Touch panel

• US 8,730,186 B2
• Filed: 05/27/2010
• Issued: 05/20/2014
• Est. Priority Date: 05/28/2009
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Tamura, Hikaru, Kozuma, Munehiro
• Primary Examiner(s): Shalwala, Bipin
• Assistant Examiner(s): Karki, Paras D
• Application Number:
  US12/788,893
• Publication Number:
  US 20100300862A1
• Time in Patent Office: 1,454 Days
• Field of Search: 345173-178, 178 18- 2004
• US Class Current: 345/173
• 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
• CPC Class Codes: G06F 3/0447 Position sensing using the local deformation of sensor cells
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 17/975 using a capacitive movable element
• CPC Class Codes: H03K 2217/96015 Constructional details for touch switches for capacitive touch switches see H03K2217/9607
• CPC Class Codes: H03K 2217/96046 Key-pad combined with display, back-lit
• CPC Class Codes: H03K 2217/9653 with illumination

Abstract

A touch sensor (touch panel) which can be formed over the same substrate as a display portion is provided. Alternatively, a touch sensor (touch panel) which does not cause degradation in the quality of an image displayed on a display portion is provided. The touch panel includes a light-emitting element and a microstructure in which a pair of electrodes facing each other is isolated with an insulating material. As the insulating material, an elastic material or a material having a hole is used so that a filler layer formed using the insulating material can be deformed when a movable portion operates. It is preferable to use a material which is softened or hardened by certain treatment (e.g., heat treatment or chemical treatment) after formation.

Claims

1. A touch panel comprising:

a microstructure over a first substrate, the microstructure comprising a lower electrode, an upper electrode over the lower electrode and a filler layer between the lower electrode and the upper electrode;

a thin film transistor over the first substrate, the thin film transistor comprising a gate electrode and a semiconductor layer;

a conductive layer over the first substrate, the conductive layer being in contact with the semiconductor layer;

an insulating layer over the thin film transistor;

a light-emitting element over the first substrate, the light-emitting element comprising a first electrode electrically connected to the conductive layer and over the insulating layer, a light-emitting layer over the first electrode and a second electrode over the light-emitting layer;

a partition wall for covering an end portion of the first electrode and the microstructure, the partition wall having an opening overlapping with the filler layer; and

a spacer over the upper electrode, the spacer overlapping with the filler layer,

wherein the spacer is provided so as to fill the opening in the partition wall,

wherein the microstructure does not overlap with the light-emitting layer,

wherein the first electrode of the light-emitting element and the upper electrode of the microstructure are spaced from each other,

wherein the lower electrode is formed using the same material as the gate electrode, and

wherein the upper electrode is formed using the same material as the first electrode.

2. The touch panel according to claim 1, further comprising a second substrate over the first substrate with the microstructure, the thin film transistor, the conductive layer, the light-emitting element and the spacer between the first substrate and the second substrate,

wherein the microstructure is configured to sense a pressure on the second substrate by movement of the upper electrode in a direction to the lower electrode.

3. The touch panel according to claim 1, wherein the filler layer is formed using a porous insulating material which can be reversibly deformed by a pressure.

4. The touch panel according to claim 3, wherein the porous insulating material is a block copolymer.

5. The touch panel according to claim 3, wherein porosity of the filler layer is higher than or equal to 20% and lower than or equal to 80%.

6. The touch panel according to claim 1, wherein the filler layer is formed using an elastic insulating material which can be reversibly deformed by a pressure.

7. The touch panel according to claim 6, wherein the elastic insulating material is one of an elastomer and a thermoplastic elastomer.

8. The touch panel according to claim 1,

wherein the spacer is formed using a material which is harder than a material of the partition wall, and

wherein the partition wall is formed using a material which is harder than the material of the filler layer.

9. The touch panel according to claim 1,

wherein the spacer is formed using a material having higher elastic modulus than the material of the partition wall, and

wherein the partition wall is formed using a material having higher elastic modulus than the material of the filler layer.

10. The touch panel according to claim 1, wherein the thin film transistor is a bottom-gate transistor.

11. The touch panel according to claim 1, wherein the semiconductor layer comprises an oxide semiconductor.

12. The touch panel according to claim 11, wherein the oxide semiconductor comprises In, Ga, Zn and O.

13. A touch panel comprising:

a microstructure over a first substrate, the microstructure comprising a lower electrode, an upper electrode over the lower electrode and a filler layer between the lower electrode and the upper electrode;

a thin film transistor over the first substrate, the thin film transistor comprising a gate electrode and a semiconductor layer;

a conductive layer over the first substrate, the conductive layer being in contact with the semiconductor layer;

an insulating layer over the thin film transistor;

a light-emitting element over the first substrate, the light-emitting element comprising a first electrode electrically connected to the conductive layer and over the insulating layer, a light-emitting layer over the first electrode and a second electrode over the light-emitting layer;

a partition wall for covering an end portion of the first electrode and the microstructure, the partition wall having an opening overlapping with the filler layer; and

a spacer over the upper electrode, the spacer overlapping with the filler layer,

wherein the spacer is provided so as to fill the opening in the partition wall,

wherein the microstructure does not overlap with the light-emitting layer,

wherein the first electrode of the light-emitting element and the upper electrode of the microstructure are spaced from each other,

wherein the lower electrode is formed using the same material as the conductive layer, and

wherein the upper electrode is formed using the same material as the first electrode.

14. The touch panel according to claim 13, further comprising a second substrate over the first substrate with the microstructure, the thin film transistor, the conductive layer, the light-emitting element and the spacer between the first substrate and the second substrate,

wherein the microstructure is configured to sense a pressure on the second substrate by movement of the upper electrode in a direction to the lower electrode.

15. The touch panel according to claim 13, wherein the filler layer is formed using a porous insulating material which can be reversibly deformed by a pressure.

16. The touch panel according to claim 15, wherein the porous insulating material is a block copolymer.

17. The touch panel according to claim 15, wherein porosity of the filler layer is higher than or equal to 20% and lower than or equal to 80%.

18. The touch panel according to claim 13, wherein the filler layer is formed using an elastic insulating material which can be reversibly deformed by a pressure.

19. The touch panel according to claim 18, wherein the elastic insulating material is one of an elastomer and a thermoplastic elastomer.

20. The touch panel according to claim 13,

wherein the spacer is formed using a material which is harder than a material of the partition wall, and

wherein the partition wall is formed using a material which is harder than the material of the filler layer.

21. The touch panel according to claim 13,

wherein the spacer is formed using a material having higher elastic modulus than the material of the partition wall, and

wherein the partition wall is formed using a material having higher elastic modulus than the material of the filler layer.

22. The touch panel according to claim 13, wherein the thin film transistor is a bottom-gate transistor.

23. The touch panel according to claim 13, wherein the semiconductor layer comprises an oxide semiconductor.

24. The touch panel according to claim 23, wherein the oxide semiconductor comprises In, Ga, Zn and O.

25. A method for manufacturing a touch panel, the method comprising the steps of:

forming a gate electrode over a substrate;

forming an insulating film over the gate electrode;

forming a semiconductor layer over the insulating film;

forming a first conductive layer and a lower electrode over the insulating film, wherein a part of the first conductive layer overlaps the semiconductor layer;

forming an insulating layer over the first conductive layer and the lower electrode;

forming an hole in the insulating layer, wherein the hole overlaps the lower electrode;

forming a filler layer in the hole;

forming a first electrode and an upper electrode spaced from each other, wherein the first electrode is electrically connected to the semiconductor layer and a part of the upper electrode overlaps the filler layer;

forming a partition wall for covering an end portion of the first electrode and the upper electrode over the insulating layer;

forming an opening in the partition wall, the opening overlapping with the filler layer;

forming a spacer so as to fill the opening, wherein the spacer overlaps the filler layer;

forming a light-emitting layer over the first electrode; and

forming a second electrode over the light-emitting layer,

wherein the lower electrode, the filler layer, the upper electrode and the spacer do not overlap with the light-emitting layer.