JPH0962203A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent disconnection of a metallic electrode to compensate electric conductivity of a transparent electrode without narrowing an arranging interval of display electrodes. SOLUTION: In the case of manufacturing a display device which has plural display electrodes X and Y arranged in one direction and in which the respective display electrodes X and Y are composed of a transparent electrode 41 and a metallic electrode 42 thinner and longer than it and the metallic electrode 42 is superposed on the transparent electrode 41, and is arranged so that a width of the display electrodes does not exceeds a maximum width of the transparent electrode over the total length of the transparent electrode 41, an end part of the transparent electrode 41 is patterned in the shape of overlapping only with a part of the arranging direction M2 of the display electrodes X and Y in the metallic electrode 42.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PDP, LCD, E having a display electrode having a laminated structure of a transparent conductive film and a metal film.
It relates to a display device such as L.

As the display has become finer, the electrodes have become thinner and more densely arranged. Therefore, there is an increasing need for a technique for preventing disconnection and short circuit between electrodes.

[0003]

2. Description of the Related Art Here, a conventional electrode structure will be described by taking a PDP (plasma display panel) which is one type of thin display device as an example.

FIG. 8 is a diagram showing the structure of a conventional PDP 90. 8 (A) is an external view, FIG. 8 (B) is a cross-sectional view of a main part,
FIG. 8C is a plan view of the display electrode. PDP90 is
A pair of substrates 110, 2 facing each other across the discharge space 300
10, a display electrode 400 arranged on the inner surface side of the front substrate 110, an AC driving dielectric layer 170 for covering the display electrode 400 with respect to the discharge space 300, and sealing for joining the peripheral portions of the substrate pair. It is composed of a material 310 and the like.

The display electrode 400 is a strip-shaped transparent electrode 410.
And a thinner metal electrode 420. Metal electrode 4
20 is a transparent electrode 41 as an auxiliary conductor for reducing the voltage drop in the display electrode 400, because the material of the transparent electrode 410 (ITO, NESA, etc.) has a relatively high resistance.
Overlaid on 0. Both the transparent electrode 410 and the metal electrode 420 are patterned by the photolithography method.

Such a display electrode 400 extends from the display screen area to the outside of the encapsulant 310 and is provided on the substrate 110.
Is connected to a drive circuit (not shown) at the edge portion thereof. However, it is known that when the display electrode 400 is led to the edge of the substrate 110 in a laminated structure in which the transparent electrode 410 and the metal electrode 420 overlap, peeling of the tip of the display electrode 400 easily occurs. (Japanese Patent Laid-Open No. 4-56039
issue). Therefore, in the PDP 90, the position of the tip of the transparent electrode 410 is within the range of the inside of the sealing material 310 in which the dielectric layer 170 is present, and only the metal electrode 420 is led out to the edge portion of the substrate 110. That is, the metal electrode 420 is
It protrudes in the extension direction of the display electrode 400 with respect to the transparent electrode 410, and the protruding portion is in contact with the substrate 110.
In addition, as shown in FIG. 8C, the tip portion 42 of the metal electrode 420 is
2 has become huge, and functions as an external connection terminal.

[0007]

In the electrode structure in which the metal electrode 420 is projected with respect to the transparent electrode 410 as described above, a step is inevitably generated at the tip position of the transparent electrode 410, and the metal electrode 420 is stepped. 421 will be included.

Conventionally, the metal electrode 420 has the step portion 421.
It often happened that the wire became thin and thin locally, resulting in disconnection. The reason why the metal electrode 420 becomes thin is that a gap is formed between the tip surface of the transparent electrode 410 and the metal film mainly when the metal film is formed to form the metal electrode 420, and the metal film is etched. This is because the etching solution permeates into the voids at the stage and the side etching progresses faster.

As an electrode structure effective in reducing the influence of side etching, Japanese Patent Laid-Open No. 4-56039 discloses that the metal electrode 420 is made thicker than the transparent electrode 410 near the end of the transparent electrode 410. A structure is disclosed in which not only the tip surface but also the side surface is covered with the metal electrode 420. However, if the metal electrode 420 is thicker than the transparent electrode 410, the arrangement interval of the display electrodes 400 is narrowed, which may cause abnormal discharge or excessive lighting. Further, it is difficult to achieve high definition by reducing the electrode pitch.

On the other hand, as a result of investigating the cause of the thin metal electrode 420, the etching mask is cut off at the step portion 421 when the metal electrode 420 is patterned, and the etching solution permeates from the cut portion to cause unscheduled etching. It turned out to be.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent disconnection of a metal electrode that supplements the conductivity of a transparent electrode without narrowing the arrangement interval of the display electrodes.

[0012]

A device according to the invention of claim 1 has a plurality of display electrodes arranged in one direction, each display electrode being a transparent electrode and a metal electrode thinner and longer than that. A display device in which the metal electrode is overlaid on the transparent electrode and the width of the display electrode does not exceed the maximum width of the transparent electrode over the entire length of the transparent electrode. The end portion is patterned into a shape that overlaps only a part of the metal electrode in the arrangement direction of the display electrodes.

At the end of the transparent electrode, an edge extending in the extending direction of the display electrode or a direction inclined with respect to the extending direction and covered with a metal electrode is formed. As a result, disconnection of the metal electrode is less likely to occur as compared with the case where only the edge in the direction orthogonal to the extending direction is covered with the metal electrode.

According to a second aspect of the present invention, the end portion of the transparent electrode is patterned in a strip shape thinner than the metal electrode. The device of the invention of claim 3 is such that the end of the transparent electrode is patterned so as to become thinner as it approaches the tip.

[0015]

FIG. 1 is a perspective view showing the internal structure of a PDP 1 according to the present invention. Further, FIG. 2 is a schematic view of the electrode structure of the PDP 1, and schematically shows the electrode arrangement form viewed from the discharge space 30.

The PDP 1 is a surface discharge type PDP having a matrix display type three-electrode structure, and is called a reflection type in terms of classification according to the arrangement form of the phosphors. In the PDP 1, a pair of display electrodes X and Y for generating surface discharge along the substrate surface are arranged on each inner line of the front glass substrate 11 for each line L of matrix display. Then, a dielectric layer 17 for AC driving is provided so as to cover the discharge space 30 with these display electrodes X and Y. A protective film 18 is vapor-deposited on the surface of the dielectric layer 17. Both the dielectric layer 17 and the protective film 18 have translucency.

Each of the display electrodes X and Y is composed of a wide linear transparent electrode 41 made of an ITO thin film and a narrow linear bus electrode 42 made of a metal thin film (Cr / Cu / Cr). ing. The width of the transparent electrode 41 is 1
The width of the bus electrode 42 is about 50 μm, and the width of the bus electrode 42 is about 60 μm. The bus electrode 42 is an auxiliary electrode for ensuring proper conductivity, and is laminated on the edge of the transparent electrode 41 on the side far from the surface discharge gap. By adopting such an electrode structure, it is possible to expand the surface discharge region and enhance the light emission efficiency while minimizing the blocking of the display light.

On the other hand, on the inner surface of the glass substrate 21 on the back side, address electrodes A are arranged so as to be orthogonal to the display electrodes X and Y. The address electrode A is provided on the base layer 22 and covered with the dielectric layer 24. On the dielectric layer 24, one partition 29 having a linear shape in plan view is provided between each address electrode A. Due to these barrier ribs 29, the discharge space 30 is arranged in the line direction (display electrodes X,
The discharge space 30 is divided into sub-pixels in the Y extension direction, and the gap size of the discharge space 30 is defined. Then, three-color phosphor layers 28R, 28G, and 28B for color display are provided so as to cover the surface of the dielectric layer 24 and the side surface of the partition 29, including the upper part of the address electrode A.

In the PDP 1, one line of matrix display corresponds to a pair of display electrodes X and Y, and one column corresponds to one address electrode A. Then, three columns correspond to one pixel. The state of accumulation of wall charges in the dielectric layer 17 is controlled by the opposing discharge between the address electrode A and the display electrode Y. When a sustaining pulse is applied to the display electrodes X and Y alternately, surface discharge occurs in the sub-pixels in which the wall charges are accumulated. The phosphor layers 28R, 28G, 28B are locally excited by the ultraviolet rays generated by the surface discharge and emit visible light of a predetermined color. Of this visible light, the light that passes through the glass substrate 11 becomes the display light.

As shown in FIG. 3, all the display electrodes X are led out to the edge portion on one end side in the line direction of the glass substrate 11, and all the display electrodes Y are led out to the edge portion on the other end side. . However, in practice, as in the conventional example, the bus electrode 42, which is an auxiliary conductor in the display electrodes X and Y, is led out to the end edge portion of the glass substrate 11, and the transparent electrode 41 is used as the bonding region a31 (see FIG. 3 is not led out to the outside of the hatched frame-shaped region 3).

The display electrode X is integrated with the common terminal Xt for the sake of simplification of the drive circuit, and is electrically shared. The display electrode Y is an individual electrode that is independent for each line in order to enable line-sequential line scanning, and an individual terminal Yt is provided at the tip of each display electrode Y. Further, the address electrode A is set to 1 in order to facilitate the terminal arrangement.
The lines are alternately extended to one end side or the other end side, and are integrated with the individual terminals At at the edge portion of the glass substrate 21 in the column direction.

In the manufacture of the PDP 1 having the above structure, the display electrodes X and Y are formed by photolithography. That is, first, ITO is evenly formed on the glass substrate 11.
A film is formed, a mask pattern made of a photosensitive resist material is provided, and the ITO film is etched to form the transparent electrode 41. The maximum thickness of the ITO film is about 2000Å.
Next, Cr / Cu / C is formed so as to cover the transparent electrode 41.
A metal film having a three-layer structure of r is formed by sputtering, and a mask pattern made of a photosensitive resist material is provided.
The metal film is etched to form the bus electrode 41. The thickness of the metal film is 2 to 4 μm.

At the time of forming such an electrode, a large-sized glass substrate 11 (for example, an outer dimension is 460 mm × 3) is used by using a roll coater method for coating a photosensitive resist material.
A solid resist layer having an appropriate thickness on the surface (40 mm) can be provided. However, if the coating surface has a step extending in a direction orthogonal to the coating direction, the resist layer tends to be locally thin at the step. When forming the bus electrode 42, a resist material is applied from one end to the other end along the extension direction of the transparent electrode 42 already formed.
That is, the coating direction is the extension direction of the transparent electrode 42 (display line direction). Therefore, the resist layer is locally thinned at the step portions formed at both ends of the transparent electrode 42 in the extension direction, and a break is likely to occur in the etching mask pattern. In the PDP 1, the shape of the end of the transparent electrode 41 is devised so as to reduce the influence of the step.

The shapes of the display electrodes X and Y will be described below. For the sake of convenience, the display electrode Y is representatively shown in the following figures.
However, in the display electrode X as well as in the display electrode Y, the end portion of the transparent electrode 41 is patterned.

FIG. 3 is a plan view of the main part of the display electrodes Y and X. In the display electrodes Y and X, the end portion 41a of the transparent electrode 41 in the extension direction M1 is notched at one end side in the width direction M2 and is patterned into a band shape thinner than the bus electrode 42. The bus electrode 42 is patterned so that one end edge in the width direction M2 matches the transparent electrode 41 and covers the end portion 41a. The width of the end portion 41a is, for example, 4
When the width is 0 μm, the width of the bus electrode 42 is 60 μm, so that the 20 μm portion of the bus electrode 42 in the width direction M2 does not overlap with the transparent electrode 41 in the range of the length of the end portion 41a in the extension direction M1.

When the shape of the transparent electrode 41 is selected in this way, the length of the portion covered by the bus electrode 42 (the broken line portion in the drawing) within the edge of the transparent electrode 41 is determined by the length of the bus electrode 42.
Can be greater than or equal to the width. Therefore, the bus electrode 4
Even if the etching solution permeates along the edge of the transparent electrode 41 during the patterning of 2, the progress of etching does not reach the entire length of the covering distance, and the bus electrode 42 is not broken. In addition, the edge e along the width direction M2
Not only 1 and e2, but also the edge e3 along the extension direction M1 in which a break in the resist layer is unlikely to occur is covered with the bus electrode 42, so that the etching solution permeates from the break in the resist layer when the bus electrode 42 is patterned, and the edge is cut off. e1,
Even if the notch corresponding to e2 occurs in the bus electrode 42, the portion corresponding to the end edge e3 is not interrupted and the bus electrode 42
Does not break.

That is, the shape of the transparent electrode 41 is a shape that is less affected by side etching and step coverage failure of the resist layer, and is advantageous in increasing the yield of forming the bus electrode 42.

4 to 7 are views showing modified examples of patterning of the transparent electrode. In the example of FIG. 4, the end portion 41Ba of the transparent electrode 41B is patterned in a right triangle shape so that the end portion 41Ba becomes thinner toward the tip. Then, the bus electrode 42 is patterned so as to cover the end portion 41Ba. In this case as well, the length of the portion (broken line portion in the drawing) e4 covered by the bus electrode 42 within the edge of the transparent electrode 41B can be made greater than or equal to the width of the bus electrode 42. Further, the edge e4 extends in a direction inclined with respect to the extension direction M1, but a break in the resist layer is less likely to occur as compared with the case where it extends in the width direction M2. Furthermore, since it becomes thinner toward the tip, the etching in the thickness direction by the etching solution that has permeated between the ITO film and the resist layer becomes more prominent as it approaches the tip when etching the ITO film, as shown in FIG. Thus, the closer the end 41Ba is to the tip, the thinner it becomes. That is, the end surface of the transparent electrode 41B becomes an inclined surface, and the covering state of the bus electrode 42 becomes good.

In the example of FIG. 5, the end portion 41 of the transparent electrode 41C is
Ca is patterned into an isosceles shape so that it becomes thinner as it approaches the tip. Then, the bus electrode 42
Is patterned so as to cover the end portion 41Ca. Also in this case, a portion of the edge of the transparent electrode 41C covered by the bus electrode 42 (broken line portion in the figure) e
The length of 5, e6 can be made larger than the width of the bus electrode 42. Moreover, since the edges e5 and e6 extend in different directions from each other, the etching liquid is less likely to permeate than when the bus electrode 42 covers only one direction. Also, FIG.
Similar to the example of, the end 41Ca becomes thinner as it approaches the tip,
The covering state of the bus electrode 42 becomes good.

In the example of FIG. 6, the end portion 41 of the transparent electrode 41D is formed.
One end side in the width direction M2 in Da is patterned in a comb shape. The bus electrode 42 is patterned so as to cover the comb-shaped portion. The comb teeth extend in the extension direction M1.

In the example of FIG. 7, the end portion 41 of the transparent electrode 41E is
Ea is patterned into a shape in which one end side in the width direction M2 is cut out in a strip shape narrower than the bus electrode 42. The bus electrode 42 is patterned so as to overlap the cutout portion of the transparent electrode 41E.

In the present invention, the counter discharge type PDP, L
It can also be applied to display devices such as CDs and ELs.

[0033]

According to the first to third aspects of the present invention,
It is possible to prevent disconnection of the metal electrode that supplements the conductivity of the transparent electrode without narrowing the arrangement interval of the display electrodes.

According to the third aspect of the present invention, the end face of the transparent electrode is an inclined face, and the state of the metal electrode covering the transparent electrode can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an internal structure of a PDP according to the present invention.

FIG. 2 is a schematic view of an electrode structure of a PDP.

FIG. 3 is a plan view of a main part of a display electrode.

FIG. 4 is a diagram showing a modification of patterning of a transparent electrode.

FIG. 5 is a diagram showing a modification of patterning of a transparent electrode.

FIG. 6 is a diagram showing a modification of patterning of a transparent electrode.

FIG. 7 is a diagram showing a modification of patterning of a transparent electrode.

FIG. 8 is a diagram showing a configuration of a conventional PDP.

[Explanation of symbols]

 1 PDP (Display Device) 41 Transparent Electrode 41B, 41C, 41D, 41E Transparent Electrode 41a End 41Ba, 41Ca, 41Da, 41Ea End 42 Bus Electrode (Metal Electrode) M1 Extension Direction M2 Width Direction (Array Direction) X, Y Display electrode

Claims (3)

[Claims] 1. A display having a plurality of display electrodes arranged in one direction, each display electrode comprising a transparent electrode and a metal electrode which is thinner and longer than the transparent electrode, the metal electrode being on the transparent electrode. A display device arranged so that the width of the display electrode overlaps and does not exceed the maximum width of the transparent electrode over the entire length of the transparent electrode, wherein an end portion of the transparent electrode is an array of the display electrodes in the metal electrode. A display device characterized by being patterned into a shape that overlaps only part of the direction. 2. The display device according to claim 1, wherein an end portion of the transparent electrode is patterned in a band shape thinner than the metal electrode. 3. The display device according to claim 1, wherein the end portion of the transparent electrode is patterned so that the end portion becomes thinner toward the tip.