High current power inductor

• US 9,558,881 B2
• Filed: 03/18/2014
• Issued: 01/31/2017
• Est. Priority Date: 07/11/2008
• Status: Active Grant

• Current Assignee: Eaton Intelligent Power Limited (Eaton Corporation PLC.)
• Original Assignee: Cooper Technologies Company (Eaton Corporation PLC.)
• Inventors: Liu, Zhuomin, Bogert, Robert James
• Primary Examiner(s): Lian, Mangtin
• Assistant Examiner(s): Hinson, Ronald
• Application Number:
  US14/217,705
• Publication Number:
  US 20140313003A1
• Time in Patent Office: 1,050 Days
• Field of Search: 336/212
• US Class Current: 1/1
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 17/043 with two, usually identical or nearly identical parts enclosing completely the coil (pot cores)
• CPC Class Codes: H01F 27/255 made from particles H01F27/26 takes precedence
• CPC Class Codes: H01F 27/2847 Sheets; Strips H01F27/2866 takes precedence
• CPC Class Codes: H01F 27/292 Surface mounted devices
• CPC Class Codes: H01F 27/303 Clamping coils, windings or parts thereof together
• CPC Class Codes: H01F 27/306 Fastening or mounting coils or windings on core, casing or other support
• CPC Class Codes: H01F 3/14 Constrictions; Gaps, e.g. air-gaps in magnetic shunt paths H01F3/12

Abstract

A surface mount power inductor includes a preformed conductive winding clip and first and second-shaped core pieces. The core pieces may be configured to reduce unbalanced force experienced in the power inductor in certain types of power management circuitry. Reduction in the unbalanced force reduces vibration of the power inductor in use, and in turn reduces acoustic noise as the power inductor operates.

Claims

1. A surface mount power inductor, comprising:

a first shaped-core piece and a second shaped-core piece each fabricated from a magnetically soft powder material, the first shaped-core piece and the second shaped-core piece being separately and independently fabricated from one another;

a preformed C-shaped conductive winding clip separately fabricated from either of the first shaped-core piece and the second shaped-core piece;

wherein the winding clip includes a main winding section, first and second legs extending from opposing ends of the main winding section, and first and second terminal lead sections extending from the respective first and second legs;

wherein the first shaped-core piece is asymmetrical and includes a bottom surface defined by opposing first and second side edges and opposing first and second end edges interconnecting the first and second side edges, wherein the first end edge is longer than the second end edge, the first and second side edges include a respective first and second recess, and the first shaped-core piece further including an upper surface and groove in the upper surface;

wherein the preformed C-shaped conductive winding clip is coupled to the first shaped-core piece without bending any portion of the winding clip around the first shaped-core piece and the first and second terminal lead sections being received in the respective first and second recess;

wherein the second shaped-core piece is coupled to the first shaped-core piece to complete the power inductor; and

wherein the main winding section of the preformed C-shaped conductive winding clip extends between the first shaped-core piece and the second shaped-core piece.

2. The surface mount power inductor of claim 1, wherein the magnetically soft powder material is a nanoamorphous powder material.

3. The surface mount power inductor of claim 1, wherein the magnetically soft powder material is an iron-based amorphous powder material.

4. The surface mount power inductor of claim 1, wherein one of the first and second shaped-core pieces is a U core.

5. The surface mount power inductor of claim 1, wherein one of the first and second shaped-core pieces is an I core.

6. The surface mount power inductor of claim 1, wherein the main winding section of the preformed C-shaped conductive winding clip is seated in the groove.

7. The surface mount power inductor of claim 1, wherein the first and second recesses extend only to one of the first and second end edges of the first shaped-core piece.

8. The surface mount power inductor of claim 1, wherein the main winding section of the preformed C-shaped conductive winding clip is spaced from each of the opposing first and second end edges of the first shaped-core piece.

9. The surface mount power inductor of claim 1, wherein the upper surface of the first shaped-core piece includes a ledge, and an edge of the groove coincides with the ledge.

10. The surface mount power inductor of claim 1, wherein the groove of the first shaped-core piece has a depth of about 0.1 mm to about 0.5 mm.

11. The surface mount power inductor of claim 10, wherein the groove has a depth of about 0.3 mm.

12. The surface mount power inductor of claim 1, wherein the second shaped-core piece includes a clip channel, the clip channel having a depth.

13. The surface mount power inductor of claim 12, wherein the depth of the groove of the first shaped-core piece is equal to the depth of the clip channel in the second shaped-core piece.

14. The surface mount power inductor of claim 1, wherein the second shaped-core piece is formed to include a first leg, a second leg, and a clip channel extending between the first and second leg sections.

15. The surface mount power inductor of claim 14, wherein the first leg has a different length than the second leg.

16. The surface mount power inductor of claim 15, wherein the main winding section of the preformed C-shaped conductive winding clip has a first width, and the first and second legs of the preformed C-shaped conductive winding clip have a second width, the first and second width being different from one another.

17. The surface mount power inductor of claim 16, wherein the second width is greater than the first width.

18. The surface mount power inductor of claim 1, wherein the second shaped-core piece are is asymmetrical.

19. The surface mount power inductor of claim 1, wherein a physical gap is established between the first shaped-core piece and the second shaped-core piece.

20. The surface mount power inductor of claim 1, wherein the groove has a depth selected to reduce an unbalanced force in the power inductor when used.

21. The surface mount power inductor of claim 20, wherein the main winding section of the preformed C-shaped conductive winding clip has a first width, and the first and second legs of the preformed C-shaped conductive winding clip have a second width, the first and second width being different from one another.

22. The surface mount power inductor of claim 20, wherein the main winding section of the preformed C-shaped conductive winding clip has a first width, and wherein, the groove of the first shaped-core piece has a width equal to the first width of the main winding section.

23. The surface mount power inductor of claim 20, wherein the main winding section of the preformed C-shaped conductive winding clip has a first width, and wherein the second shaped-core piece is formed with a clip channel, the clip channel having a width equal to the first width of the main winding section.

24. The surface mount power inductor of claim 1, wherein at least a portion of the first and second shaped-core pieces are pressed in surface contact with one another.

25. The surface mount power inductor of claim 1, wherein the main winding section of the preformed C-shaped conductive winding clip has a first width, and wherein the first and second legs and the first and second terminal lead sections of the preformed C-shaped conductive winding clip have a second width, the first and second width being different from one another.

26. The surface mount power inductor of claim 25, wherein the second width is greater than the first width.

27. The surface mount power inductor of claim 1, wherein the main winding section of the preformed C-shaped conductive winding clip is seated in the groove at a depth selected to reduce an acoustic noise while the power inductor is operating in an electrical circuit.

28. The surface mount power inductor of claim 27, wherein the groove has a depth from about 0.1 mm to about 0.5 mm.

29. The surface mount power inductor of claim 28, wherein the groove has depth of about 0.3 mm.

30. The surface mount power inductor of claim 27, wherein the groove has a depth selected to reduce the acoustic noise by about 4 dB.

31. The surface mount power inductor of claim 27, wherein the power inductor is operable with acoustic noise in a range of about 46 dB to about 49 dB in a power supply management circuit.

32. The surface mount power inductor of claim 31, wherein the power inductor is operable with acoustic noise of about 48 dB in the power supply management circuit.

33. The surface mount power inductor of claim 27, wherein the electrical circuit is a power supply management circuit and wherein the power inductor experiences a high-to-low or low-to-high current transition in the electrical circuit.

34. The surface mount power inductor of claim 27, in combination with a circuit board configured to implement power supply management circuitry.

35. The surface mount power inductor of claim 34, wherein the power supply management circuitry supplies power to a dynamic load.

36. The surface mount power inductor of claim 35, wherein the dynamic load comprises one of a CPU and a GPU.

37. The surface mount power inductor of claim 34, wherein the terminal lead sections are soldered to the board but the first shaped-core piece is not.

38. The surface mount power inductor of claim 1, wherein the first shaped-core piece has a different shape than the second shaped-core piece.