Fuse element, a fuse, a method for producing a fuse, SMD fuse and SMD circuit

• US 10,192,705 B2
• Filed: 12/23/2013
• Issued: 01/29/2019
• Est. Priority Date: 12/23/2013
• Status: Active Grant

• Current Assignee: Schurter AG (Schurter Holding AG)
• Original Assignee: Schurter AG (Schurter Holding AG)
• Inventors: Straub, Peter, Blattler, Hans-Peter
• Primary Examiner(s): Vortman, Anatoly
• Application Number:
  US15/107,091
• Publication Number:
  US 20170040136A1
• Time in Patent Office: 1,863 Days
• Field of Search: 337295
• CPC Class Codes: H01H 69/02 Manufacture of fuses
• CPC Class Codes: H01H 85/0411 Miniature fuses
• CPC Class Codes: H01H 85/06 characterised by the fusible material H01H85/11 takes precedence
• CPC Class Codes: H01H 85/08 characterised by the shape or form of the fusible member
• 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 85/20 Bases for supporting the fuse; Separate parts thereof
• CPC Class Codes: H01H 85/205 Electric connections to contacts on the base

Abstract

The invention relates to a fuse element (12_1; 12_2), comprising two connecting contacts (24_1′, 24_1″; 24_2′, 24_2″) and an interposed conductive track (26_1; 26_2), wherein the conductive track (26_1; 26_2) has a reduced line-cross-section, in relation, to the connecting contacts (24_1′, 24_1″; 24_2′, 24_2″) at least in some sections, further comprising at least one overlay (16_1; 16_2′, 16_2″), wherein the fuse element (12_1; 12_2) and the overlay (16_1; 16_2′, 16_2″) each comprise materials which undergo diffusion when a predetermined ambient temperature is exceeded and when an electric current is conducted by the fuse element (12_1; 12_2). The invention further relates to a fuse (TO) having such a fuse element (12_1; 12_2) and a base support (14), wherein the fuse element (12_1; 12_2) is disposed on a surface of the base support (14).

Claims

1. A method for producing a fuse (10), comprising the steps of:

providing at least one fuse element (12;

12′

, 12″

) having two connecting contacts (24′

, 24″

) and an interposed conductive track (26), such that the conductive track (26) has a reduced line cross-section in relation to the connecting contacts (24′

, 24″

) at least in some sections;

providing a base support (14);

providing the fuse element (12;

12′

, 12″

) with at least one overlay (16;

16′

, 16″

), wherein the fuse element (12;

12′

, 12″

) and the overlay (16;

16′

, 16″

) are each selected from materials which undergo diffusion when a predetermined ambient temperature is exceeded and when an electric current is conducted by the fuse element (12;

12′

, 12″

), and

wherein the fuse element is being connected to an external component by a reflow soldering process without the fuse element triggering at a reflow soldering process temperature occurring in this process, wherein the reflow soldering process temperature is higher than the

predetermined ambient temperature, and

arranging the at least one fuse element (12;

12′

, 12″

) on the base support (14),

wherein the at least one overlay (16_1) is arranged within the conductive track (26_1) adjacent to one of the connecting contacts (24_1′

, 24_1″

) of the fuse element (12_1).

2. The method of claim 1, wherein the line cross-section of the conductive track (26) of the provided at least one fuse element (12;

12′

, 12″

) increasingly converges gradually to the line cross-section of the connecting contacts (24′

,24″

).

3. The method of fuse claim 2, wherein the at least one overlay (16;

16′

, 16″

) is arranged at least in sections within the conductive track (26) in a region of the gradually increasing line cross-section.

4. The method of to claim 2, wherein the at least one overlay (16;

16′

, 16″

) is arranged in a region of the conductive track (26) with a gradually increasing line cross-section adjacent to a section of the conductive track (26) with minimal line cross-section.

5. The method of claim 1, wherein the material of the fuse element (12;

12′

, 12″

) comprises copper and the material of the overlay (16;

16′

, 16″

) comprises tin.

6. The method of claim 1, wherein the support (14) is made of an electrically insulating material and, wherein the at least one fuse element (12;

12′

, 12″

) is arranged on a surface of the base support (14).

7. The method of claim 6, wherein the at least one fuse element (12′

, 12″

) is arranged on opposite surfaces of the base support (14).

8. The method of claim 6, further comprising providing two base contacts (18′

, 18″

) which are each electrically connected to connecting contacts of the at least one fuse element (12′

, 12″

) and which are located on opposite ends of the base support (14).

9. The method of claim 6, further comprising coating the at least one fuse element (12;

12′

, 12″

) with a protective lacquer (22;

22′

, 22″

), especially a protective polymer lacquer.

10. A method of producing an SMD fuse, comprising the method of claim 6.

11. A method of producing an SMD circuit, comprising the method of claim 10.

12. The method according to claim 1, wherein the step of providing the fuse element (12;

12′

, 12″

) with the at least one overlay (16;

16′

, 16″

) comprises arranging the overlay (16;

16′

, 16″

) in at least one recess (20;

20′

, 20″

) introduced into the conductive track (26).

13. The method of to claim 12, wherein the at least one recess (20;

20′

, 20″

) is oriented in a continuously transverse manner in relation to the longitudinal direction of the conductive track (26).