Touch pad with flexible substrate

• US 7,439,962 B2
• Filed: 06/01/2005
• Issued: 10/21/2008
• Est. Priority Date: 06/01/2005
• Status: Active Grant

• Current Assignee: Synaptics Incorporated
• Original Assignee: Synaptics Incorporated
• Inventors: Day, Shawn P., Reynolds, Joseph Kurth
• Primary Examiner(s): Shankar; Vijay
• Application Number:
  US11/143,275
• Publication Number:
  US 20060274055A1
• Time in Patent Office: 1,238 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 touch sensor device, the touch sensor device comprising:

a flexible circuit substrate, the flexible circuit substrate comprising a relatively high-temperature-resistant flexible substrate, the flexible circuit substrate including a first plurality of pads;

a touch sensor controller, the touch sensor controller affixed to the flexible circuit substrate with a thermal bond and coupled to the first plurality of pads through a plurality of conductive traces; and

a sensor component, the sensor component comprising a relatively low-temperature-resistant flexible sensor substrate, the sensor component including a second plurality of pads formed on the relatively low-temperature-resistant flexible sensor substrate, the relatively low-temperature-resistant flexible sensor substrate including a plurality of sensing elements configured to detect a change in capacitance when an object is proximate to the sensing elements to facilitate detection of the object by the touch sensor controller, the plurality of sensing elements coupled to the touch sensor controller though the first plurality of pads and the second plurality of pads.

2. The touch sensor device of claim 1 wherein the relatively high-temperature-resistant flexible substrate comprises thermoset material and wherein the relatively low-temperature-resistant flexible sensor substrate comprises thermoplastic material.

3. The touch sensor device of claim 1 wherein the flexible circuit substrate comprises a plurality of landing pads, and wherein the touch sensor controller is affixed to the plurality of landing pads with the thermal bond.

4. The touch sensor device of claim 3 wherein the thermal bond comprises solder.

5. The touch sensor device of claim 1 wherein the flexible circuit substrate includes a tail portion, the tail portion comprising a relatively narrow portion of the flexible circuit substrate and having an end region, the end region including a plurality of electrodes for connecting to an electronic system.

6. The touch sensor device of claim 5 wherein the flexible circuit substrate includes stiffener affixed to the tail portion.

7. The touch sensor device of claim 1 wherein the relatively low-temperature-resistant flexible sensor substrate further includes a conductive shield portion, the conductive shield portion configured to shield at least a portion of the conductors on the flexible circuit substrate.

8. The touch sensor device of claim 1 wherein the sensor component further includes a second plurality of sensing elements configured to detect a change in capacitance when the object is proximate to the second plurality of sensing elements to facilitate detection of the object by the touch sensor controller, and wherein the first plurality of sensing elements and the second plurality of sensing elements are configured to determine position of the object in at least two dimensions.

9. The touch sensor device of claim 8 wherein the plurality of sensing elements is configured to determine position in a first direction and wherein the second plurality of sensing elements is configured to determine position in a second direction, and wherein the first direction and the second direction comprise different directions.

10. The touch sensor device of claim 8 wherein the plurality of sensing elements is affixed on a first side of relatively low-temperature-resistant flexible sensor substrate and wherein the second plurality of sensing elements is affixed on a second side of the relatively low-temperature-resistant flexible sensor substrate.

11. The touch sensor device of claim 8 wherein the second plurality of sensing elements is affixed on a second relatively low-temperature-resistant flexible sensor substrate.

12. The touch sensor device of claim 8 further comprising a conductive shield configured to electrically shield a portion of the touch sensor device.

13. The touch sensor device of claim 1 wherein the flexible circuit substrate includes a third plurality of pads and wherein the sensor component further comprises a second relatively low-temperature-resistant flexible sensor substrate, the second relatively low-temperature-resistant flexible sensor substrate including a fourth plurality of pads, the second relatively low-temperature-resistant flexible sensor substrate including a second plurality of sensing elements configured to detect a change in capacitance when an object is proximate to the sensing elements to facilitate detection of the object by the touch sensor controller, the second plurality of sensing elements coupled to the touch sensor controller though the third plurality of pads and the fourth plurality of pads.

14. The touch sensor device of claim 1 wherein the flexible circuit substrate includes a third plurality of pads and wherein the relatively low-temperature-resistant flexible sensor substrate further includes a fourth plurality of pads and a second plurality of sensing elements formed opposite the first plurality of sensing elements, wherein the second plurality of sensing elements is configured to detect a change in capacitance when the object is proximate to the second plurality of sensing elements to facilitate detection of the object by the touch sensor controller.

15. The touch sensor device of claim 1 wherein the flexible circuit substrate is bent to conform to a space.

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

a flexible circuit substrate, the flexible circuit substrate comprising a relatively high-temperature-resistant flexible substrate, 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 relatively low-temperature-resistant flexible substrate, 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.

17. The touch sensor device of claim 16 wherein the relatively high-temperature-resistant flexible substrate comprises thermoset material.

18. The touch sensor device of claim 16 wherein the relatively low-temperature-resistant flexible substrate comprises thermoplastic material.

19. The touch sensor device of claim 16 wherein the flexible circuit substrate comprises landing pads for the touch sensor controller, and wherein the touch sensor controller is affixed to the landing pads on the flexible circuit substrate with a thermal bond.

20. The touch sensor device of claim 16 wherein the flexible circuit substrate includes a tail portion, the tail portion including a plurality of electrodes for connecting to an electronic system.

21. The touch sensor device of claim 16 wherein the touch sensor device comprises a capacitive touch sensor device.

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

a flexible circuit substrate, the flexible circuit substrate including a first plurality of pads, wherein the flexible circuit substrate comprises a relatively high-temperature-resistant flexible substrate that is dimensionally stable up to a first relatively high temperature;

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

a sensor component, wherein the flexible sensor substrate comprises a relatively low-temperature-resistant flexible substrate that is dimensionally stable up to a second relatively low temperature, the sensor component including at least one sensing element disposed on a flexible sensor substrate for detecting an object proximate to the sensing element, the sensor component including a second plurality of pads, the at least one sensing element coupled to the touch sensor controller through the first plurality of pads and the second plurality of pads.

23. The touch sensor device of claim 22 wherein the relatively high-temperature-resistant flexible substrate comprises thermoset material.

24. The touch sensor device of claim 22 wherein the relatively low-temperature-resistant flexible substrate comprises thermoplastic material.

25. The touch sensor device of claim 22 wherein the flexible circuit substrate has a minimum conductor pitch less than a minimum conductor pitch of the sensor component.

26. The touch sensor device of claim 22 wherein the flexible circuit substrate comprises a plurality of landing pads for the touch sensor controller, and a plurality of conductive traces for electrically coupling the touch sensor controller to the first plurality of pads.

27. The touch sensor device of claim 22 wherein the touch sensor controller is affixed to the flexible circuit substrate with a thermal bond.

28. The touch sensor device of claim 27 wherein the thermal bond comprises one of a solder bond, ultrasonic weld bond, heat-activated adhesive bond, and a thermal compression bond.

29. The touch sensor device of claim 22 wherein the flexible circuit substrate further comprises a tail portion, the tail portion including a plurality of electrodes for connecting to an electronic system.

30. The touch sensor device of claim 22 further comprising a conductive shield configured to electrically shield a portion of the touch sensor device.

31. The touch sensor device of claim 30 wherein the conductive shield portion is affixed to the sensor component, and wherein conductive shield portion shields the conductors on the flexible circuit substrate.

32. The touch sensor device of claim 30 wherein the conductive shield portion is affixed to the flexible circuit substrate, and wherein conductive shield portion shields the at least one sensing element.

33. The touch sensor device of claim 22 wherein the touch sensor device comprises a capacitive touch sensor device.

34. The touch sensor device of claim 22 wherein the flexible sensor substrate comprises a transparent substrate.