Inductor with thermally stable resistance

• US 9,502,171 B2
• Filed: 03/10/2015
• Issued: 11/22/2016
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: Vishay Dale Electronics, LLC (Vishay Intertechnology Incorporated)
• Original Assignee: Vishay Dale Electronics, LLC (Vishay Intertechnology Incorporated)
• Inventors: Hansen, Thomas T., Hoffman, Jerome J., Schafer, Timothy, Schade, Nicholas J., Lange, David, Smith, Clark, Brune, Rod
• Primary Examiner(s): NGUYEN, TUYEN T
• Application Number:
  US14/642,892
• Publication Number:
  US 20160005533A1
• Time in Patent Office: 623 Days
• Field of Search: 336/65, 336/83, 336/192, 336/200, 336220-223, 336/232
• US Class Current: 1/1
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 2017/048 with encapsulating core, e.g. made of resin and magnetic powder
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse
• CPC Class Codes: H01F 3/08 made from powder powder coatings on sheets H01F3/02; on strips or ribbons H01F3/04; on wires H01F3/06
• CPC Class Codes: H01F 41/02 for manufacturing cores, coils, or magnets H01F41/14 takes precedence; for dynamo-electric machines H02K15/00

Abstract

An inductor includes an inductor body having a top surface and a first and second opposite end surfaces. There is a void through the inductor body between the first and second opposite end surfaces. A thermally stable resistive element positioned through the void and turned toward the top surface to forms surface mount terminals which can be used for Kelvin type sensing. Where the inductor body is formed of a ferrite, the inductor body includes a slot. The resistive element may be formed of a punched resistive strip and provide for a partial turn or multiple turns. The inductor may be formed of a distributed gap magnetic material formed around the resistive element. A method for manufacturing the inductor includes positioning an inductor body around a thermally stable resistive element such that terminals of the thermally stable resistive element extend from the inductor body.

Claims

1. An inductor, comprising:

an inductor body having a top surface and first and second opposite end surfaces;

a void through the inductor body; and

a thermally stable resistive element configured for Kelvin-type measurements positioned through the void, the ends of the resistive element turned along outer surfaces of the inductor body toward the top surface to form first and second opposite surface mount terminals on the top surface;

wherein each of the surface mount terminals comprises a current-carrying terminal and a separate current-sensing terminal.

2. The inductor of claim 1, further comprising a slot in the top surface of the inductor body.

3. The inductor of claim 2, wherein the ends of the thermally stable resistive element are turned toward the slot.

4. The inductor of claim 1, wherein the thermally stable resistive element comprises a resistive material operatively connected to a conductive material, wherein the surface mount terminals comprise the conductive material.

5. The inductor of claim 1, wherein the thermally stable resistive element is formed from a first material, and the first and second opposite surface mount terminals are formed from a second material that is different from the first material.

6. The inductor of claim 1, wherein the current-carrying terminals are larger than the current-sensing terminals.

7. The inductor of claim 1, wherein the inductor body comprises a magnetic powder or a distributed gap magnetic material.

8. The inductor of claim 1, wherein the resistive element comprises multiple turns.

9. A method for forming an inductor comprising:

providing a thermally stable resistive element configured for Kelvin-type measurements;

forming an inductor body having a top surface and a first and second opposite end surfaces, around the thermally stable resistive element; and

,

turning ends of the thermally stable resistive element along outer surfaces of the inductor body toward the top surface to form opposite surface mount terminals on the top surface of the inductor body, wherein each of the surface mount terminals comprises a current-carrying terminal and a separate current-sensing terminal.

10. The method of claim 9, further comprising forming a slot in the top surface of the inductor body.

11. The method of claim 10, wherein the ends of the thermally stable resistive element are turned toward the slot.

12. The method of claim 9, wherein the thermally stable resistive element comprises a resistive material operatively connected to a conductive material, wherein the surface mount terminals comprise the conductive material.

13. The method of claim 9, wherein the thermally stable resistive element is formed from a first material, and the first and second opposite surface mount terminals are formed from a second material that is different from the first material.

14. The method of claim 9, wherein the current-carrying terminals are larger than the current-sensing terminals.

15. The method of claim 9, wherein the inductor body comprises a magnetic powder or a distributed gap magnetic material.

16. The method of claim 9, wherein the resistive element comprises multiple turns.

17. An inductor comprising:

a thermally stable resistive element;

an inductor body having a top surface and first and second opposite end surfaces, the inductor body comprising a magnetic material pressed over the thermally stable resistive element;

wherein opposite ends of the thermally stable resistive element are each turned along outer side surfaces of the first and second opposite end surfaces toward the top surface of the inductor body and have ends that overlap the top surface of the inductor body to form opposite surface mount terminals, each surface mount terminal including a larger terminal for current carrying and a smaller terminal for Kelvin-type current sensing.

18. The inductor of claim 17, further comprising a slot in the top surface of the inductor body.

19. The inductor of claim 18, wherein the ends of the thermally stable resistive element are turned toward the slot.

20. The inductor of claim 17, wherein the thermally stable resistive element comprises a resistive material operatively connected to a conductive material, wherein the surface mount terminals comprise the conductive material.