JPH0935628A - Electrode formation of ac plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply form a stable composite electrode without changing layer constitution or the like, by restraining etching speed of an ITO film during patterning of a metal laminated film by annealing a front board on which the ITO film is formed. SOLUTION: For forming a composite electrode on a front board 1, an ITO film is formed on the front board 1 and thereafter the front board is annealed, and nextly a metal laminated film, which consists of a Cr first layer film, a Cu second layer film, and a Cr third layer film, is formed on the ITO film, and each film of the metal laminated film is each patterned by etching to form a bus electrode 5 of three-layer structure consisting of a Cr first layer electrode 5a, a Cu second layer electrode 5b, and a Cr third layer electrode 5c, and then a maintaining electrode 4 is formed by pattering the ITO film by etching. A change in quality of the ITO due to heat of annealing-processing restraining etching speed, the ITO film is not etched when the bus electrode is patterned, causing a stable composite electrode to be simply formed without changing a combination of the maintaining electrode of the ITO and the bus electrode.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrode forming method of an AC type plasma display panel (hereinafter referred to as PDP) which is a self-luminous flat panel display using gas discharge.

[0002]

2. Description of the Related Art FIG. 1 shows an example of the configuration of an AC PDP. As shown in the figure, a front plate 1 and a rear plate 2 made of glass are arranged in parallel and opposite to each other, and a barrier rib 3 standing on the front side of the rear plate 2 is fixed. The barrier rib 3 holds the front plate 1 and the rear plate 2 at a constant interval. And
On the back side of the front plate 1, a composite electrode including a sustain electrode 4 which is a transparent electrode and a bus electrode 5 which is a metal electrode is formed in parallel with each other, and a dielectric layer 6 is formed so as to cover the composite electrode. The MgO layer 7 is formed on it. Address electrodes 8 are formed on the front side of the back plate 2 so as to be orthogonal to the composite electrodes and between the barrier ribs 3 and are parallel to each other, and a dielectric layer 9 is formed thereon as necessary. Further, the fluorescent layer 10 is provided so as to cover the wall surface of the barrier rib 3 and the bottom surface of the cell.

In this AC type PDP, by applying a predetermined voltage from an AC power source between the composite electrodes on the front plate 1 to form an electric field, the front plate 1, the rear plate 2 and the barrier rib 3 are formed.
Discharge is performed in each cell 11 as a display element partitioned by and. Then, the fluorescent layer 10 is caused to emit light by the ultraviolet rays generated by this discharge, and an observer visually recognizes this light transmitted through the front plate 1.

[0004]

Among the composite electrodes of the front plate 1 in the AC type PDP, ITO, SnO ₂ , ZnO, etc. may be used as the material of the sustain electrode 4, but the ease of film formation and patterning is considered. Considering the above, ITO is often used. On the other hand, the bus electrode 5 is generally made of a laminated metal in consideration of the adhesion to ITO and the resistance value. However, considering the etching selectivity of each patterning, it is difficult to determine the combination of metals to be used. For example, it is desirable that the bus electrode 5 has a laminated structure of Cr / Cu / Cr, but C
Since the etchant of r etches Cu or ITO, it becomes difficult to function as a composite electrode. In order to avoid this, one more layer may be added to the bus electrode 5 or the sustain electrode 4 may be protected by a resist, but the process becomes complicated. Further, when another layer structure (Cr / Al / Cr, Al / Cr, etc.) is considered as the bus electrode 5, not only etching selectivity but also a problem such as an influence of oxidation due to heat in a later step occurs.

The present invention has been made in view of the above problems, and an object thereof is an AC in which a stable composite electrode can be easily formed without changing the layer structure or the like. An object of the present invention is to provide a method for forming an electrode of a type PDP.

[0006]

In order to achieve the above object, the present invention provides a method of forming a composite electrode in an AC type PDP having a composite electrode comprising a sustain electrode and a bus electrode on a front plate. After forming the ITO film on the front plate, the front plate is annealed, and then C on the ITO film.
forming a metal laminated film including a first layer film of r, a second layer film of Cu, and a third layer film of Cr, and patterning each film of the metal laminated film by etching to form a first layer electrode of Cr, A characteristic feature is that a bus electrode having a three-layer structure of a second layer electrode of Cu and a third layer electrode of Cr is formed, and then the ITO film is patterned by etching to form a sustain electrode.

By annealing (annealing) the front plate on which the ITO film is formed as described above, the ITO is altered and the etching rate of the ITO film at the time of patterning the metal laminated film is suppressed. That is, the etchant of Cr usually dissolves ITO, but the quality of the ITO is changed by heat during the annealing treatment of the front plate, and the etching time is increased as compared with the ITO just formed. Therefore, Cr
The ITO is not etched while the patterning is performed.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

The structure of the AC type PDP to which the present embodiment is applied is the same as that shown in FIG. 1. As shown in the enlarged view of FIG. 2, the bus electrode 5 of the composite electrodes of the front plate 1 is the sustain electrode. It has a three-layer structure of a first layer electrode 5a of Cr, a second layer electrode 5b of Cu, and a third layer electrode 5c of Cr in order from the 4th side.
Hereinafter, an embodiment of the present invention in which this composite electrode is formed on the back surface side of the front plate 1 will be described. The manufacturing procedure other than the above is the same as the conventional one, and thus the description thereof is omitted.

First, as shown in FIG. 3A, the front plate 1
I on the glass substrate to be
The TO film 20 is formed. The film thickness is 1500-2000
Å, sheet resistance is 20Ω / □, transmittance is 80
% Or more.

Next, the front plate 1 having the ITO film 20 formed thereon is annealed. When soda lime glass is used for the front plate 1, the annealing temperature is about 580 ° C. at the maximum, and it is practically preferable to heat to 400 to 500 ° C. and gradually cool. By performing the annealing treatment in this manner, the quality of ITO is changed by heat, and the etching rate thereof becomes slow. In addition, disconnection of electrodes due to warpage of glass in a firing process described later is prevented, and misalignment of alignment at the time of paneling is prevented.

After annealing the front plate 1, as shown in FIG.
As shown in (b), a first layer film 21 of Cr (thickness 500Å) and a second layer film 22 of Cu (thickness 1) are formed on the ITO film 20.
0000Å), Cr third layer film 23 (thickness 2000Å)
A metal laminated film made of is sequentially formed. The film forming method thereof is a sputtering method or a vacuum evaporation method.

Next, a photoresist is applied on the metal laminated film and dried, and then an exposure and development process is performed to pattern the photoresist R as shown in FIG. 2 (c). In the present embodiment, “OFPR-800” (5 cp) manufactured by Tokyo Ohka Kogyo Co., Ltd. is used as the photoresist R, and this is applied on the metal laminated film to a film thickness of about 6000 Å, and at 3 ° C. at 85 ° C.
After pre-baking for 0 minutes, exposure was performed for about 3 seconds through a mask, and then "NMD-" manufactured by Tokyo Ohka Kogyo Co., Ltd.
3 ”for about 60 seconds to pattern the photoresist R.

Then, after post-baking for 30 minutes, the patterned photoresist R is used as a mask to form each film 21 to 21 of the metal laminated film as shown in FIG. 3D.
23 is patterned by etching. Here, as an etchant for Cr, "AlCl ₃ .6H
₂ O: ZnCl ₂ : H ₃ PO ₄ : H ₂ O = 454 g: 1
35 g: 30 ml: 400 ml "and ammonium persulfate ((NH ₄ ) ₂ S is used as an etchant for Cu.
₂ O ₈ ) in water (80 g / l) was used. This Cr
The ITO is usually dissolved in the etchant, but the front plate 1
Since the ITO is deteriorated by heat during annealing and the etching rate is slowed, the ITO is less likely to be etched during the Cr patterning as compared with the case where the normal annealing is not performed. After etching and patterning each of the films 21 to 23 of the metal laminated film in this manner, the photoresist R is peeled off,
By washing with water and drying, the bus electrode 5 having a three-layer structure is formed as shown in FIG.

Then, the photoresist is applied again and dried, and then the photoresist R is patterned as shown in FIG. 4B through the exposure and development steps. In this case, the pattern width of the photoresist R corresponds to the line width of the sustain electrode 4. Then, as shown in FIG.
I using the patterned photoresist R as a mask
After the TO film 20 is etched and patterned into a predetermined pattern, the photoresist R is peeled off, washed with water and dried to form the sustain electrode 4 as shown in FIG. Let This ITO film 20
As an etchant, water, hydrochloric acid and nitric acid are 1: 1:
An aqueous solution mixed at a ratio of 0.08 was used. The etching time was about 2 minutes in the case of ordinary ITO, whereas it took about 10 minutes here.

In the composite electrode formed in the above process, the film thickness and the line width of ITO, which is the sustain electrode 4, are kept uniform, so that the in-plane resistance value of the electrode is constant.
It was possible to suppress disconnection and local temperature rise when the panel was turned on.

[0017]

As described above, the AC according to the present invention
The electrode forming method of the type PDP is as follows. When forming a composite electrode on the front plate, an ITO film is formed on the front plate, the front plate is annealed, and then a first layer film of Cr is formed on the ITO film. A metal laminated film including a second layer film of Cu and a third layer film of Cr is formed, and each film of the metal laminated film is patterned by etching to form a first layer electrode of Cr, Cu.
After the bus electrode having a three-layer structure of the second layer electrode of Cr and the third layer electrode of Cr is formed, the ITO film is patterned by etching to form the sustain electrode. Since the ITO deteriorates and the etching rate is suppressed, the I
Since the TO film is not etched, it is possible to change the selectivity between ITO and Cr, which have been difficult to obtain etching selectivity in the past, and the ITO sustaining electrode and the C
Without changing the combination of r / Cu / Cr bus electrodes
A stable composite electrode can be easily formed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing one configuration example of an AC type plasma display panel.

FIG. 2 is an enlarged view showing a composite electrode formed on the back side of the front plate.

FIG. 3 is a first half process drawing for explaining an electrode forming method of an AC type plasma display panel according to the present invention.

FIG. 4 is a process chart of the latter half of FIG.

[Explanation of symbols]

 1 front plate 4 sustain electrode 5 bus electrode 5a first layer electrode 5b second layer electrode 5c third layer electrode 20 ITO film 21 first layer film 22 second layer film 23 third layer film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasunori Kurima 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Within Dai Nippon Printing Co., Ltd. (72) Masanori Fukuda 1-chome, Ichigaya-Kagacho, Shinjuku-ku, Tokyo No. 1 in Dai Nippon Printing Co., Ltd.

Claims (1)

[Claims] 1. A method of forming the composite electrode in an AC type plasma display panel comprising a composite electrode comprising a sustain electrode and a bus electrode on a front plate, the method comprising: forming an ITO film on the front plate; The front plate is annealed,
Next, on the ITO film, a Cr first layer film, a Cu second layer film,
A metal laminated film composed of a Cr third layer film is formed, and each film of the metal laminated film is patterned by etching to form a Cr first layer electrode, a Cu second layer electrode, and a Cr third layer.
After forming a bus electrode having a three-layer structure of layer electrodes, I
An electrode formation method for an AC type plasma display panel, characterized in that the TO film is patterned by etching to form a sustain electrode.