KR19990034116A - Transverse electric field liquid crystal display device - Google Patents

Abstract

A transverse electric field liquid crystal display device according to an embodiment of the present invention includes a first substrate and a second substrate, a data wiring and a gate wiring arranged vertically and horizontally on the first substrate to define a pixel region, and a pair formed in parallel with the gate wiring. A common wiring, a thin film transistor formed on the gate wiring, a data electrode formed in the pixel region, a common electrode formed in the pixel region and generating a transverse electric field together with the data electrode, the first substrate and the It is made of a liquid crystal layer formed between the second substrate and the aperture ratio is improved compared to the conventional and the problem caused by disconnection of the common electrode is solved.

Description

Transverse electric field liquid crystal display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transverse electric field type liquid crystal display device. In particular, a thin film transistor is formed on a gate wiring line and two common wiring lines are formed in one pixel, thereby improving the aperture ratio and solving a problem due to disconnection of the common electrode. The present invention relates to a liquid crystal display device and a manufacturing method thereof.

In order to improve the viewing angle characteristic of the liquid crystal display device, various liquid crystal display devices such as a twisted nematic liquid crystal display device equipped with an optical compensation plate and a multi-domain liquid crystal display device have been proposed. It is difficult to solve the problem that the contrast and the color change depending on the viewing angle.

In order to solve the above problem, in recent years, a liquid crystal display device having an in-plane switching mode, which is another liquid crystal display device, has been proposed.

1 is a plan view showing a unit pixel of a conventional transverse electric field type liquid crystal display device, which is parallel to the data line 1 and the gate line 2 arranged on a substrate to define a pixel region, and the gate line 2 described above. The common wiring 3 arranged in the pixel, the thin film transistor arranged at the intersection of the gate wiring 2 and the data wiring 1, and the data arranged substantially parallel to the data wiring 1 in the pixel. It consists of the electrode 4 and the common electrode 5.

In the transverse electric field type liquid crystal display device configured as described above, when a voltage is applied from an external driving circuit, a transverse electric field parallel to the substrate is generated between the data electrode 4 and the common electrode 5. Thus, the liquid crystal molecules oriented in the liquid crystal layer rotate in accordance with the above-described transverse electric field, thereby controlling the amount of light passing through the liquid crystal layer. In the conventional liquid crystal display device, an electric field is generated in a direction perpendicular to the substrate according to the driving voltage, so that the liquid crystal molecules rotate in a direction perpendicular to the substrate, and the light transmittance is greatly changed according to the viewing angle, and gray inversion does not occur. In the transverse electric field type liquid crystal display device, since the electric field is formed in parallel with the substrate, and the liquid crystal molecules remain in parallel with the substrate, the viewing angle characteristic is improved. However, the transverse electric field type liquid crystal display device has a disadvantage in that the aperture ratio is low despite the advantage that the viewing angle characteristic is good, and accordingly, the intensity of the backlight is increased to cause the thin film transistor to malfunction. In addition, as shown in FIG. 1 during the manufacturing process, if a disconnection occurs in the a, b, c, and d areas of the common electrode, the region not connected to the common wiring 3 does not generate a transverse electric field according to the driving voltage. This can cause point defects.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the conventional transverse electric field type liquid crystal display device, and the thin film transistor is formed on the gate wiring to improve the aperture ratio, and two common wirings formed in the pixel region are formed on both sides of the common electrode. An object of the present invention is to provide a transverse electric field type liquid crystal display device and a method of manufacturing the same, in which the problems caused by disconnection are eliminated.

In order to achieve the above object, the liquid crystal display device according to the present invention comprises a first substrate and a second substrate; A plurality of gate wiring lines and common wiring lines formed on the first substrate in parallel with each other; A gate insulating film formed on the gate wiring; A semiconductor layer formed on the gate insulating film; A source electrode and a drain electrode formed on the semiconductor layer; A plurality of data lines connected to the source electrode and formed to be vertically and horizontally formed with the gate line to define a pixel area; A data electrode connected to the drain electrode and formed in the pixel region; A common electrode connected to the common wiring in the pixel area to form a transverse electric field together with the data electrode; The liquid crystal layer is formed between the first substrate and the second substrate.

The method of manufacturing a transverse electric field type liquid crystal display device includes the steps of preparing a first substrate and a second substrate; Forming a gate wiring, a common wiring, and a common electrode on the first substrate; Applying a gate insulating film on the gate wiring; Forming a semiconductor layer and an ohmic contact layer on the gate wiring to which the gate insulating film is applied; Forming a source electrode, a drain electrode, a data wiring, and a data electrode on the first substrate on which the ohmic contact layer is formed; Forming a liquid crystal layer between the first substrate and the second substrate.

1 is a view showing a conventional transverse electric field type liquid crystal display device.

2A to 2E are views illustrating a transverse electric field type liquid crystal display device and a method of manufacturing the same according to the present invention.

3A and 3B show another embodiment of the present invention.

4 is another embodiment of the present invention.

Explanation of symbols on the main parts of the drawing

10: gate wiring 11: common wiring

12: common electrode 13: semiconductor layer

14: ohmic contact layer 15: data wiring

16: data electrode

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2C illustrates a unit pixel of a transverse electric field type liquid crystal display device according to the present invention, in which a semiconductor layer 13 and an ohmic contact layer 14 are formed on a gate wiring 10 serving as a gate electrode. The data line 15 is connected to an external data driver circuit (not shown) and serves to transmit a data signal. The common electrode 12 is formed in parallel with the data electrode 16 to apply a lateral electric field to the pixel region, and the gate wiring 10 is connected to an external gate driver circuit (not shown) to transfer scan signals. do. The common wiring 11 formed on both sides of the common electrode 12 forms a capacitor together with the data electrode 16 with the gate insulating film 18 therebetween, so that the data signal voltage applied to the data electrode while the scan signal voltage is not applied. Also, even when all of the common electrodes 12 are disconnected due to a wrong process, a common voltage is applied to all portions of the common electrodes so that a normal lateral electric field is formed.

The liquid crystal display according to the present invention shown in FIGS. 3A and 3B forms a common wiring 11 in one line, but the problem of disconnection of the common electrode 12 remains, but a thin film transistor is formed on the gate wiring 10. As a result, the aperture ratio is further improved.

In the conventional transverse electric field liquid crystal display device, the thin film transistor is formed only at the intersection of the gate wiring and the data wiring, but the present invention can be formed at any position on the gator wiring 10 without reducing the aperture ratio. As shown in FIG. 2, the thin film transistor may minimize the electrical effect that may be received from the data line 15.

2A to 2E are plan views and cross-sectional views illustrating a method of manufacturing a transverse electric field type liquid crystal display device according to the present invention. First, as shown in FIG. After the thin film or Mo / Al thin film is patterned to form the gate wiring 10, the common electrode 12, and the common wiring 11, an inorganic material such as SiO _X or SiN _X is chemically deposited over the entire first substrate 17. The film is formed by vapor deposition to form the gate insulating film 18. Since the common wiring 11 is connected to both sides of the common electrode 12, the above-described problem due to the conventional disconnection can be prevented. Subsequently, as shown in FIG. 2B, amorphous silicon and n ⁺ -amorphous silicon are laminated and patterned on the gate wiring 10 to which the gate insulating film 18 is coated by CVD to form a semiconductor layer 13 and an ohmic contact layer ( 14). Subsequently, as shown in FIG. 2C, a metal film, such as a Cr film or a Mo film, formed by sputtering is patterned to form the data wiring 15 and the data electrode 16, and then SiO _X , SiN _X , or the like is subjected to chemical vapor deposition. The protective film 19 is formed by forming a film on the first substrate 17. In this case, although not shown in the drawing, the data wiring 15 serving as a source electrode is connected to the data driving circuit and serves to transmit a data signal. In addition, the data electrode 16 serving as the drain electrode forms a transverse electric field in the pixel region together with the common electrode 12. Next, as shown in FIG. 2D, a first alignment layer 20 made of polyimide or a photo-alignment material is coated on the protective film. The photoreactive material made of a polyvinylcinnamate (PVCN) -based material or a polysiloxane-based material is determined in an orientation direction by irradiation with light such as ultraviolet rays. At this time, the orientation direction is determined by the irradiation direction of the light or the property of the irradiated light, that is, the polarization direction.

Subsequently, a black matrix 22 which blocks light in the gate wiring 10, data wiring 15, and common wiring 11 by stacking and etching a metal such as Cr or CrO on the second substrate 21 by a sputtering method. ). Since the thin film transistor is formed on the gate wiring 10, the area occupied by the black matrix 22 on the liquid crystal panel is reduced and the aperture ratio is increased. Subsequently, after the color filter layer 23 is formed on the second substrate on which the black matrix 22 is formed, the second alignment layer 24 is applied. Subsequently, a liquid crystal is injected between the first substrate 17 and the second substrate 21 to form the liquid crystal layer 25.

In the transverse electric field type liquid crystal display device formed by the above-described manufacturing method, the aperture ratio is improved because the thin film transistor is formed on the gate wiring, and the common wiring is connected to both common electrodes. do.

Claims (9)

A first substrate and a second substrate, Data and gate wirings arranged vertically and horizontally on the first substrate to define pixel regions; A pair of common wiring formed in parallel with the gate wiring, A thin film transistor formed on the pixel region; A data electrode formed in the pixel region; A common electrode formed in the pixel region and generating a transverse electric field together with the data electrode; A transverse electric field liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The transverse electric field liquid crystal display device according to claim 1, wherein the thin film transistor is formed on the gate wiring. The method of claim 2, wherein the thin film transistor, Gate wiring, A gate insulating film formed on the gate wiring; A semiconductor layer formed on the gate insulating film; A transverse electric field liquid crystal display device comprising a source electrode and a drain electrode formed on the semiconductor layer. The transverse electric field liquid crystal display device according to claim 2, wherein the thin film transistor is formed in an area separated from the data line on the gate line by a predetermined distance. The transverse electric field liquid crystal display device of claim 1, wherein a partial region of the data electrode is electrically isolated from the pair of common wirings. A first substrate and a second substrate, A gate wiring and a common wiring formed on the first substrate in parallel with each other; A data line formed vertically and horizontally with the gate line to define a pixel area; A thin film transistor formed on the gate wiring line; A data electrode formed in the pixel region and receiving a data signal voltage from the thin film transistor; A common electrode formed in the pixel region and generating a transverse electric field together with the data electrode; A transverse electric field liquid crystal display device comprising a liquid crystal layer formed between the first substrate and the second substrate. The method of claim 6, wherein the thin film transistor, Gate wiring, A gate insulating film formed on the gate wiring; A semiconductor layer formed on the gate insulating film; And a source electrode and a drain electrode formed on the semiconductor layer. The transverse electric field liquid crystal display device of claim 6, wherein the thin film transistor is formed to be separated from the data line by a predetermined distance. The transverse electric field liquid crystal display device of claim 6, wherein a partial region of the data electrode is electrically isolated from the common line.