LIQUID CRYSTAL DISPLAY DEVICE

• US 20150160521A1
• Filed: 12/09/2014
• Published: 06/11/2015
• Est. Priority Date: 12/09/2013
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: TOMIOKA, Yasushi, ISHIGAKI, Toshimasa, SONODA, Hidehiro, UETA, Sumito
• Granted Patent: US 9,519,196 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133357 Planarisation layers
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/1337 Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• 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 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel

Abstract

To prevent a phenomenon that an alignment film material is difficult to flow into the through-hole where a diameter of a through-hole for connecting between a pixel electrode and a source electrode is reduced.

A liquid crystal display device comprising a TFT substrate having pixels each including a common electrode formed on an organic passivation film, an interlayer insulating film formed so as to cover the common electrode, a pixel electrode having a slit and formed on the interlayer insulating film, a through-hole formed in the organic passivation film and the interlayer insulating film, and a source electrode electrically conducted to the pixel electrode via the through-hole. A taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees. The pixel electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole. This configuration facilitates the alignment film material to flow into the through-hole, thereby solving a thickness unevenness of the alignment film in vicinity of the through-hole.

Claims

1. A liquid crystal display device comprising:

a TFT substrate having pixels each including

a common electrode formed on an organic passivation film,

an interlayer insulating film formed so as to cover the common electrode,

a pixel electrode formed on the interlayer insulating film, the pixel electrode having a slit,

a through-hole formed in the organic passivation film and the interlayer insulating film, and

a source electrode electrically conducted to the pixel electrode via the through-hole;

a counter substrate having a black matrix formed thereon; and

liquid crystal sandwiched between the TFT substrate and the counter substrate,

wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,

a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and

wherein the pixel electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole.

3. A liquid crystal display device according to claim 1, wherein the taper angle of the through-hole is equal to or more than 60 degrees.

2. A liquid crystal display device comprising:

a TFT substrate having pixels each including

a pixel electrode formed on an organic passivation film,

a through-hole formed in the organic passivation film,

a source electrode electrically conducted to the pixel electrode via the through-hole,

an interlayer insulating film formed so as to cover the pixel electrode, and

a common electrode formed on the interlayer insulating film, the common electrode having a slit;

a counter substrate having a black matrix formed thereon; and

liquid crystal sandwiched between the TFT substrate and the counter substrate,

wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,

a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and

wherein the common electrode covers part of a side wall of the through-hole but does not cover the remaining part of the side wall of the through-hole.

4. A liquid crystal display device according to claim 2, wherein the taper angle of the through-hole is equal to or more than 60 degrees.

5. A liquid crystal display device comprising:

a TFT substrate having pixels each including

a common electrode formed on an organic passivation film,

an interlayer insulating film formed so as to cover the common electrode,

a pixel electrode formed on the interlayer insulating film, the pixel electrode having a slit,

a through-hole formed in the organic passivation film and the interlayer insulating film, and

a source electrode electrically conducted to the pixel electrode via the through-hole;

a counter substrate having a black matrix formed thereon; and

liquid crystal sandwiched between the TFT substrate and the counter substrate,

wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,

a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and

the slit of the pixel electrode extends to a depth of 1 μ

m or more from a top surface of the organic passivation film or to a depth of D/4 or more from the top surface of the organic passivation film.

7. A liquid crystal display device according to claim 5, wherein the slit extends to the bottom face of the through-hole.

9. A liquid crystal display device according to claim 5, wherein the taper angle of the through-hole is equal to or more than 60 degrees.

11. A liquid crystal display device according to claim 7, wherein the taper angle of the through-hole is equal to or more than 60 degrees.

6. A liquid crystal display device comprising:

a TFT substrate having pixels each including

a pixel electrode formed on an organic passivation film,

a through-hole formed in the organic passivation film,

a source electrode electrically conducted to the pixel electrode via the through-hole,

an interlayer insulating film formed so as to cover the pixel electrode, and

a common electrode formed on the interlayer insulating film, the common electrode having a slit;

a counter substrate having a black matrix formed thereon; and

liquid crystal sandwiched between the TFT substrate and the counter substrate,

wherein, where the through-hole formed in the organic passivation film assumes a cross-section in which a top face is defined on the side of the counter substrate and a bottom face is defined on the side of the source electrode, the top face having a diameter larger than that of the bottom face, the through-hole having a depth of D,

a taper angle at a depth of D/2 of the through-hole is equal to or more than 50 degrees, and

the slit of the pixel electrode extends to a depth of 1 μ

m or more from a top surface of the organic passivation film or to a depth of D/4 or more from the top surface of the organic passivation film.

8. A liquid crystal display device according to claim 6, wherein the slit extends to the bottom face of the through-hole.

10. A liquid crystal display device according to claim 6, wherein the taper angle of the through-hole is equal to or more than 60 degrees.

12. A liquid crystal display device according to claim 8, wherein the taper angle of the through-hole is equal to or more than 60 degrees.