Abstract:
A thin film transistor array substrate is provided. A plurality of shield lines are disposed between the lead lines in a peripheral circuit region of the substrate. A connecting line connected to the shield lines is also disposed in peripheral circuit region of the substrate. The shield lines and the connecting line are formed of a metal layer so that light leakage between the lead lines of a source/drain layer or a gate layer is reduced. Furthermore, the line widths in the connecting portions of the shield lines connected to the connecting lines are smaller than the distance between the lead lines. Therefore, if a short happens between the lead lines and the shield lines, repair may be performed by cutting the connection portions between the shield lines and the connecting lines.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of Invention 
   The present invention generally relates to a liquid crystal display (LCD) and thin film transistor (TFT) array substrate thereof. More particularly, the present invention relates to a liquid crystal display and thin film transistor array substrate thereof including a peripheral circuit region with terminal-narrowed shield lines. 
   2. Description of Related Art 
   In recent years, with great advance in the fabricating technique of electrical-optical and semiconductor devices, flat panel displays (FPDs), such as liquid crystal displays (LCDs), have been developed. Due to the advantageous features of LCDs, for example, low operation voltage, no harmful radiation, light weight, and compact size, LCDs replace the conventional Cathode Ray Tube (CRT) monitors and become mainstream. 
     FIG. 1  is a simplified cross-sectional view of a conventional liquid crystal display module. The liquid crystal display module shown in  FIG. 1  comprises a thin film transistor array substrate  110 , a color filter substrate  120 , a black matrix layer  122  thereon, a sealant  130 , a liquid crystal layer  140 , polarizing films  152 ,  154  and an outer frame  160 . The black matrix layer  122  is disposed on the color filter substrate  120 . The sealant  130  is disposed between the color filter substrate  120  and the thin film transistor array substrate  110 . The liquid crystal layer  140  is disposed within the space bounded by the color filter substrate  120 , the thin film transistor array substrate  110  and the sealant  130 . Furthermore, the polarizing films  154 ,  152  are disposed on other sides of the thin film transistor array substrate  110  and the color filter substrate  120 , respectively. The outer frame  160  is disposed on the polarizing film  152 . In addition, the thin film transistor array substrate  110  can be divided into a pixel region  110   a  and a peripheral circuit region  110   b.  The peripheral circuit region  110   b  has a plurality of lead lines  112  therein for connecting pixels in the pixel region  110   a  and peripheral circuits in the peripheral circuit region  110   b.    
   In a drop filling (ODF) process for forming the liquid crystal layer  140 , if the sealant  130  is non-uniformly radiated by ultraviolet, the incompletely hardened sealant  130  may contaminate the liquid crystal  140 . For this reason, the black matrix layer  122  on the color filter substrate  100  is slightly shrunk towards the center of the panel. However, because of the slight shrink of the black matrix layer  122 , an area with light of leakage  170  is formed between the black matrix layer  122  and the sealant  130 . In addition, there is no shield between the lead lines  112  within the peripheral circuit region  110   b . Hence, light  180  emitted from the back light module may pass through the gaps between the lead lines  112 , and light-leakage occurs at the junction between the outer frame  160  and the thin film transistor array substrate  110 . 
   Therefore, in a prior solution, a shield layer, made of a first metal layer (M 1 ) and a second metal layer (M 2 ), is between the lead lines.  FIG. 2  shows a partial top view of the peripheral circuit region of the thin film transistor array substrate. Referring to  FIG. 2 , each of a plurality of shield lines M 10 , made of the first metal layer, is disposed between two source lines S 10 , each made of the second metal layer. For leakage prevention, the shield line M 10  is partially overlapped with two adjacent source leads S 10 . However, in case of particle contamination or static discharge, shorts occur at the overlap, for example, pointed by an arrow A 10  in  FIG. 2 , between the shield line M 10  and the source line S 10 . If so, a corresponding row of pixels is called a “bright line”, and the panel is not qualified. 
   SUMMARY OF THE INVENTION 
   One of the objects of the invention is to provide a thin film transistor array substrate of liquid crystal liquid, for preventing occurrence of light-leakage and improving the yields. 
   Another object of the invention is to provide a thin film transistor array substrate of liquid crystal liquid, for preventing occurrence of light-leakage and improving the yields. 
   To at least achieve the above and other objects, the invention provides a thin film transistor array substrate. The thin film transistor array substrate comprises: a substrate; a thin film transistor array, a plurality of first lines, a plurality of second lines, a plurality of first shield lines and a first connection lines. The substrate includes a pixel region and a peripheral circuit region surrounding the pixel region. The thin film transistor array is disposed in the pixel region and includes a first conductive layer and a second conductive layer. The first lines are disposed on the peripheral circuit region, and the first lines are on the same layer of the first conductive layer. The second lines are disposed on the peripheral circuit region, and the second lines are on the same layer of the second conductive layer. The first shield lines are disposed on the peripheral circuit region, and the first shield lines are between and overlapped with the second lines for preventing lights pass through the gaps between the second lines. The first connection line is electrically connected to the first shield lines. The first shield lines and the first connection line are on the same layer of the first conductive layer. The connection parts of the first shield lines to the first connection lines have widths smaller than gaps between the first lines. 
   The invention discloses a liquid crystal liquid (LCD), comprising a foresaid thin firm transistor array substrate, an opposite substrate, and a liquid crystal layer. The liquid crystal layer is between the thin firm transistor array substrate and the opposite substrate and the thin firm transistor array is used for controlling arrangements of the liquid crystal layer. 
   In the LCD, the opposite substrate comprises a color filter film substrate. The LCD further includes a backlight module, formed besides the opposite substrate or the thin firm transistor array substrate, for emitting light to the liquid crystal display panel. 
   In one embodiment, each of the first shield lines has a side part overlapping with adjacent second lines. 
   In another embodiment, the thin firm transistor array substrate further comprises a plurality of second shield lines and a second connection line. The second shield lines are disposed on the peripheral circuit region. The second shield lines are between and overlapped with the first lines, for preventing lights pass through the gaps between the second lines. The second connection line is electrically connected to the second shield lines. The second shield lines and the second connection line are on the same layer of the second conductive layer. The connection parts of the second shield lines to the second connection lines have smaller widths than the gaps between the first lines. Besides, each of the second shield lines has a overlapped part with the first lines. 
   In still another embodiment, a predetermined voltage is coupled to the first shield lines and the first connection line. Furthermore, a predetermined voltage is coupled to the second shield lines and the second connection line. 
   In still another embodiment, the first conductive layer is a gate layer and the second conductive layer is a source/drain layer. Or, the first conductive layer is a source/drain layer and the second conductive layer is a gate layer. 
   As above, in the LCD module and the TFT array substrate thereof in the invention, the shield lines made of first or second metal layer are disposed in the peripheral circuit region for preventing leakage of light. Besides, by feeding predetermined voltages on the shield lines, the signal interference between gate/source lines is improved. In case of bright lines, the narrowed terminals of the shield lines are cut off by laser for repairing bright lines. Therefore, yield of the TFT module is improved. 
   It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the invention as claimed. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. 
       FIG. 1  is a sectional view of a prior liquid crystal display (LCD) module. 
       FIG. 2  shows a top view of the peripheral circuit region of the thin film transistor array substrate. 
       FIG. 3  shows a sectional view of a LCD module according to a preferred embodiment of the invention. 
       FIG. 4  shows a top view of the thin film transistor array substrate of LCD according to a preferred embodiment of the invention. 
       FIG. 5  shows an enlargement of an area R 10  in  FIG. 4 . 
       FIG. 6  and  FIG. 7  show sectional views taken along lines I-I and II-II of  FIG. 5 , respectively. 
       FIG. 8  shows an enlargement of an area R 20  in  FIG. 4 . 
       FIG. 9  and  FIG. 10  show sectional views taken along lines III-III and IV-IV of  FIG. 8 , respectively. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     FIG. 3  shows a sectional view of a liquid crystal display (LCD) module according to a preferred embodiment of the invention. Referring to  FIG. 3 , a LCD module  200  includes a thin film transistor (TFT) array substrate  210 , an opposite substrate  207  and a liquid layer  209 . The TFT array substrate  210  is detailed described later. The liquid layer  209  is between the opposite substrate  207  and the TFT array substrate  210 . 
   In this embodiment, the opposite substrate  207  is a color filter film substrate. The LCD module  200  further includes The back-light module  260  is disposed besides opposite substrate  207  or the thin firm transistor array substrate  210 , for emitting light to the LCD panel  205 . Now, the detail explanation of the TFT array substrate  210  is as follows. 
     FIG. 4  shows a top view of the thin film transistor array substrate of LCD according to a preferred embodiment of the invention.  FIG. 5  shows an enlargement of an area R 10  in  FIG. 4 .  FIG. 6  and  FIG. 7  show sectional views taken along lines I-I&#39; and II-II&#39; of  FIG. 5 , respectively. 
   Please referring to  FIG. 4  and  FIG. 5 , the TFT array substrate  210  includes a substrate  202 , a TFT array  212 , a plurality of first lines  232  (for example, gate lines), a plurality of second lines  234  (for example, source lines), a plurality of first shield lines  242   a , and at least a first connection line  242   b , for example, two connection lines  242   b  in  FIG. 5 . The substrate  202  includes a pixel region  202   a  and a peripheral circuit region  202   b  surrounding the pixel region  202   a . The TFT array  212 , formed of multiple TFTs and the pixel electrodes (not shown), are disposed on the pixel region  202   a . The first and second lines  232  and  234  are disposed on the peripheral circuit region  202   b . The TFT array  212  is for controlling arrangements of the liquid crystal layer  209 . 
   The TFT array  212  is formed of a first metal or conducting layer (M 1  layer) and a second metal or conducting layer (M 2  layer). In the embodiment, the gate lines  232  are formed of the first metal and the source lines  234  are formed of the second metal. The first shield lines  242   a  and the first connection lines  242   b  are on the same layer. 
   Referring to  FIG. 5  and  FIG. 6 , for shielding light, each of the first shield lines  242   a  is disposed between two adjacent source lines  234  for preventing light pass through the gaps between the source lines  234 . For preventing leakage of light, sides of each shield line  242   a  is partially overlapped with the adjacent source lines  234 . Terminals of the first shield line  242   a  are electrically connected to the first connection line  242   b.    
   The first connection line  242   b  is coupled to a power supply (not shown) for coupling a predetermined voltage to the first shield lines  242   a , to improve the signal interference between the source lines  234 . This voltage improves an electrical inspection of the TFT array for checking whether there are shorts between the source lines  234  and the first shield lines  242   a . In particular, the first connection line  242   b  comprising a first outer connection line  243   a , a first inner connection line  243   b  and plurality of first connection parts  243   c . The first outer connection line  243   a  electrically connects one end of each first shield line  242   a  through one of the first connection parts  243   c , and the first inner connection line  243   b  electrically connects the other end of each of first shield line  242   a  through one the first connection parts  243   c.    
   If there is particle contamination or static discharge during process, shorts may occur in the overlap, for example, pointed by an arrow A 20  in  FIG. 5 , between the first shield lines  242   a  and the source lines  234 . The first connection parts  243   c  connecting between the first shield lines  242   a  and the first outer connection line  243   a /the first inner connection line  243   b  have smaller widths than the gaps between adjacent source lines  234 . In other words, the first connection parts  243   c  are not overlapped with the source lines  234 , as shown in  FIG. 5  and  FIG. 7 . Even there are shorts between the first shield lines  242   a  and the source lines  234 , because the first connection parts  243   c  to the source lines  234 , marked by the arrow A  30  in  FIG. 5 , are smaller and not overlapped with the source lines  234 , the shorts are repaired by cutting off the first connection parts  243   c  (marked by the arrow A 30 ) by laser. By this, yield of the TFT array substrate is improved. 
   In the above exemplified discussion, the shield lines are disposed between the source lines  234 . Other shield lines are disposed between the gate lines  232 .  FIG. 8  shows an enlargement of an area R 20  in  FIG. 4 .  FIG. 9  and  FIG. 10  show sectional views taken along lines III-III&#39; and IV-IV&#39; of  FIG. 8 , respectively. Referring to  FIG. 4  and  FIG. 8 , second shield lines  244   a  and at least a second connection line  244   b  (for example, two second connection lines in  FIG. 8 ) are formed of the second metal. Referring to  FIG. 8  and  FIG. 9 , for shielding light, each of the second shield lines  244   a  is disposed between two gate lines  232  for preventing light pass through the gaps between the gate lines  232 . For prevention of light leakage, the second shield line  244   a  is partially overlapped with two adjacent gate lines  232 . Terminals of the second shield lines  244   a  are electrically connected to the second connection line  244   b.    
   The second connection line  244   b  is coupled to a power supply (not shown) for coupling another predetermined voltage to the second shield lines  244   a , to improve signal interference between the gate lines  232 . This voltage improves an electrical inspection of the TFT array for checking whether there are shorts between the gate lines  232  and the second shield lines  244   a . In particular, the second connection line  244   b  comprising a second outer connection line  245   a , a second inner connection line  245   b  and a plurality of second connection parts  245   c . The second outer connection line  245   a  electrically connects one end of each second shield line  244   a  through one of the second connection parts  245   c , and the second inner connection line  245   b  electrically connects the other end of each second shield line  244   a  through one of the second connection parts  245   c.    
   Shorts maybe occur at the overlap, for example, pointed by an arrow A 40  in  FIG. 8 , between the gate lines  232  and the second shield lines  244   a . The second connection parts  245   c  connecting between the second shield lines  244   a  and the second outer connection line  245   a /the second inner connection line  245   b  have smaller widths than gaps between adjacent gate lines  233 . In other words, the second connection parts  245   c  are not overlapped with the gate lines  232 , as shown in  FIG. 8  and  FIG. 10 . Even there are shorts between the second shield lines  244   a  and the gate lines  232 , because the second connection parts  245   c  to the gate lines  232 , marked by A 50  of  FIG. 8 , have smaller widths and are not overlapped with the gate lines  232 , shorts are repaired by cutting off the second connection parts  245   c  by laser. By this, yield of the TFT array substrate is improved. 
   As above, in the LCD module and the TFT array substrate thereof, the shield lines made of first or second metal layer are disposed in the peripheral circuit region for preventing leakage of light. Besides, by feeding predetermined voltages on the shield lines, the signal interference between gate/source lines is improved. Connections parts of the shield lines to connection lines are not overlapped with gate/source lines and have smaller widths. When shorts occur at the overlap between the gate/source lines and the shield lines, they are repaired by cutting off by laser. Therefore, yield of the TFT module is improved. 
   It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing descriptions, it is intended that the present invention covers modifications and variations of this invention if they fall within the scope of the following claims and their equivalents.