Touch pad with flexible substrate

• US 10,254,860 B2
• Filed: 05/31/2018
• Issued: 04/09/2019
• 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): Polo, Gustavo
• Application Number:
  US15/994,696
• Publication Number:
  US 20180284913A1
• Time in Patent Office: 313 Days
• Field of Search: None
• 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 screen device comprising:

a flexible circuit substrate that is dimensionally stable up to a first temperature, wherein the flexible circuit substrate comprises at least one selected from a group consisting of a condensate film, a thermoset material, polyimide, epoxy resin, and a liquid crystal polymer film;

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

a touch controller affixed to the flexible circuit substrate and coupled to the first plurality of conductive pads via a first plurality of conductors;

a sensor component comprising;

a first flexible sensor substrate that is dimensionally stable up to a second temperature that is lower than the first temperature, wherein the first flexible sensor substrate is not dimensionally stable at the first temperature, and wherein the first flexible sensor substrate comprises at least one selected from a group consisting of a thermoplastic material, vinyl, polyethylene terephthalate (PET), polystyrene (PS), polyvinylchloride (PVC), and polycarbonate;

a second plurality of conductive pads disposed on the first flexible sensor substrate, wherein at least one of the first plurality of conductive pads is coupled to at least one of the second plurality of conductive pads;

a first plurality of capacitive sensing elements disposed on the first flexible sensor substrate and coupled to the second plurality of conductive pads via a second plurality of conductors; and

a display coupled with the sensor component.

2. The touch screen device of claim 1, wherein the first flexible sensor substrate is transparent.

3. The touch screen device of claim 1, wherein the first temperature is high enough to thermally bond the touch controller to the flexible circuit substrate without degradation to the flexible circuit substrate.

4. The touch screen device of claim 1, wherein the sensor component further comprises:

a second flexible sensor substrate that is dimensionally stable up to the second temperature, wherein the second flexible sensor substrate is not dimensionally stable at the first temperature;

a third plurality of conductive pads disposed on the second flexible sensor substrate, wherein at least one of the first plurality of conductive pads is coupled to at least one of the third plurality of conductive pads; and

a second plurality of capacitive sensing elements disposed on the second flexible sensor substrate and coupled to the third plurality of conductive pads via a third plurality of conductors.

5. The touch screen device of claim 1, wherein the sensor component further comprises a second plurality of sensing elements disposed on the first flexible sensor substrate and coupled to the second plurality of conductive pads, wherein the first plurality of capacitive sensing elements and the second plurality of sensing elements are disposed on a same side of the first flexible sensor substrate.

6. The touch screen device of claim 1, wherein the sensor component further comprises a second plurality of sensing elements disposed on the first flexible sensor substrate, wherein the first plurality of capacitive sensing elements and the second plurality of sensing elements are disposed on different sides of the first flexible sensor substrate.

7. A method for providing a sensor device comprising:

providing a flexible circuit substrate that is dimensionally stable up to a first temperature;

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

forming a first plurality of conductors using a first patterning process selected from a group consisting of conductive ink printing, metal deposition, metal etching, metal molding and metal stamping;

affixing a touch controller to the flexible circuit substrate and coupling the touch controller to the first plurality of conductive pads via the first plurality of conductors;

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

disposing a second plurality of conductive pads on the flexible sensor substrate, wherein at least one of the first plurality of conductive pads is coupled to at least one of the second plurality of conductive pads;

forming a second plurality of conductors using a second patterning process selected from the group consisting of conductive ink printing, metal deposition, metal etching, metal molding and metal stamping; and

disposing a first plurality of capacitive sensing elements on the flexible sensor substrate and coupling the second plurality of conductive pads via a second plurality of conductors.

8. The method of claim 7, wherein the conductive ink printing comprises one selected from a group consisting of screen printing, ink jet printing, offset printing, and transfer printing.

9. The method of claim 7 wherein a first conductor pitch associated with the first plurality of conductors is different from a second conductor pitch associated with the second plurality of conductors.

10. The method of claim 9, wherein the first conductor pitch is obtained using the first patterning process, wherein the second conductor pitch is obtained using the second patterning process, and wherein the first and the second patterning processes are different.

11. The method of claim 7, wherein affixing the touch controller to the flexible circuit substrate comprises a thermal bonding process selected from a group consisting of soldering, ultrasonic welding, thermally activated adhesive and thermal compression bonding.

12. The method of claim 7, wherein the second plurality of conductors comprises indium tin oxide.

13. The method of claim 7, further comprising folding the flexible circuit substrate.

14. The method of claim 7, further comprising slitting the flexible circuit substrate.

15. The method of claim 7, further comprising providing a stiffener to the flexible circuit substrate, wherein the stiffener comprises one selected from a group consisting of PET, polyimide, polystyrene and PVC.

16. The method of claim 7, further comprising providing a stiffener to the touch controller, wherein the stiffener comprises one selected from a group consisting of an acrylic, an epoxy, and a UV cured adhesive.

17. A capacitive device comprising:

a flexible circuit substrate that is dimensionally stable up to a first temperature, wherein the flexible circuit substrate comprises at least one selected from a group consisting of a condensate film, a thermoset material, polyimide, epoxy resin, and a liquid crystal polymer film;

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

a touch controller affixed to the flexible circuit substrate and coupled to the first plurality of conductive pads via a first plurality of conductors;

a sensor component comprising;

a first flexible sensor substrate that is dimensionally stable up to a second temperature that is lower than the first temperature, wherein the first flexible sensor substrate is not dimensionally stable at the first temperature, wherein the first flexible sensor substrate comprises at least one selected from a group consisting of a thermoplastic material, vinyl, polyethylene terephthalate (PET), polystyrene (PS), polyvinylchloride (PVC), and polycarbonate;

a second plurality of conductive pads disposed on the first flexible sensor substrate, wherein at least one of the first plurality of conductive pads is coupled to at least one of the second plurality of conductive pads;

a first plurality of capacitive sensing elements disposed on the first flexible sensor substrate and coupled to the second plurality of conductive pads via a second plurality of conductors; and

a display coupled with the sensor component.

18. The capacitive device of claim 17, wherein the first temperature is high enough to thermally bond the touch controller to the flexible circuit substrate without degradation to the flexible circuit substrate.

19. The capacitive device of claim 17, wherein the sensor component further comprises:

a second flexible sensor substrate that is dimensionally stable up to the second temperature, wherein the second flexible sensor substrate is not dimensionally stable at the first temperature;

a third plurality of conductive pads disposed on the second flexible sensor substrate, wherein at least one of the first plurality of conductive pads is coupled to at least one of the third plurality of conductive pads; and

a second plurality of capacitive sensing elements disposed on the second flexible sensor substrate and coupled to the third plurality of conductive pads via a third plurality of conductors.

20. The capacitive device of claim 17, wherein the sensor component further comprises a second plurality of sensing elements disposed on the first flexible sensor substrate and coupled to the second plurality of conductive pads, wherein the first plurality of capacitive sensing elements and the second plurality of sensing elements are disposed on a same side of the first flexible sensor substrate.