KR101893939B1 - Contact structure of line and LCD including the same - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a wiring contact structure capable of preventing the spreading of an alignment material and a liquid crystal display device including the same.
A feature of the present invention is that in the process of forming an alignment film on a substrate through an inkjet coating method by forming a guide groove exposing a part of the edge of the drain contact hole at the edge of the pixel electrode corresponding to the edge of the drain contact hole, So that the material can be applied to the inside of the drain contact hole.
Accordingly, it is possible to prevent the occurrence of light leakage, and it is possible to prevent a problem that the screen display quality of the liquid crystal display device is deteriorated.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wiring contact structure and a liquid crystal display device including the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a wiring contact structure capable of preventing the spreading of an alignment material and a liquid crystal display device including the same.

As the age of the information society has developed in recent years, a need has arisen for a display device having excellent characteristics such as thinning, light weight, and low power consumption, and accordingly, a flat panel display has been actively studied Liquid crystal displays (LCDs) are excellent in resolution, color display, and image quality, and are being actively applied to monitors of notebook computers and desktop computers.

The liquid crystal display device has a liquid crystal panel in which a pair of transparent insulating substrates each having a field-generating electrode formed on a surface facing each other with a liquid crystal layer interposed therebetween, The liquid crystal molecules are artificially arranged along the direction of the liquid crystal molecules, and various images are displayed through the change of the transmittance of light.

1, which is a cross-sectional view of a general liquid crystal display device, the structure of a liquid crystal display device will be described in more detail.

As shown in the figure, a liquid crystal display device includes a liquid crystal panel 10 in which an array substrate and a color filter substrate are bonded to each other with a liquid crystal layer 5 interposed therebetween, and a backlight A pixel region P is defined on one surface of a first substrate 1 called a dual array substrate and a thin film transistor T is provided in each pixel region P to form pixel regions P connected to the transparent pixel electrode 12. [

The second substrate 2 facing the first substrate 1 with the liquid crystal layer 5 therebetween is called an upper substrate or a color filter substrate. Shaped black matrix 21 that covers the pixel region P so as to expose only the pixel electrode 12 while covering the non-display elements of the black matrix 21.

For example, R (red), G (green), and B (blue) color filters 23, which are sequentially and repeatedly arranged in correspondence to the respective pixel regions P in these lattices, and transparent common electrodes (25).

At this time, polarizers 30 and 40 for selectively transmitting only specific polarized light are attached to the outer surfaces of the first and second substrates 1 and 2.

Between the liquid crystal layer 5 and the pixel electrode 12 and the common electrode 25 are disposed first and second alignment films 50a and 50b in which surfaces facing the liquid crystal are rubbed in a predetermined direction, Aligning the initial alignment state of the molecules and the alignment direction uniformly.

A seal pattern 60 is formed along the edges of the substrates 1 and 2 to prevent leakage of the liquid crystal layer 5 filled therebetween.

The pixel electrode 12 formed on the first substrate 1 is brought into contact with the drain electrode 19 of the thin film transistor T through the contact hole 16. At this time, A step is formed around the contact hole 16 by the pixel electrode 12 because the pixel electrode 12 is patterned and positioned around the hole 16. [

As a result of forming the stepped portion by the pixel electrode 12 in the vicinity of the contact hole 16 as described above, the alignment material is formed on the pixel electrode 12 in the process of forming the first alignment film 50a on the first substrate 1 The alignment material is not uniformly applied on the substrate 1 through the contact holes 16 due to the difference in level due to the step difference.

Therefore, in the region where the contact hole 16 is formed, the initial molecular arrangement and the like of the liquid crystal in the liquid crystal layer 5 can not be determined, and light leakage occurs through the region. In particular, the display quality of the liquid crystal display device is deteriorated due to the large defects observed when implementing black

SUMMARY OF THE INVENTION It is a first object of the present invention to provide an alignment film material that can be applied to a contact hole of a liquid crystal display device.

A second object of the present invention is to improve the screen display quality of the liquid crystal display device.

According to an aspect of the present invention, there is provided a semiconductor device comprising: a first substrate including a gate wiring, a data wiring, and a thin film transistor; A protective layer including a contact hole exposing a drain electrode of the thin film transistor; A pixel electrode formed on the protection layer, the pixel electrode including a guide groove contacting the drain electrode through the contact hole and exposing a part of the edge of the contact hole; A first alignment layer formed on an entire surface of the first substrate including the pixel electrode; A second substrate facing the first substrate and having a second alignment layer formed thereon; A liquid crystal layer formed in a spaced-apart space between the first and second alignment layers; And a common electrode formed on one of the first substrate and the second substrate and forming an electric field with the pixel electrode, wherein the alignment material forming the first alignment layer is guided into the contact hole through the guide groove, And a liquid crystal display device.

At this time, the guide groove is formed at the edge of the pixel electrode corresponding to the edge of the contact hole, and the edge of the contact hole has a rounded shape.

The alignment material is coated on the first substrate by an inkjet coating method and the speed of guiding the alignment material into the contact hole is adjusted by adjusting the width of the guide groove.

According to another aspect of the present invention, An insulating material formed on the substrate, the insulating material including a contact hole exposing the first wiring; A second wiring formed on the insulating material and including a guide groove contacting the first wiring through the contact hole and exposing a part of the edge of the contact hole; And a liquid material layer formed on a front surface of the substrate including the second wiring and applied to the inside of the contact hole through the guide groove.

At this time, the guide groove is formed at the edge of the second wiring corresponding to the edge of the contact hole, and the edge of the contact hole has a rounded shape.

As described above, according to the present invention, by forming the guide groove exposing a part of the edge of the drain contact hole at the edge of the pixel electrode corresponding to the edge of the drain contact hole, in the process of forming the alignment film on the substrate, So that it can be applied to the inside of the contact hole.

Accordingly, there is an effect that light leakage can be prevented from occurring, and it is possible to prevent a problem that a display quality of a liquid crystal display device is deteriorated.

1 is a cross-sectional view schematically showing a general liquid crystal display device.
2 is an exploded perspective view schematically showing a configuration of a liquid crystal display device according to an embodiment of the present invention.
3 is a cross-sectional view schematically showing a cross section of the first substrate of FIG. 2;
4A is a plan view schematically showing a connection between a common pixel electrode and a drain electrode.
4B is a plan view schematically showing a connection between a pixel electrode and a drain electrode according to an embodiment of the present invention.
5A-5B are cross-sectional views schematically showing cross-sections taken along lines A and B of FIGS. 4A and 4B;
6 is a plan view schematically showing a connection of a pixel electrode and a drain electrode according to another embodiment of the present invention.

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

2 is an exploded perspective view schematically showing a configuration of a liquid crystal display device according to an embodiment of the present invention.

As shown in the drawing, a liquid crystal display device includes a liquid crystal panel 110 in which an array substrate 112 and a color filter substrate 114 are bonded to each other with a liquid crystal layer 105 interposed therebetween as an essential element do.

A plurality of data lines 218 and a plurality of gate lines 221 are vertically and horizontally crossed to define a pixel region P on one surface of a first substrate 112 called a double bottom substrate or an array substrate.

A thin film transistor T is provided at the intersection of these two wirings and connected in a one-to-one correspondence with the transparent pixel electrode 222 provided in each pixel region P.

The second substrate 114 facing the second substrate 114 with the liquid crystal layer 105 therebetween is called an upper substrate or a color filter substrate. On one surface of the second substrate 114, a data line 218 of the first substrate 112, A black matrix 231 of a lattice shape constituting the pixel region P is formed so as to expose only the pixel electrode 222 while covering the non-display elements such as the gate line 211 and the thin film transistor T. [

In addition, R (red), G (green), and B (blue) color filters 233 which are sequentially and repeatedly arranged in correspondence with the respective pixel regions P in these lattices, and a transparent common electrode 235 covering all of them, .

Although not clearly shown in the drawing, first and second alignment films for determining the initial alignment direction of the liquid crystal are interposed at the boundary between the two substrates 112 and 114 and the liquid crystal layer 105, A seal pattern is formed along the edges of both the substrates 112 and 114 to prevent leakage of the liquid crystal layer 105. [

Since the first substrate 112 has a larger area than the second substrate 114, the edges of the first substrate 112 are exposed to the outside when the first substrate 112 and the second substrate 114 are bonded together. A plurality of connected data pads 218a and a plurality of gate pads (not shown) connected to the plurality of gate wirings 211 are located.

Therefore, the on / off signals of the thin film transistor T are sequentially applied to the gate wiring 211 to scan the pixel electrodes 222 of the selected pixel region P, When a signal is transmitted, the liquid crystal molecules between the common electrode 235 and the pixel electrode 222 are driven by the vertical electric field, and various images can be displayed due to the light transmittance change.

The first and second polarizers 130 and 140 selectively transmit only specific light to the outer surfaces of the liquid crystal panel 110. The first polarizer 130 has a polarization axis in the first direction, The second polarizing plate 140 has a polarization axis in a second direction perpendicular to the first direction.

In addition, a backlight 120 is provided to supply light from the rear surface of the liquid crystal panel 110 so that a difference in transmittance represented by the liquid crystal panel 110 is externally expressed.

The backlight 120 is divided into a side type and a direct type depending on the position of a light source (not shown) that emits light. The light of the emitted light source (not shown) is refracted by a separate light guiding plate (not shown) to be incident on the liquid crystal panel 110, and a direct light type is provided by arranging a plurality of light sources (not shown) on the back surface of the liquid crystal panel 110 Let the light enter.

The present invention is applicable to either of these.

In this case, a fluorescent lamp such as a cold cathode fluorescent lamp or an external electrode fluorescent lamp may be used as a light source (not shown). Alternatively, in addition to such a fluorescent lamp, a light emitting diode lamp may be used as a lamp.

3 is a cross-sectional view schematically showing a cross section of the first substrate of FIG.

2, the gate electrode 211, the gate electrode 211, and the gate wiring (see FIG. 2) extending from the gate wiring (221 in FIG. 2) and the gate wiring (221 in FIG. 2) are formed on the first substrate 112, A semiconductor layer 215 formed on the gate insulating layer 213 and source and drain electrodes 217 and 219 spaced from the top of the semiconductor layer 215. The thin film transistor T).

At this time, the semiconductor layer 215 is composed of an active layer 215a of pure amorphous silicon and an amorphous silicon ohmic contact layer 215b containing an impurity. At this time, the thin film transistor T is formed of amorphous A bottom gate type including silicon vias 215a and 215b is shown as an example. As a modification thereof, a top gate type including a polysilicon semiconductor layer may be formed.

A protective layer 216 is formed on the source and drain electrodes 217 and 219 and includes a drain contact hole 216a exposing a portion of the drain electrode 219. A protective layer 216 is formed on the protective layer 216, And a pixel electrode 222 connected to the drain electrode 219 through the hole 216a.

A first alignment layer 250 is formed on the pixel electrode 222 to define the initial alignment direction of the liquid crystal molecules of the liquid crystal layer 105 (see FIG. 2).

The pixel electrode 222 of the present invention includes a guide groove for guiding a moving direction of the alignment material forming the first alignment layer 250 at a portion connected to the drain electrode 219 through the drain contact hole 216a 300, see FIG. 4B).

The guide groove 300 (see FIG. 4B) exposes part of the edge of the drain contact hole 216a by preventing the pixel electrode 222 from being formed in a part of the edge of the drain contact hole 216a.

That is, a partial region where the step C of the pixel electrode 222 is not formed is formed, and the region of the pixel electrode 222 serves as a path for spreading the alignment material 250a (see FIG. 4A).

The alignment material 250a (see FIG. 4B) constituting the first alignment layer 250 is formed on the pixel electrode 222 and the protective layer (not shown) in the process of forming the first alignment layer 250 on the first substrate 112, It is possible to prevent the problem of not being applied to the inside of the drain contact hole 216a due to the step C between the drain contact hole 216a and the drain contact hole 216a.

The pixel electrode 222 formed on the passivation layer 216 generates a step C as much as the thickness of the pixel electrode 222 in the first substrate 112. [

Particularly, the step C is generated in the vicinity of the drain electrode 219 on which the pixel electrode 222 is patterned and around the drain contact hole 216a where the pixel electrode 222 is in contact.

A first alignment layer 250 is formed on the pixel electrode 222. The first alignment layer 250 is formed by applying an alignment material 250a (see FIG. 4B) and then drying the alignment layer 250a by a firing process 4B) is applied to the substrate 112 using an inkjet coating method, and then the alignment material 250a (see FIG. 4B) is coated on the alignment layer 250a The first alignment layer 250 is formed on the substrate 112 with a uniform thickness.

4B) is formed by the step C between the protective layer 216 and the pixel electrode 222 in the process of spreading the alignment material 250a (see FIG. 4B) to the front surface of the substrate 112. In this case, (See FIG.

In particular, the alignment material 250a (see FIG. 4B) is not applied to the inside of the drain contact hole 216a.

Therefore, in the region where the contact hole 216a is formed, the initial molecular arrangement of the liquid crystal molecules of the liquid crystal layer 105 (see FIG. 2) can not be determined and light leakage occurs through the region, P is observed as a large defect in the case of implementing black, the screen display quality of the liquid crystal display device is deteriorated.

4B) of the alignment material 250a (see FIG. 4B) forming the first alignment layer 250 is formed on a portion of the pixel electrode 222 connected to the drain electrode 219 through the drain contact hole 216a, (See FIG. 4B) to guide the alignment material 250a (see FIG. 4B) to the inside of the drain contact hole 216a through the guide groove 300 (see FIG. 4B).

Accordingly, it is possible to prevent the occurrence of light leakage, and it is possible to prevent a problem that the screen display quality of the liquid crystal display device is deteriorated.

This will be described in more detail with reference to FIGS. 4A to 4B.

FIG. 4A is a plan view schematically showing a connection between a pixel electrode and a drain electrode, and FIG. 4B is a plan view schematically illustrating a connection between a pixel electrode and a drain electrode according to an embodiment of the present invention.

5A and 5B are cross-sectional views schematically showing cross-sections taken along lines A and B in FIGS. 4A and 4B, and FIG. 6 is a schematic cross-sectional view of a pixel electrode and a drain electrode according to another embodiment of the present invention. Fig.

The pixel electrode 222 contacts the drain electrode 219 through the drain contact hole 216 exposing the drain electrode 219 of the thin film transistor T. [

At this time, the pixel electrode 222 is formed to completely cover the drain contact hole 216a.

Here, in the case of a liquid crystal display device, when the alignment material 250a is coated on the substrate (112 in FIG. 3), the alignment material 250a spreads to the front surface of the substrate (112 in FIG. 3) At this time, in the case of a general liquid crystal display device, as shown in FIG. 4A, the alignment material 250a is formed by the step (C in FIG. 3) of the pixel electrode 222 formed to cover the drain contact hole 216a, It does not spread out into the contact hole 216 and spreads along the edge of the pixel electrode 222 covering the edge of the drain contact hole 216a, that is, the drain contact hole 216a.

On the other hand, as shown in FIG. 4B, the pixel electrode 222 includes the guide groove 300, so that the alignment material 250a spreads into the drain contact hole 216a.

The guide groove 300 is a region where the edge of the drain contact hole 216a is exposed because the pixel electrode 222 is not formed in a part of the edge of the drain contact hole 216a, (C in FIG. 3) is not generated, and the alignment material 250a spreads into the drain contact hole 216a through the guide groove 300. As shown in FIG.

5A, the pixel electrode 222 is formed on the passivation layer 216 to cover the pixel electrode 222 (see FIG. 5A) A step C as much as the thickness of the pixel electrode 222 is generated between the pixel electrode 222 and the protective layer 216.

5B, the pixel electrode 222 exposes the edge of the drain contact hole 216a with reference to a cross-sectional view taken along the line B which is the region where the guide groove 300 is formed.

A step C is not formed between the pixel electrode 222 and the protective layer 216 in the region where the guide groove 300 is formed so that the alignment substance 250a Can be prevented from being applied to the inside of the drain contact hole 216a.

At this time, the edge of the drain contact hole 216a in which the guide groove 300 is formed is rounded so that the alignment material 250a can be more easily spread into the drain contact hole 216a through the guide groove 300 can do.

It is preferable that at least one guide groove 300 of the pixel electrode 222 is formed at the edge of the pixel electrode 222 corresponding to the edge of the drain contact hole 216a.

Referring again to FIG. 4B, if two edges of the pixel electrode 222 and the drain contact hole 216a correspond to each other, the guide groove 300 corresponds to the pixel electrode 222 and the drain contact hole 216a It is preferable that at least one pixel electrode 222 and at least one drain contact hole 216a are formed at each edge of the pixel electrode 222 and the drain contact hole 216a. Drain contact holes 216a are formed on at least one edge of the drain contact hole 216a.

The width D of the guide groove 300 can be variously changed according to the spreadability of the liquid material of the alignment material 250a and can be variously changed depending on the efficiency of the process. That is, in order to lower the spreadability of the liquid phase of the alignment material 250a or improve the efficiency of the process, in order to allow the alignment material 250a to be applied to the inside of the drain contact hole 216a more quickly, D are formed to be wide.

The guide grooves 300 of the pixel electrodes 222 may be formed by patterning a mask (not shown) corresponding to the guide grooves 300 in the process of patterning the pixel electrodes 222, The amount of light irradiated corresponding to the guide groove 300 can be adjusted.

In the foregoing description, the TN mode in which the common electrode (215 in FIG. 2) and the pixel electrode 222 are formed on the first and second substrates 112 and 114 (FIG. 2) The present invention is also applicable to the IPS mode in which the pixel electrode 222 and the common electrode (215 in FIG. 2) are both formed on the first substrate 112.

As described above, in the liquid crystal display device of the present invention, the edge of the pixel electrode 222 corresponding to the drain contact hole 216a is formed with the guide groove 300 exposing a part of the edge of the drain contact hole 216a, The alignment material 250a can be easily applied into the drain contact hole 216a in the process of forming the alignment layer 250 on the substrate 112 through the inkjet coating method.

Accordingly, it is possible to prevent the occurrence of light leakage, and it is possible to prevent a problem that the screen display quality of the liquid crystal display device is deteriorated.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

211: gate electrode, 216a: drain contact hole, 217: source electrode, 218: data wiring
219: drain electrode, 221: gate wiring, 222: pixel electrode, 250a: alignment material

Claims (8)

A first substrate including a gate wiring, a data wiring, and a thin film transistor;
A protective layer including a contact hole exposing a drain electrode of the thin film transistor;
A pixel electrode formed on the protection layer, the pixel electrode including a guide groove contacting the drain electrode through the contact hole and exposing a part of the edge of the contact hole;
A first alignment layer formed on an entire surface of the first substrate including the pixel electrode;
A second substrate facing the first substrate and having a second alignment layer formed thereon;
A liquid crystal layer formed in a spaced-apart space between the first and second alignment layers;
A common electrode formed on one of the first substrate and the second substrate and forming an electric field with the pixel electrode,
Wherein the alignment material forming the first alignment layer is guided into the contact hole through the guide groove,
Wherein the guide groove exposes a part of the protective layer corresponding to the contact hole,
The edge of the protective layer constituting the contact hole, which is formed by the upper surface and the side surface, is in contact with the alignment material,
Wherein the pixel electrode covers a part of one edge of the contact hole corresponding to one edge of the pixel electrode, the guide groove recessed toward the center of the contact hole is provided at one edge of the pixel electrode,
And a part of one edge of the contact hole is exposed to the outside by the guide groove.
delete The method according to claim 1,
Wherein edges of the protective layer forming the contact holes are rounded at the corners where the upper surface and the side surfaces are gathered.
The method according to claim 1,
Wherein the alignment material is applied on the first substrate through an inkjet coating method.
The method according to claim 1,
And adjusting a speed at which the alignment material is guided into the contact hole through adjustment of the width of the guide groove.
A substrate on which a first wiring is formed;
An insulating material formed on the substrate, the insulating material including a contact hole exposing the first wiring;
A second wiring formed on the insulating material and including a guide groove contacting the first wiring through the contact hole and exposing a part of the edge of the contact hole;
And a liquid material layer formed on a front surface of the substrate including the second wiring and applied to the inside of the contact hole through the guide groove,
/ RTI >
Wherein the guide groove exposes a part of the insulating material corresponding to the contact hole so that an edge formed by the upper surface and the side surface of the insulating material forming the contact hole is in contact with the liquid material layer,
Wherein the second wiring covers a part of one edge of the contact hole corresponding to one edge and the one edge of the second wiring is provided with the guide groove recessed toward the center of the contact hole, Is partially exposed to the outside by the guide groove.
delete The method according to claim 6,
And an edge of the insulating material forming the contact hole is rounded at the corner where the upper surface and the side surface are gathered.

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