JPH1165470A - Backlight wiring material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adequate shielding operation and a leakage current, to reduce a wiring space and to prevent the luminance of a lamp from being reduced due to leakage current by forming on one surface a shield layer of a conductive layer where sheet resistance has a specific range. SOLUTION: A thin flat square conductor is made as the wiring material of a lamp 1. A high light reflective plastic sheet in which an electrically conductive shield layer 8 having adequate electric conductivity is formed on one side, is used as an insulating body. The sheet resistance of the conductive layer, which constitutes the layer 8, is desirable to be 100 to 250 mΩ/cm<2> , preferably 120 to 200 mΩ/cm<2> . Moreover, various thermoplastic resin films are desirable for a reflection body 2 and the use of a polyester(PET) film is preferred. Thus, the reduction in the luminance of the lamp 1 caused by a leakage current is made small and the heat radiating effect of the lamp 1 is expected by bringing a portion of the layer 8 in contact with a heat radiating plate 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a wiring member used for a backlight of a display panel.

[0002]

2. Description of the Related Art Conventionally, as a wiring material for a backlight, Japanese Patent Application Laid-Open No. Hei 5-177758 discloses a plastic film or sheet substrate on which a reflective layer made of a thin film of silver or the like is formed and a metal plate support as an adhesive. A reflector which is bent along a lamp is known. Also,
Japanese Patent Application Laid-Open No. Hei 7-230004 discloses a light-reflective sheet made of a porous thermoplastic resin containing an inorganic filler which is bent, and this is a reflective sheet containing no metal.

[0003]

Conventionally, when a metal plate support is used as a component of a wiring material for a backlight, since the metal plate has a high conductivity, a leakage current from the lamp increases, and Brightness tends to decrease.
In addition, since the light reflecting sheet made of a porous thermoplastic resin containing an inorganic filler does not have a metal layer, no leak occurs because of the metal layer. However, there is a disadvantage that the electromagnetic field emitted from the lamp cannot be shielded.

[0004]

As a result of various studies on the above problems, the present inventor has found that a flat cable having a moderate conductivity (expressed by a specific range of surface resistance value) is provided on one side as a flat cable for a backlight wiring member. The present inventors have found that the provision of a shield layer of a conductive layer having the same shows an appropriate shielding action and leakage current, and have completed the present invention. That is,
The present invention provides: A flat cable in which one or a plurality of rectangular conductors are arranged, and a surface resistance value of one side is 100 to 250 mΩ /
Provided is a flat cable for backlight wiring, on which a shield layer of a conductive layer having cm ² is formed. It is also characterized in that at least one insulator reflects light of 400 to 800 nm by 90% or more. Another characteristic is that a part of the shield layer is brought into contact with the heat sink.

Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing the structure of a cable with a wiring member made of a rectangular conductor according to the present invention. FIG. 2 is a schematic diagram showing a cross section of the cable with a wiring member of FIG. 1 and 2, 1 is a lamp, 2 is a reflector, 3 is a reflector, 4 is a film, 5 is a copper foil (for example, tin-plated soft copper foil), 6 is an adhesive, 7 is a lighting circuit, 8 is a shield layer, 9 is a film, 1
Reference numeral 0 denotes a heat radiating plate made of aluminum or the like in which a part of the shield layer is in contact.

According to the present invention, first, a thin rectangular conductor is used as a wiring material of a lamp, and a high light reflective plastic sheet having a conductive layer shield layer having an appropriate conductivity formed on one surface thereof is used as an insulator. The backlight wiring material described above is an essential requirement, thereby reducing the brightness of the lamp due to the leakage current and having a shield for an electromagnetic field. The surface resistance of the conductive layer constituting the shield layer is 100 to 250 mΩ / cm ² , preferably 120 to 250 mΩ / cm ² .
Desirably, it is 200 mΩ / cm ² . The shield material is not particularly limited as long as it is a conductive material having a function of protecting electromagnetic waves. For example, a shield film on which a PET film having a conductive adhesive layer containing a silver filler or a PET film on which silver is deposited is attached. Materials can be used.

As the reflector (material), various thermoplastic resin films are desirable, for example, polypropylene, polyethylene, polyester (PET) and the like.
The use of polyester (PET) films is preferred. Further, in order to impart weather resistance, it is preferable that the reflector film contains an ultraviolet absorber. The thickness of the reflector is 5
μm or more, preferably 25 μm or more and 250 μm or less. As a highly reflective layer (reflective material) constituting the reflective surface of the reflector, a highly reflective metal powder such as silver is plated by a plating method,
A sheet deposited on the reflector by means such as a vacuum deposition method, a sputtering method, an ion beating method, or
A sheet containing an inorganic filler such as calcium carbonate and barium sulfide may be used.

When a metal powder is used, the thickness of the high reflection layer (reflection material) is 200 to 500 °, preferably 500 to 500 °.
2000 $. In addition, Ti, C is formed on the outermost layer of the high reflection layer.
An anticorrosive metal layer such as r or Ni may be formed. When a sheet containing an inorganic filler is used as a reflector, the thickness of the high reflection layer is 50 μm to 250 μm, preferably 100 μm.
μm to 200 μm. As a heat radiating plate provided in contact with the shield layer, it is desirable to use aluminum or the like having a high heat effect.

[0009] The adhesive is an adhesive bonded by the action of heat or a catalyst, such as a silicone adhesive, a polyester thermosetting resin adhesive, an epoxy resin adhesive, a polyurethane adhesive, and a cyanoacrylate. General adhesives such as a system adhesive and a hot melt adhesive can be used. The thickness of the adhesive is 0.5 to 50 μm, preferably 1
２０20 μm.

[0010]

[Action]

1) A shield layer of a conductive layer having an appropriate conductivity is formed on one side of the reflector: use of a metal plate provides an excellent shielding effect, but increases the leakage current from the lamp and increases the brightness of the lamp. Decrease. There is a positive correlation between the conductivity and the shielding effect, and a negative correlation between the conductivity and the leakage current. Therefore, by providing a shield layer having an appropriate conductivity, a cable exhibiting an appropriate shield effect and a leak current can be obtained (claim 1).

2) One-sided insulator reflects light of 400 to 800 nm by 90% or more, preferably 90% to 95%: One-sided insulator reflects light of 400 to 800 nm by 90% or more. And has a very high reflectivity, so that the light reflection efficiency can be increased as compared with an ordinary flat cable insulator (claim 2). In this case, if the reflectivity is less than 90%, the light loss of the lamp is large and sufficient brightness cannot be obtained. Also, 400-800n
Since the light of m is visible light, it is desirable to reflect the light intensively from the viewpoint of visibility as a backlight of a display device. 3) A part of the shield layer is brought into contact with a heat radiating plate such as aluminum: a heat radiating effect of lamp heat can be expected (claim 3).

Hereinafter, the present invention will be described in detail with reference to the drawings.

【Example】

(Example 1) A thin rectangular conductor having a thickness of 0.05 mm ×
A tin-plated soft copper foil with a width of 1.27 mm is sandwiched between two insulating films having a polyester resin adhesive layer formed on a PET film (Lumirror, manufactured by Toray Industries Inc.) so that the adhesive layers face each other, and thermocompression-bonded to be integrated. did. Furthermore, one P
A PET film having a conductive adhesive layer containing silver filler as conductive particles was attached to the outside of the ET film to form a shielding material. Slit this cable to a width of 10 mm,
The lamp was bent into a U-shape having a radius of curvature of about 3 mm along the lamp, and the lamp was set so as to be inserted into the U-shape. At this time, the lamp current of the lamp was measured. Note that a TDK inverter CXA-M10LL was used for lighting the lamp.

(Example 2) Tin-plated soft copper foil having a thickness of 0.05 mm and a width of 1.27 mm was used as a thin rectangular conductor.
A polyester resin adhesive layer is formed on an insulating sheet in which a polyester resin adhesive layer is formed on a PET film (Lumirror manufactured by Toray Industries, Inc.) and on a high light reflective sheet ("Super Reflector" manufactured by Sumitomo 3M Limited). The resulting sheet was sandwiched between the insulating sheets so that the adhesive layers face each other, and then thermocompression bonded to be integrated. As the shielding material, a PET film having a conductive adhesive layer using silver filler as conductive particles was used as in Example 1. This cable was bent so that the high light reflection sheet was on the lamp side, and the tube current of the lamp was measured in the same manner as in Example 1.

(Example 3) A cable having a reflective material is produced in the same manner as in Example 2, and a PET film on which silver is deposited is used as a shielding material, and the cable is bonded through a polyester resin adhesive to produce a cable. Then, the tube current of the lamp was measured for this cable in the same manner as in Example 1.

(Comparative Example 1) A cable having a reflective material was manufactured in the same manner as in Example 1, and a copper cable was used as a shielding material and bonded with an adhesive to produce a cable. The lamp current of the lamp was measured in the same manner as in Example 1. The results are shown in Table 1 below.

[Table 1]

[0016]

As described above, according to the present invention, by providing a shield layer of a conductive layer having an appropriate conductivity on one side as a flat cable for a wiring material of a lamp, an effect of exhibiting an appropriate shielding action and a leakage current can be obtained. There is. In addition, by using a plastic sheet that reflects light as an insulator as a wiring material of the lamp, the wiring space can be reduced, and a reduction in the brightness of the lamp due to leakage current can be prevented. Further, by bringing a part of the shield layer into contact with the heat radiating plate, there is a heat radiating effect of the lamp heat.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a structure of a cable with a wiring member made of a rectangular conductor according to the present invention.

FIG. 2 is a schematic view showing a cross section of the cable with a wiring member of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lamp 2 Reflector 3 Reflector 4 Film 5 Copper foil (for example, tin-plated soft copper foil) 6 Adhesive 7 Lighting circuit 8 Shield layer 9 Film 10 Heat sink

Claims (3)

[Claims] 1. A flat cable in which one or a plurality of rectangular conductors are arranged, wherein one surface has a surface resistance of 100 to 2
A flat cable for backlight wiring, wherein a shield layer of a conductive layer having 50 mΩ / cm ² is formed. 2. The method according to claim 1, wherein the at least one insulator is 400-80.
2. The flat cable for backlight wiring according to claim 1, wherein 90% or more of the light of 0 nm is reflected. 3. The flat cable for backlight wiring according to claim 1, wherein a part of the shield layer is brought into contact with the heat sink.