KR102607452B1 - Liquid crystal display and repairing method thereof - Google Patents

Abstract

A liquid crystal display device according to an embodiment of the present invention includes a first substrate, a gate line and a data line positioned on the first substrate and spaced apart from each other, a first thin film transistor connected to the gate line and the data line, and the It includes a first subpixel electrode connected to a first thin film transistor, wherein the first subpixel electrode includes a horizontal stem, a vertical stem, and a fine branch connected to the horizontal stem and the vertical stem, The thickness of the minute branch portion of the first subpixel electrode is thinner than the thickness of the horizontal stem portion and the vertical stem portion of the first subpixel electrode.

Description

Liquid crystal display device and repair method thereof {LIQUID CRYSTAL DISPLAY AND REPAIRING METHOD THEREOF}

This disclosure relates to a liquid crystal display device and a repair method thereof.

Liquid Crystal Display (LCD) is one of the most widely used flat panel displays currently. It consists of two substrates with electrodes and a liquid crystal layer inserted between them. A signal is applied to the electrodes to form a liquid crystal display. It is a display device that controls the amount of light transmitted by rearranging the liquid crystal molecules.

A thin film transistor (TFT) display panel, one of the two substrates that make up a liquid crystal display device, is a circuit board that independently drives each pixel in a liquid crystal display device or an organic light emitting diode (OLED) device. It is used.

A thin film transistor display panel is formed by crossing gate lines that transmit gate signals and data lines that transmit data signals, and consists of thin film transistors connected to the gate lines and data lines, and pixel electrodes connected to the thin film transistors.

Meanwhile, liquid crystal display devices may have display screen defects, a typical defect being a defective pixel that glows brightly on a black screen. As a way to repair such defective pixels, there is a method of making the pixel electrode of the defective pixel into an electrically floating state so that the defective pixel is not visible.

Embodiments are intended to prevent damage caused by laser energy when repairing a liquid crystal display device.

A liquid crystal display device according to an embodiment of the present invention includes a first substrate, a gate line and a data line positioned on the first substrate and spaced apart from each other, a first thin film transistor connected to the gate line and the data line, and the It includes a first subpixel electrode connected to a first thin film transistor, wherein the first subpixel electrode includes a horizontal stem, a vertical stem, and a fine branch connected to the horizontal stem and the vertical stem, The thickness of the minute branch portion of the first subpixel electrode is thinner than the thickness of the horizontal stem portion and the vertical stem portion of the first subpixel electrode.

The liquid crystal display device according to an embodiment of the present invention may further include a second thin film transistor connected to the gate line and the data line, and a second subpixel electrode connected to the second thin film transistor.

The second subpixel electrode may be spaced apart from the first subpixel electrode in a column direction.

The second subpixel electrode includes a horizontal stem, a vertical stem, and a fine branch connected to the horizontal stem and the vertical stem, and the thickness of the fine branch of the second subpixel electrode is determined by the thickness of the second subpixel electrode. It may be thinner than the thickness of the horizontal stem portion and the vertical stem portion of the pixel electrode.

The liquid crystal display device according to an embodiment of the present invention may further include a shielding electrode that is located on the same layer as the first subpixel electrode and the second subpixel electrode and overlaps the data line.

A repair method for a liquid crystal display device according to an embodiment of the present invention includes a first substrate, a gate line and a data line positioned on the first substrate and spaced apart from each other, and a first thin film transistor connected to the gate line and the data line. , and a repair method of a liquid crystal display device including a first subpixel electrode connected to the first thin film transistor and including a horizontal stem, a vertical stem, and a fine branch connected to the horizontal stem and the vertical stem. It includes the step of cutting the fine branch portion of the first sub-pixel electrode connected to the first thin-film transistor to block the connection between the first sub-pixel electrode and the first thin-film transistor. At this time, the thickness of the minute branch portion of the first subpixel electrode is thinner than the thickness of the horizontal stem portion and the vertical stem portion of the first subpixel electrode.

In the step of blocking the connection between the first subpixel electrode and the first thin film transistor, a laser may be used to cut the fine branch portion of the first subpixel electrode connected to the first thin film transistor.

A repair method for a liquid crystal display device according to an embodiment of the present invention uses the laser to cut the fine branch portion of the second subpixel electrode connected to the second thin film transistor to form the first subpixel electrode and the first subpixel electrode. A step of blocking the connection of the thin film transistor may be further included.

According to embodiments, when repairing a liquid crystal display device, a laser is used to cut the connection between a thin pixel electrode and a thin film transistor, thereby preventing damage caused by the energy of the laser.

1 is a diagram schematically showing a plan view of a liquid crystal display device according to an embodiment of the present invention.
FIG. 2 is a diagram schematically showing an example of a cross section taken along the cutting line II-II in FIG. 1.
FIG. 3 is a diagram schematically showing an example of a cross section taken along the cutting line III-III in FIG. 1.
FIG. 4 is a diagram schematically showing an example of a cross section taken along the line IV-IV of FIG. 1.
FIG. 5 is an enlarged view of area A in the liquid crystal display device of FIG. 1.
FIG. 6 is an enlarged view of area B in the liquid crystal display device of FIG. 1.

Hereinafter, with reference to the attached drawings, various embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. The invention may be implemented in many different forms and is not limited to the embodiments described herein.

In order to clearly explain the present invention, parts that are not relevant to the description are omitted, and identical or similar components are assigned the same reference numerals throughout the specification.

In addition, the size and thickness of each component shown in the drawings are arbitrarily shown for convenience of explanation, so the present invention is not necessarily limited to what is shown. In the drawing, the thickness is enlarged to clearly express various layers and areas. And in the drawings, for convenience of explanation, the thicknesses of some layers and regions are exaggerated.

Additionally, when a part of a layer, membrane, region, plate, etc. is said to be “on” or “on” another part, this includes not only cases where it is “directly above” another part, but also cases where there is another part in between. . Conversely, when a part is said to be “right on top” of another part, it means that there is no other part in between. In addition, being “on” or “on” a reference part means being located above or below the reference part, and does not necessarily mean being located “above” or “on” the direction opposite to gravity. .

In addition, throughout the specification, when a part is said to "include" a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

In addition, throughout the specification, when referring to “on a plane,” this means when the target portion is viewed from above, and when referring to “in cross section,” this means when a cross section of the target portion is cut vertically and viewed from the side.

1 is a diagram schematically showing a plan view of a liquid crystal display device according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing an example of a cross section taken along the cutting line II-II in FIG. 1. FIG. 3 is a diagram schematically showing an example of a cross section taken along the cutting line III-III in FIG. 1. FIG. 4 is a diagram schematically showing an example of a cross section taken along the line IV-IV of FIG. 1.

1 to 4, the liquid crystal display device according to an embodiment of the present invention includes a first display panel 100, a second display panel 200, and a space between the first display panel 100 and the second display panel 200. It includes a liquid crystal layer (3) located at.

First, the first display panel 100 will be described.

A gate line 121 and a storage electrode line 131 are located on the first substrate 110 made of transparent glass or plastic.

The gate line 121 mainly extends in the horizontal direction, transmits a gate signal, and includes a first gate electrode 124a, a second gate electrode 124b, and a third gate electrode 124c.

The maintenance electrode line 131 mainly extends in the horizontal direction and is applied with a constant voltage, such as a common voltage. The storage electrode line 131 includes a first storage electrode 131a surrounding the first subpixel electrode 191, which will be described later, and a second storage electrode 131b surrounding the second subpixel electrode 192. . The second storage electrode 131b includes a protrusion 131c that protrudes in the direction of the gate line 121. The protrusion 131c of the second storage electrode 131b overlaps the second contact hole 185b, which will be described later. Although not shown in FIG. 1, the horizontal portion of the first storage electrode 133a is connected to the horizontal portion of the second storage electrode 133b of the front pixel through an integrated wiring.

A gate insulating film 140 is positioned on the gate line 121 and the storage electrode line 131. The gate insulating film 140 may include silicon nitride (SiNx) or silicon oxide (SiOx). Additionally, the gate insulating layer 140 may have a multilayer structure including at least two insulating layers each having different physical properties.

A first semiconductor layer 154a, a second semiconductor layer 154b, a third semiconductor layer 154c, and a linear semiconductor layer 151 are positioned on the gate insulating film 140. Each of the first semiconductor layer 154a, the second semiconductor layer 154b, and the third semiconductor layer 154c may include a channel region. The linear semiconductor layer 151 may be located below the data line 171 and the reference voltage line 177, which will be described later.

A data line including a first source electrode 173a and a second source electrode 173b on the first semiconductor layer 154a, the second semiconductor layer 154b, the third semiconductor layer 154c, and the gate insulating film 140. (171), a data conductor including a third source electrode 173c, a first drain electrode 175a, a second drain electrode 175b, and a reference voltage line 177 including the third drain electrode 175c. (171, 173a, 173b, 173c, 175a, 175b, 175c, 177) are located.

The reference voltage line 177 receives a reference voltage. At this time, the level of the reference voltage may be higher than the level of the common voltage.

Data conductors (171, 173a, 173b, 173c, 175a, 175b, 175c, 177) and a first semiconductor layer (154a), a second semiconductor layer (154b), a third semiconductor layer (154c), and a linear semiconductor layer ( 151) An ohmic contact member may be located between them.

The first gate electrode 124a, the first source electrode 173a, and the first drain electrode 175a form a first thin film transistor together with the first semiconductor layer 154a, and the channel region of the first thin film transistor is It is formed in a portion of the first semiconductor layer 154a between the first source electrode 173a and the first drain electrode 175a. Similarly, the second gate electrode 124b, the second source electrode 173b, and the second drain electrode 175b form a second thin film transistor together with the second semiconductor layer 154b, and the second thin film transistor The channel region is formed in a portion of the second semiconductor layer 154b between the second source electrode 173b and the second drain electrode 175b. In addition, the third gate electrode 124c, the third source electrode 173c, and the third drain electrode 175c form a third thin film transistor together with the third semiconductor layer 154c, and the channel of the third thin film transistor The region is formed in a portion of the third semiconductor layer 154c between the third source electrode 173c and the third drain electrode 175c.

A protective film 180 on portions of the first, second, and third semiconductor layers 154a, 154b, and 154c where the data conductors 171, 173a, 173b, 173c, 175a, 175b, 175c, and 177 and the channel regions are formed. ) is located. The protective film 180 may include silicon nitride (SiNx) or silicon oxide (SiOx). Additionally, the protective film 180 may have a multilayer structure including an inorganic material layer and an organic material layer.

A light blocking film 220 and a color filter 230 are positioned on the protective film 180. The light shielding film 220 overlaps the gate line 121, the data line 171, and the first, second, and third thin film transistors and serves to prevent light leakage. A first contact hole 185a and a second contact hole 185b are disposed on the light shielding film 220, exposing parts of the first drain electrode 175a and the second drain electrode 175b, respectively. The color filter 230 is located in an area surrounded by the light blocking film 220 and can display one of primary colors such as red, green, and blue. However, the color filter 230 is not limited to the three primary colors of red, green, and blue, and can also display one of the colors of cyan, magenta, yellow, and white. .

The pixel electrode 190 is located on the light blocking film 220 and the color filter 230. Additionally, a shielding electrode 195 that is spaced apart from the pixel electrode 190 is located on the light shielding film 220. The pixel electrode 190 and the shielding electrode 195 may include a transparent conductive material such as ITO (Indium Tin Oxide) or IZO (Indium Zinc Oxide).

The pixel electrode 190 includes a first subpixel electrode 191 connected to the first drain electrode 175a through the first contact hole 185a, and a second drain electrode 175b through the second contact hole 185b. It includes a second subpixel electrode 192 connected to . The first subpixel electrode 191 and the second subpixel electrode 192 are adjacent to each other in the column direction, are spaced apart from each other, and have an overall shape of a square.

The first subpixel electrode 191 and the second subpixel electrode 192 include a cross-shaped stem portion consisting of vertical stem portions 191a and 192a and horizontal stem portions 191b and 192b that intersect the vertical stem portions 191a and 192a. In addition, the first subpixel electrode 191 and the second subpixel electrode 192 are divided into four subregions by horizontal stems 191b and 192b and vertical stems 191a and 192a, respectively, and each subregion includes a plurality of fine branches 191c and 192c. Additionally, the first subpixel electrode 191 includes a first extension portion 197a connected to the minute branch portion 191c of the first subpixel electrode 191, and the second subpixel electrode 192 includes a second extension portion 197a. It includes a second extension portion 197b connected to the fine branch portion 192c of the subpixel electrode 192.

Here, the first extension 197a and the second extension 197b are connected to the first drain electrode 175a and the second drain electrode 175b, respectively. Here, the thickness of the fine branch portions 191c and 192c may be thinner than the thickness of the vertical stem portions 191a and 192a and the horizontal stem portions 191b and 192b. The thickness of the fine branch portions 191c and 192c may be approximately 1/3 to 1/2 of the thickness of the vertical stem portions 191a and 192a and the horizontal stem portions 191b and 192b. Additionally, the thickness of the fine branches 191c and 192c may be the same as the thickness of the first and second extensions 197a and 197b.

The first subpixel electrode 191 and the second subpixel electrode 192 receive data voltages from the first drain electrode 175a and the second drain electrode 175b, respectively. At this time, some of the data voltage applied to the second drain electrode 175b is divided through the third source electrode 173c, and the magnitude of the voltage applied to the second subpixel electrode 192 is the same as that of the first subpixel electrode. It becomes smaller than the voltage applied to (191). In this case, the voltage applied to the first subpixel electrode 191 and the second subpixel electrode 192 is positive (+). Conversely, the voltage applied to the first subpixel electrode 191 and the second subpixel electrode 192 is positive (+). When the voltage applied to 192 is negative (-), the voltage applied to the first subpixel electrode 191 becomes smaller than the voltage applied to the second subpixel electrode 192.

Here, the area of the second subpixel electrode 192 may be 1 to 2 times the area of the first subpixel electrode 191.

The description of the thin film transistor and pixel electrode 190 described so far is an example, and the thin film transistor structure and pixel electrode design can be modified to improve side visibility.

The shielding electrode 195 overlaps the data line 171. The width of the shielding electrode 195 may be wider than the width of the data line 171. Accordingly, the shielding electrode 195 can prevent the voltage applied to the data line 171 from affecting the liquid crystal layer 3. Additionally, the thickness of the shielding electrode 195 may be the same as the vertical stem portions 191a and 192a and the horizontal stem portions 191b and 192b of the first subpixel electrode 191 and the second subpixel electrode 192. . Accordingly, the thickness of the fine branches 191c and 192c may be thinner than the thickness of the shielding electrode 195.

Meanwhile, the storage electrode line 131 is located between the first subpixel electrode 191 and the gate line 121. Accordingly, the sustain electrode line 131 can reduce signal interference between the pixel electrode 190 and the gate line 121. In addition, the vertical part of the first storage electrode 131a is located between the first subpixel electrode 191 and the data line 171, and the vertical part of the second storage electrode 131b is located between the second subpixel electrode 192 and the data line 171. It is located between lines 171. Accordingly, the first storage electrode 131a and the second storage electrode 131b are between the first subpixel electrode 191 and the data line 171 and between the second subpixel electrode 192 and the data line 171, respectively. Signal interference between signals can be reduced.

Additionally, the reference voltage line 177 overlaps the vertical stem portions 191a and 192a of the first subpixel electrode 191 and the second subpixel electrode 192. Accordingly, a decrease in the aperture ratio can be prevented.

Below, the second display panel 200 will be described.

The common electrode 270 is located on the second substrate 210 made of transparent glass or plastic.

Next, a repair method for a liquid crystal display device according to an embodiment of the present invention will be described with reference to FIGS. 5 and 6 as follows.

FIG. 5 is an enlarged view of area A in the liquid crystal display device of FIG. 1. FIG. 6 is an enlarged view of area B in the liquid crystal display device of FIG. 1.

In the repair method of a liquid crystal display device according to this embodiment, when a defect occurs in one pixel, the data voltage applied to the corresponding pixel electrode is blocked to turn the relevant pixel off, so that the defective pixel is not visible. . Accordingly, defective pixels can be repaired.

Referring to FIGS. 5 and 6 , when repairing a defective pixel, the fine branch 191c of the first subpixel electrode 191 and the fine branch 192c of the second subpixel electrode 192 are cut along the cutting line. By cutting along (C), the first extension portion 197a of the first subpixel electrode 191 connected to the first drain electrode 175a and the fine branch portion 191c of the first subpixel electrode 191 are connected to each other. The second extension portion 197b connected to the second drain electrode 175b and the fine branch portion 192c of the second subpixel electrode 192 are disconnected from each other, thereby disconnecting the first subpixel electrode 191 and the second subpixel electrode 192. 2 Prevent data voltage from being applied to the subpixel electrode 192.

In this way, as the fine branches 191c and 192c are cut, the first subpixel electrode 191 and the second subpixel electrode 192 are formed into the first drain electrode 175a and the second drain electrode 175b, respectively. The connection is blocked, so the data voltage is not applied. That is, the first subpixel electrode 191 and the second subpixel electrode 192 are in an electrically floating state, and as a result, the liquid crystal molecules maintain their initial arrangement state, always maintaining a black state. do. Accordingly, it is possible to repair defective pixels so that the defective pixels are not visible.

As described above, in the defective pixel repair step, the fine branch 191c of the first subpixel electrode 191 and the fine branch 192c of the second subpixel electrode 192 are cut using a laser. .

Generally, when using a laser, not only the fine branches 191c and 192c are cut due to the energy of the laser, but also the surrounding parts are damaged to generate spots or the fine branches 191c and 192c are cut. The lower membrane may be damaged.

In this embodiment, the thickness of the minute branches 191c and 192c of the first subpixel electrode 191 and the second subpixel electrode 192 are adjusted to the thickness of the first subpixel electrode 191 and the second subpixel electrode 192. ) is formed to be thinner than the thickness of the vertical stem portions 191a and 192a and the horizontal stem portions 191b and 192b, and the fine branch portions 191c and 192c, which are thinner portions, are cut in the step of repairing defective pixels. Accordingly, the energy of the laser can be reduced when cutting the fine branches 191c and 192c, thereby preventing damage caused by the energy of the laser.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims are also possible. It falls within the scope of rights.

121: gate line
124a, 124b, 124c: first, second, third gate electrodes
131: maintenance electrode line 151: linear semiconductor layer
154a, 154b, 154c: first, second, third semiconductor layers
171: data line
173a, 173b, 173c: first, second, third source electrodes
175a, 175b, 175c: first, second, and third drain electrodes
177: reference voltage line 190: pixel electrode
191, 192: first and second subpixel electrodes
191a, 192a: vertical stem 191b, 192b: horizontal stem
191c, 191c: fine branch 195: shielding electrode

Claims (10)

first substrate,
Gate lines and data lines located on the first substrate and spaced apart from each other,
A first thin film transistor connected to the gate line and the data line, and
Includes a first subpixel electrode connected to the first thin film transistor,
The first subpixel electrode includes a horizontal stem, a vertical stem, and a fine branch connected to the horizontal stem and the vertical stem,
In a direction perpendicular to the main plane of the first substrate, the thickness of the fine branch portion of the first subpixel electrode is thinner than the thickness of the horizontal stem portion and the vertical stem portion of the first subpixel electrode. . In paragraph 1:
a second thin film transistor connected to the gate line and the data line, and
Further comprising a second subpixel electrode connected to the second thin film transistor,
The second subpixel electrode is spaced apart from the first subpixel electrode in a column direction. In paragraph 2,
The second subpixel electrode includes a horizontal stem, a vertical stem, and a fine branch connected to the horizontal stem and the vertical stem,
In a direction perpendicular to the main plane of the first substrate, the thickness of the minute branch portion of the second subpixel electrode is thinner than the thickness of the horizontal stem portion and the vertical stem portion of the second subpixel electrode. . In paragraph 3,
The liquid crystal display device further includes a shielding electrode located on the same layer as the first subpixel electrode and the second subpixel electrode and overlapping the data line. A first substrate, a gate line and a data line located on the first substrate and spaced apart from each other, a first thin film transistor connected to the gate line and the data line, and a horizontal stem portion connected to the first thin film transistor, In the repair method of a liquid crystal display device including a first subpixel electrode including a vertical stem portion and a fine branch connected to the horizontal stem portion and the vertical stem portion,
In a direction perpendicular to the main plane of the first substrate, the thickness of the fine branch portion of the first subpixel electrode is thinner than the thickness of the horizontal stem portion and the vertical stem portion of the first subpixel electrode,
A repair method for a liquid crystal display device comprising the step of cutting the fine branch portion of the first subpixel electrode connected to the first thin film transistor to block the connection between the first subpixel electrode and the first thin film transistor. In paragraph 5,
In the step of blocking the connection between the first subpixel electrode and the first thin film transistor,
A method of repairing a liquid crystal display device using a laser to cut the fine branch portion of the first sub-pixel electrode connected to the first thin film transistor. In paragraph 6:
The liquid crystal display device is
a second thin film transistor connected to the gate line and the data line, and
Further comprising a second subpixel electrode connected to the second thin film transistor,
A repair method for a liquid crystal display device, wherein the second subpixel electrode is spaced apart from the first subpixel electrode in a column direction. In paragraph 7:
The second subpixel electrode includes a horizontal stem, a vertical stem, and a fine branch connected to the horizontal stem and the vertical stem,
In a direction perpendicular to the main plane of the first substrate, the thickness of the minute branch portion of the second subpixel electrode is thinner than the thickness of the horizontal stem portion and the vertical stem portion of the second subpixel electrode. How to repair. In paragraph 8:
A liquid crystal display device further comprising cutting the fine branch portion of the second sub-pixel electrode connected to the second thin-film transistor using the laser to block the connection between the first sub-pixel electrode and the first thin-film transistor. How to repair. In paragraph 9:
A repair method for a liquid crystal display device further comprising a shielding electrode located on the same layer as the first subpixel electrode and the second subpixel electrode and overlapping the data line.