# Patent

## Title
Electrode structure, fabrication method thereof and PDP utilizing the same

## Abstract

An electrode structure for a front board of a plasma display panel (PDP). The electronic structure connects all the sustain electrodes on the front board to prevent data transformation errors caused by holes. The fabrication method of the electronic structure is also disclosed.

## Background
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of U.S. patent application Ser. No. 10/875,773, filed Jun. 24, 2004, now U.S. Pat. No. 7,126,278.


BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrode structure, and more particularly to an electrode structure appropriate for a front board of a plasma display panel (PDP) and fabrication method thereof.
2. Description of the Related Art
PDPs are generally divided into alternating current (AC) and direct current (DC) types. The AC type PDP comprises a front board and a back board. Bus electrodes are formed on the front board. Data electrodes are formed on the back board. The front and back boards are typically glass substrates. The bus electrodes are composed of photosensitive electrode material.
In order to increase the shading values of pixels, the bus electrodes utilize two coats of a screen printing material. As shown in FIG. 1a, a dark color electrode material covers a front board 1 to form a dark color layer 3 and a light color electrode material covers the dark color layer 3 to form a light color layer 5.
The dark color electrode material is ruthenium and the light color electrode material is silver. The electrode material of the dark color layer 3 and the light color layer 5 is different such that shrinkage of the dark color layer 3 and light color layer 5 is not the same. As shown in FIG. 1b, if the shrinkage of the dark color electrode material is more than the light color electrode material, edges of the front board 1 with curl.
In order to solve the uneven shrinkage problem, a conventional method is used to control areas of the dark color layer 3 and the light color layer 5. FIG. 2a shows a conventional front board. A dark color layer 4 is formed on a front board 2 and a light color layer 6 is formed on the dark color layer 4. The area of the light color layer 6 is greater than the area of the dark color layer 4. When a scraper of a screen printing tool contacts the light color layer 6 moving from left to right, a hole 8 is generated in a left terminal of the dark color layer 4, as shown in FIG. 2b. 
FIG. 2c shows a top view of a conventional front board. An electrode pattern comprising electrodes X1 ̃Xn is formed in the front board. When the hole 8 appears in the electrode X1, the electrode X1 is cut off and malfunctions resulting in reduced PDP yield of the PDP to reduce.
SUMMARY OF THE INVENTION
An object of the present invention is to provide an electrode structure and an electrode fabrication method for preventing electrodes hole cut-off.
Accordingly, the present invention provides an electrode fabrication method. First, a substrate comprising a first region and a second region is provided. A first conductive layer is then formed overlying the first region. Next, a second conductive layer is formed overlying the first region and the second region. Finally, the second conductive layer and the underlying first conductive layer are patterned to form an electrode pattern. The electrode pattern comprises a first electrode line, a second electrode line, and a connection segment. The first electrode line and the second electrode line are disposed in parallel and formed on the first region and the second region. The connection segment connects the first electrode line and the second electrode line in the first region.
Accordingly, the present invention also provides a front board of a plasma display panel (PDP). A first region and a second region are defined on the front board. The first region is capable of displaying an image and the second region has a display driving circuit. The electrode structure comprises at least two electrode lines disposed in parallel and a connection segment. Each electrode line comprises a first segment and a second segment. The structures of the first segment and the second segment are different. The first segment is formed on the first region and the second segment on the second region. The connection segment is formed on the first region for connecting the electrode lines.



BRIEF DESCRIPTION OF THE DRAWINGS
The present invention can be more fully understood by reading the subsequent detailed description and examples with reference made to the accompanying drawings, wherein:
FIGS. 1a to 1b are cross-sections showing a conventional electrode fabrication method;
FIGS. 2a to 2c are cross-sections showing another conventional electrode fabrication method;
FIGS. 3a to 3d are cross-sections showing an electrode fabrication method of the present invention;
FIG. 4 is a top-view of the electrode structure of a second embodiment;
FIG. 5 is a top-view of the electrode structure of a third embodiment;
FIG. 6 is a top-view of the electrode structure of a fourth embodiment;
FIG. 7 is a top-view of the electrode structure of a fifth embodiment;
FIG. 8 is a top-view of the electrode structure of a sixth embodiment;
FIG. 9 is a top-view of the electrode structure of a seventh embodiment;
FIG. 10 is a structural diagram of a front board of a PDP;
FIG. 11 is a top-view of the electrode structure of an eighth embodiment.



DETAILED DESCRIPTION OF THE INVENTION
FIGS. 3a to 3d are cross-sections showing an electrode fabrication method of the present invention. First, in FIG. 3a, a glass substrate 100 comprises a first region 11, a second region C1 and a third region C2. The first region 11 comprises a display region A and a buffer region B. Bus electrodes comprise sustain electrodes and scan electrodes. A sustain electrode driving circuit is disposed in the second region C1. A scan electrode driving circuit is disposed in the third region C2. The buffer region B is disposed between the display region A and the second region C1.
Next, as shown in FIG. 3b, a first conductive layer 110 is formed overlying the display region A and the buffer region B.
Next, as shown in FIG. 3c, a second conductive layer 120 is formed overlying the display region A, the buffer region B, the first region C1 and the third region C2. A scraper of a screen printing tool moves from a left terminal to a right terminal of the glass substrate 100 such that the second conductive layer 120 completely covers the glass substrate 100 and the first conductive layer 110. Generally, the first conductive layer 110 is a dark color layer and the second conductive layer 120 is a light color layer.
Finally in FIG. 3d, the first electrode layer 110 and the second electrode layer 120 are patterned to form an electrode pattern on the glass substrate 100. The display region A and the buffer region B have the first conductive layer 110 and the second conductive layer 120. The first region C1 and the third region C2 have only the second conductive layer 120.
The electrode pattern comprises sustain electrodes X1 ̃X6 and connection segments CON1 ̃CON5. The sustain electrodes X1 ̃X6 are connected in parallel. The connection segments CON1 ̃CON5 are formed in the buffer region B and connect to the sustain electrodes X1 ̃X6. For example, the connection segment CON1 connects the sustain electrodes X1 and X2, and the connection segment CON2 connects the sustain electrodes X2 and X3. The electrode pattern further comprises scan electrodes Y1 ̃Y6 between the sustain electrodes X1 ̃X6. The scan electrodes Y1 ̃Y6 are formed in the display region A and the third regions C2.
A sustain driver 130 outputs identical sustain signals to the sustain electrodes X1 ̃X6. If a hole 8 occurs in a right terminal of the second region C1 of the sustain electrodes X1, the sustain signal is received through the connection segment CON1. When a hole occurs in any one sustain electrode, the sustain signal is received through connection segments.
In this embodiment, although the connection segments CON1 ̃CON5 are formed in the buffer region B and connected to the sustain electrodes X1 ̃X6, the present invention neither limits the location of the connection segments CON1 ̃CON5 nor the connection relationship between the connection segments CON1 ̃CON5 and the sustain electrodes X1 ̃X6.
Various connection methods are disclosed in the following. FIG. 4 is a top-view diagram of the electrode structure of a second embodiment of the invention. The connection segments CON1 ̃CON5 connect the sustain electrodes X1 ̃X6 covering the entire buffer region B. If a hole 8 occurs in the right terminal of the second region C1 of the sustain electrodes X1, the sustain signal is received through the connection segment CON1.
FIG. 5 is a top-view diagram of the electrode structure of a third embodiment. The connection segments CON1 ̃CON3 cover a portion of the buffer region B. The connection segment CON1 connects the sustain electrodes X1 and X2. The connection segment CON2 connects the sustain electrodes X3 and X4. The connection segment CON3 connects the sustain electrodes X5 and X6. Therefore, each sustain electrode is connected to the neighboring sustain electrode through at least one connection segment. If a hole 8 occurs in the right terminal of the second region C1 of the sustain electrodes X1, the sustain signal is received through the connection segment CON1.
A characteristic of the present invention is that each sustain electrode is connected to one or more sustain electrodes through the connection segment.
FIG. 6 is a top-view diagram of the electrode structure of a fourth embodiment. The connection segments CON1 ̃CON5 connect the sustain electrodes X1 ̃X6, and cover part of the buffer region B and part of the second regions C1.
FIG. 7 is a top-view diagram of the electrode structure of a fifth embodiment. The connection segments CON1 ̃CON3 cover a portion of the buffer region B and a portion of the second regions C1. In the buffer region B, the connection segments CON1 ̃CON3 comprise the first conductive layer 110 and the second conductive layer 120. In the second regions C1, the connection segments CON1 ̃CON3 have only the second conductive layer 120. The connection segment CON1 connects the sustain electrodes X1 and X2. The connection segment CON2 connects the sustain electrodes X3 and X4. The connection segment CON3 connects the sustain electrodes X5 and X6.
FIG. 8 is a top-view diagram of the electrode structure of a sixth embodiment. The connection segments CON1 ̃CON5 connect the sustain electrodes X1 ̃X6, and cover a portion of the buffer region B and the greater portion of the second regions C1.
FIG. 9 is a top-view diagram of the electrode structure of a seventh embodiment. The connection segments CON1 ̃CON3 connect the sustain electrodes X1 ̃X6, and cover a portion of the buffer region B and the greater portion of the second regions C1. The connection segment CON1 connects the sustain electrodes X1 and X2. The connection segment CON2 connects the sustain electrodes X3 and X4. The connection segment CON3 connects the sustain electrodes X5 and X6.
FIG. 10 is a structural diagram of a front board of a PDP. The front board 100 comprises first region 11 and second region C1. The first region 11 is capable of displaying an image. The second region C1 has a sustain driver 130. The bus electrodes of the front board 100 comprise sustain electrodes X1 ̃Xn and scan electrodes Y1 ̃Yn.
Sustain electrodes X1 ̃Xn are disposed in parallel. Each sustain electrode comprises a first segment formed on the first region 11 and a second segment formed on the second region C1. The first region 11 has a laminated construction with first conductive material layer. The second region C1 has only second conductive material layer. Connection segments CON1 ̃CONn-1 form on the first region 11 for connecting sustain electrodes X1 ̃Xn.
The first region 11 comprises display region A for displaying an image and buffer region B between the first region 11 and second region C1 for disposing connecting connection segments CON1 ̃CONn-1. In this embodiment, connection segments CON1 ̃CONn-1 form on a portion of buffer region B and second region C1.
In addition, the front board 100 further comprises scan electrodes Y1 ̃Yn controlled by a scan driver 140 and formed on display region A and third region C2.
When a hole 8 occurs in the right terminal of the second region C1 of any one sustain electrode, the sustain electrode also receives the sustain signal through the connection segment.
FIG. 11 is a top-view of the electrode structure of an eighth embodiment. The connection segments CON ̃CON5 connect the sustain electrodes X1 ̃X6, and cover the entire buffer region B and a portion of the second regions C1.
While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.

## Claims

1. An electrode fabrication method comprising:
providing a substrate with a first region and a second region;
forming a first conductive material layer overlying the first region;
forming a second conductive material layer overlying the first region and the second region; and
patterning the second conductive material layer and the underlying first conductive material layer to form an electrode pattern, wherein the electrode pattern comprises a first electrode line, a second electrode line, and a connection segment, the first electrode line and the second electrode line are disposed in parallel and formed on the first region and the second region, and the connection segment connects the first electrode line and the second electrode line in the first region;
wherein the first region comprises a display region and a buffer region between the display and the second region.

2. The electrode fabrication method as claimed in claim 1, wherein the connection segment is formed on the buffer region.

3. The electrode fabrication method as claimed in claim 1, wherein the first electrode line and the second electrode line have a laminated construction with first conductive material layer and second conductive material layer.

4. The electrode fabrication method as claimed in claim 1, wherein the connection segment forms on a portion of the buffer region.

5. The electrode fabrication method as claimed in claim 4, wherein the connection segment further forms on a portion of the second region.

6. The electrode fabrication method as claimed in claim 1, wherein the connection segment forms on the entire buffer region.

7. The electrode fabrication method as claimed in claim 6, wherein the connection segment further forms on a portion of the second region.