Rigidly bonded trackpad with structural stiffener

• US 10,331,178 B2
• Filed: 08/04/2017
• Issued: 06/25/2019
• Est. Priority Date: 08/04/2017
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Shah, Ketan R., Pleake, Todd David, Carpenter, Benjamin Joseph, Karavaev, George, Rice, Mark Gerard
• Primary Examiner(s): Wilson, Adrian S
• Application Number:
  US15/669,480
• Publication Number:
  US 20190041903A1
• Time in Patent Office: 690 Days
• CPC Class Codes: G06F 1/1656 Details related to functional adaptations of the enclosure, e.g. to provide protection against EMI, shock, water, or to host detachable peripherals like a mouse or removable expansions units like PCMCIA cards, or to provide access to internal components for maintenance or to removable storage supports like CDs or DVDs, or to mechanically mount accessories mounting of accessories to a computer display G06F1/1607; display hoods G06F1/1603; cooling arrangements for portable computers G06F1/203
• CPC Class Codes: G06F 1/1662 Details related to the integrated keyboard
• CPC Class Codes: G06F 1/169 the I/O peripheral being an integrated pointing device, e.g. trackball in the palm rest area, mini-joystick integrated between keyboard keys, touch pads or touch stripes G06F1/1643 takes precedence; constructional details of pointing devices G06F3/033
• CPC Class Codes: G06F 3/03547 Touch pads, in which fingers can move on a surface

Abstract

The trackpad assemblies described herein maintain minimum overall stiffness, weight, and cost requirements of a trackpad assembly, while permitting a decrease in trackpad assembly thickness as compared to conventional trackpad assemblies. The trackpad assemblies may include one or more of a four-layer PCB, structural adhesives, a structural PCB stiffener, and a structural shield assembly. These stiffening features permit increasingly thinner trackpad assemblies and associated computing devices.

Claims

1. A trackpad comprising:

a printed circuit board;

a user interface layer bonded to a first side of the printed circuit board with a structural adhesive therebetween;

a structural stiffener bonded to a second side of the printed circuit board with another structural adhesive therebetween; and

two or more attachment brackets also bonded to the second side of the printed circuit board.

2. The trackpad of claim 1, wherein the structural adhesive includes one or both of a heat-activated film and an epoxy.

3. The trackpad of claim 1, wherein the structural adhesives are rigid when cured.

4. The trackpad of claim 1, wherein the structural stiffener is a metallic alloy and the user interface layer is glass.

5. The trackpad of claim 1, wherein the printed circuit board is a four-layer printed circuit board.

6. The trackpad of claim 5, wherein the printed circuit board includes a conductive mesh within one or both of third and fourth layers of the printed circuit board.

7. The trackpad of claim 1, wherein the printed circuit board has an EM-370D epoxy resin substrate.

8. The trackpad of claim 1, further comprising:

a shield assembly rigidly attached to the printed circuit board and encapsulating one or more electronic components of the printed circuit board.

9. The trackpad of claim 8, wherein the shield assembly includes a shield wall rigidly attached to the printed circuit board and a shield lid rigidly attached to one or both of the shield wall and the printed circuit board.

10. The trackpad of claim 1, further comprising:

a metal dome switch bonded to the second side of the printed circuit board.

11. The trackpad of claim 1, wherein the trackpad has one or both of a bending stiffness of 20-22 N/mm and a thickness less than 2.0 mm.

20. The trackpad of claim 1, the structural stiffener including one or more legs, each of which generally extend between a corner of the user interface layer and an attachment bracket of the trackpad.

12. A method of manufacturing a trackpad comprising:

rigidly bonding a user interface layer to a first side of a printed circuit board using a structural adhesive;

rigidly bonding a structural stiffener to a second side of the printed circuit board using another structural adhesive; and

attaching the second side of the printed circuit board to two or more live hinges using two or more attachment brackets.

13. The method of claim 12, wherein the structural adhesives include one or both of a heat-activated film and an epoxy.

14. The method of claim 12, wherein the rigidly bonding operations include applying both of heat and pressure to the trackpad.

15. The method of claim 12, further comprising:

laminating four FR-4 epoxy resin layers together to form the printed circuit board.

16. The method of claim 12, further comprising:

rigidly attaching a shield assembly to the second side of the printed circuit board.

21. The method of claim 12, the structural stiffener including one or more legs, each of which generally extend between a corner of the user interface layer and an attachment bracket of the trackpad.

17. A computing device comprising:

a trackpad including;

a printed circuit board;

a user interface layer bonded to a first side of the printed circuit board with a structural adhesive therebetween;

a structural stiffener bonded to a second side of the printed circuit board with another structural adhesive therebetween; and

two or more attachment brackets also bonded to the second side of the printed circuit board;

a trackpad switch;

a chassis including;

a trackpad height set screw pressing against the trackpad switch to set a resting height of the trackpad with reference to a top surface of the computing device; and

a resilient stop oriented between the set screw and the chassis to absorb one or both of contact of the set screw with the chassis and reverberations therebetween.

18. The computing device of claim 17, wherein the trackpad switch is a metal dome switch.

19. The computing device of claim 17, wherein the trackpad has one or both of a bending stiffness of 20-22 N/mm and a thickness less than 2.0 mm.

22. The computing device of claim 17, the structural stiffener including one or more legs, each of which generally extend between a corner of the user interface layer and an attachment bracket of the trackpad.