LIQUID CRYSTAL DISPLAY DEVICE

• US 20180299735A1
• Filed: 06/21/2018
• Published: 10/18/2018
• 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 10,126,611 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;

a source electrode of a switching element provided on the first substrate;

an organic film provided on the source electrode;

a first electrode provided on the organic film and connected with the source electrode; and

a second substrate opposed to the first substrate,

wherein the organic film has a hole that connects the source electrode and the first electrode,

a diameter of the hole at a first position where the source electrode and the first electrode are connected is smaller than a diameter of the hole at a second position that is closer to the second substrate than the first position,

in a cross-sectional view, a width of the source electrode is smaller than the diameter at the second position of the hole, and

the first electrode has an end portion that is located between the first position of the hole and the second position of the hole.

2. The display device according to claim 1, further comprising,

an inorganic film provided between the first electrode and the organic film, and

a second electrode provided between the inorganic film and the organic film,

wherein the second electrode has an end portion that is located between the first position of the hole and the end portion of the first electrode.

3. The display device according to claim 2,

wherein the second electrode does not connect to the source electrode.

4. The display device according to claim 1,

wherein the second substrate has a light shield layer,

the light shield layer opposes the source electrode, and

in a cross-sectional view, a width of the light shield layer and the width of source electrode are the same.

5. The display device according to claim 4,

wherein, in plan view, an end of the light shield layer is located between the first position and the second position.

6. The display device according to claim 1,

wherein a taper angle of the hole at the first position of the hole is larger than a taper angle of the hole at the second position.

7. The display device according to claim 1,

wherein the organic film has a main surface parallel to the first substrate, and

the second position of the hole and the main surface are on the same plane in a cross-sectional view.