Display device and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-10580801-B2
Application number	US-201815978464-A
Country	US
Kind code	B2
Filing date	May 14, 2018
Priority date	May 29, 2017
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

The purpose of the invention is to form a flexible display device where the substrate is made of resin, wherein the TFT can be annealed in high temperature; consequently, a reliability of the TFT is improved. The concrete measure is as follows. A display device having a pixel electrode and a TFT including a semiconductor layer on a substrate comprising: a source region of the semiconductor layer connects with a source electrode, a drain region of the semiconductor layer connects with a drain electrode; the pixel electrode connects with the source electrode; the drain electrode connects with a video signal line; a distance between the drain electrode and the substrate is smaller than a distance between the semiconductor and the substrate, the semiconductor layer is formed between the pixel electrode and the substrate.

First claim

What is claimed is:

1. A display device having a pixel electrode and a TFT including a semiconductor layer on a substrate comprising:
a source region of the semiconductor layer connects with a source electrode, a drain region of the semiconductor layer connects with a drain electrode,
the pixel electrode connects with the source electrode, the drain electrode connects with a video signal line,
a distance between the drain electrode and the substrate is smaller than a distance between the semiconductor layer and the substrate,
the semiconductor layer is formed between the pixel electrode and the substrate,
wherein the drain electrode connects with the semiconductor layer via a first through hole,
the source electrode connects with the semiconductor layer via a second through hole,
the pixel electrode connects with the source electrode via a third through hole,
in the first through hole, a diameter nearer to the substrate is bigger than a diameter nearer to the semiconductor layer,
in the second through hole, a diameter nearer to the substrate is bigger than a diameter nearer to the semiconductor layer,
in the third through hole, a diameter nearer to the substrate is bigger than a diameter nearer to the pixel electrode.

2. The display device according to claim 1 ,
wherein the semiconductor layer is poly-Si, a gate electrode that constitutes the TFT works as a light shield layer for a channel of the TFT.

3. The display device according to claim 1 ,
wherein the semiconductor layer is oxide semiconductor, a gate electrode that constitutes the TFT works as a light shield layer for a channel of the TFT.

4. The display device according to claim 1 ,
wherein the semiconductor layer is oxide semiconductor, the TFT is a dual gate type TFT in that a gate electrode is formed at an upper side and at a lower side of the oxide semiconductor.

5. The display device according to claim 1 ,
wherein the substrate is made of polyimide.

6. The display device according to claim 1 ,
wherein the display device is a liquid crystal display device.

7. The display device according to claim 1 ,
wherein the display device is an organic EL display device.

8. A liquid crystal display device comprising: a first substrate having a pixel electrode and a TFT, and a liquid crystal sandwiched between the first substrate and a second substrate,
wherein an alignment film is formed on a surface that contacts the liquid crystal at each of the first substrate and the second substrate,
the alignment film is not formed in a through hole that connects the pixel electrode and the TFT,
wherein a source of a semiconductor layer connects with a source electrode, a drain of the semiconductor layer connects with a drain electrode, the pixel electrode connects with the source electrode, the drain electrode connects with a video signal line,
a distance between the drain electrode and the substrate is smaller than a distance between the semiconductor layer and the first substrate, and
wherein the drain electrode connects with the semiconductor layer via a first through hole,
the source electrode connects with the semiconductor layer via a second through hole,
the pixel electrode connects with the source electrode via a third through hole,
in the first through hole, a diameter nearer to the first substrate is bigger than a diameter nearer to the semiconductor layer,
in the second through hole, a diameter nearer to the first substrate is bigger than a diameter nearer to the semiconductor layer,
in the third through hole, a diameter nearer to the first substrate is bigger than a diameter nearer to the pixel electrode.

9. The display device according to claim 8 ,
wherein the TFT includes a semiconductor layer and a gate electrode,
the semiconductor layer is poly-Si, the gate electrode works as a light shield layer for a channel of the TFT.

10. The display device according to claim 8 ,
wherein the TFT includes a semiconductor layer and a gate electrode, the semiconductor layer is oxide semiconductor, the gate electrode works as a light shield layer for a channel of the TFT.

11. The display device according to claim 8 ,
wherein the first substrate is made of polyimide.

Assignees

• Japan Display Inc

Inventors

• Suzumura Isao
• Watakabe Hajime
• Hanada Akihiro
• Watanabe Hirokazu
• Yamaguchi Yohei
• Shiokawa Marina
• Kimura Ryotaro

Classifications

• G02F1/136286

  Wiring, e.g. gate line, drain line · CPC title

• G02F1/1368

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G02F1/136227

  Through-hole connection of the pixel electrode to the active element through an insulation layer · CPC title

• G02F1/136209

  Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element · CPC title

• G02F1/133305

  Flexible substrates, e.g. plastics, organic film · CPC title