KR20070072966A - Color filter substrate and fabricating method thereof - Google Patents

Abstract

A color filter substrate and a manufacturing method thereof are provided to maintain a cell gap uniformly and to implement a color with high saturation. A black matrix(140) is formed on a substrate and divides a pixel area having a reflection area and a transmission area. At least two color filters(142) with different transmittance are formed on the reflection area. An insulating pattern(144) is formed on the color filter and makes the difference of a cell gap between the reflection area and the transmission area. The first color filter is formed at the reflection area and the transmission area in order to form a light hole at a partial area of the reflection area. The second color filter is filled with the first light hole, formed with the same height as the first color filter and has the low transmittance in comparison with the first color filter.

Description

Color filter substrate and its manufacturing method {Color Filter Substrate And Fabricating Method Thereof}

1 is a plan view illustrating a transflective thin film transistor array substrate and a color filter substrate according to the present invention.

FIG. 2 is a cross-sectional view illustrating a color filter substrate and a thin film transistor array substrate cut along the line "I-I '" in FIG. 1.

3 is a cross-sectional view illustrating another embodiment of the color filter substrate illustrated in FIG. 2.

4A and 4B are diagrams illustrating transmittances of a color filter of a liquid crystal display having a color filter of a liquid crystal display having a conventional light hole and a second color filter filled in the light hole according to the present invention.

5A through 5F are cross-sectional views illustrating a method of manufacturing the color filter substrate illustrated in FIG. 2.

<Description of Symbols for Main Parts of Drawings>

101,111 substrate 102 gate line

104: data line 106: gate electrode

108: source electrode 110: drain electrode

112: gate insulating film 114: active layer

116: ohmic contact layer 118: protective film

120 contact hole 122 pixel electrode

130: reflective electrode 138: light hole

140: black matrix 142: color filter

144: insulating pattern 146: common electrode

150: color filter substrate 160: thin film transistor substrate

The present invention relates to a color filter substrate and a method for manufacturing the same, and more particularly, to a color filter substrate and a method for manufacturing the same, which can realize a high color saturation and uniform cell gap.

In general, a liquid crystal display (LCD) displays an image by allowing each of the liquid crystal cells arranged in a matrix form on a liquid crystal panel to adjust light transmittance according to a video signal.

The transflective liquid crystal display of the liquid crystal display has advantages of transmissive and reflective. The transflective liquid crystal display operates in a reflection mode when the external light is sufficient, and in a transmission mode using the backlight unit when the external light is insufficient. Therefore, the transflective liquid crystal display device can reduce power consumption than the transmissive liquid crystal display device and is not subject to external light, unlike the reflective liquid crystal display device.

The transflective liquid crystal display includes a reflection area for implementing an image using external light and a transmission area for implementing an image using internal light (backlight unit). The external light incident to the reflective region is reflected by the reflective electrode via the liquid crystal layer and emitted to the outside via the liquid crystal layer again. In addition, the internal light of the backlight unit incident to the transmission region passes through the liquid crystal layer and is emitted to the outside. In this case, the external light of the reflective region passes through the color filter twice, whereas the internal light of the transmissive region passes through the color filter once.

In order to solve this problem, a double cell gap type liquid crystal display device having a light hole (LH) has been proposed.

The liquid crystal display of a dual cell gap type having a light hole includes a light hole for compensating for color difference, and an insulating pattern for compensating for an optical path difference between a transmission area and a reflection area.

The light hole is formed to penetrate a part of the color filter positioned in the reflection area, thereby compensating for the color difference according to the number of passes of the color filter in the reflection area and the transmission area. The insulating pattern compensates the optical path difference between the internal light and the transmitted light by allowing the cell gap of the transmission area to be twice the cell gap of the reflection area.

In the dual cell gap type liquid crystal display having the light holes as described above, an insulating pattern formed to overlap the light holes is stepped in a region overlapping the light holes by the light holes. In addition, the spacer formed on the insulating pattern is also stepped in the region overlapping with the light hole by the light hole, so that the cell gap of the entire liquid crystal display panel is not uniform.

Accordingly, the technical problem to be achieved by the present invention relates to a color filter substrate and a method of manufacturing the same, which can make the cell gap uniform and implement high color saturation.

In order to achieve the above technical problem, the color filter substrate according to the present invention comprises a black matrix formed on the substrate and separating the pixel region having a reflection region and a transmission region; At least two color filters formed to have different transmittances in the reflection area; And an insulating pattern formed on the color filter to different cell gaps between the reflective area and the transparent area.

The at least two color filters may include a first color filter formed in the reflection area and the transmission area to provide a light hole in a portion of the reflection area; And a second color filter filled in the first light hole and formed at the same height as the first color filter, and having a transmittance different from that of the first color filter.

The second color filter may have a transmittance lower than that of the first color filter.

The size of the pigment included in the second color filter is smaller than the size of the pigment included in the first color filter.

The insulating pattern may be formed to overlap the second color filter.

The insulating pattern may be formed at a height similar to a cell gap of the reflective region.

In order to achieve the above technical problem, a method of manufacturing a color filter substrate according to the present invention includes the steps of forming a black matrix on the substrate for separating the pixel region having a reflection region and a transmission region; Forming at least two color filters having different transmittances in the reflective region; And forming an insulating pattern on the color filter that makes the cell gap between the reflective area and the transparent area different.

The forming of the at least two color filters may include forming a first color filter in the reflection area and the transmission area to provide a light hole in a portion of the reflection area; And forming a second color filter having a different transmittance from the first color filter in the first light hole at the same height as the first color filter.

Hereinafter, exemplary embodiments of the present invention will be described with reference to FIGS. 1 to 5F.

1 is a plan view illustrating a transflective liquid crystal display panel according to the present invention, and FIG. 2 is a cross-sectional view illustrating a liquid crystal display panel cut along the line "I-I '" in FIG. 1.

The transflective liquid crystal display panel illustrated in FIGS. 2 and 3 includes a thin film transistor substrate 160 having a thin film transistor array and a color filter substrate 150 having a color filter array.

The thin film transistor substrate 160 may include a thin film transistor connected to the gate line 102 and the data line 104, a pixel electrode 122 connected to the thin film transistor and formed in the pixel region, and a reflective region RA of the pixel region. The reflective electrode 130 is formed.

The thin film transistor selectively supplies the data signal from the data line 104 to the pixel electrode 122 in response to the gate signal from the gate line 102. To this end, the thin film transistor includes a pixel electrode through a gate electrode 106 connected to the gate line 102, a source electrode 108 included in the data line 104, and a contact hole 120 penetrating through the passivation layer 118. An active layer 114 forming a channel between the source electrode 108 and the drain electrode 110 while overlapping the drain electrode 110, the gate electrode 106, and the gate insulating layer 112 connected therebetween. And an ohmic contact layer 116 for ohmic contact between the active layer 114, the source electrode 108, and the drain electrode 110.

The pixel electrode 122 is formed of a transparent conductive material having a high transmittance and positioned in a pixel region provided at the intersection of the data line 104 and the gate line 102. The pixel electrode 122 is formed on the passivation layer 118 applied to the entire lower substrate 101 and is electrically connected to the drain electrode 110 through the contact hole 120. The pixel electrode 122 generates a potential difference from the common electrode 146 by a data signal supplied through the thin film transistor. This potential difference causes the liquid crystal to rotate, and the light transmittance is determined according to the degree of rotation of the liquid crystal in each of the reflective and transmissive regions.

The reflective electrode 130 reflects external light incident through the color filter substrate 150 toward the color filter substrate 150. The region in which the reflective electrode 130 is formed becomes the reflective region RA among the pixel regions, and the region in which the reflective electrode 130 is not formed becomes the transmissive region TA of each pixel region.

The color filter substrate 150 has a light hole formed to penetrate the black matrix 140 to prevent light leakage, the color filter 142 for color implementation, and a part of the color filter 142 positioned in the reflection area RA. 138, an insulating pattern 144 formed to overlap the light hole 138, a common electrode 146 forming a vertical electric field with the pixel electrode 122, and a spacer 148 holding the cell gap d1 of the liquid crystal display panel. An array of color filters is formed on the upper substrate 111.

The light hole 138 is formed to penetrate a portion of the first color filter 142a positioned in the reflective region RA to provide a filling region of the second color filter 142b.

The color filter 142 includes first and second color filters 142a and 142b formed in the pixel area provided by the black matrix 140.

The first color filter 142a is formed for each of red (R1), green (G1), and blue (B1) in the remaining areas except for the light hole 138, and thus red (R), green (G), and blue (B). Implement

The second color filter 142b is formed to fill the light hole 138 for each of red (R2), green (G2), and blue (B2) to implement red (R), green (G), and blue (B). . In this case, the second color filter 142b has a lower transmittance than the first color filter 142a. To this end, the second color filter 142b made of a pigment and a polymer has a smaller pigment size and a higher polymer content than the first color filter 142a. Alternatively, the second color filter 142b has a lower pigment content than the first color filter 142a and a higher polymer content than the first color filter 142a.

As described above, the liquid crystal display using the second color filter 142b having a lower transmittance than the first color filter 142a may implement a color having a higher saturation in the reflection area than the conventional liquid crystal display having the light hole. This will be described with reference to FIGS. 4A and 4B.

As shown in FIG. 4A and Table 1, the conventional liquid crystal display having a light hole has a predetermined transmittance for each of the red (R), green (G), and blue (B) color filters. That is, the conventional red (R) color filter has a transmittance of 32 to 95%, the green color filter (G) has a transmittance of 20 to 80%, and the blue (B) color filter has a transmittance of 48 to 94%.

Y (transmittance of specific wavelength band) CR R 53.4    6.0% G 78.5 B 46.6 W 59.5

On the other hand, the liquid crystal display according to the present invention, in which the second color filter 142b is filled in the light hole 138, as shown in FIG. 4B and Table 2, compared to the color filter of the liquid crystal display having the conventional light hole. The red (R), green (G) and blue (B) color filters not only have high transmittance but also have a wide transmittance range. That is, the red (R) color filter according to the present invention has a transmittance of 15 to 99%, the green (G) color filter has a transmittance of 56 to 98%, and the blue (B) color filter has a transmittance of 13 to 93%. Have

Y (transmittance of specific wavelength band) CR R 52.6    6.3% G 91.0 B 55.3 W 66.3

As described above, the color filter of the liquid crystal display according to the present invention has a higher transmittance and a wider range of transmittance than the conventional liquid crystal display. Accordingly, the liquid crystal display according to the present invention may implement a color having a higher saturation compared to a liquid crystal display having a conventional light hole.

The insulating pattern 144 is formed on the second color filter 142b filled in the light hole 138 to a height of about 1/2 the cell gap d2. By the insulating pattern 144, the lengths of the optical paths passing through the liquid crystal layer in the reflection area RA and the transmission area TA are the same. As a result, the external light incident to the reflective region RA is reflected by the reflective electrode 130 via the liquid crystal layer and emitted to the outside via the liquid crystal layer. In addition, the internal light of the backlight unit incident to the transmission area TA passes through the liquid crystal layer and is emitted to the outside. Accordingly, since the lengths of the optical paths in the reflection area RA and the transmission area TA are the same, the transmission efficiency of the reflection mode and the transmission mode of the liquid crystal display device is the same.

Meanwhile, as illustrated in FIG. 3, the insulating pattern 144 may be formed to be filled in the light hole 138, and the second color filter 142b may be formed on the insulating pattern 144.

The common electrode 146 is formed on the upper substrate 111 to control the movement of the liquid crystal using the supplied common voltage.

The spacer 148 is formed to overlap the insulating pattern 144 on the common electrode 146 to maintain a cell gap between the thin film transistor substrate 160 and the color filter substrate 150. The spacer 148 is formed to have a height d1 about 1/2 of the cell gap d2 similar to the height of the insulating pattern 144.

As described above, the transflective color filter substrate according to the present invention is filled with a first color filter for providing a light hole and a second color filter having a low transmittance in the light hole. Accordingly, the semi-transmissive color filter substrate according to the present invention eliminates the step between the first and second color filters, thereby eliminating the step between the insulating pattern, the common electrode, and the spacer itself formed thereon, thereby making the entire liquid crystal cell gap uniform. In addition, the semi-transmissive color filter substrate according to the present invention may implement a color having a higher saturation than a conventional liquid crystal display having a light hole by filling the second color filter in the light hole.

5A to 5E are cross-sectional views illustrating a method of manufacturing a color filter substrate of a transflective liquid crystal display panel according to the present invention.

Referring to FIG. 5A, a black matrix 140 is formed on the upper substrate 101.

In detail, an opaque layer is applied on the upper substrate 101 through a sputtering or spin coating process. As the opaque layer, an opaque metal layer such as chromium or an opaque resin is used. The opaque layer is patterned by a photolithography process and an etching process to form a black matrix 140.

Referring to FIG. 5B, a first color filter 142a having a light hole 138 is formed in each pixel area on the upper substrate 101 on which the black matrix 140 is formed.

Specifically, a resin layer that implements a predetermined color is formed on the upper substrate 111 on which the black matrix 140 is formed. The resin layer that implements the predetermined color is patterned by a photolithography process to form color filters R1, G1, and B1 having predetermined colors having the light holes 138 in the pixel region. In this manner, the red, green, and blue color filters R1, G1, and B1 included in the first color filter 142a are formed.

Referring to FIG. 5C, a second color filter 142b is formed on the upper substrate 111 on which the first color filter 142a is formed.

Specifically, a resin layer that implements a predetermined color is formed on the upper substrate 111 on which the black matrix 140 is formed. The resin layer implementing the predetermined color is patterned by a photolithography process to form color filters R2, G2, and B2 having predetermined colors filled in the light holes 138 of the pixel region. In this manner, the red, green, and blue color filters R2, G2, and B2 included in the second color filter 142b are formed.

Referring to FIG. 5D, an insulating pattern 144 is formed on the upper substrate 111 on which the second color filter 142b is formed.

Specifically, an insulating film is formed on the upper substrate 111 on which the second color filter 142b is formed by spin coating or spinless coating. The insulating layer is patterned by a photolithography process and an etching process to form an insulation pattern 144 overlapping the second color filter. As the insulating film, an organic insulating material such as acrylic resin or an inorganic insulating material such as silicon nitride is used.

Referring to FIG. 5E, a common electrode 146 is formed on the upper substrate 111 on which the insulation pattern 144 is formed.

In detail, the common electrode 146 is formed by depositing a transparent conductive layer on the entire surface of the upper substrate 111 on which the insulating pattern 144 is formed through a deposition method such as sputtering. As the transparent conductive layer, a transparent conductive material such as indium tin oxide or the like is used.

Referring to FIG. 5F, a spacer 148 is formed on the upper substrate 111 on which the common electrode 146 is formed.

Specifically, a spacer 148 is formed by applying an entire surface of an organic insulating layer on the upper substrate 111 on which the common electrode 146 is formed, and then patterning the organic insulating layer by a photolithography process and an etching process. Here, an organic insulating material such as an acrylic resin is used for the organic insulating film.

As described above, the color filter substrate and the method of manufacturing the same according to the present invention are filled with a first color filter for providing a light hole and a second color filter having a low transmittance in the light hole. Accordingly, the color filter substrate and the method of manufacturing the same according to the present invention eliminate the step between the first and second color filters, thereby eliminating the step between the insulating pattern, the common electrode, and the spacer itself formed thereon, thereby making the entire liquid crystal cell gap uniform. . In addition, the color filter substrate and the method of manufacturing the same according to the present invention can implement a color having a higher saturation than the conventional liquid crystal display having a light hole.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

Claims (11)

A black matrix formed on the substrate and dividing a pixel region having a reflection region and a transmission region; At least two color filters formed to have different transmittances in the reflection area; And an insulating pattern formed on the color filter and different in cell gaps between the reflective and transmissive regions. The method of claim 1, The at least two color filters A first color filter formed in the reflection area and the transmission area to provide a light hole in a portion of the reflection area; And a second color filter filled in the first light hole and formed at the same height as the first color filter, and having a transmittance different from that of the first color filter. The method of claim 2, And the second color filter has a transmittance lower than that of the first color filter. The method of claim 2, The size of the pigment included in the second color filter is smaller than the size of the pigment included in the first color filter, and the content of the polymer included in the second color filter is higher than the content of the polymer included in the first color filter. A color filter substrate, characterized in that. The method of claim 2, The size of the pigment included in the second color filter is the same as the size of the pigment included in the first color filter, the content of the polymer included in the second color filter is less than the content of the polymer included in the first color filter The color filter substrate, characterized in that the high, the content of the pigment contained in the second color filter is lower than the content of the pigment contained in the first color filter. The method of claim 2, The insulation pattern is formed so as to overlap the second color filter. The method of claim 6, The insulating pattern is a color filter substrate, characterized in that formed in the height similar to the cell gap of the reflective region. Forming a black matrix on the substrate, the black matrix dividing a pixel region having a reflection region and a transmission region; Forming at least two color filters having different transmittances in the reflective region; And forming an insulating pattern on the color filter, the insulating pattern differenting the cell gap between the reflective area and the transparent area. The method of claim 8, Forming the at least two color filters Forming a first color filter in the reflective and transmissive regions to provide light holes in a portion of the reflective region; And forming a second color filter having a different transmittance from the first color filter in the first light hole at the same height as the first color filter. The method of claim 9, And the second color filter has a transmittance lower than that of the first color filter. The method of claim 9, The insulation pattern is formed to overlap with the second color filter method of manufacturing a color filter substrate.

Images