Column spacer design for a display incorporating a third metal layer

• US 9,395,583 B2
• Filed: 09/06/2012
• Issued: 07/19/2016
• Est. Priority Date: 06/06/2012
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Apple Inc.
• Inventors: Kim, Kyung-Wook, Chang, Shih Chang, Chen, Cheng, Park, Young-Bae, Zhong, John Z.
• Primary Examiner(s): DUDEK, JAMES A
• Application Number:
  US13/605,918
• Publication Number:
  US 20130329150A1
• Time in Patent Office: 1,412 Days
• Field of Search: 349/156
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/13396 Spacers having different sizes
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• 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 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/13439 characterised by their electrical, optical, physical properties; materials therefor; method of making
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/12 electrode
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

A display that contains a column spacer arrangement which takes advantage of a protrusion on a TFT substrate is provided. One set of column spacers is disposed on top of the protrusion, while a second set of column spacers of substantially the same height as the first set of column spacers are disposed throughout the display. In this way, the display is adequately protected against deformation from external forces while at the same maintaining enough room to allow for a liquid crystal to spread out during the manufacturing process.

Claims

1. A display pixel stackup, comprising:

a top cover;

a transistor substrate;

a plurality of common electrodes disposed on the transistor substrate;

a metal layer in contact with a first common electrode of the plurality of common electrodes, wherein the metal layer forms a protrusion on the transistor substrate;

a fluid layer disposed between the top cover and the transistor substrate; and

a plurality of column spacers, wherein a first column spacer of the plurality of column spacers is configured to contact the protrusion on the transistor substrate and directly touches the metal layer,

wherein the plurality of common electrodes correspond to one or more pixel electrodes for generating an electric field across at least one pixel of the display pixel stackup.

2. The display pixel stackup of claim 1, wherein the transistor substrate is a TFT substrate, and the protrusion of the transistor substrate is created above a pixel TFT of the TFT substrate.

3. The display pixel stackup of claim 1, wherein the first column spacer is disposed on top of a pixel TFT.

4. The display pixel stackup of claim 1, wherein the metal layer forms an electrical connection between at least two of the plurality of common electrodes.

5. The display pixel stackup of claim 1, wherein the plurality of common electrodes are disposed on the transistor substrate in a common on top arrangement.

6. The display pixel stackup of claim 1, wherein the plurality of common electrodes are disposed on the transistor substrate in a common on bottom arrangement.

7. The display pixel stackup of claim 1, wherein the first column spacer directly touches the first common electrode.

8. The display pixel stackup of claim 1, wherein the first column spacer directly touches a dielectric material disposed on top of the metal layer.

9. A method of arranging a plurality of column spacers on a display pixel stackup, the method comprising:

disposing a plurality of common electrodes on a transistor substrate of the display pixel stackup;

disposing a metal layer in contact with at least one of the plurality of common electrodes, wherein the metal layer forms a protrusion on the transistor substrate; and

disposing a first column spacer of the plurality of column spacers such that the first column spacer is configured to contact the protrusion on the transistor substrate and directly touches the metal layer,

wherein the plurality of common electrodes correspond to one or more pixel electrodes for generating an electric field across at least one pixel of the display pixel stackup.

10. The method of claim 9, wherein the transistor substrate is a TFT substrate, and the protrusion on the TFT substrate is disposed above a pixel TFT on the TFT substrate.

11. The method of claim 9, wherein the protrusion on the transistor substrate is created above a planarized portion of the transistor substrate.

12. The method of claim 9, wherein the metal layer forms an electrical connection between at least two of the plurality of common electrodes.

13. The method of claim 9, wherein the plurality of common electrodes are disposed on the transistor substrate in a common on top arrangement.

14. The method of claim 9, wherein the plurality of common electrodes are disposed on the transistor substrate in a common on bottom arrangement.

15. The method of claim 9, wherein the first column spacer is disposed above the protrusion of the transistor substrate such that the first column spacer directly touches a top edge of the protrusion on the transistor substrate.

16. The method of claim 9, wherein the first column spacer directly touches the first common electrode.

17. The method of claim 9, wherein the first column spacer directly touches a dielectric material disposed on top of the metal layer.