LIQUID CRYSTAL DISPLAY DEVICE

• US 20170146872A1
• Filed: 01/09/2017
• Published: 05/25/2017
• Est. Priority Date: 10/31/2013
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: TOMIOKA, Yasushi, HYODO, Yosuke, SONODA, Hidehiro, KUNIMATSU, Noboru
• Granted Patent: US 9,778,520 B2
• Time in Patent Office: Days
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133788 by light irradiation, e.g. linearly polarised light photo-polymerisation
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2202/02 organic material
• CPC Class Codes: H01L 27/1218 with a particular composition or structure of the substrate

Abstract

In a liquid crystal display device, a common electrode is formed on an organic passivation film, an interlayer insulating film is formed on the common electrode, a pixel electrode with a slit is formed on the interlayer insulating film, and a through hole is formed in the organic passivation film and the interlayer insulating film, so that the pixel electrode is connected to a source electrode of a TFT through the through hole. Further, the taper angle around the upper base of the through hole is smaller than the taper angle around the lower base. Thus, the alignment film material can easily flow into the through hole when the diameter of the through hole is reduced to connect the pixel and source electrodes, preventing display defects such as uneven brightness due to the absence of the alignment film or due to the alignment film irregularity around the through hole.

Claims

1. A display device comprising:

a first substrate including a first electrode, an organic film formed on the first electrode, and a second electrode electrically connected to the first electrode through a through hole that is formed in the organic film,

wherein the through hole has a first portion and a second portion, the second portion is closer to the first substrate than the first portion is, the second portion is arranged between the first substrate and the first portion,

wherein the second portion is steeper than the first portion, and

wherein the second electrode has a slit which overlaps the first portion.

2. The display device according to claim 1,

wherein a taper angle of the second portion is greater than a taper angle of the first portion.

3. The display device according to claim 1,

wherein the slit does not overlap with the first electrode, in a plan view.

4. The display device according to claim 1,

wherein the slit is outside of an end of the first electrode.

5. The display device according to claim 1, further comprising a third electrode formed on the organic film, an inorganic film formed on the third electrode,

wherein the inorganic film is formed between the second electrode and the third electrode,

wherein the third electrode is not electrically connected with the first electrode,

wherein the third electrode overlaps with the slit.

6. The display device according to claim 1,

wherein the first electrode is used as a light shielding film.

7. The display device according to claim 1, further comprising a second substrate opposing to the first substrate,

wherein the second substrate has a light shield film,

wherein the light shield film overlaps with the first electrode, in a plan view.

8. The display device according to claim 1, further comprising a TFT formed on the first substrate,

wherein the first electrode is a source electrode of the TFT.

9. The display device according to claim 8,

wherein the first electrode is electrically connected to a semiconductor layer of the TFT.

10. The display device according to claim 1, further comprising an alignment film formed to cover the first substrate,

wherein the alignment film is a photo alignment film.

11. The display device according to claim 1,

wherein the organic film is used as a color filter.

12. A display device comprising:

a first substrate including a first electrode, an organic film formed on the first electrode, and a second electrode electrically connected to the first electrode through a through hole that is formed in the organic film,

the through hole has a bottom portion and a top portion, the bottom portion is closer to the first substrate than the top portion is,

a wall of the through hole is steeper at the bottom portion than at the top portion,

wherein the second electrode has a slit which overlaps with the top portion of the through hole.

13. The display device according to claim 12,

wherein a taper angle of the wall at the bottom portion is greater than a taper angle of the wall at the top portion.

14. The display device according to claim 12,

wherein the slit does not overlap with the first electrode, in a plan view.

15. The display device according to claim 12,

wherein the slit is outside of an end of the first electrode.

16. The display device according to claim 12, further comprising a third electrode formed on the organic film, an inorganic film formed on the third electrode,

wherein the inorganic film is formed between the second electrode and the third electrode,

wherein the third electrode is not electrically connected with the first electrode, wherein the third electrode overlaps with the slit.

17. The display device according to claim 12,

wherein the first electrode is used as a light shielding film.

18. The display device according to claim 12, further comprising a second substrate opposing to the first substrate,

wherein the second substrate has a light shield film,

wherein the light shield film overlaps with the first electrode, in a plan view.

19. The display device according to claim 12, further comprising an alignment film formed cover the first substrate,

wherein the alignment film is a photo alignment film.

20. The display device according to claim 12,

wherein the organic film is used as a color filter.