PROTECTIVE DEVICE

• US 20110057761A1
• Filed: 09/03/2010
• Published: 03/10/2011
• Est. Priority Date: 09/04/2009
• Status: Active Grant

• Current Assignee: Cyntec Co. Ltd. (Delta Electronics Incorporated)
• Original Assignee: Cyntec Co. Ltd. (Delta Electronics Incorporated)
• Inventors: Chen, Kuo-Shu, Lin, Hung-Ming, Wang, Chung-Hsiung, Liu, Chun-Tiao, Luo, Wen-Shiang
• Granted Patent: US 9,129,769 B2
• Time in Patent Office: Days
• US Class Current: 337/297
• CPC Class Codes: H01H 2085/0283 Structural association with a semiconductor device
• CPC Class Codes: H01H 2085/466 with remote controlled forced fusing
• CPC Class Codes: H01H 69/022 of printed circuit fuses
• CPC Class Codes: H01H 85/0047 Heating means
• CPC Class Codes: H01H 85/0241 Structural association of a fuse and another component or apparatus switches with built-in fuses H01H9/10, spark-gap arresters H01H85/44, transformers and inductances H01F27/402, capacitors H01G2/14, lamps H01K1/66, semiconductors H01L23/5256 or H01L23/62
• CPC Class Codes: H01H 85/0411 Miniature fuses
• CPC Class Codes: H01H 85/046 Fuses formed as printed circuits
• CPC Class Codes: H01H 85/048 Fuse resistors
• CPC Class Codes: H01H 85/11 with applied local area of a metal which, on melting, forms a eutectic with the main material of the fusible member, i.e. M-effect devices
• CPC Class Codes: H01H 85/48 Protective devices wherein the fuse is carried or held directly by the base

Abstract

A protective device including a substrate, a conductive section and a bridge element is provided. The conductive section is supported by the substrate, wherein the conductive section comprises a metal element electrically connected between first and second electrodes. The metal element serves as a sacrificial structure having a melting point lower than that of the first and second electrodes. The bridge element spans across the metal element in a direction across direction of current flow in the metal element, wherein the bridge element facilitates breaking of the metal element upon melting.

Claims

1. A protective device, comprising:

a substrate,

a conductive section supported by the substrate, wherein the conductive section comprises a metal element electrically connected between first and second electrodes, wherein the metal element serves as a sacrificial structure having a melting point lower than that of the first and second electrodes; and

a bridge element spanning across the metal element in a direction across direction of current flow in the metal element, wherein the bridge element facilitates breaking of the metal element upon melting.

2. The protective device as in claim 1, wherein at least one end of the bridge element is fixedly supported on the substrate.

3. The protective device as in claim 2, wherein both ends of the bridge element are fixedly supported on the substrate.

4. The protective device as in claim 1, further comprising an intermediate support disposed between the metal element and the substrate.

5. The protective device as in claim 4, wherein at least one end of the bridge element is fixedly supported on the intermediate support.

6. The protective device as in claim 4, wherein both ends of the bridge element are fixedly supported on the intermediate support.

7. The protective device as in claim 1, wherein the bridge element comprises an elongated structure.

8. The protective device as in claim 7, wherein the elongated structure comprises an arc or a bending shape.

9. The protective device as in claim 1, further comprising an auxiliary medium having a portion disposed between the bridge element and the metal element.

10. The protective device as in claim 9, further comprising another auxiliary medium disposed between the metal element and the substrate, wherein said another auxiliary medium having a melting point lower than that of the metal element.

11. The protective device as in claim 9, further comprising a heat-generating element supported by the substrate, providing heat to at least the metal element and the auxiliary medium.

12. The protective device as in claim 11, wherein the bridge element and auxiliary medium are positioned in line with the heat generating element.

13. The protective device as in claim 12, wherein the heat-generating element is supported between the metal element and the substrate.

14. The protective device as in claim 13, wherein the heat-generating element is supported by a side of the substrate away from the heating element.

15. The protective device as in claim 14, further comprising an intermediate layer between the metal element and the intermediate support, wherein the intermediate layer has a fusing temperature lower than the melting temperature of the metal element.

16. The protective device as in claim 9, wherein the auxiliary medium is a flux or a solder layer.

17. The protective device as in claim 4, further comprising a heat insulation portion between the heating element and the first and second electrodes, wherein heat transfer to the intermediate support is at a higher rate than that to the first and second electrodes.

18. The protective device as in claim 4, wherein the intermediate support comprises an extension of an electrode coupled to a heat-generating element.

19. The protective device as claimed in claim 1, wherein the substrate comprise a first insulating block, and a second insulating block under the first and second electrodes, wherein a thermal conductivity coefficient of the first insulating bock is greater than that of the second insulating block.