Two circuit board touch-sensor device

• US 8,373,664 B2
• Filed: 12/18/2006
• Issued: 02/12/2013
• Est. Priority Date: 12/18/2006
• Status: Active Grant

• Current Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Original Assignee: Cypress Semiconductor Corporation (Infineon Technologies AG)
• Inventors: Wright, David G.
• Primary Examiner(s): Lao, Lun-Yi
• Assistant Examiner(s): Tryder, Gregory J
• Application Number:
  US11/642,025
• Publication Number:
  US 20080142352A1
• Time in Patent Office: 2,248 Days
• Field of Search: 345173-175, 178 1801- 1806, 178 1901- 1903, 439492-499, 439 67- 85
• US Class Current: 345/173
• CPC Class Codes: G06F 2203/04111 Cross over in capacitive digitiser, i.e. details of structures for connecting electrodes of the sensing pattern where the connections cross each other, e.g. bridge structures comprising an insulating layer, or vias through substrate
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• 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: H01H 2203/03 printed on casing
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

An apparatus and method for detecting a presence of a conductive object on a sensor array of a first circuit board using active electronic components of a second circuit board, which is coupled to the first circuit board. The apparatus may include a first circuit board, which includes a sensor array of sensor elements, and a second circuit board, coupled to the first circuit board, including sensing circuitry to measure capacitance on the sensor array of the first circuit board. The method may include measuring a capacitance on the sensor array using the active electronic components of the second circuit board, and processing the measured capacitance.

Claims

1. A method, comprising:

providing a first circuit board including a first capacitive sense array of sense elements and interconnecting sensor traces disposed on a first side of the first circuit board and a second capacitive sense array of sense elements and interconnecting sensor traces disposed on a second side of the first circuit board, wherein the first circuit board comprises no active electronic components to detect a presence of a conductive object on the capacitive sense array; and

detecting a presence of a conductive object on the first and second capacitive sense array of the first circuit board using active electronic components of a second circuit board coupled to the first circuit board, wherein the second circuit board is one-sided and comprises a set of conductive contacts on one side of the second circuit board, the set of conductive contacts to provide signals from the first capacitive sense array of sense elements and the second capacitive sense array of sense elements to the active electronic components, and wherein the first and second circuit boards are coupled with a pressure contact connector having conductive ink traces coupled to the first interconnecting sensor traces and to the set of conductive contacts, and wherein the second interconnecting sensor traces are coupled directly to the set of conductive contacts on the one-sided second circuit board.

2. The method of claim 1, wherein detecting the presence of the conductive object comprises:

measuring a capacitance on the first and second capacitive sense array using the active electronic components of the second circuit board; and

processing the measured capacitance.

3. The method of claim 1, wherein the first circuit board further comprises a keyboard matrix, and wherein the method further comprises detecting a button press on the keyboard matrix.

4. A method, comprising:

providing a first circuit board including a substrate with a first plurality of capacitive sense elements and interconnecting sensor traces disposed on a first side of the substrate and a second plurality of capacitive sense elements and interconnecting sensor traces disposed on a second side of the substrate, wherein the first circuit board comprises no active electronic components to detect a presence of a conductive object on the plurality of capacitive sense elements;

providing a second circuit board, wherein the second circuit board is one-sided and comprises a set of conductive contacts on one side of the second circuit board, the set of conductive contacts to provide signals from the first plurality of capacitive sense elements and interconnecting sensor traces and the second plurality of capacitive sense elements and interconnecting sensor traces to active electronic components to detect a presence of a conductive object on the first and second plurality of capacitive sense elements; and

coupling the first and second circuit boards with a pressure contact connector having conductive ink traces coupled to the first plurality of interconnecting sensor traces and to the set of conductive contacts, wherein the second plurality of interconnecting sensor traces are coupled directly to the set of conductive contacts on the one-sided second circuit board.

5. The method of claim 4, wherein providing the first circuit board comprises:

disposing a single sheet of polymer film as a substrate of the one or more substrates; and

printing conductive ink on the single sheet of polymer film to form the first and second plurality of capacitive sense elements and interconnecting sensor traces of the first circuit board.

6. The method of claim 5, wherein the single sheet of polymer film is Polyethylene Terephthalate (PET).

7. The method of claim 5, wherein the conductive ink comprises silver.

8. The method of claim 4, wherein the first circuit board and the second circuit board are disposed in different planes and partially overlap.

9. The method of claim 8, wherein the pressure contact connector is a compressive clamp.

10. The method of claim 8, wherein the pressure contact connector is a spring metal clip.

11. The method of claim 4, wherein coupling the first and second circuit board comprises:

providing a set of conductive contacts on one side of the first circuit board; and

disposing the set of conductive contacts on one side of the first circuit board and the set of conductive contacts on the second circuit board to be in contact with each other.

12. The method of claim 11, wherein disposing both sets of conductive contacts comprises:

disposing a compressive material on the first circuit board;

disposing a housing on the compressive material; and

making a compression contact with a fastener.

13. The method of claim 4, further comprising disposing row and column traces of a keyboard matrix on the one or more substrates of the first circuit board.

14. The method of claim 4, wherein coupling the first and second circuit boards comprises coupling the first and second circuit boards using anisotropic conductive adhesive.

15. The method of claim 4, wherein coupling the first and second circuit boards comprises coupling the first and second circuit boards using an elastomer and screw.

16. An apparatus, comprising:

a first circuit board including a first capacitive sense array of sense elements and a first plurality of interconnecting sensor traces disposed on a first side of the first circuit board and a second capacitive sense array and a second plurality of interconnecting sensor traces disposed on a second side of the first circuit board; and

a one-sided second circuit board coupled to the first circuit board, including a set of conductive contacts on one side of the second circuit board, the set of conductive contacts to provide signals from the first capacitive sense array of sense elements and interconnecting sensor traces and the second capacitive sense array of sense elements and interconnecting sensor traces to sensing circuitry to measure capacitance on the first and second capacitive sense array of the first circuit board, wherein the first and second circuit boards are coupled with a pressure contact connector having conductive ink traces coupled to the first plurality of interconnecting sensor traces and to the set of conductive contacts, and wherein the second plurality of interconnecting sensor traces are coupled directly to the set of conductive contacts on the one-sided second circuit board.

17. The apparatus of claim 16, wherein the first circuit board comprises polymer film.

18. The apparatus of claim 16, wherein the second circuit board comprises processing circuitry to process the measured capacitance.

19. The apparatus of claim 18, further comprising a processing device disposed on the second circuit board and coupled to the capacitive sense array of the first circuit board, wherein the processing device comprises the sensing circuitry and the processing circuitry.

20. The apparatus of claim 18, further comprising a third circuit board coupled to the second circuit board, wherein the third circuit board comprises a host processing device.

21. The apparatus of claim 16, further comprising a connector to couple the first circuit board and the second circuit board.

22. The apparatus of claim 21, wherein the connector comprises a fastener.

23. The apparatus of claim 21, wherein the connector comprises an anisotropic conductive adhesive.

24. The apparatus of claim 21, wherein the connector comprises a screw and an elastomer.

25. The apparatus of claim 16, wherein the first circuit board comprises a single sheet of polymer film as a substrate and conductive ink as a plurality of capacitive sense elements and interconnecting sensor traces of the capacitive sense array.

26. The apparatus of claim 16, wherein the first circuit board comprises:

a single sheet of polymer film as a substrate;

a first layer of conductive ink to form a first set of capacitive sense elements and interconnecting sensor traces of the capacitive sense array;

a second layer of conductive ink to form a second set of capacitive sense elements and interconnecting sensor traces of the capacitive sense array; and

an insulating ink disposed between the first and second layers of conductive ink.

27. The apparatus of claim 26, wherein the polymer film is Polyethylene Terephthalate (PET).

28. The apparatus of claim 27, wherein the conductive ink comprises silver.

29. The apparatus of claim 16, wherein the first circuit board comprises no active electronic components to measure capacitance on the plurality of capacitive sense elements, and wherein the second circuit board comprises active electronic components to measure capacitance on the plurality of capacitive sense elements.

30. An apparatus, comprising:

a first circuit board comprising a first plurality of capacitive sense elements and interconnecting sensor traces disposed on a first side of the first circuit board and a second plurality of capacitive sense elements and interconnecting sensor traces disposed on a second side of the first circuit board; and

means for detecting a presence of a conductive object on the plurality of capacitive sense elements of the first circuit board, wherein the means for detecting the presence of the conductive object is disposed on a one-sided second circuit board that is not the first circuit board and comprising a set of conductive contacts on one side of the second circuit board, the set of conductive contacts to provide signals from the first plurality of capacitive sense elements and interconnecting sensor traces and the second plurality of capacitive sense elements and interconnecting sensor traces to the means for detecting the presence, wherein the first circuit board is coupled to the second circuit board with a pressure contact connector having conductive ink traces coupled to the first plurality of interconnecting sensor traces and to the set of conductive contacts, and wherein the second plurality of interconnecting traces are coupled directly to the set of conductive contacts on the one-sided second circuit board.

31. The apparatus of claim 30, wherein the means for detecting the presence of the conductive object comprise:

means for measuring capacitance on the sense array of the first circuit board; and

means for processing the measured capacitance.

32. The apparatus of claim 30, further comprising means for connecting the first circuit board and the means for detecting.

33. A system, comprising:

a first capacitive sense array of capacitive sense elements and a first plurality of interconnecting sensor traces disposed on a first side of a first circuit board and a second capacitive sense array of capacitive sense elements and a second plurality of interconnecting sensor traces disposed on a second side of the first circuit board, wherein the first circuit board comprises no active electronic components to detect a presence of a conductive object on the capacitive sense array;

a keyboard matrix comprised of conductive traces disposed on the first circuit board; and

a second circuit board coupled to the first circuit board, wherein the second circuit board is one-sided and comprises a set of conductive contacts on one side of the second circuit board, the set of conductive contacts to provide signals from the first capacitive sense array of capacitive sense elements and interconnecting sensor traces and the second capacitive sense array of capacitive sense elements and interconnecting sensor traces to active electronic components to detect the presence of the conductive object on the capacitive sense array, wherein the first and second circuit boards are coupled with a pressure contact connector having conductive ink traces coupled to the first plurality of interconnecting sensor traces and to the set of conductive contacts, and wherein the second plurality of interconnecting sensor traces are coupled directly to the set of conductive contacts on the one-sided second circuit board.

34. The system of claim 33, wherein the active components comprise:

a first integrated circuit that is mounted to a substrate of the second circuit board; and

a second integrated circuit that is mounted to the substrate of the second circuit board, wherein the first integrated circuit is a touch-sensor pad controller, and wherein the second integrated circuit is a keyboard controller.

35. The system of claim 33, wherein the keyboard matrix of conductive traces is disposed on a third circuit board coupled to the second circuit board.

36. The system of claim 33, wherein the active electronics are configured to measure a capacitance on the first and second capacitive sense array of the second circuit board.

37. The system of claim 33, wherein the active electronics are configured to detect a button press on one of a plurality of keyboard keys of the keyboard matrix.