CN100416354C - Pixel structure and repairing method thereof - Google Patents

Abstract

The invention relates to a pixel structure which is suitable for being driven by a scanning line and a data line on a substrate. The active element is disposed on the substrate and electrically connected to the scan line and the data line. The protective layer covers the scan line, the data line and the active device, and has a first opening exposing a portion of the data line. The pixel electrode is electrically connected with the active element. Based on the above, the pixel structure provided by the invention can be used for improving the display quality of the liquid crystal display panel.

Description

Pixel Structure and Its Repair Method

technical field

The present invention relates to a pixel structure and its repairing method, and in particular to a pixel structure and its repairing method for a liquid crystal display.

Background technique

Since the invention of the first black-and-white television with a cathode ray tube (Cathode Ray Tube, CRT) as the working mode, display technology has been evolving at a rapid pace. However, due to the disadvantages of large size, heavy weight, high radiation and poor image quality of displays made of cathode ray tubes, new flat-panel display technologies are constantly being developed. Among these flat panel display technologies, Liquid Crystal Display (LCD) technology, which has the advantages of thinness, lightness, power saving, low radiation, full color, and portability, is the most sophisticated and popularized. For example, mobile phones, digital cameras, digital video cameras, personal digital assistants (PDAs), notebook computers, LCD TVs, etc. have their scope of application.

Although the liquid crystal display technology has matured, some defects will inevitably occur in the manufacturing process of the liquid crystal display panel, and these defects will cause image quality degradation when displayed on the liquid crystal display. However, if these defective liquid crystal display panels are discarded directly, the manufacturing cost will be greatly increased. Generally speaking, it is very difficult to achieve zero defect rate only by improving the process technology, so the defect repair technology of the liquid crystal display panel becomes quite important. In the conventional technology, repairing defects of the liquid crystal display panel is usually performed by means of laser welding or laser cutting. Taking a thin film transistor liquid crystal display (TFT-LCD) as an example, laser welding or cutting is usually performed after the thin film transistor array (TFT array) is fabricated. However, due to the design of the pixel structure, not every defect can be repaired quickly, and even some defects cannot be repaired.

FIG. 1A shows a top view of a conventional TFT array substrate, and FIG. 1B shows a cross-sectional view along line A-A' of FIG. 1A. Please refer to FIG. 1A and FIG. 1B at the same time. A conventional thin film transistor array substrate 100 includes a substrate 110 , a plurality of scan lines 120 , a plurality of data lines 130 and a plurality of pixel structures 140 . Wherein, the scan lines 120 , the data lines 130 and the pixel structures 140 are all disposed on the substrate 110 .

The pixel structures 140 are electrically connected to corresponding scan lines 120 and data lines 130 , and each pixel structure 140 includes a thin film transistor 142 and a transparent electrode 144 . Wherein, the thin film transistor 142 includes a gate 142a, an amorphous silicon channel layer 142b, a source 142c and a drain 142d. The gate 142a is connected to the scan line 120, and the gate 142a and the scan line 120 are a first metal layer. In addition, the source electrode 142c is connected to the data line 130, and the data line 130, the source electrode 142c and the drain electrode 142d are the second metal layer. In addition, the transparent electrode 144 is electrically connected to the drain electrode 142d.

After the TFT substrate 100 is assembled with a color filter (not shown) and liquid crystals (not shown) are injected, a liquid crystal display panel (not shown) can be formed. However, when the above-mentioned thin film transistor 142 in the thin film transistor substrate 100 fails, the pixel structure 140 cannot work normally. Taking a normally white liquid crystal display panel as an example, when the liquid crystal display panel displays a black picture, the pixel structure 140 that cannot function normally will form a bright spot on the liquid crystal display panel. In order to avoid forming bright spots on the liquid crystal display panel, the bright spots must be repaired into dark spots by a laser repair process. The conventional laser repair is to fuse the drain 142d and the gate 142a together by laser, so that the transparent electrode 144 is permanently applied with a low gate voltage (gate low voltage, Vgl). The pixel structure 140 repaired in this way will form dark spots on the liquid crystal display panel.

However, when the liquid crystal display panel displays certain images, such as a completely white image, the repaired pixel structures 140 still form dark spots on the liquid crystal display panel, resulting in defects in the displayed image. In addition, in order to increase the viewing angle of the liquid crystal display panel, a compensation film is usually arranged on the liquid crystal display panel. The compensation film will cause the repaired pixel structure 140 to form a tiny bright spot on the liquid crystal display panel, thereby reducing the quality of the display image.

Contents of the invention

In view of the above, an object of the present invention is to provide a pixel structure capable of improving the quality of a display image.

Another object of the present invention is to provide a method for repairing pixel structures to quickly repair defective pixel structures.

Based on the above purpose or other purposes, the present invention proposes a pixel structure, which is suitable for being driven by a scanning line and a data line on a substrate, and the pixel structure includes an active device, a protective layer and a pixel electrode. The active element is arranged on the substrate and is electrically connected with the scanning line and the data line. The protection layer covers the scanning lines, the data lines and the active components, and the protection layer has a first opening, and the first opening exposes part of the data lines. The pixel electrode is electrically connected with the active device.

According to an embodiment of the present invention, the first opening further exposes part of the active device.

According to an embodiment of the present invention, the first opening further exposes part of the pixel electrode.

According to an embodiment of the present invention, the protective layer further has a second opening, the second opening exposes part of the active device, and the pixel electrode is partially filled in the second opening.

According to an embodiment of the present invention, the protective layer further has a second opening, and the second opening exposes a part of the pixel electrode.

According to an embodiment of the present invention, the pixel structure further includes a repair electrode, the repair electrode is disposed on the protection layer, and partially fills the first opening to be electrically connected to the data line, and the repair electrode is electrically connected to the pixel electrode. insulation. In addition, the repair electrode and the pixel electrode are of the same film layer.

According to an embodiment of the present invention, the first opening exposes at least one-third of the width of the data line.

According to an embodiment of the invention, the active device includes a thin film transistor.

The present invention also proposes a method for repairing the pixel structure, which is suitable for repairing any of the above pixel structures. The method for repairing the pixel structure includes forming a conductor layer above the data line and on the pixel electrode, and the data line passes through the conductor layer. It is electrically connected with the pixel electrode.

According to an embodiment of the present invention, the method for forming the conductor layer includes laser chemical vapor deposition.

Based on the above, in the pixel structure of the present invention, since the protective layer has at least one opening, it exposes part of the data lines. When the active element fails to function normally, a conductor layer can be formed above the opening to electrically connect the data line and the pixel electrode. The repaired pixel structure will form a dark spot when the liquid crystal display panel is configured with a display mode of a normal white screen and displays a black screen. When the liquid crystal display panel is configured with a display mode of a normal white screen and no signal is applied to the data line, the repaired pixel structure will form a bright spot to avoid the defect of a full white screen. In addition, by using the method for repairing the pixel structure of the present invention, defective pixel structures can be quickly repaired, thereby improving the zero bright point ratio of the liquid crystal display panel and reducing the production cost of the liquid crystal display panel.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

FIG. 1A shows a top view of a conventional thin film transistor array substrate.

Fig. 1B is a cross-sectional view along line A-A' of Fig. 1A.

FIG. 2A is a schematic structural diagram of a pixel structure according to a first embodiment of the present invention.

Fig. 2B is a cross-sectional view along line B-B' of Fig. 2A.

FIG. 2C is a schematic diagram of a repairing method for the pixel structure in FIG. 2A .

FIG. 2D shows a cross-sectional view along line C-C' of FIG. 2C.

FIG. 3A is a schematic structural diagram of a pixel structure according to a second embodiment of the present invention.

Fig. 3B is a cross-sectional view along line D-D' of Fig. 3A.

FIG. 3C is a schematic diagram of a repairing method for the pixel structure in FIG. 3A .

FIG. 3D shows a cross-sectional view along line E-E' of FIG. 3C.

FIG. 4A is a schematic structural diagram of a pixel structure according to a third embodiment of the present invention.

Fig. 4B is a cross-sectional view along line F-F' of Fig. 4A.

FIG. 4C is a schematic diagram of a repairing method for the pixel structure in FIG. 4A .

FIG. 4D shows a cross-sectional view along line G-G' of FIG. 4C.

FIG. 5A is a schematic structural diagram of a pixel structure according to a fourth embodiment of the present invention.

FIG. 5B is a cross-sectional view along line H-H' of FIG. 5A.

FIG. 5C is a schematic diagram of a repairing method for the pixel structure in FIG. 5A .

FIG. 5D shows a cross-sectional view along line I-I' of FIG. 5C.

FIG. 6A is a schematic structural diagram of a pixel structure according to a fifth embodiment of the present invention.

Fig. 6B shows a cross-sectional view along line J-J' of Fig. 6A.

FIG. 6C is a schematic diagram of a repairing method for the pixel structure in FIG. 6A .

FIG. 6D shows a cross-sectional view along line K-K' of FIG. 6C.

100: TFT array substrate 110: Substrate

120: Scanning line 130: Data line

140, 200, 300, 400, 500, 600: pixel structure

142: thin film transistor 142a, 210a: gate

142b, 210b: amorphous silicon channel layer 142c, 210c: source

142d, 210d: drain 144: transparent electrode

210: active components 220, 320, 420, 520: protective layer

220a, 320a, 420a, 520a: first opening

420b, 520b: second opening 230, 330, 530: pixel electrode

240, 340, 440, 540, 640: conductor layer

610: Repair electrodes

Detailed ways

first embodiment

FIG. 2A is a schematic structural diagram of a pixel structure according to a first embodiment of the present invention, and FIG. 2B is a cross-sectional view along line B-B' of FIG. 2A . Please refer to FIG. 2A and FIG. 2B at the same time. The pixel structure 200 is fabricated on a substrate 110 and driven by a scan line 120 and a data line 130 on the substrate 110 . The pixel structure 200 includes an active device 210 , a protection layer 220 and a pixel electrode 230 . Wherein, the active device 210 is disposed on the substrate 110 and is electrically connected to the scan line 120 and the data line 130 . In addition, the passivation layer 220 covers the scan lines 120 , the data lines 130 and the active device 210 , and the passivation layer 220 has a first opening 220 a exposing part of the data lines 130 . The pixel electrode 230 is electrically connected to the active device 210 .

Based on the above, the substrate 110 is, for example, a glass substrate, a quartz substrate, or a substrate of other suitable materials. The scan lines 120 are, for example, aluminum alloy wires or wires formed of other suitable conductive materials. The data line 130 can be a chromium metal wire, an aluminum alloy wire, or a wire formed of other suitable conductive materials.

The active device 210 is, for example, a thin film transistor or other tri-polar switching devices with three terminals. The material of the protective layer 220 is, for example, silicon nitride or other suitable materials. The pixel electrode 230 is, for example, a transparent electrode, a reflective electrode, or a transflective electrode, and the material of the pixel electrode 230 may be indium tin oxide (ITO). ), indium zinc oxide (IZO), metal or other transparent or opaque conductive materials.

More specifically, in this embodiment, the active device 210 is a thin film transistor. The active device 210 includes a gate 210a, an amorphous silicon channel layer 210b, a source 210c and a drain 210d. Wherein, the gate 210a is connected to the scan line 120, and the gate 210a and the scan line 120 are the first metal layer. In addition, the source electrode 210c is connected to the data line 130, and the data line 130, the source electrode 210c and the drain electrode 210d are the second metal layer.

In addition, in this embodiment, the first opening 220 a of the passivation layer 220 exposes part of the data line 130 , and the first opening 220 a preferably exposes more than one-third of the width of the data line 130 . In addition, the first opening 220a also exposes part of the active device 210 (for example, part of the drain 210d ). In addition, as shown in FIG. 2B , the pixel electrode 230 is disposed on the passivation layer 220 and partially fills the first opening 220 a to be electrically connected to the drain 210 d of the active device 210 . It should be noted that the pixel electrode 220 is not connected to the data line 130 . Furthermore, although the pixel electrode 230 in this embodiment is disposed on the protective layer 220 , the pixel electrode 230 may also be disposed under the protective layer 220 .

The above pixel structure 200 can be applied to manufacture a liquid crystal display panel (not shown). However, in the manufacturing process of the liquid crystal display panel, if the pixel structure 200 has some defects and cannot operate normally, the pixel structure 200 will form a bright spot when it is matched with a normally white liquid crystal display panel. . At this time, the defective pixel structure 200 can be repaired, so that the repaired pixel structure 200 forms a dark spot on the liquid crystal display panel. The method of repairing the pixel structure 200 will be described in detail later.

FIG. 2C is a schematic diagram of a repairing method for the pixel structure in FIG. 2A , and FIG. 2D is a cross-sectional view along line CC' of FIG. 2C . Please refer to FIG. 2C and FIG. 2D at the same time. The method for repairing the pixel structure 200 is to form a conductive layer 240 above part of the data line 130 , part of the drain electrode 210 d and part of the pixel electrode 230 . After the conductive layer 240 is formed, the data line 130 is electrically connected to the pixel electrode 230 through the conductive layer 240 . In addition, the method of forming the conductor layer 240 is, for example, laser chemical vapor deposition (laser chemical vapor deposition, laser CVD) or other suitable methods. Taking the laser chemical vapor deposition method as an example, the method of depositing the conductor layer 240 is to irradiate tungstenhexaca rbonyl (W(CO) ₆ ) gas with an ultraviolet laser (ultraviolet laser, UV laser), so as to form on the pixel structure 200 The conductive layer 240 made of tungsten metal has a chemical reaction formula as follows:

Since the conductive layer 240 is electrically connected between the data line 130 and the pixel electrode 230 , when the liquid crystal display panel is configured with a normal white screen display mode and displays a black screen, the pixel electrode 230 is always in a charged state. This will make the pixel structure 200 form a dark spot on the LCD panel. When the liquid crystal display panel is equipped with a normal white screen display mode and displays a full white screen, since all the data lines 130 do not transmit data signals, the pixel electrodes 230 will not be in a charged state, and the repaired pixel structure 200 will be formed. A dot on the LCD panel. But at this time, since the liquid crystal display panel displays a completely white image, the repaired pixel structure 200 will not cause defects in the display image. In addition, the pixel electrode 230 is not always maintained at a low gate voltage, even if a compensation film is disposed on the liquid crystal display panel, micro bright spots will not appear on the liquid crystal display panel.

Since this repair method only needs to deposit a conductive layer 240 by laser chemical vapor deposition, it can quickly repair the defective pixel structure 200, thereby improving the zero-brightness ratio of the liquid crystal display panel and reducing the production cost of the liquid crystal display panel.

It should be noted that, in this embodiment, although the repair method of the pixel structure 200 is to form a conductive layer 240 above part of the data line 130, part of the drain electrode 210d and part of the pixel electrode 230, so that the data line 130 It is electrically connected with the pixel electrode 230 . However, in other embodiments, the repairing method of the pixel structure 200 may also only form a conductive layer 240 on a part of the data lines 130 and a part of the pixel electrodes 230 so as to electrically connect the data lines 130 and the pixel electrodes 230 .

second embodiment

FIG. 3A is a schematic structural diagram of a pixel structure according to a second embodiment of the present invention, and FIG. 3B is a cross-sectional view along line D-D' of FIG. 3A. FIG. 3C is a schematic diagram of a repairing method for the pixel structure in FIG. 3A , and FIG. 3D is a cross-sectional view along line E-E' of FIG. 3C . Please refer to FIG. 3A and FIG. 3B at the same time. The pixel structure 300 of this embodiment is similar to the pixel structure 200 of the first embodiment. Located on the drain 210d of the active device 210 . In addition, the first opening 320 a exposes at least one-third of the line width of the data line 130 , and the first opening 320 a also exposes part of the pixel electrode 330 .

Please refer to FIG. 3C and FIG. 3D at the same time, the repairing method of the pixel structure 300 is the same as the repairing method of the pixel structure 200 . The repairing method of the pixel structure 300 is to form a conductive layer 340 on part of the data line 130 , on a part of the drain electrode 210 d and on a part of the pixel electrode 330 , and the data line 130 is electrically connected to the pixel electrode 330 through the conductive layer 340 . In addition, the method of forming the conductor layer 340 is, for example, laser chemical vapor deposition or other suitable methods.

third embodiment

FIG. 4A is a schematic structural diagram of a pixel structure according to a third embodiment of the present invention, and FIG. 4B is a cross-sectional view along line F-F' of FIG. 4A. Please refer to FIG. 4A and FIG. 4B at the same time, the pixel structure 400 is similar to the pixel structure 200 of the first embodiment, the difference is that: the first opening 420a of the protective layer 420 only exposes part of the data line 130, and at least exposes the data One-third of the width of the line 130 , but the first opening 420 a does not expose the pixel electrode 230 . In addition, the protective layer 420 also has a second opening 420b, the second opening 420b exposes part of the active device 210 (that is, part of the drain 210d is exposed), and the pixel electrode 230 is partially filled in the second opening 420b, so as to It is electrically connected with the drain 210d of the active device 210 .

4C is a schematic diagram of a repairing method for the pixel structure in FIG. 4A , and FIG. 4D is a cross-sectional view along line G-G' of FIG. 4C . Please refer to FIG. 4C and FIG. 4D at the same time. The repair method of the pixel structure 400 is similar to the repair method of the pixel structure 200. The repair method of the pixel structure 400 is to form a conductive layer 440 on the protective layer 420, and the conductive layer 440 covers part of the data. The line 130 and part of the pixel electrode 230, and the conductive layer 440 is also partially filled in the first opening 420a. The data line 130 can be electrically connected to the pixel electrode 230 through the conductive layer 440 . The method for forming the conductive layer 440 is, for example, laser chemical vapor deposition or other suitable methods.

It should be noted that in this embodiment, although the first opening 420a exposing part of the data line 130 is located beside the active device 210 , in other embodiments, the first opening 420a is not limited to be on the side of the active device 210 beside. For example, the first opening 420a can be located on the data line 130 and farther away from the active device 210, and the repairing method of the pixel structure 400 is the same as above.

Fourth embodiment

FIG. 5A is a schematic structural diagram of a pixel structure according to a fourth embodiment of the present invention, and FIG. 5B is a cross-sectional view along line H-H' of FIG. 5A . Please refer to FIG. 5A and FIG. 5B at the same time, the pixel structure 500 is a modification of the pixel structure 400 of the third embodiment. The pixel electrode 530 of the pixel structure 500 is disposed under the protective layer 520 and located above the drain 210 d of the active device 210 . And the first opening 520 a exposes at least one-third of the width of the data line 130 . The protection layer 520 also has a second opening 520 b , the second opening 520 b exposes a part of the pixel electrode 530 , and the pixel electrode 530 is electrically connected to the drain 210 d of the active device 210 .

5C is a schematic diagram of a repairing method for the pixel structure in FIG. 5A , and FIG. 5D is a cross-sectional view along line I-I' of FIG. 5C . Please refer to FIG. 5C and FIG. 5D at the same time. The repair method of the pixel structure 500 is similar to the repair method of the pixel structure 200. The repair method of the pixel structure 500 is to form a conductor layer 540 on the protection layer 520, that is, on part of the data line 130 A conductive layer 540 is formed above and part of the pixel electrode 530 . The conductive layer 540 partially fills the first opening 520 a and the second opening 520 b, and the data line 130 can be electrically connected to the pixel electrode 530 through the conductive layer 540 . The method for forming the conductive layer 540 is, for example, laser chemical vapor deposition or other suitable methods.

fifth embodiment

FIG. 6A is a schematic structural diagram of a pixel structure according to a fifth embodiment of the present invention, and FIG. 6B is a cross-sectional view along line J-J' of FIG. 6A. Please refer to FIG. 6A and FIG. 6B at the same time, the pixel structure 600 is a modification of the pixel structure 400 of the third embodiment, the difference is that: the pixel structure 600 includes a repair electrode 610 . The repair electrode 610 is disposed on the passivation layer 420 and partially fills the first opening 420 a to be electrically connected to the data line 130 , while the repair electrode 610 is electrically insulated from the pixel electrode 230 . More specifically, the repair electrode 610 and the pixel electrode 230 are the same film layer.

FIG. 6C is a schematic diagram of a repairing method for the pixel structure in FIG. 6A , and FIG. 6D is a cross-sectional view along line K-K' of FIG. 6C . Please refer to FIG. 6C and FIG. 6D at the same time. The repair method of the pixel structure 600 is similar to the repair method of the pixel structure 400. The repair method of the pixel structure 600 is to form a conductive layer 640 on the protection layer 420 to cover part of the repair electrode 610 and Part of the pixel electrode 230 . The data line 130 is electrically connected to the repair electrode 610 , and the conductor layer 640 is electrically connected to the repair electrode 610 , so the data line 130 can be electrically connected to the pixel electrode 230 through the conductor layer 640 . The method for forming the conductive layer 640 is, for example, laser chemical vapor deposition or other suitable methods.

Since the conductive layer 640 is formed on the repairing electrode 610 instead of partially filling the first opening 420a, it is possible to avoid disconnection of the conductive layer 640 caused by too steep slope at the edge of the first opening 420a. Therefore, the repair yield will be higher.

In summary, the pixel structure and the repairing method of the pixel structure proposed by the present invention have at least the following advantages:

1. In the pixel structure of the present invention, since the protective layer has at least one opening, which exposes part of the data lines, when the active device fails to function normally, a conductive layer can be formed above the opening to electrically connect the data lines between the pixel electrodes. When the liquid crystal display panel adopts the normal white screen display mode and displays a black screen, the pixel structure after repair will not form bright spots, so the user is not easy to perceive the pixel structure after repair.

2. The pixel structure repairing method of the present invention can be used to repair defective pixel structures, so when the liquid crystal display panel adopts the normal white screen display mode and displays a black screen, no bright spots or micro bright spots will be formed on the liquid crystal display panel . In this way, the zero-brightness rate of the liquid crystal display panel can be increased, thereby reducing the production cost of the liquid crystal display panel.

3. The manufacturing and repairing method of the pixel structure of the present invention is compatible with the current manufacturing process, and there is no need to purchase additional manufacturing equipment except for changing the design of several photomasks.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in this art can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, this The scope of protection of the invention should be defined by the claims.

Claims (11)

1. a dot structure is suitable for driving by an one scan line on the substrate and a data line, and this dot structure comprises:

One active member is disposed on this substrate, and is electrical connected with this sweep trace and this data line;

One protective seam covers this sweep trace, this data line and this active member, and this protective seam has one first perforate, and this this data line of first perforate expose portion; And

One pixel electrode electrically connects with this active member.

2. dot structure according to claim 1, wherein this first perforate this active member of expose portion more.

3. dot structure according to claim 1, wherein this first perforate this pixel electrode of expose portion more.

4. dot structure according to claim 1, wherein this protective seam has more one second perforate, this this active member of second perforate expose portion, and the part of this pixel electrode is inserted this second perforate.

5. dot structure according to claim 1, wherein this protective seam has more one second perforate, this this pixel electrode of second perforate expose portion.

6. dot structure according to claim 1 comprises that more one repairs electrode, be disposed on this protective seam, and part inserts in this first perforate being electrically connected at this data line, and this repairing electrode and this pixel electrode is electrically insulated.

7. dot structure according to claim 6, wherein this repairing electrode and this pixel electrode are same rete.

8. dot structure according to claim 1, wherein this first perforate expose at least this data line width 1/3rd.

9. dot structure according to claim 1, wherein this active member comprises thin film transistor (TFT).

10. the method for repairing and mending of a dot structure is suitable for repairing arbitrary described dot structure in the claim 1 to 6, and the method for repairing and mending of this dot structure comprises:

Forming a conductor layer above this data line with on this pixel electrode, and this data line electrically connects by this conductor layer and this pixel electrode.

11. the method for repairing and mending of dot structure according to claim 10, the method that wherein forms this conductor layer comprises the laser chemical vapor deposition method.

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