Color filter substrate for liquid crystal display device and method for fabricating the same
View Patent ↗A color filter substrate includes a black matrix on a transparent insulating substrate, the blacking matrix defining a pixel area, color filters in the pixel area, an overcoating layer over the black matrix and the color filters, the overcoating layer having a plurality of grooves, a plurality of column spacers on the overcoating layer, and a plurality of ball spacers in the grooves of the overcoating layer.
1. A color filter substrate, comprising:
a black matrix on a transparent insulating substrate, the blacking matrix defining a pixel area;
color filters in the pixel area;
an overcoating layer over the black matrix and the color filters, the overcoating layer having a plurality of grooves;
a plurality of column spacers on the overcoating layer; and
a plurality of ball spacers in the grooves of the overcoating layer,
wherein the ball spacers has a protrusion height greater than a protrusion height of the column spacers.
2. The color filter substrate of claim 1 , wherein the column spacers and the ball spacers overlap the black matrix.
3. The color filter substrate of claim 1 , wherein the column spacers and the ball spacers are alternately located with one another.
4. The color filter substrate of claim 1 , wherein the overcoating layer includes the same material as the column spacers.
5. The color filter substrate of claim 1 , wherein the protrusion height of the ball spacers is about 11/10 to 13/10 of the protrusion height of the column spacers.
6. The color filter substrate of claim 1 , wherein the density of the ball spacers is about 50 spacers/mm2 to 300 spacers/mm2.
7. The color filter substrate of claim 1 , wherein the sum of the top surface areas of the column spacers is about 0.2% to 1.0% of the surface area of the transparent insulating substrate.
8. The color filter substrate of claim 1 , wherein the grooves overlap the black matrix.
9. The liquid crystal display device having the color filter substrate of claim 1 , further comprising:
an array substrate; and
a liquid crystal layer between the array substrate and the color filter substrate.
10. A method for fabricating a color filter substrate, comprising:
forming a black matrix defining a pixel area on a transparent insulating substrate;
forming color filters in the pixel area;
forming an overcoating layer over the black matrix and the color filers, the overcoating layer having a plurality of grooves;
forming column spacers on the overcoating layer; and
disposing ball spacers in the grooves of the overcoating layer,
wherein the forming the column spacers includes forming the column spacer having a protrusion height less than a protrusion height of the ball spacers.
11. The method of claim 10 , wherein the column spacers and the ball spacers are formed overlapping the black matrix.
12. The method of claim 10 , wherein the column spacers and the ball spacers are formed to be alternately located with one another.
13. The method of claim 10 , wherein the column spacers and the overcoating layer are simultaneously formed.
14. The color filter substrate of claim 10 , wherein the protrusion height of the ball spacers is about 11/10 to 13/10 of the protrusion height of the column spacers.
15. The method of claim 10 , wherein the density of the ball spacers is 50 spacers/mm2 to 300 spacers/mm2.
16. The method of claim 10 , wherein the sum of the top surface areas of the column spacers is about 0.2% to 1.0% of the surface area of the transparent insulating substrate.
17. The method of claim 10 , wherein the forming the overcoating layer includes forming the grooves overlapping the black matrix.
18. The method of claim 10 , wherein the forming the overcoating layer and the forming the column spacers include depositing a planarizing layer on the transparent insulating substrate.