KR20060010561A - Liquid crystal display device and method of manufacturing the same - Google Patents

Abstract

The present invention relates to a liquid crystal display device. The liquid crystal display of the present invention includes a first substrate having a signal line and an insulating film formed on the signal line, a second substrate facing the first substrate and having a black matrix corresponding to the signal line, and the first and second substrates. And a liquid crystal layer positioned between the curved lines, wherein the insulating layer is formed with a curved portion along the signal line. As a result, a liquid crystal display device having improved luminance is provided.

Description

Liquid crystal display and its manufacturing method {LIQUID CRYSTAL DISPLAY DEVICE AND METHOD OF MANUFACTURING THE SAME}

1 is a layout view of a thin film transistor substrate according to a first embodiment of the present invention,

2 is a cross-sectional view of a liquid crystal panel according to a first embodiment of the present invention according to II-II of FIG.

3A and 3B are conceptual views illustrating curved portions according to the first and second embodiments, respectively,

4A to 4C are cross-sectional views illustrating a method of manufacturing a thin film transistor substrate according to a first embodiment of the present invention.

5 is a cross-sectional view illustrating a method of manufacturing a thin film transistor substrate according to a third embodiment of the present invention.

Explanation of Signs of Major Parts of Drawings

121: gate line 131: data line 151: insulating film 221, 222, 223: black matrix

The present invention relates to a liquid crystal display device and a manufacturing method thereof. More specifically, the present invention relates to a liquid crystal display device using a light incident from the backlight unit adjacent to the gate line and the data line for increasing the brightness, and a method of manufacturing the same.

 The liquid crystal display device includes a thin film transistor substrate on which a thin film transistor is formed, a color filter substrate on which a color filter layer is formed, and a liquid crystal panel on which a liquid crystal layer is positioned. Since the liquid crystal panel is a non-light emitting device, a backlight unit for irradiating light may be disposed on the rear surface of the thin film transistor substrate. Light transmitted from the backlight unit is controlled according to the arrangement of the liquid crystal layer.

In addition, in order to drive each pixel of the liquid crystal panel, a driving circuit, and a data driver and a gate driver for receiving a driving signal from the driving circuit and applying a signal to data lines and gate lines in the display area are provided.

A black matrix is formed on the color filter substrate to prevent light from entering the thin film transistor and to distinguish each pixel. The black matrix is formed along thin film transistors, gate lines, and data lines.

In this case, the width of the gate line and the data line is generally about 6 to 7 μm, whereas the corresponding black matrix is about 20 μm. Therefore, the light irradiated from the backlight unit adjacent to the gate line and the data line is blocked by the black matrix and thus cannot be used to increase the luminance of the liquid crystal display.

Accordingly, an object of the present invention is to provide a liquid crystal display device that uses the light emitted from the backlight unit adjacent to the gate line and the data line to increase luminance.

Still another object of the present invention is to provide a method of manufacturing the liquid crystal display device as described above.

The object is a first substrate having a signal line and an insulating film formed on the signal line, a second substrate facing the first substrate and having a black matrix corresponding to the signal line, and between the first and second substrates. A liquid crystal display device comprising a liquid crystal layer located therein, which is achieved by forming a curved portion in the insulating film along the signal line.

The refractive index of the insulating film is preferably larger than the refractive index of the liquid crystal layer.

In this case, the curved portion is preferably recessed toward the signal line, and may be curved outward toward the black matrix or curved inward toward the signal line.

When the refractive index of the insulating film is smaller than the refractive index of the liquid crystal layer, the curved portion preferably protrudes toward the black matrix.

The width of the black matrix is preferably larger than the width of the signal line.

It is preferable that the said insulating film is an organic photosensitive film.

Another object of the present invention is to provide a method for manufacturing a liquid crystal display device, the method comprising: forming a signal line on a substrate material; depositing an insulating film on the signal line; and patterning the insulating film to have a curved portion along the signal line. It can be achieved by including a step.

The patterning step of the insulating film is. It is preferable to further include the step of applying a photosensitive film on top of the insulating film, the photosensitive film using a mask having a slit.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. In the following, a film is formed (located) on top of another film, not only when two films are in contact with each other but also when another film is between two layers. It also includes the case where it exists. In addition, hereinafter, a signal line indicates a gate line and / or a data line.

FIG. 1 is a layout view of a thin film transistor substrate according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view of a liquid crystal panel according to a first embodiment of the present invention according to II-II of FIG. 1.

The liquid crystal panel 10 according to the first exemplary embodiment of the present invention includes a thin film transistor substrate 100, a color filter substrate 200 facing the thin film transistor substrate, and a liquid crystal layer 300 positioned therebetween.

Although not shown, the liquid crystal display further includes a backlight unit, a driving circuit, an external casing, and the like positioned on the rear surface of the thin film transistor substrate 100.

First, the thin film transistor substrate 100 will be described.

Gate wirings 121, 122, and 123 are formed on the first substrate material 110. The gate wirings 121, 122, and 123 may be a metal single layer or multiple layers. The gate lines 121, 122, and 123 include a gate line 121 extending in a horizontal direction and a gate electrode 122 of a thin film transistor connected to the gate line 121. Here, the gate pad 123 positioned outside the display area is one end of the gate line 121, and the width of the gate pad 123 is extended for connection with an external circuit.

On the first substrate material 110, a gate insulating layer 141 made of silicon nitride (SiNx) or the like covers the gate lines 121, 122, and 123.

A semiconductor layer 142 made of a semiconductor such as amorphous silicon is formed on the gate insulating layer 141 of the gate electrode 122, and n + is doped with silicide or n-type impurities at a high concentration on the semiconductor layer 142. An ohmic contact layer 143 made of a material such as hydrogenated amorphous silicon is formed. The ohmic contact layer 143 is divided into two parts around the gate electrode 122.

Data lines 131, 132, 133, and 134 are formed on the ohmic contact layer 143 and the gate insulating layer 141. The data lines 131, 132, 133, and 134 may also be single layers or multiple layers of metal layers. The data wires 131, 132, 133, and 134 are formed in a vertical direction and intersect the gate line 121 to define a pixel to define a pixel and a branch of the data line 131 and the data line 131. A drain electrode 133 which is separated from the source electrode 132 and the source electrode 132 that extends to the top and is formed on the ohmic contact layer 143 opposite to the source electrode 132 with respect to the gate electrode 122. ). The data pad 134 positioned outside the display area is one end of the data line 131, and the width of the data pad 134 is extended for connection with an external circuit.

On top of the data lines 131, 132, 133, and 134 and the semiconductor layer 142 which is not covered, silicon nitride, an a-Si: C: O film deposited by a plasma-enhanced chemical vapor deposition (PECVD) method, or a- An insulating film 151 made of a Si: O: F film, an acrylic organic insulating film, a transparent photosensitive film, or the like is formed. The insulating layer 151 has contact holes 181 and 183 for exposing the drain electrode 133 and the data pad 134, respectively, and the contact hole 182 for exposing the gate pad 123 together with the gate insulating layer 141. Also formed. In addition, curved portions 191 are formed in the insulating layer 151 along the signal lines 121 and 131. The curved portion 191 will be described later.

The pixel electrode layer 171 is formed on the insulating layer 151. The pixel electrode layer 171 is usually made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO).

Next, the color filter substrate 200 will be described.

Black matrices 221, 222, and 223 are formed on the second substrate material 210. The black matrix 221 positioned on the top of the thin film transistor serves to block direct light irradiation to the thin film transistor. Amorphous silicon thin film transistor is because light leakage current easily flows by light. The black matrix 222 positioned above the gate line 121 and the black matrix 223 positioned above the data line 131 distinguish between red, green, and blue filters. The black matrices 221, 222, and 223 may include photosensitive organic materials to which black pigments are added. As the black pigment, carbon black or titanium oxide is used.

The color filter layer 231 is formed by repeating the red, green, and blue filters on the black matrices 221, 222, and 223. The color filter layer 231 serves to impart color to light emitted from the backlight unit (not shown) and passed through the liquid crystal layer 300. The color filter layer 231 generally includes a photosensitive organic material.

An overcoat layer 241 is formed on the black matrices 221, 222, and 223 not covered by the color filter layer 231 and the color filter layer 231. The overcoat layer 241 serves to protect the color filter layer 231 while planarizing the color filter layer 231, and an acrylic epoxy material is generally used.

The common electrode layer 251 is formed on the overcoat layer 241. The common electrode layer 251 is made of a transparent conductive material such as indium tin oxide (ITO) or indium zinc oxide (IZO). The common electrode layer 251 directly applies a voltage to the liquid crystal layer 300 together with the pixel electrode layer 171 of the thin film transistor substrate.

Hereinafter, the curved portions 191 formed on the insulating film 151 will be described with reference to FIGS. 3A and 3B, which illustrate the curved portions 191 according to the first and second embodiments, respectively. Although only the curved portion 191 corresponding to the data line 131 has been described, this may also be applied to the gate line 131.

3A, the curved portion 191 formed in the insulating layer 151 is recessed toward the data line 131. In addition, the curved portion 191 is curved outward toward the black matrix 222. In addition, the curved portion 191 formed as described above refracts light irradiated adjacent to the data line 191 from the backlight unit to the outside. That is to change the path of the light not to be blocked by the black matrix 222. Accordingly, light that is not blocked by the data line 131 but blocked by the black matrix 222, that is, light that passes through the 'A' region of FIG. 2, also passes through the liquid crystal layer 300 and the color filter layer 231. It is emitted to the outside of the liquid crystal panel 10. As a result, the luminance of the liquid crystal display device is increased.

In this case, the refractive index of the insulating layer 151 should be larger than that of the liquid crystal layer 300. In the first embodiment, the curved portion 191 acts as a convex lens to the light from the backlight unit to distribute the light. When the refractive index of the insulating layer 151 is smaller than the refractive index of the liquid crystal layer 300, the curved portion 191 may collect light. Therefore, light is refracted toward the black matrix 222 so that the brightness of the liquid crystal display is not improved.

3B, the curved portion 191 of the second embodiment is also recessed toward the data line 131. However, unlike the first embodiment, the curved portion 191 is curved inward toward the data line 131. The curved portion 191 of the second embodiment also disperses the light supplied adjacent to the data line 131 and exits the liquid crystal panel 10 through the liquid crystal layer 300 and the color filter layer 231.

At this time, as in the first embodiment, the refractive index of the insulating layer 151 should be larger than that of the liquid crystal layer 300. In the second embodiment, the curved portion 191 acts as a concave lens to the light from the backlight unit to distribute the light. However, when the refractive index of the insulating layer 151 is smaller than the refractive index of the liquid crystal layer 300, the curved portion 191 collects light toward the black matrix 222. Therefore, the luminance of the liquid crystal display device is not improved.

Unlike the first and second embodiments, when the refractive index of the insulating layer 151 is smaller than the refractive index of the liquid crystal layer 300, the curved portion 191 may be protruded to face the black matrix 222. In this case, the curved portion 191 may also be curved outward toward the black matrix 222 or may be curved inward toward the data line 131.

Hereinafter, a method of manufacturing the thin film transistor substrate 100 according to the first embodiment of the present invention will be described.

4A to 4C are cross-sectional views illustrating a method of manufacturing the thin film transistor substrate 100 according to the embodiment of the present invention.

First, as shown in FIG. 4A, thin film transistors and signal lines 121 and 131 are formed on the first substrate material 110. The detailed process is as follows.

After the gate metal layer is deposited on the first substrate material 110, the gate metal layer 121 includes a gate line 121, a gate electrode 122, a gate pad 123, and the like, patterned by a photolithography process using a mask. , 122, 123. Next, three layers of the gate insulating layer 141, the semiconductor layer 142, and the ohmic contact layer 143 are sequentially stacked, and the semiconductor layer 142 and the ohmic contact layer 143 are photo-etched to form an upper portion of the gate electrode 122. An island-shaped semiconductor layer 142 and an ohmic contact layer 143 are formed on the gate insulating layer 141. Next, the data metal layer is deposited and patterned by a photolithography process using a mask to be connected to the data line 131 and the data line 131 crossing the gate line 121 to extend to the upper portion of the gate electrode 122. Data lines 131, 132, 133, and 134 including a source electrode 132 and a drain electrode 133 facing the same are formed. Subsequently, the ohmic contact layer 143 that is not covered by the data wires 131, 133, and 134 is etched to be separated on both sides of the gate electrode 122, and the semiconductor layer 142 is exposed. In order to stabilize the surface of the exposed semiconductor layer 142, it is preferable to perform an oxygen plasma.

Next, as shown in FIG. 4B, an insulating film 151 is formed and a photoresist film 500 is applied thereon. The photoresist film 500 is then exposed to ultraviolet rays through a mask 400. The mask 400 used at this time includes a mask substrate 410 made of quartz or the like, and a light shielding film 420 formed on the mask substrate 410 and provided with an exposure pattern.

An exposure pattern B for forming the contact hole 181 and an exposure pattern C for forming the curved portion 191 are formed in the light blocking film 420. In the exposure pattern B for forming the contact hole 181, the light shielding film 420 is removed to correspond to the shape of the contact hole 181. On the other hand, the exposure pattern C for forming the curved portion 191 is a slit pattern that transmits ultraviolet rays. In the slit pattern, the width of the slit is wide at the center portion, and the width of the slit is narrow at the peripheral portion.

When the ultraviolet ray is irradiated on the photoresist film 500 using the mask 400, the polymers are completely decomposed at the portion directly exposed to the light, and the polymers are not completely decomposed at the portion where the slit pattern is formed. When the polymers decomposed through the post-exposure development are removed, the photosensitive film 500 of the 'D' portion corresponding to the exposure pattern B is completely removed, and the photosensitive film 500 of the 'E' portion corresponding to the exposure pattern C is completely removed. ) Will only be removed. When the photosensitive film 500 of the 'E' portion is described in detail, the thickness of the photosensitive film 500 is relatively thin in the central portion of the wide slit, and the thickness of the photosensitive film 500 is relatively thick in the peripheral portion of the narrow slit. do.

4C illustrates that the insulating film 151 is etched and patterned using the photosensitive film pattern formed through exposure and development. The insulating layer 151 is provided with a contact hole 181 for connecting the pixel electrode 171 and the drain electrode 1133 and a curved portion 191 formed on the signal lines 121 and 131. The curved portion 191 is formed by etching a lot in the central portion where the photoresist film 500 is thin during the etching process of the insulating layer 151, and a little etching in the peripheral region where the photoresist film 500 is thick.

Thereafter, when the pixel electrode 171 is deposited and patterned as shown in FIG. 2, the thin film transistor substrate 100 is completed.

Instead of the slit of the mask 400 used to form the curved portion 191 in the above embodiment, a grid pattern or a translucent film may be used. In the case of using the translucent film, a thin film having a different transmittance or a thin film may be used to control the transmittance when fabricating the mask 400.

5 is a cross-sectional view illustrating a method of forming a thin film transistor substrate 100 according to a third embodiment of the present invention. The insulating film 151 in the third embodiment is a transparent photosensitive film. Therefore, as in the first embodiment, the process of applying, exposing and developing the photoresist film 500 and etching the insulation film 151 is not necessary.

A method of forming the curved portion 191 is to adjust the exposure area so that the pattern as shown in FIG. 5 is formed when the insulating film 151 is coated and then exposed. When heat is applied in the state as shown in FIG. 5, the insulating layer 151 is reflowed to form the curved portion 191.

In FIG. 5, the contact hole 181 for connecting the pixel electrode 171 and the drain electrode 133 is not illustrated, but the contact hole 181 is formed through a separate exposure. However, when the contact hole 181 is designed so as not to be blocked in the reflow process of the insulating layer 151, the heating for forming the curved portion 191 may be performed while the contact hole 181 is formed.

Looking at the manufacturing method of the color filter substrate 200 as follows.

First, black matrices 221, 222, and 223 are formed on the second substrate material 210. The black matrices 221, 222, and 223 may be made of a photosensitive material to which black pigments are added, and are completed by applying, developing, and baking. Thereafter, the color filter layer 231 is formed, and the color filter layer 231 is alternately formed with red, green, and blue filters for each pixel.

When the color filter layer 231 is completed, the overcoat layer 241 is formed to planarize the color filter layer 231 and protect the color filter layer 231. When the common electrode layer 251 is deposited on the overcoat layer 241 by sputtering or the like, the color filter substrate 200 is completed.

As described above, according to the present invention, there is provided a liquid crystal display device which uses the light emitted from the backlight unit around the gate line and the data line to increase the luminance by forming a curved portion in the insulating film on the signal line. Also provided is a method of manufacturing such a liquid crystal display device.

Claims (10)

A first substrate having a signal line and an insulating film formed on the signal line, a second substrate facing the first substrate and having a black matrix corresponding to the signal line, and a liquid crystal layer positioned between the first and second substrates; In the liquid crystal display device comprising: And a curved portion is formed in the insulating film along the signal line. The method of claim 1, The refractive index of the insulating film is greater than the refractive index of the liquid crystal layer. The method of claim 2, And the curved portion is recessed toward the signal line. The method of claim 3, And the curved portion is curved outward toward the black matrix. The method of claim 3, And the curved portion is curved inwardly toward the signal line. The method of claim 1, The refractive index of the insulating film is smaller than the refractive index of the liquid crystal layer, And the curved portion protrudes toward the black matrix. The method of claim 1, And the width of the black matrix is greater than the width of the signal line. The method of claim 1, And the insulating film is an organic photosensitive film. In the manufacturing method of the liquid crystal display device, Forming a signal line on the substrate material; Depositing an insulating film on the signal line; And patterning the insulating layer to have a curved portion along the signal line. The method of claim 8, The patterning step of the insulating film is. Applying a photoresist film on top of the insulating film; The method of manufacturing a liquid crystal display device further comprising the step of photosensitive the photosensitive film using a mask having a slit.

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