FUSIBLE SUBSTRATE

• US 20100066477A1
• Filed: 04/17/2009
• Published: 03/18/2010
• Est. Priority Date: 04/21/2008
• Status: Active Grant

• Current Assignee: Littelfuse Incorporated, Purdue Research Foundation (The Trustees of Purdue University (d/b/a Purdue University))
• Original Assignee: Littlefuse Incorporated, Purdue Technology Center
• Inventors: Whitney, Stephen J., Youngblood, Jeffrey P., Barriball, Edward D., Travis, William, Kittle, Milea J., Book, Sarah M.
• Granted Patent: US 8,525,633 B2
• Time in Patent Office: Days
• US Class Current: 337/290
• CPC Class Codes: H01H 2085/0412 specially adapted for being mounted on a printed circuit board
• CPC Class Codes: H01H 85/0073 Expansion or rupture of the insulating support for the fusible element
• CPC Class Codes: H01H 85/0411 Miniature fuses

Abstract

A fuse element includes a substrate disposed between first and second terminals. The substrate includes an electrically insulative material. A conductive film is disposed on a first surface of the substrate and in electrical contact with the first terminal and second terminals.

Claims

1. A fuse element comprising:

a first terminal;

a second terminal;

a substrate disposed between the first and second terminals, the substrate comprising an electrically insulative material;

a conductive film disposed on a first surface of the substrate and in electrical contact with the first terminal and second terminals.

2. The fuse element of claim 1 wherein the substrate comprises a ceramic material.

3. The fuse element of claim 1 wherein the film comprises a metal selected from the group consisting of copper, gold, and mixtures thereof.

4. The fuse element of claim 1 wherein a coefficient of thermal expansion of the substrate is lower than a coefficient of thermal expansion of the coating.

5. The fuse element of claim 1 wherein the substrate has a cylindrical shape.

6. The fuse element of claim 5 wherein the conductive film is disposed on an outer surface of the substrate.

7. The fuse element of claim 1 wherein the substrate has a rectangular cross section and four outer surfaces extending between the terminals.

8. The fuse element of claim 7 wherein the conductive film is disposed on one of the outer surfaces of the substrate.

9. A fuse element comprising:

a first terminal;

a second terminal; and

a substrate disposed between the first and second terminals, the substrate comprising a conductive polymer material.

10. The fuse element of claim 9 wherein the conductive polymer material includes metal particles dispersed in a polymer matrix.

11. The fuse element of claim 9 wherein the conductive polymer material includes a doped polymer material.

12. A fuse element comprising:

a first terminal;

a second terminal;

a substrate disposed between the first and second terminals, the substrate composed of a material with a melting point between 300°

C. and 800°

C.; and

a layer comprising a conductive material disposed over the substrate.

13. The fuse element of claim 12 wherein the substrate is composed of a wax.

14. The fuse element of claim 12 wherein the substrate is capable of withstanding a temperature of 260°

C. for at least 2 minutes without melting.

15. A fuse element comprising:

a first terminal;

a second terminal;

a conductive material disposed between the first terminal and the second terminal; and

a substrate disposed between the conductive material and one of the first terminal and the second terminal, the substrate composed of a material with a melting point between 300°

C. and 800°

C.

16. The fuse element of claim 15 wherein the substrate comprises a first substrate, further comprising a second substrate disposed between the conductive material and the other of the first terminal and the second terminal.

17. The fuse element of claim 15 wherein the substrate is capable of withstanding a temperature of 260°

C. for at least 2 minutes without melting.