CN100432766C - Laser repairing structure of liquid crystal display and method thereof - Google Patents

Abstract

A laser repairing structure and method for TFT panel is to arrange a first metal conductor with a contact hole in the source-drain electrode layer and connected to the pixel electrode electrically, to extend the first metal conductor until it is overlapped with the grid line of the last pixel, to repair the pixel bright point by laser irradiation, or to arrange two second metal conductors partially overlapped with the data line and the first metal conductor respectively on the grid electrode layer, to electrically connect one second metal conductor to repair the pixel bright point or to electrically connect two second metal conductors to repair the broken data line by laser irradiation.

Description

Laser repair structure and method of liquid crystal display

technical field

The invention relates to a structure of a thin film transistor liquid crystal display panel, and in particular provides a laser repair structure and method to improve display quality.

Background technique

Usually, the liquid crystal of Thin Film Transistor-Liquid Crystal Display (TFT-LCD) is filled in a thin film transistor (Thin Film Transistor, TFT) substrate containing electrodes and a color filter (Color Filter, CF) containing electrodes. ) between the substrates, and the transparency of the liquid crystal to light is controlled by the voltage supplied to the electrodes.

The display area of the TFT (Thin Film Transistor) panel contains many pixels arranged in a matrix, and a pixel (pixel) area is surrounded by the intersection of two gate lines and two data lines. Defined by a rectangular area, in addition to the pixel electrode, the pixel also includes a thin film transistor element and a storage capacitor. The thin film transistor is a switching element, and its switching state is determined by the scanning signal from the gate line and the data signal from the data line. To control, and a storage capacitance line (storage capacitance line) also through the pixel to form a storage capacitor, its function is to keep the existing signal of the pixel electrode until the arrival of the next signal.

As we all know, thin film transistor liquid crystal displays are currently developing towards the application field of TV, and the panels are gradually moving towards large-size design, so the complexity and difficulty of the manufacturing process are also increasing with the continuous increase in size. Therefore, it is very difficult It is easy to take into account the constraints of the manufacturing process and suppress the influence of manufacturing process errors on the display quality of the panel in the design, and they are the important keys that affect the production capacity and yield rate.

In the production process of TFT panels, pixels are often susceptible to process pollution or electrostatic damage, resulting in line defects (line defects) and point defects (pixel defects). Refers to pixel defects caused by abnormal short circuit or open circuit of thin film transistors.

Point defects can be divided into white defect, dark defect, dull defect, etc. The so-called bright point is bright even in a completely black screen, so the human eye is very sensitive to it and Easily identifiable, so it's best to patch bright spots into dark spots that are always dark, or at least patch bright spots into dull shimmering spots.

In general, laser repair is used when only a few bright spots occur.

1 is a schematic top view of a traditional TFT panel pixel with a laser-repaired bright spot structure. The data line 114 transmits the data signal to the source electrode 100, and the gate signal passes through the gate line 104 of the gate electrode layer on the transparent glass substrate. For transmission, the storage capacitor line 110 in the pixel is located at the gate electrode layer to provide a common voltage, the semiconductor electrode 102 is covered by the source electrode 100 and the drain electrode 106 respectively, and the contact hole 108 is used to electrically connect the pixel electrode 112 and The drain electrode 106, an additional metal 116 of the source-drain electrode layer below the pixel electrode 112 is electrically connected to the pixel electrode 112 through the contact hole 120, and the additional metal 116 is prepared for laser repair when necessary, and Another floating metal 118 located on the gate electrode layer is also prepared for laser repair when necessary. The floating metal 118 overlaps with the data line 114 and the additional metal 116 in regions 124 and 122 respectively.

Once the pixel is found to be a bright spot, the laser beam can irradiate the areas 124 and 122 from the lower surface of the transparent glass substrate to electrically connect the data line 114 and the additional metal 116, so that the data signal can be directly transmitted to the pixel electrode through the contact hole 120 112, and then convert the bright spots into shimmer spots.

However, this laser repair structure for bright spots requires an additional metal with a contact hole in the source-drain electrode layer under the pixel electrode, so the additional metal will reduce the aperture ratio of the pixel.

In addition to point defects, line defects sometimes occur in the production process of TFT panels, which also need to be repaired.

2 is a schematic top view of a traditional TFT panel pixel with a laser-repaired line defect structure. The data line 214 is disconnected in the area 216, and the gate signal is transmitted through the gate line 204 of the gate electrode layer on the transparent glass substrate. But because the data line 214 is disconnected in the area 216, the data signal cannot be transmitted to the source electrode 200 of this pixel, nor can it be transmitted to the source electrodes of other pixels connected to the data line 214. The storage capacitor line 210 in the pixel is located at the gate electrode. The pole electrode layer provides a common voltage. The semiconductor electrode 202 is partially covered by the source electrode 200 and the drain electrode 206 respectively. The contact hole 208 is used to electrically connect the pixel electrode 212 and the drain electrode 206, and is prepared to be used as a laser when necessary. The two repairing components 218 and 220 for repairing extend from the storage capacitor line 210 to the data line 214 and overlap with the data line 214 in regions 222 and 224 respectively.

Once the disconnected area 216 of the data line 214 is found, the laser beam can first irradiate the areas 222 and 224 from the lower surface of the transparent glass substrate to electrically connect the data line 214 and the storage capacitor line 210, and then use a low-energy laser The region 226 is irradiated to melt away part of the pixel electrode 212 , and then a high-energy laser is irradiated to the region 226 to cut off part of the storage capacitor line 210 until it is disconnected at the region 226 . Therefore, the data line 214 is turned on again through the part of the storage capacitor line 210 , and thus the data signal can be transmitted to the source electrodes of all pixels connected to the data line 214 .

However, because the pixel electrode is usually composed of indium tin oxide (Indium Tin Oxide, ITO) or indium zinc oxide (Indium Zinc Oxide, IZO), it is very difficult to control the melting of the pixel electrode by laser, and this laser The structure and method of repairing line defects requires the use of low-energy lasers to melt off the volatilized part of the pixel electrodes, so it is very difficult to control.

Therefore, the structure and method of this kind of laser repair line defects are complicated and risky. Furthermore, it uses the storage capacitor line as the lead wire for laser repair, and it is easy to cause a short circuit between the data line and the storage capacitor line during laser repair. So the repair yield is poor.

Contents of the invention

As mentioned in the background technology, the traditional structure and method of laser repairing TFT panel pixel bright spots of TFT-LCD will reduce the aperture ratio of the pixel, while the traditional structure and method of laser repairing data line disconnection need to use low-energy laser to Melting off the volatile part of the pixel electrode, the repair procedure is complicated, difficult to control and high risk, and it is easy to cause a bad short circuit between the data line and the storage capacitor line, so the repair yield is poor.

One of the objectives of the present invention is to solve the above-mentioned problem of lower aperture ratio caused by repairing pixel bright spots. Firstly, a first metal conductor electrically connected to the pixel electrode through a contact hole is provided on the source-drain electrode layer. The area of the first metal conductor is located within the area of the storage capacitor line, so the aperture ratio of the pixel will not vary. reduce.

Secondly, the present invention has two embodiments that can be used to repair pixel bright spots. The first embodiment is to extend the aforementioned first metal conductor until it overlaps with the gate line of the previous pixel, so that they can be passed through in the subsequent repair step. The laser irradiates the electrical connection, and this repair structure and method will repair the bright spots into dark spots.

The second embodiment is to arrange a second metal conductor partially overlapping with the data line and the aforementioned first metal conductor on the gate electrode layer, so that they can be electrically connected through laser irradiation in the subsequent repair step. This repair structure and method will repair the bright spots into micro-bright spots.

Another object of the present invention is not only to repair pixel bright spot defects, but also to repair data line disconnection defects. In the subsequent repairing step, the data line and the aforementioned first metal conductor can be electrically connected through laser irradiation, so as to achieve the function of repairing the disconnection defect of the data line.

One of the objectives of the present invention is that no laser is needed to melt off the volatilized pixel electrodes, so the repair procedure is simple, easy to control and low risk.

Another object of the present invention is that compared with the TFT panel without repair structure, this embodiment does not need to add additional photomask or process.

Therefore, the laser repair structure and method of the present invention can effectively improve repair efficiency and reduce production cost.

Description of drawings

FIG. 1 is a schematic top view of a TFT panel pixel with a laser-repaired bright spot structure according to the first prior art of the present invention.

FIG. 2 is a schematic top view of a TFT panel pixel with a laser-repaired line defect structure according to the second prior art of the present invention.

FIG. 3A is a schematic top view of a TFT panel pixel with a laser-repaired bright spot structure according to a first embodiment of the present invention.

3B is a schematic cross-sectional view along line A-A' of FIG. 3A and is used to illustrate the cross-sectional structure of a TFT panel pixel with a laser-repaired bright spot structure.

3C is a schematic cross-sectional view along the line B-B' in FIG. 3A and is used to illustrate the cross-sectional structure of a TFT panel pixel with a laser-repaired bright spot structure after laser irradiation.

FIG. 4A is a schematic top view of a TFT panel pixel with a laser repaired bright spot and line defect structure according to a second embodiment of the present invention.

4B is a schematic cross-sectional view along line C-C' of FIG. 4A and is used to illustrate the cross-sectional structure of a TFT panel pixel with a laser-repaired bright spot and line defect structure after laser irradiation.

Detailed ways

FIG. 3A is a schematic top view of a TFT panel pixel with a laser-repaired bright spot structure according to an embodiment of the present invention.

The data line 314 transmits the data signal to the source electrode 300, and the gate signal is transmitted through the gate line 304 of the pixel. The storage capacitor line 310 in the pixel is located at the gate electrode layer to provide a common voltage. The source electrode 300 and the drain The pole electrodes 306 partially overlap with the semiconductor electrodes 302, and the contact holes 308 are used to electrically connect the pixel electrodes 312 and the drain electrodes 306: a metal conductor 316 of the source-drain electrode layer above the storage capacitor line 310 has two Two extensions 321 and 323 can be repaired by laser when necessary; except for the extensions 321 and 323, the metal conductor 316 is located within the area of the storage capacitor line 310, and the extensions 321 and 323 extend from the edge of the storage capacitor line 310 to the gate line 305 of the last pixel, and overlap with the regions 320 and 322 respectively; generally speaking, the material of the metal conductor 316 is selected from the following: aluminum, copper, gold, chromium, tantalum, titanium, manganese, Nickel, molybdenum, niobium, neodymium, silver.

3B is a schematic cross-sectional view along the line AA' of FIG. 3A, a gate insulator 326 is interposed between the metal conductor 316 and the storage capacitor line 310 on the substrate 324, and the substrate 324 is usually made of transparent glass. In addition to a contact hole 318 for electrically connecting the metal conductor 316 and the pixel electrode 312, a protective insulator 328 is located between the metal conductor 316 and the pixel electrode 312. Generally speaking, the gate insulator 326 and the protective insulator 328 are made of silicon oxide or Silicon nitride, and the conductive pixel electrode 312 is composed of ITO or IZO.

Once the pixel is found to be a bright spot, the laser beam can irradiate one of the areas 320 and 322 from the lower surface of the substrate 324. FIG. 3C is a schematic cross-sectional view along the line BB' of FIG. 3A to illustrate the area 320 The cross-sectional structure after being irradiated by the laser, the area 320 of the metal conductor 316 is electrically connected to the gate line 305 of the previous pixel through the molten metal 330, so the gate signal of the previous pixel can directly pass through the molten metal 330 and the contact hole 318 is transmitted to the pixel electrode 312, thus turning the bright point of this pixel into a dark point to achieve the purpose of repairing.

The pattern design of the metal conductor 316 makes the aperture ratio of the pixel not reduced, which is one of the advantages of this embodiment, and, since the metal conductor 316 is located at the source-drain electrode layer, it can be simultaneously connected with the source and the drain. form. Therefore, this embodiment does not need to add additional photomasks or processes, and this embodiment provides a structure and method for simple laser bright spot repair without using laser to melt off the volatile pixel electrodes.

Another embodiment of the present invention is shown in FIG. 4A, the data line 414 transmits the data signal to the source electrode 300, and a contact hole 418 is used to electrically connect the metal conductor 416 and the pixel electrode 312, and the implementation shown in FIG. 3A The difference is that this embodiment has two floating metals 420 and 422 located on the same layer as the gate line 304 of this pixel. They are also prepared for laser repair when necessary. The floating metals 420 and 422 The areas 424, 428 and areas 426, 430 are respectively overlapped with the data line 414 and the metal conductor 416. Usually, the material of the metal conductor 416, the floating metal 420 and 422 is selected from the following: aluminum, copper, gold, Chromium, tantalum, titanium, manganese, nickel, molybdenum, niobium, neodymium, silver.

4B is a schematic cross-sectional view along the line CC' of FIG. 4A , the floating metal 420 is located on the substrate 324, and before the laser repair, the area 424 of the data line 414 and the area 426 of the metal conductor 416 are both in one. The gate insulator 326 is electrically isolated from the floating metal 420 , and a protective insulator 328 is located between the region 426 of the metal conductor 416 and the pixel electrode 312 .

Once the pixel is found to be a bright spot, the laser beam can irradiate the areas 424, 426 of the floating metal 420 or the areas 428, 430 of the floating metal 422 from the lower surface of the substrate 324. For example, referring to FIG. 4B, the areas 424, 426 have been lasered irradiated, the data line 414 and the metal conductor 416 are electrically connected through the molten metal 438, 440, so the data signal can be directly transmitted to the pixel electrode 312 through the contact hole 418, thus turning the bright spot of the pixel into a micro-bright spot to achieve repair the goal of.

Another purpose of this embodiment is to repair the line defect of the data line. Once the disconnection portion 442 in FIG. 422 in the regions 428 and 430, so the data line 414 is electrically connected to the floating metals 422 and 420 in the regions 428 and 424 respectively, and the metal conductor 416 is electrically connected to the floating metals 422 and 420 in the regions 430 and 426 respectively. Therefore, the data signal can be transmitted from the area 424 to the area 428 via the metal conductor 416 , thereby avoiding the disconnection portion 442 . In other words, the data signal can be transmitted via the metal conductor 416 to achieve the purpose of repair.

In this embodiment, the area of the metal conductor 416 with the contact hole 418 is located within the area of the storage capacitor line 310 . Same as the previous embodiment, this type of pattern design will not reduce the aperture ratio of the pixel.

Because the metal conductor 416 is located at the source-drain electrode layer, it can be formed simultaneously with the source and drain electrodes, while the floating metal 420 and the floating metal 422 are located at the gate electrode layer, which can be formed simultaneously with the gate electrode, Therefore, compared with the TFT panel without repair structure, this embodiment does not need to add additional mask or process.

Similar to the previous embodiment, this embodiment provides a simple laser bright spot and data line break repair structure and method that does not need to use laser to melt off the volatilized pixel electrode, and this embodiment can not only repair bright spot defects, but also repair data lines. Line defects are a unique advantage of this embodiment.

In summary, the present invention provides a convenient and simple method for repairing pixel bright spots. To achieve this purpose, firstly, a first metal conductor electrically connected to the pixel electrode through a contact hole is provided on the source-drain electrode layer. One of the important features of the present invention is that the area of the first metal conductor is located within the area of the storage capacitor line, so the aperture ratio of the pixel will not decrease.

Secondly, the present invention has two embodiments that can be used to repair pixel bright spots. One embodiment is to extend the first metal conductor until it overlaps with the gate line of the previous pixel, so that they can be repaired by laser light in the subsequent repair step. Irradiating the incoming electrical connection, this kind of repair structure and method will repair the bright spots into dark spots.

Another embodiment is to arrange a second metal conductor partially overlapping with the data line and the first metal conductor on the gate electrode layer, so that they can be electrically connected through laser irradiation in the subsequent repair step. The structure and method can repair the bright spots into micro-brightness points, and this kind of repair structure can repair the disconnected data line only by setting two second metal conductors. Therefore, this embodiment can not only repair bright spot defects, but also repair data line defects, which is a unique advantage of this embodiment.

Another important feature of the present invention is that no laser is required to melt off the volatile pixel electrodes.

Another feature of the present invention is that compared with the TFT panel without repair structure, this embodiment does not need to add additional mask or process.

Therefore, the laser repair structure and method of the present invention can effectively improve repair efficiency and reduce production cost.

The above-described embodiments are only to illustrate the technical ideas and characteristics of the present invention, and its purpose is to enable those familiar with the technical field to understand the content of the present invention and implement it accordingly. When the patent scope of the present invention cannot be limited, that is, Equivalent changes or modifications made according to the spirit disclosed in the present invention should still be covered within the patent scope of the present invention.

Claims (20)

1. the laser preparing structure of a thin-film transistor display panel comprises a plurality of pixels, and this pixel of wherein each further comprises:

One substrate;

One gate line, this gate line is arranged on this substrate along the direction of row;

One capacitor storage beam, this capacitor storage beam are arranged on this substrate and with this gate line and are not in contact with one another;

One gate insulator, this gate insulator are arranged on this substrate and cover this gate line and this capacitor storage beam;

One data line, this data line is arranged on this gate insulator along the direction of delegation;

One protection insulator, this protection insulator covers this data line;

One pixel electrode, this pixel electrode are arranged on this protection insulator; And

One metallic conductor, this metallic conductor is arranged on this gate insulator and has at least one elongated area, this metallic conductor except this elongated area is arranged in the zone of this capacitor storage beam, this elongated area is that the edge from this capacitor storage beam begins to extend, partly overlap up to gate line with the pixel of previous column, wherein, this metallic conductor is to be electrical connected with one first contact hole and this pixel electrode, and the gate line of the pixel of this capacitor storage beam and this previous column all is separated by with this gate insulator and this metallic conductor and is electrically insulated.

2. the laser preparing structure of thin-film transistor display panel as claimed in claim 1 is characterized in that, also comprises the semiconductor electrode, and this semi-conducting electrode is arranged on this gate insulator.

3. the laser preparing structure of thin-film transistor display panel as claimed in claim 2 is characterized in that, also comprises a drain electrode, and this drain electrode is arranged on this semi-conducting electrode, and wherein this drain electrode is electrical connected with one second contact hole and this pixel electrode.

4. the laser preparing structure of thin-film transistor display panel as claimed in claim 1 is characterized in that, the material of this metallic conductor is from following any selection: aluminium, copper, gold, chromium, tantalum, titanium, manganese, nickel, molybdenum, niobium, neodymium, silver.

5. the laser preparing structure of thin-film transistor display panel as claimed in claim 1 is characterized in that, the material of this substrate is a clear glass.

6. the laser preparing structure of thin-film transistor display panel as claimed in claim 1 is characterized in that, the material of this pixel electrode is one of indium tin oxide and indium-zinc oxide or its combination.

7. the laser preparing structure of thin-film transistor display panel as claimed in claim 1 is characterized in that, the material of this gate insulator and this protection insulator is one of monox and silicon nitride or its combination.

8. the laser preparing structure of a thin-film transistor display panel comprises a plurality of pixels, and wherein each this pixel further comprises:

One substrate;

One gate line, this gate line is arranged on this substrate along the direction of row;

One capacitor storage beam, this capacitor storage beam are arranged on this substrate and with this gate line and are not in contact with one another;

One gate insulator, this gate insulator are arranged on this substrate and cover this gate line and this capacitor storage beam;

One data line, this data line is arranged on this gate insulator along the direction of delegation;

One protection insulator, this protection insulation system covers this data line;

One pixel electrode, this pixel electrode are arranged on this protection insulator;

One first metallic conductor, this first metallic conductor is arranged on this gate insulator and has at least one elongated area, this first metallic conductor zone except this elongated area is arranged in the zone of this capacitor storage beam, wherein this first metallic conductor is to be electrical connected with one first contact hole and this pixel electrode, and this capacitor storage beam is to be separated by and to be electrically insulated with this gate insulator and this first metallic conductor; And

At least one second metallic conductor, this second metallic conductor is arranged on this substrate and it overlaps with this elongated area part of this data line and this first metallic conductor respectively, and wherein this data line and this first metallic conductor all are separated by with this gate insulator and this second metallic conductor and are electrically insulated.

9. the laser preparing structure of thin-film transistor display panel as claimed in claim 8 is characterized in that, also comprises the semiconductor electrode, and this semi-conducting electrode is arranged on this gate insulator.

10. the laser preparing structure of thin-film transistor display panel as claimed in claim 9 is characterized in that, also comprises a drain electrode, and this drain electrode is arranged on this semi-conducting electrode, and wherein this drain electrode is electrical connected with one second contact hole and this pixel electrode.

11. the laser preparing structure of thin-film transistor display panel as claimed in claim 8, it is characterized in that the material of this first metallic conductor and this second metallic conductor is from following any selection: aluminium, copper, gold, chromium, tantalum, titanium, manganese, nickel, molybdenum, niobium, neodymium, silver.

12. the laser preparing structure of thin-film transistor display panel as claimed in claim 8 is characterized in that, the material of this substrate is a clear glass.

13. the laser preparing structure of thin-film transistor display panel as claimed in claim 8 is characterized in that, the material of this pixel electrode is one of indium tin oxide and indium-zinc oxide or its combination.

14. the laser preparing structure of thin-film transistor display panel as claimed in claim 8 is characterized in that, the material of this gate insulator and this protection insulator is for appointing monox and the silicon nitride of selecting.

15. the laser repairing method of a thin-film transistor display panel comprises a plurality of pixels of formation, the step that wherein forms at least one this pixel comprises:

One substrate is provided;

Form a gate line, this gate line is set on this substrate along a direction that is listed as;

Form a capacitor storage beam, this capacitor storage beam is set on this substrate and with this gate line, is not in contact with one another;

Form a gate insulator, this gate insulator is set on this substrate and cover this gate line and this capacitor storage beam;

Form a data line, this data line is set on this gate insulator along the direction of delegation;

Form a protection insulator, this protection insulator is set on this data line;

Form a pixel electrode, this pixel electrode is set on this protection insulator;

Form one first metallic conductor, this first metallic conductor is set on this gate insulator and make this first metallic conductor have at least one elongated area, this first metallic conductor zone except this elongated area is arranged in the zone of this capacitor storage beam, wherein this first metallic conductor is to be electrical connected with one first contact hole and this pixel electrode, and this capacitor storage beam is to be separated by and to be electrically insulated with this gate insulator and this first metallic conductor;

Form two second metallic conductors, be provided with those second metallic conductors on this substrate and its overlap with this elongated area part of this data line and this first metallic conductor respectively, wherein this data line and this first metallic conductor all are separated by with this gate insulator and those second metallic conductors and are electrically insulated;

Shine the overlapping zone of beam of laser light at least those second metallic conductors and this data line to electrically connect at least one those second metallic conductor and this data line from the lower surface of this substrate at least one; And

Shine the overlapping zone of beam of laser light at least those second metallic conductors and this first metallic conductor to electrically connect at least one those second metallic conductor and this first metallic conductor from the lower surface of this substrate at least one.

16. the laser repairing method of thin-film transistor display panel as claimed in claim 15 is characterized in that, also comprises to form the semiconductor electrode, this semi-conducting electrode is positioned on this gate insulator.

17. the laser repairing method of thin-film transistor display panel as claimed in claim 16, it is characterized in that, also comprise formation one drain electrode, this drain electrode is positioned on this semi-conducting electrode, and wherein this drain electrode is to be electrical connected with one second contact hole and this pixel electrode.

18. the laser repairing method of thin-film transistor display panel as claimed in claim 15, it is characterized in that the material of this first metallic conductor and those second metallic conductors is from following any selection: aluminium, copper, gold, chromium, tantalum, titanium, manganese, nickel, molybdenum, niobium, neodymium, silver.

19. as the laser repairing method of the thin-film transistor display panel as described in the claim 15, wherein the material of this substrate is a clear glass.

20. the laser repairing method of thin-film transistor display panel as claimed in claim 15 is characterized in that, the material of this pixel electrode is one of indium tin oxide and indium-zinc oxide or its combination.

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