JPH06160601A - Grounding electrode structure of panel with multilayered conductive antireflection film - Google Patents

Abstract

PURPOSE:To enable easy grounding by forming conductive antireflection films having a front surface consisting of a nonconductive layer on a panel, then forming a grounding electrode consisting of ultrasonic solder on the nonconductive layer of the front surface. CONSTITUTION:The multilayered transparent conductive antireflection films 21 are formed on a substrate 11. The antireflection films 21 consist of 4-layered films of H/L/H/L consisting, successively from the substrate 11 side, a transparent conductive layer 23 having a high refractive index, a low-refractive index layer 25, a high-refractive index layer 27 and a front surface low-refractive index layer 29. A transparent substrate consisting of glass, etc., is used as the substrate 11. Multi component oxides, such as Cd2SnO4, and tin oxide, etc., are used as the transparent conductive material. After the multilayered transparent conductive antireflection films 21 are formed on the substrate 11 in such a manner, the grounding electrode consisting of the ultrasonic solder 31 (solder soldered by an ultrasonic soldering method) is formed on the front surface low-refractive index layer 29 which is the uppermost layer. The direct soldering onto the antireflection films 21 is possible according to this structure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has a moderate electrical conductivity,
In addition, the present invention relates to a structure for taking out a ground electrode of a panel on which a multilayer conductive antireflection film having an antireflection function is formed.

[0002]

2. Description of the Related Art In a television, a display of a computer terminal, etc., a transparent conductive film is formed on a front glass panel for the purpose of preventing malfunction due to charging and adhesion of dust. Further, since the transparent conductive film has a large difference in refractive index from the glass substrate and the reflectance of the glass substrate is high, it is provided as a multilayer laminated film with conductivity and antireflection function, and thus an easy-to-see screen is provided.

[0003] Conventionally, as such a conductive anti-reflection film, Al ₂ O from the substrate side ₃ -In ₂ O ₃ -MgF ₂ or C
_3- layer film consisting of eF ₃ film (Katsube et al., Optics, Vol. 7, No. 6)
No. 250-254 (1978)), ITO / MgF ₂
/ ITO / MgF ₂ 4-layer film (Japanese Patent Laid-Open No. 61-16889)
9 JP), ITO-MgF ₂ - refractive index from 2.05 to 2.
2 thin film-a four-layer film composed of MgF ₂ film (Japanese Patent Publication No. 4-15
No. 443) is known.

As described above, in the case of the multilayer conductive antireflection, the uppermost layer is made of Mg because of the restriction of the film design as the antireflection film.
Since it is necessary to use a non-conductive, low-refractive-index film such as F ₂ or SiO ₂ , an earth electrode is provided on the uppermost layer, and an electrical conductivity between the lower conductive thin film is provided via the non-conductive uppermost layer. It has been considered that the conduction is inefficient and sufficient ground characteristics cannot be obtained.

Therefore, a method of printing a conductor paste in advance on a panel substrate of glass, plastic or the like and baking it to form a ground electrode, and forming a conductive antireflection film on this is generally performed.

[0006]

However, the method of forming the ground electrode using the conductor paste has the following drawbacks. (1) The first layer formed on the conductor paste is ITO
Since it is necessary to form the conductive anti-reflection film, the degree of freedom in designing the conductive anti-reflection film is limited.

(2) If the conductive antireflection film is formed on the entire surface of the conductor paste, grounding cannot be established, so it is necessary to expose a part of the conductor paste by masking. Masking for this is troublesome, and also
Positioning becomes difficult when masking and then attaching the ground terminal.

In Japanese Patent Laid-Open No. 2-256089, a conductive paste is formed on a portion having an uneven surface portion, so that even when a conductive antireflection film is formed on the entire surface, the conductive paste is collected from the conductive paste portion on the uneven portion. It has been reported that it can be powered. However, also in this case, it is necessary to form the surface irregularities and control the degree of irregularities, and the following drawbacks cannot be eliminated.

(3) As the conductor paste, a silver paste is generally used because of its cost and resistance. However, since the panel glass is strengthened, the silver paste should be baked at too high a temperature. I can't. Therefore, the characteristics of the silver paste cannot be fully brought out, the adhesion to the panel substrate becomes weak, and the dissolution resistance (salt water immersion test) and humidity resistance test (50 ° C-90% RH)
Discoloration or peeling may occur at x 24 Hr), and reliability of product quality cannot be obtained.

(4) In order to solve the problem of (3), it is necessary to bake the printed silver paste at a high temperature of about 600 ° C. at which the tempering treatment of the panel glass is diminished. For that purpose, it is necessary to strengthen the glass panel after the paste is baked and hardened, but this requires a considerably large-scale facility and is often not realistic.

The present invention provides a ground electrode structure which does not require a baking process like a conductor paste, has few restrictions on the film design of the conductive antireflection film, and can be formed by simple equipment. It is a thing.

[0012]

A ground electrode structure for a panel with a multilayer conductive antireflection film according to the present invention has a multilayer conductive antireflection film having an uppermost layer made of a nonconductive thin film and at least one transparent conductive layer. In the panel formed with, a ground electrode made of solder is formed on the uppermost layer by ultrasonic soldering, and electrical continuity is established between the ground electrode and the transparent conductive layer. To do.

[0013]

EXAMPLE FIG. 1 is a schematic sectional view showing an example of the earth electrode structure of the present invention. A multilayer transparent conductive antireflection film 21 is formed on the substrate 11, and the multilayer transparent conductive antireflection film 21 has a high refractive index transparent conductive layer 23, a low refractive index layer 25, and a high refractive index layer 25 from the substrate 11 side. The H / L / H / L four-layer film is formed by sequentially forming the refractive index layer 27 and the surface low refractive index layer 29. A transparent substrate such as glass is used as the substrate 11.

As a transparent conductive material forming the transparent conductive layer 23, ITO (Indium Tin Oxide;
Tin-doped indium oxide), ZnO doped with Al or Si, or Cd ₂ SnO ₄
A complex oxide such as tin oxide is used.

As the material for forming the low refractive index layers 25 and 29, those having a refractive index of 1.35 to 1.55 are preferable, and magnesium fluoride (MgF ₂ ) and silicon dioxide (SiO ₂ ).
₂ ) Dielectrics such as oxides are typical.

As the material forming the high refractive index layer 27,
Those having a refractive index of 1.8 to 2.9 are preferable, and titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), hafnium oxide (HfO ₂ ), zirconium oxide (ZrO ₂ ), T
A dielectric oxide such as iO ₂ + Pr ₆ O ₁₁ or ZrO ₂ + TiO ₂ or a transparent conductive material such as ITO is used.

The specific layer structure is such that the central wavelength peak that lowers the reflectance is determined, and the transparent conductive material, the high refractive index material and the low refractive index material to be used are selected, and the refractive index and the number of laminated layers of these materials are selected. From this, the optimum film thickness of each layer can be determined. Each of the layers 23 to 29 forming the multilayer transparent conductive antireflection film 21 can be formed on the substrate 11 by a usual thin film forming method such as a vacuum deposition method or a sputtering method.

In the present invention, after the multilayer transparent conductive antireflection film 21 is formed on the substrate 11 in this way, the ultrasonic solder 31 is formed on the uppermost surface low refractive index layer 29.
A ground electrode made of (solder soldered by ultrasonic soldering method) is formed.

In the ultrasonic soldering method, as shown in FIG. 2, a chip 41 heated by a chip heating heater 47 is used.
(Tip of the iron) through the horn 43 to the ultrasonic transducer 45
The ultrasonic soldering solder is supplied to the chip 41 to bond the ultrasonic solder 31 while ultrasonically vibrating the ultrasonic wave. According to the ultrasonic soldering method, it is possible to perform soldering directly on the surface of the multilayer transparent conductive antireflection film 21, and between the transparent conductive layer 23 and the lower transparent conductive layer 23, it is necessary for collecting current for grounding. A good electrical continuity can be achieved. The reason for this is not always clear, but according to the study by the present inventor, the ultrasonic solder 31 has the transparent conductive layer 23 in the layer.
It was confirmed that it diffused and invaded inside or in the vicinity thereof, and it was also confirmed that there was reproducibility.

In the above description, the lowermost layer is the transparent conductive layer 23.
The case where the ground electrode made of the ultrasonic solder 31 is provided on the multilayer transparent conductive antireflection film 21 made of the four-layer film described above has been described, but the present invention is not limited to this, and the number of layers and the conductive film having various film configurations are used. The first layer on the substrate side does not necessarily have to be a transparent conductive layer, and a plurality of transparent conductive layers may be provided.

The method of grounding the earth electrode composed of the ultrasonic solder 31 to the outside is not particularly limited. For example, the method of directly connecting the earth wire 51 to the ultrasonic solder 31 (see FIG. 3).
(A)), a method of connecting the ground wire 51 to the ultrasonic solder 31 with the normal solder 53 (FIG. 3 (B)) A metal claw 55 is clamped to the ultrasonic solder 31 and grounded via the claw 55. Any method such as connecting to a wire (not shown) (FIG. 3C) may be used.

[0022]

According to the present invention, after a conductive antireflection film having a surface formed of a non-conductive layer on the panel is formed on the panel, an ultrasonic solder is applied on the surface non-conductive layer. By forming such a grounding electrode, it is possible to establish electrical continuity required for grounding with the transparent conductive layer inside the conductive antireflection film. Therefore, it is not necessary to print and sinter the conductive paste in advance to form the ground electrode.
The conductive antireflection film can be grounded easily regardless of the film structure, the film design is highly flexible, and large-scale equipment is not required.

Experimental Example On a transparent glass substrate, an ITO thin film (23.43 nm),
SiO ₂ thin film (31.58 nm), TiO ₂ thin film (9
5.93 nm), surface SiO ₂ thin film (83.57 nm)
Were sequentially formed to form a transparent conductive antireflection film. Cerasolzer # 297 (solder for ultrasonic soldering, Asahi Glass Co., Ltd.) was used on this surface SiO ₂ thin film using an ultrasonic soldering device Sunborder USM-III (manufactured by Asahi Glass Co., Ltd.).
(Manufactured by K.K.) was soldered to form an earth electrode as shown in FIG. The resistance value of the ITO transparent conductive layer and the ground electrode was 0.5Ω or less, which showed good ground characteristics.

Further, the following strength test was attempted on the above-mentioned glass panel with a conductive antireflection film on which the ground electrode was formed, but the ground electrode did not peel or discolor, and all passed. MIL indicates the US military standard.

(1) Solvent resistance test: NaCl by weight
1: Water immersed in 22.3 salt water for 24 hours, MIL-C
-675C. 4.5.7 (2) Moisture resistance test: 50 ° C.-90% RH × 24 hours,
MIL-C-475C. 4.5.8 (3) Immerse in methylene chloride for 8 hours

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a ground electrode structure of a panel with a multilayer conductive antireflection film of the present invention.

FIG. 2 is an explanatory diagram showing an ultrasonic soldering method.

FIG. 3 is an explanatory diagram showing a method of connecting a ground electrode and an external terminal.

[Explanation of symbols]

 11 Substrate 21 Multilayer Transparent Conductive Antireflection Film 23 Transparent Conductive Layer 25 Low Refractive Index Layer 27 High Refractive Index Layer 29 Surface Low Refractive Index Layer 31 Ultrasonic Solder 41 Chip 43 Horn 45 Ultrasonic Transducer 47 Heater 51 Earth Wire 53 Normal Solder 55 claws

Claims (1)

[Claims] 1. In a panel in which a multilayer conductive antireflection film having a non-conductive thin film as the uppermost layer and having at least one transparent conductive layer is formed, an earth made of solder is formed on the uppermost layer by ultrasonic soldering. An earth electrode structure for a panel with a multilayer conductive antireflection film, characterized in that an electrode is formed and electrical continuity is established between the earth electrode and the transparent conductive layer.