JP2005234492A - Substrate for display device, liquid crystal display panel, liquid crystal display device, and defect inspection method of wiring for repair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a board for a display device that comprises wiring for repair to restore disconnection defect occurring in a data bus line, actualizes a repaired data bus line when the wiring for repair is short-circuited, and easily performs discrimination with line defect occurring due to another cause, and to provide a liquid crystal display panel and device as well as a defect inspection method of wiring for repair. <P>SOLUTION: AM-LCD1 has the wiring 23a for repair that restores the data bus line 27, in which disconnection occurs, connected with a common potential feeding conduction pattern 25 through an electrostatic protection element part 20. The electrostatic protection element part 20 has first and second high resistance elements 19, 21 which are serially connected. A short circuit defect detecting wiring 91 for detecting the short circuit of the wiring 23a for repair is connected at the connection point of the first and second high resistance elements 19, 21. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a display device substrate including a gate bus line, a data bus line, and a switching element on a substrate, a liquid crystal display panel using the same, and a liquid crystal display device (Liquid Crystal Display; LCD) using the same. The present invention relates to a display device substrate having repair wiring for repairing a disconnection defect generated in a data bus line, a liquid crystal display panel using the same, and a liquid crystal display device using the same.

  In recent years, an active matrix liquid crystal display (AM-LCD) has been widely used in office automation (OA) equipment such as personal computers. In addition, for use in a display device such as an engineering workstation (EWS), the AM-LCD screen has been increased in size and definition. However, the pattern density of data bus lines, gate bus lines, and the like formed on a thin film transistor (TFT) substrate increases with the increase in size and definition of the screen of the AM-LCD. The probability of occurrence of defects increases. In particular, in order to increase the aperture ratio, it is required to make the data bus line constant or thin. For this reason, the probability of occurrence of a disconnection defect in the data bus line is increased, and the increase in the disconnection defect is a serious problem. In order to improve the manufacturing yield, the relief process of the disconnection defect generated in the data bus line is increasingly important. In order to relieve the disconnection defect of the data bus line, a disconnection repair process for connecting the data bus line in which the disconnection has occurred and a repair wiring for repairing the disconnection outside the display area is widely used.

  By the way, in the manufacturing process of a TFT substrate and a liquid crystal display panel, the TFT substrate and the liquid crystal display panel are easily exposed to static electricity caused by various factors. Therefore, a device for protecting the data bus line, the TFT element and the like formed on the TFT substrate from a failure due to static electricity is required. In particular, a conductive pattern such as a data bus line in an electrically independent state (floating state) is likely to generate a high voltage due to static charge, and easily causes a failure such as a short circuit or destruction of the conductive pattern. The above-described repair wiring for repairing the data bus line is also in a floating state until it is used for repairing the disconnection defect of the data bus line, so some countermeasure against static electricity is necessary. Therefore, in order to stabilize the potential of the repair wiring, the repair wiring is connected to the common potential supply conductive pattern through a high resistance element so that charges generated by static electricity can be discharged.

  Generally, an element having nonlinear resistance characteristics such as a TFT is used as the high resistance element. If an interlayer short circuit due to pattern failure or electrostatic breakdown occurs in the element, the repair wiring and the common potential supply conductive pattern may be short-circuited. When the repair wiring and the common potential supply conductive pattern are short-circuited, the potential of the repaired data bus line is pulled to the common potential, resulting in a line defect. In general, since the common electrode is set to approximately the center potential of the data voltage (gradation voltage), in the case of a normally black type AM-LCD, it becomes a dark line defect.

  The cause of failure in disconnection repair is that the load increases because the repair wiring is connected to the data bus line, and the drive capability of the data driver IC that drives the data bus line is insufficient, resulting in a delay in the data signal. Is mentioned. Further, when the disconnected data bus line and the repair wiring are connected, a part of the repair wiring comes into contact with the common electrode (counter electrode), and the repair wiring and the counter electrode are short-circuited. . In either case, the result is a dark line defect, so just looking at the display screen will determine whether the defect is due to an increase in the repair wiring load or a short circuit between the repair wiring and the counter electrode. There is a problem that it is difficult.

  FIG. 12 shows a schematic configuration of an AM-LCD 201 that repairs a disconnection defect of a data bus line using a repair wiring. When the data bus line is disconnected, the portion where the data bus line and the repair wiring intersect outside the display area on the data driver integrated circuit (IC) mounting side and the non-mounting side is connected by laser processing or the like. The data signal output from the data driver IC is supplied from the data driver IC non-mounting side via the gate bus line / data bus line printed circuit board (PCB). The repair wiring on the non-mounting side of the data driver IC is connected to the common potential supply conductive pattern through a high resistance body to prevent static electricity. As shown in FIG. 12A, an AM-LCD 201 includes a TFT substrate 203 in which pixel electrodes, TFTs, and the like are formed for each pixel region, and a counter substrate 205 in which a color filter (CF) layer, a common electrode, and the like are formed. Are bonded to each other, and a liquid crystal is sealed between them.

  The TFT substrate 203 has a gate bus line PCB 209 on which a plurality of gate driver ICs 213 for driving a plurality of gate bus lines are mounted, and a data bus line on which a plurality of data driver ICs 211 for driving a plurality of data bus lines are mounted. PCB 207 is provided. The gate driver IC 213 is connected to a gate bus line lead line 217 formed at the left end of the TFT substrate 203 in the drawing. The data driver IC 211 is connected to a data bus line lead line 215 formed at the lower end of the TFT substrate 203 in the drawing. Both PCBs 207 and 209 output a gate pulse and a data voltage to a predetermined gate bus line or data bus line based on a predetermined signal output from a control circuit (not shown).

  Further, the AM-LCD 201 has a repair wiring 223 that repairs a short circuit defect in the data bus line. The repair wiring 223 includes repair wirings 223a to 223g. On the TFT substrate 203, a repair wiring 223a extending in the left-right direction is formed at the upper end portion of the substrate in the drawing, and a repair wiring 223b extending in the left-right direction at the lower end portion of the substrate in the drawing. In FIG. 12A, the repair wiring 223b is illustrated in the vicinity of the second data driver IC 211 from the right in the figure, but is also formed in the vicinity of the other data driver IC 211 in the same manner.

  Each data driver IC 211 is formed with a repair wiring 223c extending in the vertical direction in the drawing. On the data bus line PCB 207, a repair wiring 223d extending in the horizontal direction in the figure is formed. Each gate driver IC 213 is formed with a repair wiring 223e extending in the left-right direction in the drawing. On the gate bus line PCB 209, a repair wiring 223f extending in the vertical direction in the figure is formed. A repair wiring 223g that connects the repair wiring 223d and the repair wiring 223f is formed on a flexible printed circuit board (FPC) (not shown). By assembling the AM-LCD 201, the repair wirings 223a to 223g are connected to form the repair wiring 223. The repair wiring 223a is connected to a common potential supply conductive pattern 225 that supplies a potential to the common electrode via a high resistance element 219 that is an ESD protection element that protects the repair wiring 223a from static electricity.

  Next, a method for repairing the data bus line 227 in which the disconnection defect has occurred will be described with reference to FIGS. FIG. 12B is an enlarged view of the intersection between the data bus line 227 and the repair wiring 223b. FIG.12 (c) has shown the cross section cut | disconnected by the AA line of FIG.12 (b). As shown in FIG. 12C, on the glass substrate 244, a repair wiring 223b, an insulating film 235, a data bus line 227, and a final protective film 237 are laminated in this order. As shown in FIG. 12B, the data bus line 227 in which the disconnection defect occurs among the data bus lines 227 and 229 is irradiated with laser light at the four corners of the intersecting portion that intersects the repair wiring 223b. The data bus line 227 and the repair wiring 223b are connected to each other at the connection portion 231 by laser light irradiation. The data bus line 227 and the repair wiring 223a are also connected in the same manner. As a result, the data signal output from the data driver IC 211 is sent to the repair wiring 223b, the repair wiring 223c, the repair wiring 223d, the repair wiring 223g, the repair wiring 223f, the repair wiring 223e, and the repair wiring 223a. The data bus line 227 is supplied in order.

  FIG. 13 shows a schematic configuration of another AM-LCD 201 that repairs a disconnection defect of a data bus line using repair wiring. FIG. 13A shows a schematic configuration of the AM-LCD 201, FIG. 13B is an enlarged view of the intersection between the repair wiring 223b and the repair wiring 223b ′, and FIG. The cross section cut | disconnected by the BB line of (b) is shown. As shown in FIG. 13A, the repair wiring 223 further includes two types of repair wirings 223a 'and 223b'. The repair wiring 223a 'is formed in the vicinity of the repair wiring 223a in the vicinity of the repair wiring 223b in the plane of the substrate so as to be substantially parallel to the repair wiring 223a and substantially the same length as the repair wiring 223b. The repair wiring 223b 'is formed to extend from the lower end portion of the substrate in the drawing to intersect the left end portion of the repair wiring 223b in the drawing.

  As shown in FIG. 13C, the repair wiring 223 b ′ and the repair wiring 223 b intersect with each other through the insulating film 235. As shown in FIG. 13B, at the time of defect repair, the repair wiring 223b ′ is irradiated with laser light at the four corners of the intersecting portion intersecting the repair wiring 223b ′, and the repair wiring 223b ′ and the repair wiring 223b. Are connected at the connection portion 231. The repair wiring 223a 'is connected to the repair wiring 223a in the same manner. The data bus line 227 and the repair wirings 223a and 223b are connected by the method described above. Thereby, the data signal output from the data driver IC 211 is sent to the repair wiring 223b, the repair wiring 223b ′, the repair wiring 223c, the repair wiring 223d, the repair wiring 223g, the repair wiring 223f, the repair wiring 223e, The repair wiring 223a and the repair wiring 223a ′ are supplied in this order to the data bus line 227.

  FIG. 14 is an enlarged view of the high resistance element 219 which is an ESD protection element provided between the gate driver IC 213 non-mounting side end of the repair wiring 223a on the non-mounting side of the data driver IC 211 and the common potential supply conductive pattern 225. . The high resistance element 219 includes three TFTs 239, 241, and 243, and acts as a discharge path to the common potential supply conductive pattern 225 when a charge flows into the repair wiring 223a during the manufacturing process for some reason. . As shown in FIG. 14, gate electrodes (G) of first to third TFTs 239, 241, and 243 are formed on a glass substrate 244. The gate electrodes (G) of the second and third TFTs 241 and 243 are formed electrically isolated from other wiring structures. A gate insulating film (not shown) is formed on the gate electrode (G) and the glass substrate 244.

  An operation semiconductor layer 245 made of a-Si is patterned on the gate insulating film formed on each gate electrode (G) of the first to third TFTs 239, 241, and 243. A source electrode (S) and a drain electrode (D) are formed on both sides of each operating semiconductor layer 245. The end portions of the source electrodes (S) / drain electrodes (D) run over the operating semiconductor layers 245, and the end portions of the source electrodes (S) / drain electrodes (D) and the lower gates when viewed in the substrate surface direction. A region where the electrode (G) overlaps is formed.

  A contact hole 247 is formed in the conductor 253 including the drain electrodes (D) of the second and third TFTs 241 and 243. A contact hole 249 is formed at one end portion of the gate electrode (G) of the first TFT 239 disposed below the conductor 253 via a gate insulating film. The drain electrode (D) of the second and third TFTs 241 and 243 and the gate electrode (G) of the first TFT 239 are connected by an ITO layer 251 through the two contact holes 247 and 249. The drain electrode (D) of the first TFT 239 and the source electrode (S) of the second TFT 241 are connected to a repair wiring 223a (not shown in FIG. 14). The source electrodes (S) of the first and third TFTs 239 and 243 are connected to a common potential supply conductive pattern 225 (not shown in FIG. 14).

  The high resistance element 219 acts as a discharge path to the common potential supply conductive pattern 225 of the charge flowing into the repair wiring 223a during the manufacturing process of the TFT substrate 203. The high resistance element 219 needs to have a high resistance value so that the repair wiring 223a and the common potential supply conductive pattern 225 maintain an electrically insulated state after the AM-LCD 201 is manufactured. The resistance values of the first to third TFTs 239, 241, and 243 in the conductive state are about 1 MΩ. This value is suitable for both discharging the static electricity generated in the repair wiring 223a and insulating the repair wiring 223a and the common potential supply conductive pattern 225 after the manufacture of the AM-LCD 201 is completed. is there. For this reason, a high resistance element having a TFT like the high resistance element 219 is widely used as an electrostatic protection element.

  However, the distance between the source electrode and the drain electrode must be about several to several tens of micrometers in order to set the resistance value when the TFT is conductive to about 1 MΩ. Generally, the source electrode and the drain electrode of the TFT are in the same layer. Since they are formed of the same metal material, the possibility that both of them are short-circuited due to TFT pattern defects is not low. In addition, since there are many overlapping portions of different conductive layers in the TFT, the ESD protection element itself may be short-circuited by being exposed to a high voltage due to static electricity. In such a case, the potential of the repair wiring 223a becomes the potential applied to the common electrode, or becomes an intermediate potential between the original data voltage and the common potential depending on the degree of short circuit. In any case, since the potential difference between the pixel electrode and the counter electrode becomes smaller than a desired value, the normally-black AM-LCD 201 becomes a dark line.

By the way, there are other reasons why the data bus line subjected to the repair process of the disconnection defect becomes a dark line. For example, when a capacitance is added to the repair wiring 223 for some reason, or a resistance value between the repair wiring 223 and the data driver IC 211 increases, a data signal supplied to the data bus line 227 via the repair wiring 223. Becomes dull compared to the original data signal, and the data signal cannot be sufficiently written to the pixel electrode. Further, when the disconnection of the data bus line 227 is repaired by irradiating a laser beam between the data bus line 227 and the repair wiring 223a to connect the data bus line 227 and the repair wiring 223a, the TFT substrate 203 is restored. A part of the conductive layer such as the data bus line 227 formed thereon may protrude and come into contact with the counter electrode. Further, the data bus line 227 may be in contact with the counter electrode due to the patterning failure of the data bus line 227. In either case, the result is a dark line.
JP-A-11-271722

  As described above, when the data bus line 227 is a line defect such as a dark line even after the disconnection repair process, a detailed defect analysis is required to identify the cause, and the defect analysis is very difficult. There is a problem of requiring a lot of time and labor.

  The object of the present invention is excellent in preventing electrostatic breakdown, and in particular, when a repair wiring is short-circuited, a data bus line subjected to a repair process is made obvious and easily distinguished from a line defect caused by another cause. An object of the present invention is to provide a display device substrate, a liquid crystal display panel, a liquid crystal display device, and a repair wiring defect inspection method that can be performed.

  The object is to connect a repair wiring for repairing a disconnection defect of a data bus line, an electrostatic protection element portion for protecting the repair wiring from static electricity, and the repair wiring via the electrostatic protection element portion. And a common conductive wiring for maintaining the voltage of the display device.

  According to the present invention, it is possible to prevent electrostatic breakdown of bus lines and switching elements in the panel manufacturing process, and in addition, when the repair wiring is short-circuited, the repaired data bus line is made obvious. It is possible to easily distinguish the line defect caused by the cause.

[First Embodiment]
A display device substrate, a liquid crystal display panel, a liquid crystal display device, and a repair wiring defect inspection method according to the first embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the AM-LCD 1 according to the present embodiment will be described with reference to FIG. FIG. 1 shows a schematic configuration of an AM-LCD 1 having a redundant structure electrostatic protection element unit 20. As shown in FIG. 1, an AM-LCD 1 includes a TFT substrate (display device substrate) 3 in which pixel electrodes, TFTs, and the like are formed for each pixel region, and a counter substrate 5 in which a CF layer, a common electrode, and the like are formed. And a liquid crystal display panel in which the liquid crystal is sealed therebetween.

  On the TFT substrate 3, a PCB 9 for a gate bus line on which a plurality of gate driver ICs 13 for driving a plurality of gate bus lines are mounted, and a data bus line on which a plurality of data driver ICs 11 for driving a plurality of data bus lines are mounted. PCB 7 is provided. The gate driver IC 13 is connected to a gate bus line lead line 17 formed at the left end of the TFT substrate 3 in the figure. The data driver IC 11 is connected to a data bus line lead line 15 formed at the lower end of the TFT substrate 3 in the figure. Both PCBs 7 and 9 are adapted to output a gate pulse and a data voltage to a predetermined gate bus line or data bus line based on a predetermined signal output from a control circuit (not shown).

  The counter substrate 5 has a CF layer in which any one of red (R), green (G), and blue (B) is formed for each pixel region. An alignment film for aligning liquid crystal molecules in a predetermined direction is formed on the opposing surfaces of both substrates 3 and 5.

  A polarizing plate (not shown) is attached to the surface of the TFT substrate 3 opposite to the element formation surface. On the opposite side of the polarizing plate to the TFT substrate 3, a backlight unit (not shown) composed of, for example, a linear primary light source and a planar light guide plate is disposed. On the other hand, a polarizing plate (not shown) is attached to the surface of the counter substrate 5 opposite to the CF forming surface.

  Further, the AM-LCD 1 has a repair wiring 23 for repairing a short circuit defect in the data bus line. The repair wiring 23 is composed of repair wirings 23a to 23g. On the TFT substrate 3, a repair wiring 23 a extending in the left-right direction at the upper end portion of the substrate in the drawing and a repair wiring 23 b extending in the left-right direction at the lower end portion of the substrate in the drawing are formed outside the display region. . In FIG. 1, the repair wiring 23 b is illustrated in the vicinity of the second data driver IC 11 from the right in the drawing, but is similarly formed in the vicinity of the other data driver ICs 11.

  The data driver IC 11 is formed with a repair wiring 23c extending in the vertical direction in the drawing. On the data bus line PCB 7, a repair wiring 23d extending in the horizontal direction in the figure is formed. Each gate driver IC 13 is formed with a repair wiring 23e extending in the left-right direction in the drawing. On the gate bus line PCB 9, a repair wiring 23f extending in the vertical direction in the figure is formed. A repair wiring 23g that connects the repair wiring 23d and the repair wiring 23f is formed on an FPC (not shown). By assembling the AM-LCD 1, the repair wirings 23a to 23g are connected to form the repair wiring 23. Further, the repair wiring 23a is connected to a common potential supply conductive pattern 25 that supplies a potential to the common electrode through an electrostatic protection element unit 20 including an ESD protection element that protects the repair wiring 23a from static electricity. The electrostatic protection element unit 20 has a redundant structure having first and second high resistance elements 19 and 21 connected in series.

  The method for repairing the disconnection defect of the data bus line of the AM-LCD 1 is the same as the repair method for the conventional AM-LCD 201. If a disconnection defect occurs in the data bus line 27 formed on the TFT substrate 3, the four corners of the intersection between the data bus line 27 and the repair wirings 23a and 23b are irradiated with laser light to repair the data bus line 27. The wiring lines 23a and 23b are connected. As a result, the data signal output from the data driver IC 11 is sent to the repair wiring 23b, the repair wiring 23c, the repair wiring 23d, the repair wiring 23g, the repair wiring 23f, the repair wiring 23e, and the repair wiring 23a in this order. The data is supplied to the data bus line 27 side that is electrically disconnected from the data driver IC 11 by disconnection.

  Next, a schematic configuration of the electrostatic protection element unit 20 will be described with reference to FIG. 2A is a schematic view of the vicinity of the electrostatic protection element unit 20, FIG. 2B is an enlarged view of the electrostatic protection element unit 20, and FIG. 2C is an equivalent circuit of the electrostatic protection element unit 20. Show. As shown in FIG. 2A, the electrostatic protection element unit 20 includes first and second high resistance elements 19 and 21 connected in series. The first high resistance element 19 is connected to the repair wiring 23a. The second high resistance element 21 is connected to the common potential supply conductive pattern 25. The second high-resistance element 21 only needs to be connected to a common conductive wiring that maintains a predetermined voltage like the common potential supply conductive pattern 25, and may be connected to a reference potential (ground).

  Next, the circuit configuration of the first and second high resistance elements 19 and 21 will be described with reference to FIGS. As shown in FIGS. 2B and 2C, the first high resistance element 19 includes first to third TFTs 29, 31, and 33. The second high resistance element 21 includes first to third TFTs 49, 51, and 53. The first TFTs 29 and 49 are used for discharging charges generated by static electricity to the repair wiring 23 a to the common potential supply conductive pattern 25. The second and third TFTs 31, 33, 51 and 53 are used for controlling the gate voltage of the first TFTs 29 and 49.

  First, the circuit configuration of the first high resistance element 19 will be described. On the glass substrate 44, the gate electrodes (G) of the first to third TFTs 29, 31, and 33 are formed. The gate electrodes (G) of the second and third TFTs 31 and 33 are formed electrically isolated from other wiring structures. A gate insulating film (not shown) is formed on the gate electrode (G) and the glass substrate 44.

  On the gate insulating film formed on each gate electrode (G) of the first to third TFTs 29, 31, and 33, an operation semiconductor layer 35 made of a-Si is patterned. A source electrode (S) and a drain electrode (D) are formed on both sides of each operating semiconductor layer 35. The end portions of the source electrodes (S) / drain electrodes (D) run over the operating semiconductor layers 35 and the end portions of the source electrodes (S) / drain electrodes (D) and the lower gates as viewed in the substrate surface direction. A region where the electrode (G) overlaps is formed.

  A contact hole 41 is formed in the conductor 47 including the drain electrodes (D) of the second and third TFTs 31 and 33. A contact hole 43 is formed at one end of the gate electrode (G) of the first TFT 29 disposed below the conductor 47 via a gate insulating film. The drain electrode (D) of the second and third TFTs 31 and 33 and the gate electrode (G) of the first TFT 29 are connected by an ITO layer 39 via the two contact holes 41 and 43. The drain electrode (D) of the first TFT 29 and the source electrode (S) of the second TFT 31 are connected to a repair wiring 23a (see FIG. 2A). The source electrodes (S) of the first and third TFTs 29 and 33 are connected to the drain electrode (D) of the first TFT 49 and the source electrode (S) of the second TFT 51 constituting the second high resistance element 21. ing.

  The second high resistance element 21 has a circuit configuration similar to that of the first high resistance element 19. On the glass substrate 44, the gate electrodes (G) of the first to third TFTs 49, 51, 53 are formed. The gate electrodes (G) of the second and third TFTs 51 and 53 are formed electrically isolated from other wiring structures. A gate insulating film is formed on the gate electrode (G).

  On the gate insulating film formed on each gate electrode (G) of the first to third TFTs 49, 51 and 53, an operation semiconductor layer 55 made of a-Si is patterned. A source electrode (S) and a drain electrode (D) are formed on both sides of each operating semiconductor layer 55. The end portions of the source electrodes (S) / drain electrodes (D) run over the operating semiconductor layers 55, and the end portions of the source electrodes (S) / drain electrodes (D) and the lower gates when viewed in the substrate surface direction. A region where the electrode (G) overlaps is formed.

  A contact hole 61 is formed in the conductor 67 including the drain electrodes (D) of the second and third TFTs 51 and 53. A contact hole 63 is formed at one end of the gate electrode (G) of the first TFT 49 disposed below the conductor 67 via a gate insulating film. The drain electrode (D) of the second and third TFTs 51 and 53 and the gate electrode (G) of the first TFT 49 are connected by the ITO layer 59 through the two contact holes 61 and 63. The drain electrode (D) of the first TFT 49 and the source electrode (S) of the second TFT 51 are connected to the source electrodes (S) of the first and third TFTs 29 and 33 constituting the first high resistance element 19. ing. The source electrodes (S) of the first and third TFTs 49 and 53 are connected to the common potential supply conductive pattern 25 (see FIG. 2A).

Next, the operation of the electrostatic protection element unit 20 will be described. As shown in FIG. 2C, when a positive high voltage is generated in the repair wiring 23a with respect to the connection point between the first and second high resistance elements 19 and 21 due to static electricity, the second and third TFTs 31 are provided. , 33 is applied with a high voltage internally divided by parasitic capacitances (C2 _gs , C2 _gd , C3 _gs , C3 _gd ) to form channels in the second and third TFTs 31, 33. Is done. As a result, current flows through the second and third TFTs 31 and 33, and the potential of the conductor 47 also rises. As a result, a channel is formed in the first TFT 29 and the conductivity is increased, so that charges due to static electricity are released.

The charge released from the repair wiring 23 a flows through the first TFT 29 to the connection point between the first and second high resistance elements 19 and 21. As a result, a positive high voltage with respect to the common potential supply conductive pattern 25 is generated at the connection point between the first and second high resistance elements 19 and 21. In this case, a high voltage internally divided by parasitic capacitances (C2 _gs , C2 _gd , C3 _gs , C3 _gd ) is applied to the gate electrodes (G) of the second and third TFTs 51 and 53, respectively. A channel is formed by the third TFTs 51 and 53. As a result, current flows through the second and third TFTs 51 and 53, and the potential of the conductor 67 also rises. As a result, a channel is formed in the first TFT 49 and the conductivity is increased, so that charges due to static electricity are released.

  The resistance values of the first and second high resistance elements 19 and 21 are each about several hundred kΩ to several MΩ. For this reason, the first and second high-resistance elements 19 and 21 have a sufficient resistance value so that the repair wiring 23a and the common potential supply conductive pattern 25 can be electrically opened even if they are used alone. Therefore, even if one of the first and second high-resistance elements 19 and 21 has a defect such as a short circuit, the other high-resistance element that operates normally has a sufficient resistance value with the repair wiring 23a. Secured. As described above, the electrostatic protection element unit 20 can sufficiently prevent the repair wiring 23a and the common potential supply conductive pattern 25 from being short-circuited due to electrostatic breakdown or the like.

  FIG. 3 shows a circuit configuration example of another high resistance element. FIG. 3A is an enlarged view of the high resistance element 68, and FIG. 3B shows an equivalent circuit of the high resistance element 68. As shown in FIG. 3, the high resistance element 68 includes first and second TFTs 69 and 71. On the glass substrate (not shown), the gate electrodes (G) of the first and second TFTs 69 and 71 are formed. A gate insulating film (not shown) is formed on the gate electrode (G) and the glass substrate.

  An operation semiconductor layer 73 made of a-Si is patterned on the gate insulating film formed on each gate electrode (G) of the first and second TFTs 69 and 71. A source electrode (S) and a drain electrode (D) are formed on both sides of each operating semiconductor layer 73. The ends of the source electrodes (S) / drain electrodes (D) run over the operating semiconductor layers 73, and the ends of the source electrodes (S) / drain electrodes (D) and the lower gates as viewed in the substrate surface direction. A region where the electrode (G) overlaps is formed.

  A contact hole 81 is formed in the vicinity of the drain electrode (D) of the first TFT 69 of the conductor 75 including the drain electrode (D) of the first TFT 69 and the source electrode (S) of the second TFT 71. A contact hole 79 is formed at one end of the gate electrode (G) of the first TFT 69. The drain electrode (D) and the gate electrode (G) of the first TFT 69 are connected by an ITO layer 77 through the two contact holes 79 and 81.

  A contact hole 87 is formed in the vicinity of the drain electrode (D) of the second TFT 71 of the conductor 76 including the source electrode (S) of the first TFT 69 and the drain electrode (D) of the second TFT 71. A contact hole 85 is formed at one end of the gate electrode (G) of the second TFT 71. The drain electrode (D) and the gate electrode (G) of the second TFT 71 are connected by the ITO layer 83 through the two contact holes 85 and 87.

  Next, the operation of the high resistance element 68 will be described. As shown in FIG. 3B, when a positive high voltage is generated in the conductor 75 with respect to the conductor 76, the high voltage is applied to the gate electrode (G) of the first TFT 69, and the first TFT 69. A channel is formed. As a result, the conductivity of the first TFT 69 is increased, so that the charge charged in the conductor 75 is released. Further, when a positive high voltage is generated in the conductor 76 with respect to the conductor 75, the charge charged in the conductor 76 by the second TFT 71 is released.

  Thus, the high resistance element 68 can release the electric charge when any of the conductors 75 and 76 is charged with a predetermined potential difference. Therefore, the two high resistance elements 68 connecting the conductor 75 and the conductor 76 can be used for the electrostatic protection element unit 20.

  FIG. 4 shows a circuit configuration example of still another high resistance element. 4A is an enlarged view of the high resistance element 89, and FIG. 4B shows an equivalent circuit of the high resistance element 89. FIG. As shown in FIG. 4, the high resistance element 89 has one TFT. A TFT gate electrode (G) is formed on a glass substrate (not shown). The gate electrode (G) is formed electrically isolated from other wiring structures. A gate insulating film (not shown) is formed on the gate electrode (G) and the glass substrate.

  An operating semiconductor layer 90 made of a-Si is patterned on the gate insulating film formed on the gate electrode (G) of the TFT. A source electrode (S) and a drain electrode (D) are formed on both sides of the operating semiconductor layer 90. The end portions of the source electrodes (S) / drain electrodes (D) run over the operating semiconductor layers 90, and the end portions of the source electrodes (S) / drain electrodes (D) and the lower gates as viewed in the substrate surface direction. A region where the electrode (G) overlaps is formed.

Next, the operation of the high resistance element 89 will be described. As shown in FIG. 4B, when a positive high voltage is generated at the source electrode (S) with respect to the drain electrode (D), the gate electrode (G) has internal capacitance due to parasitic capacitances (C _gs , C _gd ). A divided high voltage is applied to form a channel. As a result, the conductivity of the TFT increases, so that the charge charged in the source electrode (S) is released.

  As described above, the high resistance element 89 can release the charge when either the source electrode (S) or the drain electrode (D) is charged with a predetermined potential difference. Therefore, the two high resistance elements 89 in which the source electrode (S) and the drain electrode (D) are connected can be used for the electrostatic protection element unit 20.

  According to the present embodiment, even if a charge due to static electricity is generated in the repair wiring 23a in the manufacturing process of the AM-LCD 1, the electrostatic protection element portion 20 can release the charge, so that the repair wiring 23a can be electrostatically destroyed. Can be prevented. Further, since the electrostatic protection element unit 20 includes the first and second high resistance elements 19 and 21, even if one of the first and second high resistance elements 19 and 21 is damaged by static electricity. The short circuit between the repair wiring 23a and the common potential supply conductive pattern 25 can be prevented by the other high resistance element operating normally. Thus, since the electrostatic protection element unit 20 exhibits an excellent prevention function against electrostatic breakdown, the manufacturing yield of the AM-LCD 1 can be improved, and the manufacturing cost can be reduced and the cost of the AM-LCD 1 can be reduced.

[Second Embodiment]
A display device substrate, a liquid crystal display panel, a liquid crystal display device, and a repair wiring defect inspection method according to a second embodiment of the present invention will be described with reference to FIGS. First, a schematic configuration of the AM-LCD 1 according to the present embodiment will be described with reference to FIG. FIG. 5 shows a schematic configuration of the AM-LCD 1 of the present embodiment. FIG. 5A shows a schematic configuration of the AM-LCD 1, and FIG. 5B is an enlarged view of the electrostatic protection element unit 20. As shown in FIG. 5, the AM-LCD 1 includes a short-circuit defect detection wiring 91 that is connected to the connection point of the first and second high resistance elements 19 and 21 and is used to detect a short circuit of the repair wiring 23a. It has a feature in that it has. Components having the same functions and functions as those shown in FIG.

  The short-circuit defect detection wiring 91 is formed on the TFT substrate 3. The short-circuit defect detection wiring 91 is formed by extending from the connection point of the first and second high-resistance elements 19 and 21 to the right side of the substrate and extending to the left side of the substrate. The short-circuit defect detection wiring 91 is connected via a gate driver IC 13 to an inspection signal supply circuit 93 that outputs an inspection signal for short-circuit defect inspection disposed on the PCB 9 for gate bus lines.

  As shown in FIG. 5B, the repair wiring 23 a is connected to the short-circuit defect detection wiring 91 through the first high resistance element 19. The short-circuit defect detection wiring 91 is further connected to the common potential supply conductive pattern 25 via the second high resistance element 21. Contact holes 99 and 103 are formed at the end of the short-circuit defect detection wiring 91. A contact hole 97 is formed at the end of the source electrode (S) of the first and third TFTs 29 and 33 of the first high resistance element 19. The short-circuit defect detection wiring 91 and the source electrodes (S) of the first and third TFTs 29 and 33 are connected by the ITO layer 95 through the two contact holes 97 and 99. A contact hole 105 is formed at the end of the drain electrode (D) of the first TFT 49 and the source electrode (S) of the second TFT 51 of the second high resistance element 21. The short-circuit defect detection wiring 91, the drain electrode (D) of the first TFT 53, and the source electrode (S) of the second TFT 49 are connected by the ITO layer 101 through the two contact holes 103 and 105. Thus, the short-circuit defect detection wiring 91 is connected to the connection point of the first and second high resistance elements 19 and 21.

  A switch (both not shown) is provided at the output terminal of the inspection signal supply circuit 93. When the switch is turned on, the short-circuit defect detection wiring 91 is electrically connected to the output terminal of the inspection signal supply circuit 93. When the switch is turned off, the short-circuit defect detection wiring 91 is output from the inspection signal supply circuit 93. Electrically disconnected from the terminal. When the short-circuit defect detection wiring 91 is disconnected from the output terminal of the inspection signal supply circuit 93, the short-circuit defect detection wiring 91 enters a floating state. The inspection signal supply circuit 93 has a plurality of resistors and variable resistors for resistance-dividing a predetermined voltage, and can supply a DC voltage inspection signal to the short-circuit defect detection wiring 91. Further, the inspection signal supply circuit 93 can supply an inspection signal different from the phase and cycle of the data signal supplied to the data bus line to the short-circuit defect detection wiring 91 based on a control signal output from a control unit (not shown). It is like that.

  The resistance values of the first and second high resistance elements 19 and 21 are each about several hundred kΩ to several MΩ. For this reason, the first and second high-resistance elements 19 and 21 have a sufficient resistance value so that the repair wiring 23a and the common potential supply conductive pattern 25 can be electrically opened even if they are used alone. However, in order to set the resistance values of the first and second high resistance elements 19 and 21 to several hundred kΩ to several MΩ, the channel length of each TFT 29, 31, 33, 49, 51, 53 (source electrode (S) And the distance between the drain electrode (D) and the drain electrode (D) must be about 3 to 10 μm. Since the channel length is short in this manner, there is a possibility that the source electrode (S) and the drain electrode (D) may be short-circuited due to a TFT patterning defect in the photolithography process or the like of the TFT substrate 2 or adhesion of conductive foreign matter. is there.

  When a short-circuit defect occurs in the first high resistance element 19, the repair wiring 23a and the short-circuit defect detection wiring 91 are short-circuited. When the AM-LCD 1 is used, the short-circuit defect detection wiring 91 is disconnected from the inspection signal supply circuit 93 and is in a floating state. In this case, since the short-circuit defect detection wiring 91 has a high impedance, the effect of the short circuit between the repair wiring 23a and the short-circuit defect detection wiring 91 does not occur in the repair wiring 23a. Further, since the second high resistance element 21 operates normally, the repair wiring 23 a is electrically disconnected from the common potential supply conductive pattern 25. Therefore, even if the disconnection defect of the data bus line 27 is repaired by the repair wiring 23 a electrically connected to the short-circuit defect detection wiring 91, no line defect occurs in the data bus line 27.

  Further, when a short circuit defect occurs in the second high resistance element 21, the common potential supply conductive pattern 25 and the short circuit defect detection wiring 91 are short-circuited. Since the first high-resistance element 19 operates normally, the repair wiring 23a and the common potential supply conductive pattern 25 are electrically disconnected. Therefore, even if the disconnection defect of the data bus line 27 is repaired by the repair wiring 23 a electrically connected to the short-circuit defect detection wiring 91, no line defect occurs in the data bus line 27.

  Thus, even if the short-circuit defect detection wiring 91 is connected to the electrostatic protection element part 20, the electrostatic protection element part 20 can exhibit an excellent prevention function against electrostatic breakdown. Further, since the electrostatic protection element unit 20 of the present embodiment has a circuit configuration similar to that of the electrostatic protection element unit of the above embodiment, the electrostatic protection element unit 20 is charged by static electricity generated in the repair wiring 23a. Can be released.

  On the other hand, even when the short-circuit defect detection wiring 91 cannot be brought into a floating state due to circumstances of the external circuit or the like, the repair can be performed by applying an inspection signal independent of the counter potential from the external circuit to the short-circuit defect detection wiring 91 through the connection electrode. It is possible to easily determine the presence or absence of a wiring short circuit. First, a predetermined data voltage is supplied to the data bus line. Next, an inspection signal is input from the inspection signal supply circuit 93 to the short-circuit defect detection wiring 91. The voltage value of the inspection signal is set to a value different from the predetermined voltage of the data signal and the voltage applied to the common electrode (counter electrode). Generally, the counter potential is set to a value that is approximately 1 to 2 V lower than the center potential of the data signal. Therefore, the voltage of the inspection signal is set to a value higher or lower by about several volts than the voltage of the counter electrode.

  For example, the voltage of the inspection signal is set to a value higher than the voltages of the counter electrode and the data signal. When the repair wiring 23a and the short-circuit defect detection wiring 91 are short-circuited, the voltage value of the data bus line 27 restored by the repair wiring 23a becomes a voltage between the data signal and the inspection signal. In this case, the effective voltage applied to the liquid crystal with the positive polarity increases, and the effective voltage applied to the liquid crystal with the negative polarity decreases. Thereby, the effective voltage applied to the data bus line 27 is different from the effective voltage applied to the other data bus lines. Therefore, the pixel connected to the data bus line 27 has a luminance different from that of other pixels, and it can be detected that the repair wiring 23a and the short-circuit defect detection wiring 91 are short-circuited.

  Further, the state of the line defect of the data bus line 27 can be changed according to the relationship between the voltage value of the inspection signal input to the repair wiring 23a and the voltage value of the data signal input to the data bus line. For example, if the entire screen is darkened halftone so that the voltage of the inspection signal is higher than the voltage of the data signal, the data bus line 27 becomes a relatively bright line. Further, if the entire screen is set to a light halftone so that the voltage of the inspection signal is lower than the voltage of the data signal, the data bus line 27 becomes a relatively dark line. In this way, it is possible to easily determine whether or not the defect repair processing for the data bus line 27 is successful. It should be noted that a short circuit between the repair wiring 23a and the short-circuit defect detection wiring 91 can be detected by applying an inspection signal to the short-circuit defect detection wiring 91 not only during the defect inspection but also during use of the AM-LCD 1.

  Further, the inspection signal output from the inspection signal supply circuit 93 is not limited to a DC signal, and may be an AC signal. For example, when inspection signals having different amplitudes, phases, or frequencies of data signals are input to the short-circuit defect detection wiring 91, the luminance of the pixels connected to the data bus line 27 changes based on the inspection signals. The success or failure of the defect repair process 27 can be easily determined. If the voltage value of the inspection signal is changed and the bright line or the dark line remains and the state of the data bus line 27 does not change, it can be seen that the repair wiring 23a is not in contact with the data bus line 27. In this case, it can be seen that the repair wiring 23a or a part of the conductive layer of the data bus line 27 protrudes and contacts the common electrode or the like by the defect repair processing of the data bus line 27.

  Without inputting the inspection signal to the short-circuit defect detection wiring 91, the voltage value or voltage waveform of the short-circuit defect detection wiring 91 can be monitored to inspect the repair wiring 23a for defects. For example, if the same signal as the data signal input to the data bus line 27a is detected by the short-circuit defect detection wiring 91, it is understood that the repair wiring 23a and the short-circuit defect detection wiring 91 are short-circuited. Further, a data signal is input to each data bus line so that the entire screen is displayed in white, and a voltage of a predetermined gradation signal is applied to the data bus line 27. If the voltage of the gradation signal is detected by the short-circuit defect detection wiring 91, it can be understood that the short-circuit defect detection wiring 91 and the repair wiring 23a are short-circuited. As described above, when a data signal different from that of the other data bus lines is input only to the data bus line 27, a short circuit between the repair wiring 23a and the short circuit defect detecting wiring 91 can be easily determined.

  Since the screen cannot be displayed in the manufacturing process of the TFT substrate 2, the inspection method is particularly effective. In the array process for manufacturing the TFT substrate 2 and the cell process for manufacturing the liquid crystal display panel, the voltage is measured at a connection portion between the short-circuit defect detection wiring 91 and the gate driver IC 13. In the module process for connecting the liquid crystal display panel and the two PCBs 7 and 9, the voltage is measured using a test pad (not shown) provided on the PCB 9 for the gate bus line. When a short-circuit between the repair wiring 23a and the short-circuit defect detection wiring 91 is detected by the above-described repair wiring defect inspection method, laser light is irradiated to the connection portion between the repair wiring 23a and the first high-resistance element 19. Then, the repair wiring 23a and the first high resistance element 19 are cut and separated. Thereby, the line defect of the data bus line 27 can be repaired.

  According to the present embodiment, since the electrostatic protection element unit 20 is a redundant structure having the first and second high resistance elements 19 and 21, it exhibits an excellent prevention function against electrostatic breakdown. Even if the disconnection repair process is performed or the data bus line 27 has a line defect such as a dark line, the short-circuit defect detection wiring 91 can be used to detect a short circuit in the repair wiring 23a. Thereby, it is possible to repair a defective portion in the manufacturing process. Therefore, detailed failure analysis for specifying the cause of the line defect is not required, and a great amount of time and labor required for failure analysis can be reduced, thereby reducing the manufacturing cost of the AM-LCD 1 and reducing the cost of the AM-LCD 1. Can be planned.

  Next, a first modification of the present embodiment will be described with reference to FIGS. In the above-described embodiment, the voltage of the short-circuit defect detection wiring 91 is measured by using a connection portion between the short-circuit defect detection wiring 91 and the gate driver IC 13 or a test pad provided on the gate bus line PCB 9. On the other hand, the present modification is characterized in that a voltage measuring pad for measuring the voltage is provided. 6 and 7 are enlarged views of a connection portion between the TFT substrate 2 and the gate bus line PCB 9. As shown in FIG. 6, the short-circuit defect detection wiring 91 is connected to a connection terminal 111 a that connects the gate driver IC 13 formed at the end of the TFT substrate 2. In the short-circuit defect detection wiring 91, a voltage measurement pad 107 branched at the end of the TFT substrate 2 is formed. The voltage measurement pad 107 is formed with a line width of 1 to 2 mm.

  A connection terminal 111 b connected to the repair wiring 23 a and a connection terminal 111 c connected to the gate bus line lead line 17 are formed at the end of the TFT substrate 2. On the connection terminals 111a, 111b, and 111c, the gate driver IC 13 is thermocompression bonded via an unillustrated anisotropic conductive film (ACF). The gate driver IC 13 has an IC chip 13a and a tape carrier package (TCP) film 13b. The IC chip 13a is mounted on the TCP film 13b. A lead wire 113b for connecting the IC chip 13a and the connection terminal 111c is formed on the TCP film 13b.

  The TCP film 13b is formed with lead wires 113a for connecting the IC chip 13a and the connection terminals 109c provided on the gate bus line PCB 9. Furthermore, the lead film 92 which connects the connection terminal 111a and the connection terminal 109a provided on the PCB 9 for gate bus lines is formed on the TCP film 13b. The connection terminal 109a is connected to an inspection signal supply circuit 93 (not shown in FIG. 6). A repair wiring 23e is formed on the TCP film 13b, and the repair wiring 23e connects the connection terminal 111b and the connection terminal 109b provided on the gate bus line PCB9. The connection terminal 109b is connected to a repair wiring 23f (not shown in FIG. 6). The gate driver IC 13 is connected to the gate bus line PCB 9 by thermocompression bonding or soldering.

  The voltage measurement pad 107 is exposed even when the counter substrate 5 is bonded to the TFT substrate 2 and the gate driver IC 13 is pressed. For this reason, the voltage of the short-circuit defect detection wiring 91 can be measured in any of the array process, the cell process, and the module process of the AM-LCD 1. If the voltage of the short-circuit defect detection wiring 91 is measured by the voltage measurement pad 107, it is not necessary to perform probing on the short-circuit defect detection wiring 91. Therefore, the short-circuit defect detection wiring 91 is damaged or disconnected by probing. Will disappear. Further, when the inspection signal supply circuit 93, the inspection pad, or the connection terminal 109a cannot be provided due to the restriction of the PCB 9 for the gate bus line, the voltage can be measured or the inspection signal can be input by the voltage measurement pad 107. Thus, the voltage measurement pad 107 can be used not only as a measurement pad for measuring a voltage but also as an input terminal for an inspection signal.

  As shown in FIG. 7, even if the short-circuit defect detection wiring 91 is not connected to the connection terminal 111a, the short-circuit defect of the repair wiring 23a can be detected. Since the voltage measurement pad 107 is exposed in each process, the voltage of the short-circuit defect detection wiring 91 is measured during the manufacturing process of the AM-LCD 1 or an inspection signal is input to the short-circuit defect detection wiring 91. be able to.

  Each of the above embodiments is a case where there is one repair wiring, but there are a plurality of repair wirings in the case of a structure that can repair the disconnection of a plurality of data bus lines in the panel. To do. Even in such a case, the above embodiment can be applied. The first embodiment shown in FIG. 1 can be applied as it is. In the case of the second embodiment shown in FIG. 6, it is necessary to overcome the conductive layer pattern of the same layer in order to draw a part of the short-circuit defect detection wiring to the connection terminal portion. Application is possible if reconnection using a pixel electrode layer (ITO layer) is performed.

  As described above, according to this modification, even when the inspection signal supply circuit 93 and the inspection pad cannot be provided, the voltage of the short-circuit defect detection wiring 91 is measured using the voltage measurement pad 107, or the short circuit is detected. An inspection signal can be input to the defect detection wiring 91. As a result, since a short circuit of the repair wiring 23a can be detected in the manufacturing process of the AM-LCD 1, a great amount of time and labor required for failure analysis can be reduced, and the manufacturing cost of the AM-LCD 1 can be reduced.

  Next, a second modification of the present embodiment will be described with reference to FIGS. In the above embodiment, one pair of the repair wiring 23a and the first high resistance element 19 is provided. On the other hand, this modification is characterized in that a plurality of sets (four in this example) of repair wirings 23a and first high resistance elements 19 are provided. FIG. 8 shows a schematic configuration of the AM-LCD 1 of this modification. FIG. 9 is an enlarged view of the electrostatic protection element unit 20. The AM-LCD 1 can repair a disconnection defect of a plurality (four in this example) of data bus lines.

  As shown in FIG. 8, the AM-LCD 1 includes four repair wirings 23a, 24a, 26a, and 28a, one short-circuit defect detection wiring 91, and four first high resistance elements 19a, 19b, and 19c. 19d and one second high resistance element 21. One end of the repair wiring 23a is connected to the first high resistance element 19a, and the other end of the repair wiring 23a is connected to the repair wiring 23e. One end of the repair wiring 24a is connected to the first high resistance element 19b, and the other end of the repair wiring 24a is connected to the repair wiring 24b. One end of the repair wiring 26a is connected to the first high resistance element 19c, and the other end of the repair wiring 26a is connected to the repair wiring 26b. One end of the repair wiring 28a is connected to the first high resistance element 19d, and the other end of the repair wiring 28a is connected to the repair wiring 28b.

  The short-circuit defect detection wiring 91 is connected to a connection point between the first high resistance elements 19 a to 19 d and the second high resistance element 21. The second high resistance element 21 is connected to the common potential supply conductive pattern 25. Accordingly, the short-circuit defect detection wiring 91 is connected to the common potential supply conductive pattern 25 via the second high resistance element 21.

  Although not shown in FIG. 8, the repair wirings 24b, 26b, and 28b include a source bus line PCB 9, an FPC (not shown) that connects both PCBs 7, 9, a data bus line PCB 7, a data driver IC 11 and data. Repair wirings formed on the TFT substrate 2 in the vicinity of the driver IC 11 are connected in this order.

  As shown in FIG. 9, the short-circuit defect detection wiring 91 is connected to the source electrodes (S) of the first and third TFTs 29 and 33 of the first high resistance elements 19a to 19d. Further, the short-circuit defect detection wiring 91 is connected to the drain electrode (D) of the first TFT 49 and the source electrode (S) of the second TFT 51 of the second high resistance element 21. The respective conductive layer wirings formed in the same layer of the short-circuit defect detection wiring 91, the first high resistance elements 19a to 19d and the second high resistance element 21 do not cross each other. Therefore, the short-circuit defect detection wiring 91, the source electrodes (S) of the first and third TFTs 29 and 33 of the first high resistance elements 19 a to 19 d, and the source electrode (S) of the second TFT 51 are: Patterning can be performed in the same layer without changing the pixel electrode layer or the contact hole.

  By the way, when any two or more of the first high resistance elements 19a to 19d are short-circuited due to electrostatic breakdown, the data bus lines in which the disconnection defect has been repaired are short-circuited. In this case, the data signals input to the shorted data bus line influence each other and a line defect occurs. In this case, an inspection signal is input to the short-circuit defect detection wiring 91 or the voltage of the short-circuit defect detection wiring 91 is measured to detect a short circuit in the repair wirings 23a, 24a, 26a, and 28a.

  When any two or more of the repair wirings 23a, 24a, 26a, and 28a are short-circuited to the short-circuit defect detection wiring 91, the polarity of the data signal input to the shorted data bus line is different. Since the data signals act to reduce the voltage amplitude of the data signal, the data signal approaches the voltage value of the common electrode. In this case, in the AM-LCD 1 using normally black (NB) type liquid crystal, the data bus line is a dark line. On the other hand, when the polarity of the data signal input to the shorted data bus line is the same, the entire surface looks normal in the same color display. When the data bus line itself is short-circuited to the common electrode due to a short circuit between the layers, the data bus line appears as a dark line. Therefore, it is necessary to input an inspection signal to the short-circuit defect detection wiring 91 so that the display differs from the case of short-circuiting between data bus lines or short-circuiting between the data bus line and the common electrode.

  FIG. 10 shows an example of each voltage waveform for explaining the defect inspection method for the repair wiring in the present modification. As shown in FIG. 10, the data signal Vsig input to the data bus line 27 is inverted in polarity every horizontal period. The positive voltage of the data signal Vsig is 11.6V, and the negative voltage of the data signal Vsig is 0.2V. The center voltage Vsigc of the data signal Vsig is 5.9V. The common voltage Vcom applied to the common electrode is 5.1 V, which is slightly lower than the center voltage Vsigc. When the voltage of the gate pulse Vg is 24V, the pixel TFT is turned on, and the data signal Vsig input to the data bus line 27 is input to the pixel electrode. When the voltage of the gate pulse Vg is −5V, the pixel TFT is turned off. When the gate pulse Vg is switched from 24V to −5V, a feedthrough phenomenon occurs in the pixel TFT, and the holding voltage Vp held in the pixel electrode is slightly lower than the applied voltage 11.6V.

  The inspection signal Ve is a DC voltage of 15V higher than the positive voltage value 11.6V of the data signal Vsig. When the inspection signal Ve is input to the data bus line through the short-circuit portion, the data bus line is always a bright line in the NB type AM-LCD 1. Thus, the repair wirings 23a, 24a, 26a, and 28a that are short-circuited to the short-circuit defect detection wiring 91 can be detected.

  Even if the inspection signal Ve is an AC signal having a frequency different from that of the data signal input to the data bus line, the repair wirings 23a, 24a, 26a due to a short circuit between the data bus lines, a short circuit between the data bus line and the common electrode, or the like. , 28a can be detected. For example, when the frequency of polarity inversion of the inspection signal Ve is lower than the frequency of polarity inversion of the data signal, the data bus line short-circuited to the short-circuit defect detection wiring 91 can be detected as a noticeable flickering line. Since the flicker is conspicuous for human eyes at 60 Hz or less, the frequency of the inspection signal Ve may be about 30 Hz.

  In order to detect a short circuit between the repair wirings 23a, 24a, 26a and 28a and the short circuit defect detection wiring 91 by inputting an inspection signal to the short circuit defect detection wiring 91, not only during the inspection, but always the inspection signal. May be applied to the short-circuit defect detection wiring 91. Since the short-circuit defect detection wiring 91 is connected to the common potential supply conductive pattern 25 via the second high-resistance element 21, the voltage applied to the short-circuit defect detection wiring 91 is applied to the common potential supply conductive pattern 25. There is no impact. Further, when a voltage is applied to the short-circuit defect detection wiring 91 and the voltage of the common potential supply conductive pattern 25 changes, it can be detected that the second high-resistance element 21 is short-circuited. If the inspection signal is always input, it is not necessary to change the setting of the inspection signal and the connection state for the inspection, so that it is possible to shorten the time to identify the cause of the failure and reduce the number of inspection processes.

  As described above, according to this modification, even in the AM-LCD 1 having the repair wirings 23 a, 24 a, 26 a, and 28 a, the voltage of the short-circuit defect detection wiring 91 is measured or an inspection signal is sent to the short-circuit defect detection wiring 91. For example, a short circuit of the repair wirings 23a, 24a, 26a, and 28a can be detected. As described above, since the short circuit of the repair wirings 23a, 24a, 26a, and 28a can be detected in the manufacturing process of the AM-LCD 1, a great amount of time and labor required for failure analysis can be reduced, and the manufacturing cost of the AM-LCD 1 can be reduced. The cost of the AM-LCD 1 can be reduced.

  Next, a modification of the above modification will be described with reference to FIG. The AM-LCD 1 of the above modification includes four sets of repair wirings 23a, 24a, 26a, and 28a and first high resistance elements 19a, 19b, 19c, and 19d, and one short-circuit defect detection wiring 91. One second high resistance element 21 is included. On the other hand, this modification is characterized in that a plurality of sets (four in this example) of repair wires, first and second high resistance elements, and short-circuit defect detection wires are provided. . FIG. 11 is an enlarged view of the electrostatic protection element unit 20 of the present modification.

  As shown in FIG. 11, the electrostatic protection element unit 20 has four first and second high resistance elements connected in series. The repair wiring 23a is connected to the common potential supply conductive pattern 25 via the first and second high resistance elements 19a and 21a. A short-circuit defect detection wiring 91a is connected to a connection point between the first and second high resistance elements 19a and 21a. The repair wiring 24a is connected to the common potential supply conductive pattern 25 via the first and second high resistance elements 19b and 21b. A short-circuit defect detection wiring 91b is connected to a connection point between the first and second high resistance elements 19b and 21b. The repair wiring 26a is connected to the common potential supply conductive pattern 25 via the first and second high resistance elements 19c and 21c. A short-circuit defect detection wiring 91c is connected to a connection point between the first and second high resistance elements 19c and 21c. The repair wiring 28a is connected to the common potential supply conductive pattern 25 via the first and second high resistance elements 19d and 21d. A short-circuit defect detection wiring 91d is connected to a connection point between the first and second high resistance elements 19d and 21d. Although not shown, inspection signal supply circuits are connected to the short-circuit defect detection wirings 91a, 91b, 91c, and 91d, respectively.

  Since the short-circuit defect detection wiring 91a is formed in the same layer as the connection wiring of the second high resistance elements 21b, 21c, 21d and the common potential supply conductive pattern 25, the intersection of each conductive layer wiring is a pixel electrode. Layers and contact holes (both not shown) are connected and connected. Similarly, the short-circuit defect detection wiring 91b is formed in the same layer as the connection wiring between the second high-resistance elements 21c and 21d and the common potential supply conductive pattern 25, so that the intersection of each conductive layer wiring is a pixel. They are connected by electrode layers and contact holes (both not shown). Similarly, the short-circuit defect detection wiring 91c is formed in the same layer as the connection wiring between the second high-resistance element 21d and the common potential supply conductive pattern 25, so that the intersection of each conductive layer wiring is a pixel electrode. Layers and contact holes (both not shown) are connected and connected.

  According to this modification, the short-circuit defect detection wires 91a, 91b, 91c, 91d are provided for the repair wires 23a, 24a, 26a, 28a. As a result, the voltage of each short-circuit defect detection wiring 91a, 91b, 91c, 91d is measured, or a different inspection signal is input to each short-circuit defect detection wiring 91a, 91b, 91c, 91d. A short circuit of the wirings 23a, 24a, 26a, and 28a can be detected. As described above, since the short circuit of the repair wirings 23a, 24a, 26a, and 28a can be detected in the manufacturing process of the AM-LCD 1, a great amount of time and labor required for failure analysis can be reduced, and the manufacturing cost of the AM-LCD 1 can be reduced. The cost of the AM-LCD 1 can be reduced.

  According to the present embodiment, the repair wiring 23 a and the short-circuit defect detection wiring 91 are connected via the first high-resistance element 19, and the short-circuit defect detection wiring 91 is further connected via the second high-resistance element 21. By connecting the common potential supply conductive pattern 25, a direct short circuit between the repair wiring 23a and the common potential supply conductive pattern 25 can be avoided. When the repair wiring 23a and the short-circuit defect detection wiring 91 are short-circuited, a data bus line subjected to repair processing by supplying an inspection signal independent of the common potential to the short-circuit defect detection wiring 91 And can be easily distinguished from line defects caused by other causes.

The defect inspection method for the display device substrate, the liquid crystal display panel, the liquid crystal display device, and the repair wiring according to the embodiment described above is summarized as follows.
(Appendix 1)
Repair wiring to repair the disconnection defect of the data bus line,
An electrostatic protection element for protecting the repair wiring from static electricity;
A display device substrate comprising: a common conductive wiring that is connected to the repair wiring via the electrostatic protection element portion and maintains a predetermined voltage.
(Appendix 2)
In the display device substrate according to attachment 1,
The display device substrate, wherein the electrostatic protection element portion includes first and second high resistance elements connected in series.
(Appendix 3)
In the display device substrate according to attachment 2,
The display device substrate, wherein the first and second high resistance elements include thin film transistors.
(Appendix 4)
In the display device substrate according to any one of appendices 1 to 3,
The display device substrate, wherein the common conductive wiring has a common potential supply conductive pattern for supplying a common potential to a common electrode.
(Appendix 5)
In the display device substrate according to any one of appendices 2 to 4,
A display device substrate comprising: a short-circuit defect detection wiring which is connected to a connection point of the first and second high-resistance elements and detects a short circuit of the repair wiring.
(Appendix 6)
In the display device substrate according to attachment 5,
The display device substrate, wherein the short-circuit defect detection wiring includes a voltage measurement pad for measuring an applied voltage.
(Appendix 7)
The substrate for a display device according to any one of appendices 1 to 6,
A counter substrate disposed opposite to the display device substrate;
A liquid crystal display panel comprising: a liquid crystal sealed between the display device substrate and the counter substrate.
(Appendix 8)
The liquid crystal display panel according to appendix 7,
An inspection signal supply circuit for supplying an inspection signal for inspecting a short-circuit defect to the short-circuit defect detection wiring.
(Appendix 9)
In a defect inspection method for inspecting a defect generated in a repair wiring for repairing a disconnection defect of a data bus line,
A repair wiring defect inspection method, comprising: detecting a short circuit of the repair wiring based on a voltage value applied to a short-circuit defect detection wiring used for short-circuit defect detection.
(Appendix 10)
In the defect inspection method for repair wiring according to appendix 9,
Input an inspection signal for short-circuit defect inspection into the short-circuit defect detection wiring,
A repair wiring defect inspection method, comprising: detecting a short circuit of the repair wiring based on a voltage value applied to the repair wiring or a display state of a screen.

It is a figure which shows schematic structure of AM-LCD1 by the 1st Embodiment of this invention. It is an enlarged view of the electrostatic protection element part 20 formed in AM-LCD1 by the 1st Embodiment of this invention. It is a figure which shows the circuit structural example of another high resistance element used for AM-LCD1 by the 1st Embodiment of this invention. It is a figure which shows the circuit structural example of another high resistance element used for AM-LCD1 by the 1st Embodiment of this invention. It is a figure which shows schematic structure of AM-LCD1 by the 2nd Embodiment of this invention. It is AM-LCD1 of the 1st modification by the 2nd Embodiment of this invention, Comprising: It is an enlarged view of the connection part of TFT substrate 2 and PCB9 for gate bus lines. It is AM-LCD1 of the 1st modification by the 2nd Embodiment of this invention, Comprising: It is an enlarged view of the connection part of TFT substrate 2 and PCB9 for gate bus lines. It is a figure which shows schematic structure of AM-LCD1 of the 2nd modification by the 2nd Embodiment of this invention. It is AM-LCD1 of the 2nd modification by the 2nd Embodiment of this invention, Comprising: It is an enlarged view of the electrostatic protection element part 20. FIG. It is AM-LCD1 of the 2nd modification by the 2nd Embodiment of this invention, Comprising: It is a figure which shows an example of each voltage waveform for demonstrating the defect inspection method of the wiring for repair. It is a modification of the 2nd modification by the 2nd Embodiment of this invention, Comprising: It is an enlarged view of the electrostatic protection element part 20. FIG. It is a figure which shows schematic structure of AM-LCD201 which repairs the disconnection defect of a data bus line using the conventional wiring for repair. It is a figure which shows schematic structure of another AM-LCD201 which repairs the disconnection defect of a data bus line using the conventional wiring for repair. It is an enlarged view of the high resistance element 219 formed in the conventional AM-LCD201.

Explanation of symbols

1,201 AM-LCD
3, 203 TFT substrate 5, 205 Counter substrate 7, 207 PCB for data bus line
9,209 PCB for gate bus line
11, 211 Data driver IC
13, 213 Gate driver IC
13a IC chip 13b TCP film 15, 215 Data bus line lead line 17, 217 Gate bus line lead line 19, 19a to 19d First high resistance element 20 Static electricity protection element part 21, 21a to 21d Second high resistance element 23 223 repair wirings 23a-23f, 24a, 24b, 26a, 26b, 28a, 28b, 223a-223g, 223a ', 223b' repair wiring 25, 225 common potential supply conductive patterns 27, 227, 229 data bus line 29, 49, 69, 239 First TFT
31, 51, 71, 241 Second TFT
33, 53, 243 Third TFT
35, 55, 73, 90, 245 Operating semiconductor layer 39, 59, 77, 83, 251 ITO layer 41, 43, 61, 63, 79, 81, 85, 87, 247, 249 Contact hole 44, 244 Glass substrate 47 , 67, 75, 76, 253 Conductors 68, 89, 219 High resistance elements 91, 91a to 91d Short-circuit defect detection wiring 93 Inspection signal supply circuits 92, 113a, 113b Lead wire 107 Voltage measurement pads 109a, 109b, 109c , 111a, 111b, 111c connecting terminal 231 connecting portion 235 insulating film 237 final protective film

Claims (5)

Repair wiring to repair the disconnection defect of the data bus line,
An electrostatic protection element for protecting the repair wiring from static electricity;
A display device substrate comprising: a common conductive wiring that is connected to the repair wiring via the electrostatic protection element portion and maintains a predetermined voltage. The display device substrate according to claim 1,
The display device substrate, wherein the electrostatic protection element portion includes first and second high resistance elements connected in series. The display device substrate according to claim 2,
A display device substrate comprising: a short-circuit defect detection wiring which is connected to a connection point of the first and second high-resistance elements and detects a short circuit of the repair wiring. A substrate for a display device according to any one of claims 1 to 3,
A counter substrate disposed opposite to the display device substrate;
A liquid crystal display panel comprising: a liquid crystal sealed between the display device substrate and the counter substrate. In a defect inspection method for inspecting a defect generated in a repair wiring for repairing a disconnection defect of a data bus line,
A repair wiring defect inspection method, comprising: detecting a short circuit of the repair wiring based on a voltage value applied to a short-circuit defect detection wiring used for short-circuit defect detection.

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