickness of m or less and a thickness variation of 0.8 μm or less.

The present invention is an electromagnetic wave shield member for a display, which comprises a film substrate and an overcoat layer that overcoats the film substrate, and shields electromagnetic waves from the display, wherein the film substrate is the above display. Is an electromagnetic wave shield member for a display, which is an electromagnetic wave shield substrate for a display.

Furthermore, the present invention is a method for producing an electromagnetic wave shielding film substrate for a display, which comprises a polyester film-based substrate having an adhesive layer and a mesh copper foil, which is adhered to the polyester film-based substrate. A step of forming an agent layer, a step of attaching a copper foil having an average surface roughness of 0.40 μm or less of a bonding surface on the adhesive layer formed on a base material, and a step of etching the copper foil to form a mesh A method of manufacturing an electromagnetic wave shielding film substrate for a display, comprising:

Further, the present invention is the method for producing an electromagnetic wave shielding film substrate for a display, wherein the step of forming the copper foil is carried out by a continuous roll laminating method.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described.
The electromagnetic wave shield member for a display of the present invention, the film substrate thereof, and the method for producing the same will be specifically described by way of examples, but the present invention is not limited thereto. In the present invention, the average surface roughness is JIS
It means an arithmetic mean roughness (Ra) defined by B0601, and is measured based on the standard.

The first embodiment will be described. The electromagnetic wave shielding film substrate for a display of the present example is composed of a polyester film-based base material having an adhesive layer, and a copper foil of a mesh, and the copper foil has an average surface roughness of a bonding surface with the adhesive layer. It is 0.40 μm or less. By using a copper foil having an average surface roughness of 0.40 μm or less on the bonding surface with the adhesive layer, the surface of the adhesive layer on which the copper foil is formed becomes smooth and the adhesive on the copper foil portion removed by etching It is possible to obtain an electromagnetic wave shield film for a display, which has a small surface roughness of the layer, is less likely to contain bubbles and dust even when overcoated, and has good transparency and visibility. As a copper foil, the thickness is 12 μm or less, and the thickness variation is 0.8 μm.
The following electrolytic copper foil and the like can be used.

A method of manufacturing the electromagnetic wave shielding film substrate for display of Example 1 will be described. As a thin metal foil 1
A 125 μm thick polyester film (trade name; EN) is used as a transparent plastic film by using an electrolytic copper foil of 0 μm thickness product (trade name; PBR-10A, manufactured by Nippon Denki Co., Ltd., abbreviated as “copper foil 1” hereinafter) Bullet S, manufactured by Unitika Ltd., hereinafter abbreviated as "film A") was used.

First, the adhesive is continuously applied to the film A,
An adhesive layer was formed by drying. As the adhesive, a polyester adhesive (trade name: Byron UR-1400, manufactured by Toyobo Co., Ltd.) was used. This adhesive has a glass transition point Tg8
It is 3 ° C. The drying condition was 120 ° C. × 1 minute, and the thickness of the adhesive layer after drying was 20 μm to obtain an adhesive film.

The adhesive film and the copper foil I were continuously roll-laminated. The structure of this equipment is general, and comprises an unwinding device for the material to be laminated, a preheating device before laminating, a laminating roll capable of heating / pressurizing, and a winding device. The preheating device heats the object to be laminated.
If it is bonded to a pressure roll, it will be deformed by a sudden temperature change and wrinkles will be created, so it is installed in advance to moderate the temperature change by heating the object to be laminated, such as a film or thin metal. It is an indispensable equipment when processing.

The laminating speed was 2 m / min, and the temperature of the non-laminated product by preheating was 150 to 16
0 ℃, laminating roll surface temperature 150 ℃, pressure 10K
An electromagnetic wave shielding film substrate for display (hereinafter abbreviated as "MCF1") was obtained at g / cm.

A comparative example 1 will be described. The metal copper foil used was a 12 μm thick product (trade name; F2-WS, manufactured by Mitsui Mining & Smelting Co., Ltd., hereinafter abbreviated as “copper foil 1 ′”). The transparent plastic film is the same as in Example 1.

In the same manner as in Example 1, a substrate II for electromagnetic wave shielding film for display (hereinafter abbreviated as "MCFII") was obtained by roll lamination. The laminating speed was 2 m / min, the temperature of the non-laminated product by preheating was 140 to 150 ° C., and the surface temperature of the laminating roll was 14
The temperature was 0 ° C. and the pressure was 10 Kg / c.

A comparative example 2 will be described. The metal copper foil used was a 12 μm thick product (trade name; JTCAM, manufactured by Mitsui Mining & Smelting Co., Ltd., hereinafter abbreviated as “copper foil III”). The transparent plastic film is the same as in Example 1.

In the same manner as in Example 1, an electromagnetic wave shielding film substrate III for display (hereinafter abbreviated as "MCFIII") was obtained by roll laminating. The laminating speed was 2 m / min, the temperature of the non-laminated product by preheating was 140 to 150 ° C., and the surface temperature of the laminating roll was 1
The temperature was 40 ° C. and the pressure was 10 kg / c.

Regarding the MCFs used in the above-mentioned Examples and Comparative Examples, a copper foil was used as a mesh by etching and a transparent resin was overcoated, and the obtained members were examined for visible light transmittance and transparency. It was The physical properties of MCF and the measurement results are shown in FIG. In terms of ease of transmittance, ◯ means that the transparency is practically sufficient, Δ means that the transparency is partially insufficient in practice, and × means that the transparency is not suitable for practical use. .

Looking at these measurement results, the MCF of Example 1
It can be seen that in comparison with the MCFs of Comparative Examples 1 and 2, the visible light transmittance is higher, the transparency is easier, and there is no practical problem.

[0028]

According to the present invention, the electromagnetic wave shielding property,
It is possible to obtain an electromagnetic wave shield member for a display having good transparency and non-visibility, a film substrate thereof, and a manufacturing method thereof.

[Brief description of drawings]

FIG. 1 is a diagram illustrating physical properties and measurement results of MCF used in Examples and Comparative Examples.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masamitsu Fukuyama             Hitachi, Shimodate City, Ibaraki Prefecture             Seigo Co., Ltd. Goshomiya Works (72) Inventor Hiroshi Nomura             Hitachi, Shimodate City, Ibaraki Prefecture             Seigo Co., Ltd. Goshomiya Works F-term (reference) 4F100 AB17B AK41A AK41G AT00C                       BA02 BA03 BA07 BA10A                       BA10C CB00 DC16B EC182                       EH012 EJ152 EJ192 JA20B                       JD08 JK15B YY00B                 5E321 AA04 BB21 BB41 CC16 GG05                       GH01                 5G435 AA01 AA16 BB02 BB06 GG33                       KK07

Claims (5)

[Claims] 1. An electromagnetic wave shielding film substrate for a display, comprising a polyester film-based base material having an adhesive layer and a mesh copper foil, wherein the copper foil is an average surface of a joint surface with the adhesive layer. The roughness is 0.
An electromagnetic wave shielding film substrate for a display, which has a thickness of 40 μm or less. 2. The copper foil has a thickness of 12 μm or less, and
The electromagnetic wave shielding film substrate for a display according to claim 1, which is an electrolytic copper foil having a thickness variation of 0.8 μm or less. 3. An electromagnetic wave shield member for a display, which comprises a film substrate and an overcoat layer for overcoating the film substrate, and shields electromagnetic waves from a display, wherein the film substrate is the one according to claim 1 or 2. An electromagnetic wave shielding member for a display, which is the electromagnetic wave shielding substrate for a display as described above. 4. A method for producing an electromagnetic wave shielding film substrate for a display, comprising a polyester film-based base material having an adhesive layer and a mesh copper foil, wherein the adhesive layer is formed on the polyester film-based base material. And a step of sticking a copper foil having an average surface roughness of 0.40 μm or less of a bonding surface on the adhesive layer formed on the base material,
And a step of etching a copper foil to form a mesh, the method for producing an electromagnetic wave shielding film substrate for a display. 5. The method of manufacturing an electromagnetic wave shielding film substrate for a display according to claim 4, wherein the step of forming the copper foil is performed by a continuous roll laminating method.