Structurally resilient positive temperature coefficient material and method for making same

Patent metadata

Field	Value
Publication number	US-10325702-B2
Application number	US-201615168546-A
Country	US
Kind code	B2
Filing date	May 31, 2016
Priority date	May 31, 2016
Publication date	Jun 18, 2019
Grant date	Jun 18, 2019

Abstract

Structurally supported positive temperature coefficient (PTC) materials are disclosed. Furthermore, methods to provide structurally supported PTC materials are disclosed. In one implementation, a structurally supported PTC material includes a support structure that is at least partially covered by a PTC material. In one example, the support structure is a mesh material integrated at least partially in the PTC material.

First claim

We claim:

1. An apparatus, comprising:
a support structure formed of a mesh comprising a plurality of strands defining a plurality of apertures; and
a positive temperature coefficient (PTC) material covering the support structure such that an entirety of the mesh is embedded within the PTC material with no part of the mesh extending outside of the PTC material to thereby provide the support structure integrated in the PTC material.

2. The apparatus according to claim 1 , wherein the support structure comprises a mesh material, a multi-hole spacer, or a plurality of single hole spacers.

3. The apparatus according to claim 1 , wherein the support structure comprises at least one of an electrically nonconductive material and an electrically conductive material.

4. The apparatus according to claim 1 , wherein the PTC material comprises polymer and conductive particles.

5. The apparatus according to claim 1 , wherein the support structure comprises glass, Kevlar, polymer, ceramic, carbon fiber, insulated metal, electrically conductive material or fabric.

6. The apparatus according to claim 1 , wherein the PTC material at least partially fills one or more of the plurality of apertures.

7. The apparatus according to claim 6 , wherein each of the plurality of strands have a diameter of approximately 50 μm and each of the plurality of apertures has a width of at least 115 μm.

8. The apparatus according to claim 6 , wherein the mesh material comprises a free open area of approximately 55% and a thermal stability of approximately 250 degrees Celsius.

9. The apparatus according to claim 1 , wherein the support structure is structurally stable up to a force of approximately 150 kg/cm 2 and thermally stable up approximately 250 degrees Celsius.

10. The apparatus according to claim 1 , wherein the PTC material comprises first and second opposite surfaces, the apparatus further comprising an electrically conductive layer disposed over at least one of the first and second opposite surfaces.

11. A method, comprising:
providing a support structure formed a mesh comprising a plurality of strands defining a plurality of apertures; and
at least partially covering the support structure with a positive temperature coefficient (PTC) material such that an entirety of the mesh is embedded within the PTC material with no part of the mesh extending outside of the PTC material to thereby provide the support structure integrated in the PTC material.

12. The method according to claim 11 , wherein the support structure comprises a mesh material, a multi-hole spacer, or a plurality of single hole spacers.

13. The method according to claim 11 , wherein the support structure comprises at least one of an electrically nonconductive material and an electrically conductive material.

14. The method according to claim 11 , wherein the PTC material comprises polymer and conductive particles.

15. The method according to claim 11 , wherein the support structure comprises glass, Kevlar, polymer, ceramic, carbon fiber, insulated metal, electrically conductive material or fabric.

16. The method according to claim 11 , wherein the PTC material at least partially fills one or more of the plurality of apertures.

17. The method according to claim 16 , wherein each of the plurality of strands have a diameter of approximately 50 μm and each of the plurality of apertures has a width of at least 115 μm.

18. The method according to claim 16 , wherein the mesh material comprises a free open area of approximately 55% and a thermal stability of approximately 250 degrees Celsius.

19. The method according to claim 11 , wherein the support structure is structurally stable up to a force of approximately 150 kg/cm 2 and thermally stable up to approximately 250 degrees Celsius.

20. The method according to claim 11 , wherein the PTC material comprises first and second opposite surfaces, the method further comprising disposing an electrically conductive layer over at least one of the first and second opposite surfaces.

Assignees

• Littelfuse Inc

Inventors

• Tsang Chun-Kwan
• Chen Jianhua

Classifications

• H01C17/06

  adapted for coating resistive material on a base · CPC title

• H01C7/02 Primary

  having positive temperature coefficient · CPC title

• H01C7/027

  consisting of conducting or semi-conducting material dispersed in a non-conductive organic material · CPC title

• H01C7/008

  Thermistors (H01C7/02 - H01C7/06 take precedence) · CPC title