KR20030066089A - Method of manufacturing liquid crystal display apparatus - Google Patents

Abstract

PURPOSE: A method for manufacturing a liquid crystal display is provided to reduce the number of pattern masks required for forming an organic insulating film having an uneven structure, thereby reducing an inferior rate. CONSTITUTION: A non-photo sensitive material(160) including a plurality of photo sensitive particles(161) is applied on a first substrate(110). The plurality of photo sensitive particles are exposed. The exposed plurality of photo sensitive particles are developed. The non-photo sensitive material from which the photo sensitive particles have been removed is thermally processed to form an organic insulating film having an unevenness structure. A reflective electrode is formed on the organic insulating film in a uniform thickness. A second substrate is aligned. Liquid crystal is interposed between the first substrate and the second substrate.

Description

Manufacturing method of liquid crystal display device {METHOD OF MANUFACTURING LIQUID CRYSTAL DISPLAY APPARATUS}

The present invention relates to a method for manufacturing a liquid crystal display device, and more particularly, to a method for manufacturing a liquid crystal display device capable of reducing the overall number of steps.

In today's information society, the role of display devices becomes more and more important, and various display devices are widely used in various industrial fields. BACKGROUND With the rapid advance of semiconductor technology, liquid crystal display devices having thin and light display devices and low power consumption are widely used in accordance with the miniaturization and light weight of various information processing devices.

The liquid crystal display device is classified into a transmissive liquid crystal display device which receives an external light generated from the outside and displays an image and a reflective liquid crystal display device which receives its own generated light and displays an image.

Recently, a reflection-transmissive liquid crystal display device that can secure visibility that is appropriate to ambient light has been developed to realize high quality images while reducing power consumption.

Such a reflection-transmissive liquid crystal display displays an image in a reflection mode using external light where the amount of external light is abundant, and transmits using its own light generated by consuming electric energy charged therein when the amount of external light is insufficient. Display the image in mode.

Recently, the reflection-transmissive liquid crystal display device has been continuously studied to improve the image quality of the luminance in the reflection mode. Conventional reflection-transmissive liquid crystal displays for meeting this trend have the following structure.

The reflection-transmissive liquid crystal display device includes a thin film transistor (hereinafter, referred to as TFT) substrate, a color filter substrate provided to face the TFT substrate, and a liquid crystal layer injected between the TFT substrate and the color filter substrate. Is done.

A plurality of TFTs and pixel electrodes are formed on the TFT substrate, and an organic insulating film for insulating the pixel electrode and the remaining portion except the drain electrode of the TFT is interposed between the plurality of TFTs and the pixel electrodes.

A pixel electrode in contact with the drain electrode is formed on the organic insulating layer. In this case, the pixel electrode is incident from a reflecting electrode for reflecting the external light incident through the color filter substrate and exiting through the color filter substrate to the outside and a light source unit (not shown) disposed on the rear surface of the TFT substrate. It includes a transparent electrode for transmitting the self-light as it is.

In this case, in order to increase the amount of reflection of the external light reflected by the reflective electrode, and to adjust the emission angle of the external light to improve the viewing angle of the reflection-transmissive liquid crystal display device, the surface of the organic insulating film is formed in a concave-convex structure. need. This is called "embossing process".

Here, the process of performing the embossing process will be described with reference to FIGS. 1A to 1D.

1A to 1D are cross-sectional views illustrating a process of forming an organic insulating film having an uneven structure on a thin film transistor substrate according to a conventional manufacturing method.

Referring to FIG. 1A, a TFT 20 including a gate electrode 21, a drain electrode 22, and a source electrode 23 is formed on the insulating substrate 10, and an organic insulating layer 30 is coated thereon. do. Subsequently, a first mask 40 having a pattern for completely exposing a region where a contact hole (not shown) is to be formed in the organic insulating layer 30 is disposed on the organic insulating layer 30, thereby forming the organic insulating layer 30. (30) is first exposed.

Next, referring to FIG. 1B, in order to form a plurality of grooves (not shown) on the organic insulating layer 30, a second mask 50 having a pattern for exposing a region corresponding to the grooves is formed. The organic insulating film 30 is secondarily exposed by disposing it.

Thereafter, as illustrated in FIG. 1C, the contact hole 31 exposing the drain electrode 23 and the plurality of grooves 32 are exposed by a developing process of developing the exposed region of the organic insulating layer 30. Form.

Referring to FIG. 1D, by performing a heat treatment process to smooth the surface of the organic insulating layer 30, the organic insulating layer 30 protrudes with the recessed region 33 having a relatively low height and a relatively high height. The region 34 has a concave-convex structure in which the region 34 repeatedly appears.

Subsequently, although not shown in the drawings, a process of depositing a reflective electrode on the organic insulating layer 30 having such an uneven structure is performed. In this case, since the reflective electrode has the same concave-convex structure as the organic insulating layer 30, the reflection amount of the external light is increased, and the viewing angle of the reflection-transmissive liquid crystal display device is improved.

However, since the two-pattern masks 40 and 50 are used to manufacture the organic insulating layer 30, the number of manufacturing processes is large and the process is difficult. As a result, the manufacturing period of the reflection-transmissive liquid crystal display device becomes long, and of course, the manufacturing process. As the number and manufacturing period increase, frequent process defects occur.

Accordingly, it is an object of the present invention to provide a method of manufacturing a liquid crystal display device which can reduce the total number of manufacturing processes.

1A to 1D are cross-sectional views illustrating a process of forming an organic insulating film having an uneven structure on a thin film transistor substrate according to a conventional manufacturing method.

2 is a cross-sectional view showing in detail a reflection-transmissive liquid crystal display device according to an embodiment of the present invention.

3A to 3F are cross-sectional views illustrating in detail a process of forming an organic insulating layer having a concave-convex structure on a thin film transistor substrate according to a first embodiment of the present invention.

4A to 4D are cross-sectional views illustrating in detail a process of forming an organic insulating layer having a concave-convex structure on a thin film transistor substrate according to a second embodiment of the present invention.

Method for manufacturing a liquid crystal display device according to the present invention for achieving the above object, i) applying a non-photosensitive material comprising a plurality of photosensitive particles on a first substrate, ii) applying a plurality of photosensitive particles Exposing, iv) developing the plurality of exposed photosensitive particles, iii) heat treating the non-photosensitive material from which the plurality of photosensitive particles have been removed to form an organic insulating film having an uneven structure, iii) the organic Forming a reflective electrode with a uniform thickness on the insulating film, i) aligning a second substrate provided to face the first substrate, and iii) forming a liquid crystal between the first substrate and the second substrate. Injecting.

According to an aspect of the present invention, there is provided a method of manufacturing a liquid crystal display device, including: i) applying an organic insulating film including a plurality of particles on a first substrate, and ii) applying a reflective electrode on the organic insulating film. Forming, iii) aligning a second substrate provided opposite the first substrate, and iii) injecting a liquid crystal between the first substrate and the second substrate.

In this case, the diameter of the plurality of particles is greater than the height of the organic insulating layer laminated on the first substrate.

According to the present invention, in the process of forming an organic insulating film having a concave-convex structure on the first substrate, after applying a non-photosensitive material including a plurality of photosensitive particles on the first substrate patterning the photosensitive particles and the concave-convex structure The method of forming the organic insulating film which has a is used. Therefore, the number of processes for manufacturing the liquid crystal display device can be reduced.

Hereinafter, with reference to the accompanying drawings, it will be described in detail the present invention.

2 is a cross-sectional view showing in detail a reflection-transmissive liquid crystal display device according to an embodiment of the present invention.

Referring to FIG. 2, the reflection-transmissive liquid crystal display includes a liquid crystal display panel 400 for displaying an image and a backlight assembly (not shown) for supplying light to the liquid crystal display panel 400.

The liquid crystal display panel 400 includes a TFT substrate 100, a color filter substrate 200 provided to face the TFT substrate 100, and a gap between the TFT substrate 100 and the color filter substrate 200. The liquid crystal layer 300 is injected.

The TFT substrate 100 is a substrate on which a plurality of TFTs 120 are formed on a transparent first substrate 110 made of an insulating material such as glass, quartz, or sapphire.

That is, the TFT 120 including the gate electrode 121, the drain electrode 126, and the source electrode 125 is formed on the TFT substrate 100, and the organic insulating layer 130 is formed thereon.

The organic insulating layer 130 includes a contact hole 131 for partially exposing the drain electrode 126. The surface of the organic insulating layer 130 has a protruding region 133 and a recessed region 132. It has an uneven structure that appears repeatedly. Here, the protruding region 133 is a region where the height from the first substrate 110 is relatively high, and the recessed region 132 is a region where the height from the first substrate 110 is relatively low.

On the organic insulating layer 130, a transparent electrode 140 made of indium thin oxide (ITO) or indium zinc oxide (IZO) is provided to have a uniform thickness. Therefore, the transparent electrode 140 has the same surface structure as that of the organic insulating layer 130.

On the transparent electrode 140, a reflective electrode 150 having a transmission window 151 for partially exposing the transparent electrode 140 is provided to have a uniform thickness. Here, the reflective electrode 150 has the same surface structure as the surface structure of the organic insulating layer 130.

Therefore, a larger surface area than that when the reflective electrode 150 is formed flat can be ensured. As a result, the reflection-transmissive liquid crystal display is increased by increasing the amount of external light L1 generated from the outside of the reflection-transmissive liquid crystal display and incident on the TFT substrate 100 to be reflected on the reflective electrode 150. To increase the brightness. In addition, by forming the surface of the reflective electrode 150 in the concave-convex structure, it is possible to improve the viewing angle of the reflection-transmissive liquid crystal display by adjusting the exit angle of the external light (L1).

The transmission window 151 is generated from the backlight assembly to transmit the self-light L2 incident from the rear side of the TFT substrate 100 of the liquid crystal display panel 400 as it is.

Meanwhile, the color filter substrate 200 is a substrate on which an RGB color pixel 220 and a common electrode 230 are formed on a transparent second substrate 210 made of an insulating material such as glass, quartz, or sapphire. When the RGB color pixel 220 is formed on the color filter substrate 200, the common electrode 230 is provided with a uniform thickness thereon. In this case, the color filter substrate 200 is disposed such that the common electrode 230 faces the transparent electrode 140 and the reflective electrode 150 of the TFT substrate 100.

As such, when the TFT substrate 100 and the color filter substrate 200 are coupled to each other, the liquid crystal 300 is injected therebetween. As a result, the liquid crystal display panel 400 is completed.

The reflection-transmissive liquid crystal display displays an image by reflecting the external light L1 by the reflective electrode 150 when the amount of the external light L1 is abundant, and displays the amount of the external light L1. When this is insufficient, the image is displayed by transmitting the self-light L2 through the transmission window 151.

Hereinafter, a process of forming the organic insulating layer 130 having an uneven structure on the TFT substrate 100 will be described in detail with reference to the accompanying drawings.

3A to 3F are cross-sectional views illustrating in detail a process of forming an organic insulating layer having a concave-convex structure on a thin film transistor substrate according to a first embodiment of the present invention.

Referring to FIG. 3A, a TFT 120 including a gate electrode 121, a source electrode 125, and a drain electrode 126 is formed on the first insulating substrate 110.

First, a first metal film (not shown) made of aluminum (Al), chromium (Cr), or molybdenum tungsten (MoW) is deposited on the first insulating substrate 110, and then patterned to form a gate electrode 121. . Thereafter, the gate insulating layer 122 made of silicon oxide is provided on the first insulating substrate 110 except for the gate electrode 121 and the gate electrode 121.

Thereafter, an amorphous silicon film and an n ⁺ amorphous silicon film doped in-situ are sequentially stacked on the gate insulating film 122 by a plasma chemical vapor deposition method. Next, the stacked amorphous silicon film and the n ⁺ amorphous silicon film are patterned to form the semiconductor layer 123 and the ohmic contact layer 124 in a region corresponding to the gate electrode. The semiconductor layer 123 may be converted into a polysilicon layer by irradiating an amorphous silicon film with a laser having a predetermined intensity.

Then, source and drain electrodes 125 and 126 are formed on the gate insulating layer 122 to partially overlap the ohmic contact layer 124. As a result, the TFT 120 is formed on the first insulating substrate 110.

Referring to FIG. 3B, a non-photosensitive material 160 including a plurality of photosensitive particles 161 is coated on the first insulating substrate 110 on which the TFT 120 is formed.

The non-photosensitive material 160 is made of poly-carbonate or poly-arylate that is transparent and does not react with light, and the plurality of photosensitive particles 161 are exposed to light. It consists of polymer particles like acrylic resin reacted by. In addition, the photosensitive particles 161 may have a viscosity different from that of the non-photosensitive material 160 so as not to be mixed with the non-photosensitive material 160.

Here, the process method is divided into two cases according to the diameter of the plurality of photosensitive particles 161 will be described. That is, the first is when the diameter (d1) of the plurality of photosensitive particles 161 is less than or equal to the height (d2) of the non-photosensitive material 160, the second is the diameter (d1) of the plurality of photosensitive particles ) Is greater than the height d2 of the non-photosensitive material.

First, the first case will be described, and the second case will be described later with reference to FIGS. 4A to 4D.

As shown in FIG. 3B, since the diameter d1 of the plurality of photosensitive particles 161 is smaller than the height d2 of the non-photosensitive material 160, the plurality of photosensitive particles 161 may be non-photosensitive. Completely covered by material 160. In this case, any one of the plurality of photosensitive particles 161 is disposed on the drain electrode 126.

Thereafter, the plurality of photosensitive particles 161 are exposed. Here, even if the plurality of photosensitive particles 161 are completely covered by the non-photosensitive material 160, the non-photosensitive material 160 may be sufficiently exposed because it is transparent.

Thereafter, when the exposed plurality of photosensitive particles 161 are developed, as shown in FIG. 3C, the plurality of photosensitive particles 161 are removed and only the non-photosensitive material 160 remains.

In this case, the plurality of photosensitive particles 161 are removed to completely expose the drain electrode 126 of the TFT 120.

Next, when a predetermined heat is applied to the non-photosensitive material 160, the non-photosensitive material 160 is deformed by the heat to correspond to an area where the plurality of photosensitive particles 161 are removed. 160 will fall. That is, the organic insulating layer 130 having a surface structure in which the protruding region 133 having a relatively high height and the recessed region 132 having a relatively low height is repeatedly formed is formed.

In addition, the organic insulating layer 130 is completely removed at a position corresponding to the drain electrode 126 to form a contact hole 131 for exposing the drain electrode 126.

Thereafter, as illustrated in FIG. 3E, the transparent electrode 140 made of ITO or IZO is coated with a uniform thickness on the organic insulating layer 130. Here, the transparent electrode 140 has the same surface structure as that of the organic insulating layer 130.

As shown in FIG. 3F, the reflective electrode having the transmission window 151 for partially exposing the transparent electrode 140 is stacked on the transparent electrode 140 with a uniform thickness. The reflective electrode 150 has excellent reflectance such as an alloy of aluminum (Al), silver (Ag), aluminum-copper (Al-Cu) or an alloy of aluminum-silicon-copper (Al-Si-Cu), which has excellent reflectance. Made of metal. Here, the reflective electrode 150 has the same surface structure as that of the organic insulating layer 130.

Hereinafter, the second case described above with reference to FIGS. 4A to 4D will be described in detail. That is, in the second case, the diameter d1 of the plurality of photosensitive particles is larger than the height d2 of the non-photosensitive material.

4A to 4D are cross-sectional views illustrating in detail a process of forming an organic insulating layer having a concave-convex structure on a thin film transistor substrate according to a second embodiment of the present invention.

Referring to FIG. 4A, since the diameter d1 of the plurality of photosensitive particles 171 is greater than the height d2 of the non-photosensitive material 170, the plurality of photosensitive particles 171 may include the non-photosensitive material 170. It is not completely covered by, but partially exposed.

Here, the first and second photosensitive particles 171a and 171b of the plurality of photosensitive particles 171 are disposed at positions where a contact hole (not shown) for exposing the drain electrode 126 is formed.

As shown in FIG. 4A, after the first mask 180 having the pattern corresponding to the region where the contact hole is to be formed is disposed on the non-photosensitive material 170, the first and second photosensitive particles ( 171a and 171b are exposed.

Referring to FIG. 4B, when the exposed first and second photosensitive particles 171a and 171b are developed, only the first and second photosensitive particles 171a and 171b are removed from the non-photosensitive material 170. As a result, the contact hole 131 is formed.

In this case, since the diameter d1 of the plurality of photosensitive particles 171 is greater than the height d2 of the non-photosensitive material 170, a part of the plurality of photosensitive particles 171 may be formed on the non-photosensitive material 170. Exposed and not covered. Accordingly, the organic insulating layer 130 having a surface structure in which the protruding region 136 having a relatively low height and the recessed region 135 having a relatively high height is repeatedly formed is formed.

Referring to FIG. 4C, a transparent electrode 140 made of ITO or IZO is stacked on the organic layer insulating layer 130 with a uniform thickness. Here, the transparent electrode 140 has the same surface structure as that of the organic insulating layer 130.

Next, referring to FIG. 4D, the reflective electrode 150 having the transmission window 151 for partially exposing the transparent electrode 140 is stacked on the transparent electrode 140 with a uniform thickness. In this case, the reflective electrode 150 has the same surface structure as that of the organic insulating layer 130.

In the second case, the protruding region 136 of the organic insulating layer has a convex shape due to the plurality of photosensitive particles 171, but the recessed region 135 has a flat shape and thus receives the external light as compared with the first case. The efficiency of reflecting can be reduced. However, in the second case, since the heat treatment process performed in the first case is not required, the number of processes for manufacturing the reflection-transmissive liquid crystal display device can be further reduced.

According to the present invention, the step of forming an organic insulating film having a concave-convex structure on the first substrate, patterning the plurality of photosensitive particles after applying a non-photosensitive material containing a plurality of photosensitive particles on the first substrate This is done by going through the steps.

Therefore, the number of pattern masks required for forming the organic insulating film having the uneven structure can be reduced, and the number of processes can be reduced, thereby reducing the process period and the defective rate that can occur in the process.

Although described with reference to the examples, those skilled in the art can understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention described in the claims below. There will be.

Claims (8)

Iii) applying a non-photosensitive material comprising a plurality of photosensitive particles on the first substrate; Ii) exposing the plurality of photosensitive particles; Iii) developing the plurality of exposed photosensitive particles; Iii) heat treating the non-photosensitive material from which the plurality of photosensitive particles have been removed to form an organic insulating film having an uneven structure; Iii) forming a reflective electrode with a uniform thickness on the organic insulating film; Iii) aligning a second substrate provided to face the first substrate; And Iii) injecting a liquid crystal between the first substrate and the second substrate. The method of claim 1, wherein the plurality of photosensitive particles are polymer particles made of an acrylic resin. The method of claim 2, wherein a diameter of the plurality of photosensitive particles is smaller than a height at which the non-photosensitive material is coated on the first substrate. The method of claim 1, wherein the non-photosensitive material is made of poly-carbornate or poly-arylate. The method of claim 1, further comprising applying a transparent electrode on the organic insulating layer having the uneven structure. Iii) applying an organic insulating film comprising a plurality of particles on the first substrate; Ii) forming a reflective electrode on the organic insulating film Iii) aligning a second substrate provided to face the first substrate; And Iii) injecting a liquid crystal between the first substrate and the second substrate, The diameter of the plurality of particles is larger than the height of the organic insulating film laminated on the first substrate manufacturing method of the liquid crystal display device. The method of claim 6, wherein the plurality of particles are made of a transparent material. The method of claim 6, further comprising applying a transparent electrode on the organic insulating layer.