Two circuit board touch-sensor device

• US 20080142352A1
• Filed: 12/18/2006
• Published: 06/19/2008
• 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.
• Granted Patent: US 8,373,664 B2
• Time in Patent Office: Days
• US Class Current: 200/600
• 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 sensor array of sensor elements of a touchpad, wherein the first circuit board comprises no active electronic components to measure capacitance; and

detecting a presence of a conductive object on the touchpad of the first circuit board using active electronic components of a second circuit board coupled to the first circuit board.

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

measuring a capacitance on the sensor 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 a the keyboard matrix.

4. A method, comprising:

providing a first circuit board including one or more substrates with a plurality of capacitance sensor elements and interconnecting sensor traces, wherein the first circuit board comprises no active electronic components to measure capacitance;

providing a second circuit board, wherein the second circuit board comprises active electronic components to measure capacitance; and

coupling the first and second circuit boards.

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 plurality of capacitance sensor elements and interconnecting sensor traces of the first circuit board.

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

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

8. The method of claim 5, wherein printing conductive ink comprises:

printing a first set of capacitance sensor elements and interconnecting sensor traces on the single sheet of polymer film;

printing an insulating ink over the first set of capacitance sensor elements and interconnecting sensor traces; and

printing a second set of capacitance sensor elements and interconnecting sensor traces on the insulating ink.

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

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

providing a second set of conductive contacts on the second circuit board; and

disposing both sets of conductive contacts to be in contact with each other.

10. The method of claim 9, 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.

11. 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.

12. 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.

13. The method of claim 4, wherein coupling the first and second circuit boards comprises coupling the first and second circuit boards using a pressure contact connector.

14. 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. The apparatus of claim 14, wherein the first circuit board is polymer film.

15. An apparatus, comprising:

a first circuit board including a sensor array of sensor elements of a touchpad; 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.

17. The apparatus of claim 15, wherein the second circuit board comprises processing circuitry to process the capacitance measured capacitance.

18. The apparatus of claim 17, further comprising a processing device coupled to the sensor array, wherein the processing device comprises the sensing circuitry and the processing circuitry.

19. The apparatus of claim 17, further comprising a third circuit board coupled to the second circuit board, wherein the third circuit board comprises a host.

20. The apparatus of claim 15, wherein the sensor array comprises one or more substrates with a plurality of capacitance sensor elements and interconnecting sensor traces, wherein the first circuit board comprises no active electronic components to measure capacitance on the plurality of capacitance sensor elements, and wherein the second circuit board comprises active electronic components to measure capacitance on the plurality of capacitance sensor elements.

21. The apparatus of claim 20, 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 15, wherein the first circuit board comprises a single sheet of polymer film as a substrate and conductive ink as a plurality of capacitance sensor elements and interconnecting sensor traces of the sensor array.

26. The apparatus of claim 15, 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 capacitance sensor elements and interconnecting sensor traces of the sensor array;

a second layer of conductive ink to form a second set of capacitance sensor elements and interconnecting sensor traces of the sensor 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.

30. The apparatus of claim 22, wherein the means for detecting comprise:

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

means for processing the measured capacitance.

29. An apparatus, comprising:

a first circuit board comprising a plurality of capacitance sensor elements; and

means for detecting a presence of a conductive object on the plurality of capacitance sensor elements of the first circuit board, wherein the means for detecting the presence of the conductive object is disposed on a second circuit board that is not the first circuit board.

31. The apparatus of claim 29, further comprising means for connecting the first circuit board and the means for detecting.

32. The apparatus of claim 29, further comprising means for reducing a thickness of the first circuit board.

33. A system, comprising:

a sensor array of sensor elements disposed on a first circuit board, wherein the first circuit board comprises no active electronic components to detect the presence of a conductive object on the sensor array;

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

a second circuit board coupled to the first circuit board, wherein the second circuit comprises active electronic components to detect the presence of the conductive object on the sensor array.

34. 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.

35. The system of claim 33, wherein the active electronics are configured to measure a capacitance on the sensor array of the second circuit board.

36. 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.

37. 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 is a keyboard controller.