Touch pad with flexible substrate

• US 8,330,742 B2
• Filed: 11/29/2011
• Issued: 12/11/2012
• 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:
  US13/306,551
• Publication Number:
  US 20120068968A1
• Time in Patent Office: 378 Days
• Field of Search: 345173-179, 178 1801- 1807, 178 1901- 1906, 178 2001- 2004
• US Class Current: 345/174
• 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 touch sensor device, comprising:

a flexible circuit substrate dimensionally stable up to a first temperature, wherein the first temperature allows thermal bonding to the flexible circuit substrate without significant thermally induced degradation;

a first at least one conductive pad disposed on the flexible circuit substrate;

a sensor substrate that is dimensionally stable up to a second temperature that is lower than the first temperature but is not dimensionally stable at the first temperature;

at least one conductive sensing element disposed on the sensor substrate; and

a second at least one conductive pad disposed on the sensor substrate, wherein the second at least one conductive pad is coupled to the first at least one conductive pad, and wherein the second at least one conductive pad is coupled to the at least one conductive sensing element.

2. The touch sensor device of claim 1, further comprising a touch sensor controller.

3. The touch sensor device of claim 2, wherein the first temperature is high enough to thermally bond the touch sensor controller to the flexible circuit substrate without degradation to the flexible circuit substrate.

4. The touch sensor device of claim 2, further comprising a second at least one conductive sensing element disposed on the sensor substrate and wherein the touch sensor controller is configured to select one of said at least one conductive sensing element and the second at least one conductive sensing element.

5. The touch sensor device of claim 1, wherein the touch sensor device is a capacitive sensor device.

6. The touch sensor device of claim 1, wherein the second temperature is substantially lower than the first temperature.

7. The touch sensor device of claim 1, wherein the sensor substrate is flexible.

8. The touch sensor device of claim 1, wherein the sensor substrate is transparent.

9. A touch screen device, comprising:

a flexible circuit substrate dimensionally stable up to a first temperature, wherein the first temperature allows thermal bonding to the flexible circuit substrate without significant thermally induced degradation;

a first at least one conductive pad disposed on the flexible circuit substrate;

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

at least one conductive sensing element disposed on the sensor substrate, wherein the at least one conductive sensing element is substantially transparent; and

a second at least one conductive pad disposed on the sensor substrate, wherein the second at least one conductive pad is coupled to the first at least one conductive pad, and wherein the second at least one conductive pad is coupled to the at least one conductive sensing element.

10. The touch screen device of claim 9, further comprising a touch screen controller.

11. The touch screen device of claim 10, wherein the first temperature is high enough to thermally bond the touch screen controller to the flexible circuit substrate without degradation to the flexible circuit substrate.

12. The touch screen device of claim 10, further comprising a second at least one conductive sensing element disposed on the sensor substrate and wherein the touch screen controller is configured to select one of said at least one conductive sensing element and the second at least one conductive sensing element.

13. The touch screen device of claim 9, wherein the touch screen device includes a capacitive sensor device.

14. The touch screen device of claim 9, wherein the second temperature is substantially lower than the first temperature.

15. The touch screen device of claim 9, wherein the sensor substrate is flexible.

16. A method of providing a touch sensor device, comprising:

providing a flexible circuit substrate that is dimensionally stable up to a first temperate that allows thermal bonding to the flexible circuit substrate without significant thermally induced degradation to the flexible circuit substrate, wherein a first plurality of conductive pads are disposed on the flexible circuit substrate; and

providing a sensor substrate that is dimensionally stable up to a second temperature that is lower than the first temperature but is not dimensionally stable at the first temperature, wherein a plurality of conductive sensing elements are disposed on the sensor substrate, wherein a second plurality of conductive pads are disposed on the sensor substrate, and wherein the second plurality of conductive pads couple the first plurality of conductive pads with the plurality of conductive sensing elements.

17. The method of claim 16, further comprising thermally bonding a touch sensor device controller to the flexible circuit substrate.

18. The method of claim 16 wherein the first temperature is high enough such that the step of thermally bonding the touch sensor device controller to the flexible circuit substrate is performed without degradation to the flexible circuit substrate.

19. The method of claim 16, wherein the second temperature is substantially lower than the first temperature.

20. The method of claim 16, wherein the sensor substrate is flexible.