Thermally fused spacers

Patent metadata

Field	Value
Publication number	US-9852853-B2
Application number	US-201514882964-A
Country	US
Kind code	B2
Filing date	Oct 14, 2015
Priority date	Oct 14, 2015
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

Example implementations relate to thermally fused spacers. In one example, keyboard membranes including thermally fused spacers include a first circuit including a first conductive trace and a first key contact of the keyboard membrane, where the first conductive trace is coupled to the first key contact, a second circuit including a second conductive trace and a second key contact of the keyboard membrane, where the second conductive trace is coupled to the second key contact, and wherein the second key contact is to couple to the first key contact, and a spacer formed of a layer of thermoplastic material, a first thermoplastic film, and a second thermoplastic film, where the spacer is fused via the first thermoplastic film to the first circuit and via the second thermoplastic film to the second circuit.

First claim

What is claimed:

1. A keyboard membrane, comprising:
a first circuit including a first conductive trace and a first key contact of the keyboard membrane, wherein the first conductive trace is coupled to the first key contact;
a second circuit including a second conductive trace and a second key contact of the keyboard membrane, wherein the second conductive trace is coupled to the second key contact, and wherein the second key contact is to couple to the first key contact; and
a spacer formed of a layer of thermoplastic material, a first thermoplastic film, and a second thermoplastic film, wherein the spacer is fused via the first thermoplastic film to the first circuit and via the second thermoplastic film to the second circuit.

2. The keyboard membrane of claim 1 , wherein the spacer overlays an entire length of at least one of the first conductive trace and the second conductive trace.

3. The keyboard membrane of claim 1 , wherein the spacer includes a continuous layer overlaying at least a portion of the first conductive trace and at least a portion of the second conductive trace, and wherein the spacer includes cutouts in communication with at least one vent.

4. The keyboard membrane of claim 1 , wherein the spacer is fused to the first circuit and the second circuit to seal the first conductive trace and the second conductive trace.

5. The keyboard membrane of claim 1 , wherein the layer of thermoplastic material is from 10 microns to 1000 microns thick.

6. The keyboard membrane of claim 1 , comprising an opening to permit the first key contact to contact the second key contact.

7. A keyboard membrane, comprising:
a first circuit including a first face, a first conductive trace, and a first key contact;
a spacer formed of a layer of thermoplastic material, a first thermoplastic film, and a second thermoplastic film, wherein the spacer is directly fused via the first thermoplastic film to the first face of the first circuit to seal the first conductive trace; and
a second circuit including a second face, a second conductive trace, and a second key contact, wherein the spacer is directly fused via the second thermoplastic film to the second face of the second circuit to seal the second conductive trace.

8. The keyboard membrane of claim 7 , comprising at least a portion of an opening extending from the first key contact to the second key contact and through the spacer.

9. The keyboard membrane of claim 7 , comprising a vent included in the second circuit, wherein the vent extends through an entire thickness of the second circuit.

10. The keyboard membrane of claim 7 , wherein the thermoplastic material comprises polyethylene terephthalate.

11. The keyboard membrane of claim 7 , wherein keyboard membrane is free of printed adhesive between the first circuit and the second circuit.

12. A method of manufacture of a keyboard membrane, comprising:
providing a first circuit including a first conductive trace and a first key contact of the keyboard membrane, wherein the first conductive trace is coupled to the key contact;
providing a second circuit including a second conductive trace and a second key contact of the keyboard membrane, wherein the second conductive trace is coupled to the second key contact;
disposing a first thermoplastic film on a first face of a layer of thermoplastic material;
disposing a second thermoplastic film on a second face of the layer of thermoplastic material to form a spacer; and
causing the first thermoplastic film and the second thermoplastic film to a reach a temperature above respective glass transition temperatures of the first thermoplastic film and the second thermoplastic film to fuse the spacer to the first circuit and the second circuit when the spacer is adjacent to the first circuit and the second circuit to form the keyboard membrane.

13. The method of claim 12 , wherein causing the first thermoplastic film and the second thermoplastic film to reach the temperature above the respective glass transition temperatures comprises heating the first thermoplastic film and the second thermoplastic film to a temperature between about 40° C. to about 65° C.

14. The method of claim 13 , wherein causing the first thermoplastic film and the second thermoplastic film to reach the temperature above the respective glass transition temperatures comprises applying at least 448 kilopascals of pressure to the first thermoplastic film and the second thermoplastic film.

15. The method of claim 12 , wherein the method of manufacture of the keyboard membrane does not employ a printing adhesive, an ultraviolet curable ink, nor a solvent based adhesive.

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Armendariz Luis C

Classifications

• H01H2229/024

  Packing between substrate and membrane · CPC title

• H01H2211/00

  Spacers · CPC title

• H01H13/703 Primary

  characterised by spacers between contact carrying layers · CPC title

• H01H13/88

  Processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards · CPC title

• H01H2227/036

  Minimise height · CPC title