KR970009047B1 - Display elements with repair function - Google Patents

Abstract

None.

Description

Display element with repair function and repair method

1 is a diagram for explaining a wiring structure of a display device such as a liquid crystal display device.

2 is a view showing an embodiment of the wiring structure of the display element according to the present invention, and in particular, shows an embodiment of the wiring structure of the TFT LCD.

FIG. 3 is a diagram showing one embodiment of this cross-sectional structure at the cut line A-A 'of FIG.

4 is a view showing another embodiment of the wiring structure of the display device according to the present invention.

FIG. 5 is a view showing an embodiment of a cross-sectional structure at the cutting line B-B 'of FIG.

FIG. 6 is a view showing an insulating film defect in the cross-sectional structure shown in FIG.

7 is a view showing still another embodiment of the wiring structure of the display device according to the present invention.

8 is a view showing another embodiment of the wiring structure of the display device according to the present invention.

9 is a view showing another embodiment of the wiring structure of the display device according to the present invention.

FIG. 10 is a view showing a cross-sectional structure at cut line C-C 'of FIG.

11A to 13C are diagrams for describing a method of repairing a defect due to a short circuit between the data electrode and the gate electrode.

14A to 16D are diagrams for describing a method of repairing a defect due to disconnection of a data electrode.

* Explanation of symbols for the main parts of the drawings

201: data electrode 202: gate electrode

203: pixel electrode

The present invention relates to a display element, and more particularly, to a liquid crystal display element having a repair function and a repair method thereof.

There are two types of liquid crystal display devices, a simple matrix type and an active matrix type in which switching elements are arranged for each pixel. Among them, an active matrix type has a favorable aspect for high definition. The switching elements used in the active matrix type include a thin film diode and a thin film transistor, and a thin film transistor liquid crystal display (TFT LCD) is a thin film diode liquid crystal display (TFD LCD). ) Multi-gradation display is easier than

However, such TFT LCDs frequently cause defects in the wiring forming process because many electrodes are formed on the panel. If any one of the wiring processes fails in the LCD panel, the panel itself becomes defective, and therefore, a wiring forming process for reducing defects should be performed as much as possible. However, no matter how strict the process, it is very difficult not to generate any defects. Therefore, in the manufacture of a TFT LCD, it is proposed that a redundancy portion for wiring be attached in order to increase the yield. That is, in addition to the gate electrode and the data electrode for driving, a separate gate electrode and a separate data electrode are further provided for fail-safe and fail-repair or the panel is passive. The ring will be installed in the part. Here, the passive portion of the panel refers to a peripheral portion in which no pixel is formed in the panel. Here, the failure-stability means that the operation can be normally performed without any repair even when a failure occurs, and the failure-repair means that the operation can be normally performed through the repair in case of a failure.

For a detailed description of the liquid crystal display device to which the redundant portion is attached for the conventional defect-repair, see US Patent No. 4,840,459.

However, the liquid crystal display devices to which the redundant portion is attached for the conventional defect-fixing have the following problem points.

First, separate pads for driving the gate electrode and the data electrode, which are further configured, are drawn out. Separate pads require a separate driver to create a problem in that the peripheral circuit is complicated.

Second, if disconnection occurs at two or more points in one gate electrode or one data electrode, there is a problem that it cannot be repaired.

Third, there is a problem in that a short circuit due to a defective interlayer insulating film cannot be repaired at the point where the gate electrode and the data electrode cross each other.

Fourth, there is a problem that a signal delay occurs because the path formed due to repair is excessively bypassed.

Accordingly, an object of the present invention is to provide a display device that can solve the above problems.

Another object of the present invention is to provide a method for repairing a display element.

In order to achieve the above object, the present invention provides a plurality of first electrodes arranged in parallel with each other; A net structure arranged in parallel with each other, separated from the first electrodes through a predetermined insulating film, and arranged perpendicularly to the arrangement direction of the first electrodes, each having a plurality of paths at portions intersecting the first electrodes. The display device includes a plurality of second electrodes formed of a material, and the second electrodes are made of a material which can be selectively disconnected according to an external signal, thereby providing a display device having a repair function for defective wiring.

In order to achieve the above another object, a data electrode which runs in a vertical direction, and a gate electrode having a net shape having a plurality of paths at portions intersecting with the data electrode and insulated from the data electrode by a predetermined insulating film in a horizontal direction In the display device provided therein, a method of repairing a short circuit due to poor insulation between the data electrode and the gate electrode includes selectively disconnecting gate electrodes on both sides of a portion where a short circuit occurs. In addition, the method for repairing disconnection of the data electrode may include: selectively shorting intersection points between the data electrode and the gate electrode adjacent to the disconnected portion; And selectively disconnecting the gate electrodes adjacent to the shorted intersection point.

Next, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram for explaining a wiring structure of a display device such as a liquid crystal display device.

In FIG. 1, the first electrodes, that is, the data electrodes D1, D2, D3, D4, D5, D6, D7, and D8, are arranged vertically, and the second electrodes, that is, the gate electrodes G1, G2, G3, G4, G5 and G6 are arranged horizontally. Reference numeral 100 denotes a portion where pixels are formed in the active region of the liquid crystal display. In such a display device, if a short circuit occurs at the intersection 103 of the gate electrode G3 and the data electrode D4 due to poor interlayer insulation, the liquid crystal display device operates abnormally. Therefore, the function to repair these defects should be presented. If the data electrode D3 is disconnected at the point 101 and the pad for the data electrode is located at the top, the cells located at the bottom from the point 101 are not driven at all. Similarly, if the gate electrode G4 is disconnected at the point 102 and the pad for the gate electrode is located on the left side, the cells located on the right side from the point 102 are not driven at all.

2 is a view showing an embodiment of the wiring structure of the display element according to the present invention, and in particular, shows an embodiment of the wiring structure of the TFT LCD. Reference numeral 201 denotes a data electrode, reference numeral 202 denotes a gate electrode, and reference numeral 203 denotes a pixel electrode. The pixel electrode is usually formed of a transparent electrode such as ITO. As can be seen in the figure, the data electrodes are arranged in parallel to each other, the gate electrodes are formed in a mesh structure, and the traveling direction thereof is perpendicular to the traveling direction of the data electrode. Reference numeral 201a denotes a drain electrode of the thin film transistor, and a portion 202b protruding to the right of the data electrode serves as a source electrode of the thin film transistor. The pixel electrode 203 is connected to the drain of the thin film transistor and defines a liquid crystal cell. Reference numeral 204 denotes a transistor layer such as an amorphous silicon layer, which becomes the drain region, channel region and source region of the thin film transistor.

FIG. 3 is a diagram showing one embodiment of the cross-sectional structure at the cut line A-A 'of FIG. 2, and particularly, a cross-sectional structure when the reverse staggered thin film transistor is configured.

Referring to FIG. 3, a gate electrode 202 is selectively formed on the rear glass substrate 301a, and an insulating film 302 is formed on the glass substrate 301a. Here, the insulating film 302 serves as a gate insulating layer of the MOS transistor. The transistor layer 204 is selectively formed on the insulating film 302, and the data electrode 201, the source electrode 201b of the thin film transistor, and the drain electrode 201a are formed on the transistor layer 204. The source electrode 201b of the thin film transistor is formed in the form of a protrusion of the data electrode. That is, the source electrode of the thin film transistor is integrated with the data electrode. The insulating film 302 is made of a material that can be selectively disconnected by external stress, that is, an external signal. For example, it should have a thickness that can be opened by a laser and consist of a material that reacts to the laser.

A junction film 304 is formed at the junction of the transistor layer 204 and the source electrode of the thin film transistor and at the junction of the transistor layer 204 and the drain electrode 201a of the thin film transistor, wherein the junction film 304 is the source electrode. And since the drain electrode is formed of a metal layer, it is a film formed by implanting impurities at a high concentration so that the metal layer adheres well to the transistor layer 204. Reference numeral 303 denotes a protective film, and reference numeral 305 denotes an alignment film. The common electrode 307 is formed on the front glass substrate 301b, and the liquid crystal is injected between the alignment layer 305 and the common electrode 307.

4 is a view showing another embodiment of the wiring structure of the display device according to the present invention.

Referring to FIG. 4, the gate electrode 202 is configured to have three or more paths at portions intersecting with the data electrodes, unlike in FIG. 2. Such a structure provides a function for repairing a short circuit between the data electrode and the gate electrode. A detailed description thereof will be made using FIGS. 11A to 13C.

The liquid crystal display device having the gate electrode and the data electrode as described with reference to FIGS. 2 to 4 further includes an opposite electrode corresponding to the storage capacitance method.

FIG. 5 is a view showing an embodiment of the cross-sectional structure in the section line B-B 'of FIG. 4, and the same reference numerals as in FIG.

In FIG. 5, the data electrode 201 crosses the upper portion of the gate electrode 202, and the data electrode 201 and the gate electrode 202 are electrically insulated by the insulating film 302. However, if a defect occurs in the insulating film 302 during the manufacturing process, the data electrode 201 and the gate electrode 202 are shorted as shown in FIG.

FIG. 7 is a view showing another embodiment of the wiring structure of the display device according to the present invention, and the same reference numerals as in FIGS. 2 and 4 are used.

In FIG. 7, unlike in FIGS. 2 and 4, a portion of the gate electrode 202 having a mesh structure surrounds the pixel electrode 203. Thus, the gate electrode simultaneously serves as an electrode for forming the additional capacitance capacitor.

8 is a view showing another embodiment of the wiring structure of the display device according to the present invention, wherein reference numerals are the same as those used above.

In Fig. 8, almost all of these are similar to Fig. 7, with only four paths (two in Fig. 7) at the portion where the gate electrode 202 and the data electrode 201 cross. As such, when the gate electrode 202 has a path of three or more (four in the figure) at the intersection with the data electrode 201, in addition to ensuring fail-safe due to multiplexing of the gate electrode Open fault repair function of the data electrode 201 and short fault repair function of the data electrode 201 and the gate electrode 202 are provided.

9 is a view showing another embodiment of the wiring structure of the display device according to the present invention. In the wiring structure shown in FIG. 9, the gate electrode has a separation groove, and a separation layer 900 is formed in the separation groove. do. That is, the isolation layer 900 is formed by being integrated with the gate electrode 202, and overlaps with the pixel electrode 203 of the gate electrode 202 to perform the function of the additional capacitance capacitor electrode and to repair the defective parts. It performs the function of separating the parts that constitute the path In FIG. 9, the separation layers are formed on both sides of the portion intersecting the data electrode. Alternatively, only one of the separation layers may be formed.

FIG. 10 shows a cross-sectional structure at the cut line CC ′ of FIG. 9, in which a gate electrode 202 is selectively arranged on the rear glass substrate 301a, and a separation layer 900 is incorporated into the gate electrode 202. FIG. It is formed. As can be seen in the drawing, it can be seen that the gate electrodes 202 positioned on the left and right sides of the separation layer 900 are separated. In addition, the separation layer 900 should have an electrically insulating property. Since the separation layer 900 is different from the drawing, the separation layer 900 may be formed of the same material as the insulating layer 302. The data electrode 201 and the pixel electrode 203 are selectively formed on the insulating film 302, and the protective film 303 and the alignment film 305 are sequentially formed on the entire surface. The common electrode 307 is formed on the front glass substrate 301b, and the liquid crystal 306 is enclosed between the common electrode 307 and the alignment layer 305.

In order to explain the wiring structure of the display device, the drawings illustrated in FIGS. 2 to 10 are drawn with attention to the shape of the wiring structure, unlike the actual size. Therefore, the size in the actual wiring structure may be different from the drawings.

11A to 13C are diagrams for describing a fail-repair function of the wiring structure of the display device according to the present invention. In particular, FIGS. 11A to 13C illustrate a short circuit failure between the data electrode 201 and the gate electrode 202. Figures for explaining the repair function for.

FIG. 11A is a diagram schematically showing the wiring structures shown in FIGS. 2 and 7. In FIG. 11A, there are two places where the gate electrode 202 and the data electrode 201 cross each other. First, when the gate electrode 202 and the data electrode 201 are short-circuited at the intersection point SP1, the portions designated as the repair mask R1 and the repair mask R2 in the gate electrode 202 may be externally provided, such as a laser. Destroy using signal. In this way, the electrical structures of the data electrode 201 and the gate electrode 202 can be represented schematically as shown in FIG. 11B. In FIG. 11B, reference numeral DL denotes an electrical structure of the data electrode, and reference numeral GL denotes an electrical structure of the gate electrode.

On the other hand, when a short occurs between the data electrode 201 and the gate electrode 202 at the intersection point SP2 in FIG. 11A, the repair mask R3 and the repair mask R4 of the gate electrode 202 are generated. The designated part is destroyed by using an external signal. In this way, the electrical structures of the data electrode 201 and the gate electrode 202 can be represented as shown in FIG. 11C. In FIG. 11C, as in FIG. 11B, reference numeral DL denotes the electrical structure of the data electrode, and reference numeral GL denotes the electrical structure of the gate electrode. However, in the case of having a wiring structure as shown in FIG. 11A, if a short occurs at two or more intersections, a shortcoming cannot be repaired. In order to overcome this disadvantage, the wiring structure and the defect-repair where the gate electrode has three or more paths will be described below.

FIG. 12AA schematically illustrates wiring structures corresponding to the wiring structures shown in FIGS. 4 and 8, and the paths of the gate electrodes 202 at the intersections of the gate electrodes 202 and the data electrodes 201 are illustrated. A wiring structure of 3 is shown.

In FIG. 12A, there are three places where the gate electrode 202 and the data electrode 201 intersect.

First, when the gate electrode 202 and the data electrode 201 are short-circuited at the intersection point SP3, the portions designated as the repair mask R5 and the repair mask R6 among the gate electrodes 202 may be externally provided, such as a laser. Destroy using signal. In this way, the electrical structures of the data electrode 201 and the gate electrode 202 can be represented schematically as shown in FIG. 12B. In FIG. 12B, reference numeral DL denotes an electrical structure of the data electrode, and reference numeral GL denotes an electrical structure of the gate electrode, indicating that one of three paths of the gate electrode 202 is lost. have.

On the other hand, in FIG. 12A, when a short occurs between the data electrode 201 and the gate electrode 202 at the intersection point SP4 and the intersection point SP5, the repair mask R7 of the gate electrode 202, The parts designated as the repair mask R8, the repair mask R9, and the repair mask R10 are destroyed using an external signal. In this way, the electrical structures of the data electrode 201 and the gate electrode 202 can be represented as shown in FIG. 12C. As can be seen in FIG. 12C, it can be seen that two paths are cut out by repairing the three paths of the gate electrode 202. Here, reference numeral DL denotes the electrical structure of the data electrode, and reference numeral GL denotes the electrical structure of the gate electrode.

FIG. 13A schematically shows the wiring structure shown in FIG. 9, and has a separation groove to distinguish a portion forming additional capacitance and a portion forming a plurality of paths in the gate electrode 202, and the gate electrode ( The gate path is four at the intersection of the 202 and the data electrode 201. In particular, the separation groove 900 is formed in the separation groove.

In FIG. 13A, when the gate electrode 202 and the data electrode 201 are short-circuited at the intersection point SP6, portions of the gate electrode 202 designated as the repair mask R11 and the repair mask R12 are separated from the laser. It is destroyed using the same external signal. In this way, the electrical structure of the data electrode 201 and the gate electrode 202 can be represented schematically as shown in FIG. 13B. Here, DL denotes an electrical structure of the data electrode, and GL denotes an electrical structure of the gate electrode, and it can be seen that one of four paths of the gate electrode 202 is lost.

FIG. 13C shows the gate electrode 202 when a short occurs between the data electrode 201 and the gate electrode 202 at the intersection SP6, the intersection SP8, and the intersection SP9 in FIG. 12A. And it shows that the electrical structure of the data electrode 201, it can be seen that all of the remaining paths are cut out of one of the four paths of the gate electrode 202 except for the one in which the short circuit does not occur. The repairing method of the short circuits generated in this way includes a repair mask R11, a repair mask R12, a repair mask R15, a repair mask R16, a repair mask R17, and a repair mask R18 of the gate electrode 202. The part designated by) is destroyed by using an external signal.

14A to 16D are diagrams for describing a method of repairing an open defect of the data electrode 201.

First, FIG. 14A illustrates a wiring structure in which the path of the gate electrode 202 is 3 at the portion where the data electrode 201 and the gate electrode 202 intersect. In such a wiring structure, when the gate electrode 202 is open at the point F1, the gate electrode 202 at the crossing point RS1 and the crossing point RS2 using an external signal such as a laser and An external signal such as a laser is shorted to the data electrode 201, and the gate electrode is connected to a portion designated as the repair mask R19 ', the repair mask R20', the repair mask R21, and the repair mask R22. Use to break or disconnect. The shorting of the gate electrode 202 and the data electrode 201 is performed by destroying the insulating film 302 existing between the gate electrode 202 and the data electrode 201. When the disconnection defect of the data electrode 201 is repaired in this manner, the electrical structure DL of the gate electrode and the electrical structure DL of the data electrode can be represented as shown in FIG. 14B.

FIG. 14C illustrates the electrical structure GL of the gate electrode and the electrical structure DL of the data electrode when the case where the data electrode 201 is open at the point F2 is repaired. Such a repair method for disconnection failure destroys the insulating film existing between the gate electrode 202 and the data electrode 201 at the crossing point RS2 and the crossing point RS3 to break the gate electrode 202 and the data electrode 201. The gate electrode 202, which is short-circuited and positioned at the portions designated as the repair mask R21 ', the repair mask R22', the repair mask R19 and the repair mask R20, is broken or opened. It is to let.

FIG. 15A illustrates a structure in which the separation layer 900 is contained in the gate electrode 202 having the path of the gate electrode 202 at a portion where the gate electrode 202 and the data electrode 201 cross each other. In FIG. 15A, when the data electrode 201 is open at the point F3, the gate electrodes 202 and the data electrode 201 at intersections adjacent thereto, that is, at the intersection point RS4 and the intersection point RS5, are shown. ) Is short-circuited, and a portion of the gate electrode 202 designated as the repair mask R23, the repair mask R24, the repair mask R27, and the repair mask R28 is opened using an external signal. ) In this repair, the electrical structure DL of the data electrode and the electrical structure GL of the gate electrode can be represented as shown in FIG. 15B.

FIG. 15C shows the electrical structure GL of the gate electrode and the electrical structure DL of the data electrode when the disconnection of the data electrode 201 simultaneously generated at the points F3 and F4 is repaired. to be. Such a repair method for disconnection of the data electrode short-circuits the gate electrode 202 and the data electrode 201 at the intersection point RS4 and the intersection point RS6 and repairs the repair mask R23 of the gate electrode 202. The parts designated as the repair mask R24, the repair mask R29, and the repair mask R30 are disconnected.

FIG. 15D is a diagram showing the electrical structure GL of the gate electrode and the electrical structure DL of the data electrode when the disconnection of the data electrode 201 generated at the point F4 is repaired. The repair method for such a defect short-circuits the gate electrode 202 and the data electrode 201 at the intersection point RS5 and the intersection point RS6, repair mask R25, repair mask R26, repair mask. The gate electrode is selectively disconnected using R29 and the repair mask R30.

Unlike FIG. 16A, FIG. 16A is a structure in which the separation layer is integrated on only one side. In FIG. 16A, when the data electrode 201 is disconnected at the point F6, the data electrode and the gate electrode at the crossing point RS8 and the crossing point RS9 are shorted and the repair mask of the gate electrode 202 is shorted. The portions designated as R23, repair mask R36, repair mask R38, and repair mask R39 are opened using an external signal. In this repair, the electrical structure DL of the data electrode and the electrical structure GL of the gate electrode can be represented as shown in FIG. 16B. On the other hand, if the data electrode 201 is disconnected at the point F7, the data electrode 201 and the gate electrode 202 at the intersection RS9 and the intersection RS10 are shorted and a repair mask of the gate electrodes is shorted. (If the portions designated as R39, repair mask R40, repair mask R35, and repair mask R37 are disconnected using an external signal, the electrical structure DL of the data electrode and the electrical structure of the gate electrode ( GL) is shown as in FIG. 16C.

16D shows the electrical structure GL of the gate electrode and the electrical structure DL of the data electrode when the disconnection of the data electrode 201 simultaneously generated at the points F7 and F8 is repaired. to be. The repair method for such a defect short-circuits the gate electrode 202 and the data electrode 201 at the intersection RS9 and the intersection RS11, and repairs the mask R34, repair mask R35, and repair mask. The gate electrode is selectively disconnected using R39 and the repair mask R41.

In addition to the repair method described above, there may be various repair methods according to each wiring structure.

As described above, the present invention relates to a display device having a defective repair function, and has an effect of increasing the yield of the display device by providing a repair function that is strengthened than a conventional defective repair function. In particular, when the display device is a TFT LCD, the wiring structure is very fine, so that the yield is a major variable for mass production.

In addition, the present invention has the advantage that can be programmed by a series of defect repair process according to each pattern by arranging the defects by pattern. And since the repair is made at the point where the defect occurred or near, it is possible to save time by performing the repair of the defect by automation by connecting the measuring equipment and the laser repair system to check whether the defect has occurred or not. Thereby, productivity can be improved.

Claims (6)

A plurality of first electrodes arranged in parallel with each other; A net structure arranged in parallel with each other, separated from the first electrodes through a predetermined insulating film, and arranged perpendicularly to the arrangement direction of the first electrodes, each having a plurality of paths at portions intersecting the first electrodes. A plurality of second electrodes formed of; A plurality of thin film transistors each having a source connected to the first electrode and a gate connected to the second electrode and arranged in a matrix; A plurality of pixel electrodes connected to the drains of the thin film transistors and defining a cell; And a liquid crystal which is selectively switched according to a signal applied to the plurality of pixel electrodes to change its arrangement state, and the second electrodes may be selectively disconnected according to an external signal. And a repair function for defective wiring by allowing the insulating film formed between the first electrode and the second electrode to be selectively destroyed at the intersection point of the second electrode. The display device of claim 1, wherein the plurality of second electrodes have at least three traveling paths at portions intersecting the first electrodes. The display device of claim 1, wherein the second electrodes have a form overlapping with peripheral portions of the pixel electrodes. The display device of claim 3, wherein the second electrodes have separation grooves for separating portions overlapping the pixel electrodes and portions adjacent to the first electrodes. In a display element comprising a data electrode which runs in a vertical direction, and a gate electrode of a net shape which runs in a horizontal direction and is insulated from the data electrode by a predetermined insulating film and has a plurality of paths at an intersection with the data electrode. The method of repairing a short circuit due to an insulation failure between an electrode and the gate electrode is to search for a portion in which a short circuit occurs between the data electrode and the gate electrode and to disconnect a portion of the gate electrode corresponding to both sides of the short circuit portion. Designation process; And selectively disconnecting some of the gate electrodes designated as portions to be disconnected by applying an external signal. In a display element comprising a data electrode which runs in a vertical direction, and a gate electrode of a net shape which runs in a horizontal direction and is insulated from the data electrode by a predetermined insulating film and has a plurality of paths at an intersection with the data electrode. A method for repairing disconnection of an electrode may include selectively shorting intersections between a data electrode and a gate electrode adjacent to the disconnected portion; And selectively disconnecting the gate electrodes adjacent to the shorted intersection point.