Touch pad with flexible substrate

• US 8,085,250 B2
• Filed: 09/12/2008
• Issued: 12/27/2011
• Est. Priority Date: 06/01/2005
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Reynolds, Joseph Kurth, Day, Shawn P.
• Primary Examiner(s): Shankar, Vijay
• Application Number:
  US12/209,762
• Publication Number:
  US 20090002339A1
• Time in Patent Office: 1,201 Days
• Field of Search: 345173-179, 178 1801- 1807, 178 1901- 1906
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04102 Flexible digitiser, i.e. constructional details for allowing the whole digitising part of a device to be flexed or rolled like a sheet of paper
• CPC Class Codes: G06F 2203/04107 Shielding in digitiser, i.e. guard or shielding arrangements, mostly for capacitive touchscreens, e.g. driven shields, driven grounds
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04164 Connections between sensors and controllers, e.g. routing lines between electrodes and connection pads
• CPC Class Codes: G06F 3/044 by capacitive means
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• 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: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/960765 Details of shielding arrangements
• CPC Class Codes: H05K 1/0201 Thermal arrangements, e.g. for cooling, heating or preventing overheating
• CPC Class Codes: H05K 1/0218 by printed shielding conductors, ground planes or power plane H05K1/0236 takes precedence
• CPC Class Codes: H05K 1/0274 Optical details, e.g. printed circuits comprising integral optical means H05K1/0269 takes precedence; coupling light guides with opto-electronic components G02B6/42
• CPC Class Codes: H05K 1/144 Stacked arrangements of planar printed circuit boards
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: H05K 2201/041 Stacked PCBs, i.e. having neither an empty space nor mounted components in between
• CPC Class Codes: H05K 2201/10128 Display
• CPC Class Codes: H05K 2201/10151 Sensor

Abstract

A touch sensor device is provided that uses a flexible circuit substrate to provide an improved input device. Specifically, the present invention uses a touch sensor controller affixed to the flexible circuit substrate, which is coupled to a sensor component to provide a flexible, reliable and cost effective touch sensor suitable for a wide variety of applications. In one embodiment the touch sensor uses a flexible circuit substrate that provides relatively high temperature resistance. This allows the touch sensor controller to be affixed using reliable techniques, such as various types of soldering. The sensor component can comprise a relatively low-temperature-resistant substrate that can provide a cost effective solution. Taken together, this embodiment of the touch sensor provides reliability and flexibility at relatively low cost.

Claims

1. A method of providing a capacitive touch sensor device comprising:

providing a flexible circuit substrate, the flexible circuit substrate dimensionally stable up to a first temperature, wherein said first temperature is relatively high;

disposing a first plurality of conductive pads on the flexible circuit substrate;

providing a flexible sensor substrate, the flexible circuit substrate dimensionally stable only up to a second temperature, wherein the second temperature is relatively low, and wherein the flexible sensor substrate is substantially transparent;

disposing a plurality of conductive sensing elements on the flexible sensor substrate, wherein the plurality of conductive sensing elements is substantially transparent;

disposing a second plurality of conductive pads on the flexible sensor substrate, the second plurality of conductive pads ohmically coupled to the plurality of conductive sensing elements;

electrically coupling the plurality of conductive sensing elements with the first plurality of conductive pads through the second plurality of conductive pads.

2. A touch screen device comprising:

a flexible circuit substrate, the flexible circuit substrate dimensionally stable up to a first temperature, the flexible circuit substrate including a first plurality of pads;

a sensor component, the sensor component comprising;

a flexible sensor substrate that is dimensionally stable up to, but not above, a second temperature substantially lower than the first temperature, wherein the flexible sensor substrate is substantially transparent,

a plurality of conductive sensing elements for detecting an object proximate to the plurality of conductive sensing elements, wherein the plurality of conductive sensing elements is substantially transparent, and

a second plurality of pads ohmically coupled to the plurality of conductive sensing elements, wherein the plurality of conductive sensing elements is electrically coupled to the first plurality of pads through the second plurality of pads; and

a display coupled with the sensor component.

3. The device of claim 2, wherein the plurality of conductive sensing elements is arranged in a first direction, and wherein the sensor component further comprises:

a second sensor substrate overlapped with the flexible sensor substrate, wherein the second sensor substrate is substantially transparent, and

a second plurality of conductive sensing elements disposed on the second sensor substrate, wherein the second plurality of conductive sensing elements is substantially transparent, and wherein the second plurality of conductive sensing elements is arranged in a second direction substantially orthogonal to the first direction.

4. The device of claim 2 wherein the flexible sensor substrate comprises a first surface and a second surface opposite the first surface, wherein the plurality of conductive sensing elements is disposed on the flexible sensor substrate by being disposed on the first surface, and wherein the plurality of conductive sensing elements is arranged in a first direction, the device further comprising:

a second plurality of conductive sensing elements disposed on the second surface, wherein the second plurality of conductive sensing elements is arranged in a second direction substantially orthogonal to the first direction.

5. The device of claim 2 wherein the plurality of conductive sensing elements is arranged in a first direction, the device further comprising:

a second plurality of conductive sensing elements, the second plurality of conductive sensing elements arranged in a second direction substantially orthogonal to the first direction, wherein the second plurality of conductive sensing elements is substantially transparent, and wherein the plurality of conductive sensing elements and the second plurality of conductive sensing elements are both on a first side of the flexible sensor substrate; and

an insulative material separating the plurality of conductive sensing elements and the second plurality of conductive sensing elements, wherein the insulative material is substantially transparent.

6. The device of claim 2, further comprising:

a conductive shield configured to shield the plurality of conductive sensing elements, wherein the shield is substantially transparent.

7. A touch sensor device, the touch sensor device comprising:

a flexible circuit substrate, the flexible circuit substrate dimensionally stable up to a first relatively high temperature, the flexible circuit substrate including a first plurality of pads;

a touch sensor controller affixed to the flexible circuit substrate; and

a sensor component, the sensor component comprising a substantially transparent flexible substrate that is dimensionally stable up to a second relatively low temperature, the sensor component including at least one sensing element for detecting an object proximate to the sensor component, the sensor component including a second plurality of pads, the at least one sensing element electrically coupled to the flexible circuit substrate through the first plurality of pads and the second plurality of pads.

8. The device of claim 7, wherein the at least one sensing element is configured to detect a position of the object in at least two dimensions, the at least one sensing element comprising:

a first plurality of sensing elements arranged in a first direction; and

a second plurality of sensing elements arranged in a second direction substantially orthogonal to the first direction.

9. The device of claim 7, wherein the sensor component further comprises a feature for lamination.

10. A capacitive touch sensor device comprising:

a flexible circuit substrate, the flexible circuit substrate dimensionally stable up to a first temperature, wherein said first temperature is relatively high;

a first plurality of conductive pads disposed on the flexible circuit substrate;

a flexible sensor substrate, the flexible sensor substrate dimensionally stable up to, but not past, a second temperature, wherein the second temperature is relatively low;

a first plurality of conductive sensing elements disposed on the flexible sensor substrate and

a second plurality of conductive pads disposed on the flexible sensor substrate and ohmically coupled to the first plurality of conductive sensing elements, wherein each of the first plurality of conductive sensing elements is electrically coupled to at least one of the first plurality of conductive pads through the second plurality of conductive pads.

11. The device of claim 10, further comprising:

a light-emitting component coupled to the flexible circuit substrate.

12. The device of claim 10, wherein the first plurality of conductive sensing elements is configured for resistive sensing.

13. The device of claim 10, wherein at least one of the flexible circuit substrate and the flexible sensor substrate has a bent shape.

14. The device of claim 10, wherein all conductive sensing elements in the capacitive touch sensor device, including all conductive sensing elements of the first plurality of conductive sensing elements, are aligned along a first direction, and wherein the first plurality of conductive sensing elements overlaps more than half of the flexible sensor substrate.

15. The device of claim 10, wherein at least two of the first plurality of conductive sensing elements are substantially rectangular.

16. The device of claim 10, wherein the first plurality of conductive sensing elements is arranged in a first direction, the device further comprising:

a second plurality of conductive sensing elements, the second plurality of conductive sensing elements arranged in a second direction different from the first direction.

17. The device of claim 16, wherein sensing elements of the first plurality of conductive sensing elements have diamond-shaped portions, and wherein sensing elements of the second plurality of conductive sensing elements have diamond-shaped portions non-overlapped with the diamond-shaped portions of the first plurality of conductive sensing elements.

18. The device of claim 16, further comprising:

a second sensor substrate overlapped with the flexible sensor substrate, wherein the second plurality of conductive sensing elements is disposed on the second sensor substrate.

19. The device of claim 16, wherein the flexible sensor substrate comprises a first surface and a second surface opposite the first surface, wherein the first plurality of conductive sensing elements is disposed on the flexible sensor substrate by being disposed on the first surface, and wherein the second plurality of conductive sensing elements is disposed on the second surface.

20. The device of claim 16, wherein the second plurality of conductive sensing elements is disposed on a same side of the flexible sensor substrate as the first plurality of conductive sensing elements, the device further comprising:

an insulative material separating the first plurality of conductive sensing elements and the second plurality of conductive sensing elements.

21. The device of claim 10, further comprising:

a conductive shield configured to shield the first plurality of conductive sensing elements.

22. The device of claim 21, further comprising:

a shield substrate, wherein the conductive shield is disposed on the shield substrate.

23. The device of claim 10, wherein the flexible circuit substrate includes at least two portions separated by a slit.

24. The device of claim 10, wherein the first plurality of conductive pads and the second plurality of conductive pads are ohmically connected through at least one of an anisotropic conductive film and a conductive adhesive.

25. The device of claim 10, wherein the flexible circuit substrate and the flexible sensor substrate differ in thickness.