Liquid crystal display panel with different substrate materials and method of making the liquid crystal display panel

• US 20070012925A1
• Filed: 05/22/2006
• Published: 01/18/2007
• Est. Priority Date: 06/08/2005
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hong, Wang-su, Lee, Woo-jae
• Granted Patent: US 7,598,103 B2
• Time in Patent Office: Days
• US Class Current: 257/72
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/1341 Filling or closing of cells
• CPC Class Codes: G02F 1/1362 Active matrix addressed cells G02F1/134336, G02F1/134363 take precedence
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate

Abstract

An LCD panel with mixed substrate materials and a method of making the LCD panel are presented. The LCD panel is made of a first substrate, a second substrate disposed substantially parallel to the first substrate, and a liquid crystal layer disposed between the first substrate and the second substrate. The first substrate includes a glass substrate, a TFT formed on the glass substrate, and a color filter formed on the TFT. The second substrate includes a plastic substrate and a common electrode formed on the plastic substrate. Forming the color filter on the TFT eliminates the need to form black matrices on the second substrate, preventing misalignment of the two substrates due to different heat sensitivities. Since there is no concern of substrate misalignment caused by heat, laser beam can be used to cut the substrates during the manufacture of the LCD panel.

Claims

1. An LCD panel comprising:

a first substrate comprising a glass substrate, a TFT formed on the glass substrate, and a color filter formed on the TFT;

a second substrate comprising a plastic substrate and a common electrode formed on the plastic substrate, the second substrate disposed substantially parallel to the first substrate; and

a liquid crystal layer disposed between the first substrate and the second substrate.

2. The LCD panel of claim 1, wherein the common electrode directly contacts with the plastic substrate.

3. The LCD panel of claim 1, wherein the color filter comprises at least two layers having different colors, the two layers overlapping each other on the TFT.

4. The LCD panel of claim 1, wherein the color filter comprises at least three layers having different colors, the three layers overlapping one another on the TFT.

5. The LCD panel of claim 1, wherein the plastic substrate is thinner than the glass substrate.

6. The LCD panel of claim 1, further comprising a pixel electrode disposed on the color filter, wherein the pixel electrode is connected to the TFT through a contact hole extending through a protective layer covered by the color filter.

7. A method of making an LCD panel comprising:

attaching a first substrate to a second substrate, wherein the first substrate includes a glass substrate and the second substrate includes a plastic substrate; and

irradiating the first and the second substrates with a laser beam to cut the first and the second substrates along a beam path.

8. The method of claim 7, further comprising cooling the first substrate.

9. The method of claim 8, wherein the cooling is performed by contacting the first substrate with a cooling plate of 25°

C. or less.

10. The method of claim 7, wherein the laser is shined onto a surface of the second substrate that is not covered by the first substrate.

11. The method of claim 7, wherein the laser uses carbon dioxide as a source.

12. The method of claim 7, wherein the first substrate is a dummy glass substrate capable of supporting the second substrate.

13. The method of claim 7, wherein the first substrate and the second substrate are attached to each other by a sealant.

14. The method of claim 13, wherein the sealant is at least partly cut by the laser beam.

15. The method of claim 13, wherein a liquid crystal layer is disposed between the first substrate and the second substrate.

16. The method of claim 7, wherein the first substrate further comprises a TFT and a color filter formed on the TFT.

17. The method of claim 7, wherein the second substrate further comprises a common electrode contacting with the plastic substrate.

18. The method of claim 7, wherein the plastic substrate is thinner than the glass substrate.

19. A method of making an LCD panel comprising:

adhering a first substrate to a second substrate, the first substrate comprising a glass substrate and the second substrate comprising a plastic substrate, the first substrate having an overlap area that overlaps the second substrate and a pad area that extends beyond the second substrate; and

directing a laser beam to the first substrate and the second substrate along edges of the overlap area to cut the first substrate and the second substrate with the laser beam.

20. The method of claim 19, wherein the second substrate is supported by a dummy glass substrate while receiving the laser beam.

21. The method of claim 20, wherein the laser beam is irradiated onto a surface of the dummy glass substrate that is not covered by the second substrate.

22. The method of claim 19, further comprising directing the laser beam along a circumference of the pad area to cut the first substrate.

23. The method of claim 19, further comprising directing the laser beam along a circumference of the overlap area to cut the second substrate.