Method of forming a power module with a magnetic device having a conductive clip

• US 8,701,272 B2
• Filed: 10/05/2005
• Issued: 04/22/2014
• Est. Priority Date: 10/05/2005
• Status: Active Grant

• Current Assignee: Altera Corporation (Intel Corporation)
• Original Assignee: Enpirion, Inc. (Intel Corporation)
• Inventors: Lotfi, Ashraf W., Wilkowski, Mathew A., Liakopoulos, Trifon M., Weld, John D.
• Primary Examiner(s): Tugbang, A. Dexter
• Application Number:
  US11/243,787
• Publication Number:
  US 20070074386A1
• Time in Patent Office: 3,121 Days
• Field of Search: 296/021, 296/04, 296/06, 298/27, 298/41, 252/62.15 R, 252/62.6, 336/82, 336/83, 336/200, 336/208, 336/219, 336/209
• US Class Current: 29/602.1
• CPC Class Codes: H01F 17/04 with magnetic core
• CPC Class Codes: H01F 2027/2814 with only part of the coil or of the winding in the printed circuit board, e.g. the remaining coil or winding sections can be made of wires or sheets
• CPC Class Codes: H01F 27/2847 Sheets; Strips H01F27/2866 takes precedence
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/45147 Copper (Cu) as principal constituent
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49052 Different loop heights
• CPC Class Codes: H01L 2224/49096 horizontal
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/495 Lead-frames or other flat leads H01L23/498 takes precedence; lead frame interconnections between components H01L23/52
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 24/49 of a plurality of wire connectors
• CPC Class Codes: H01L 25/16 the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00011 Not relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01015 Phosphorus [P]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/19105 : in a side-by-side arrangement on a common die mounting substrate
• CPC Class Codes: H01L 2924/19107 : off-chip wires
• CPC Class Codes: H02M 3/003 : Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: Y10T 29/4902 : Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49073 : by assembling coil and core
• CPC Class Codes: Y10T 29/49076 : From comminuted material
• CPC Class Codes: Y10T 29/49121 : Beam lead frame or beam lead device
• CPC Class Codes: Y10T 29/49146 : with encapsulating, e.g., potting, etc.

Abstract

A method of forming a power module located on a conductive substrate by providing power conversion circuitry. The method of providing the power conversion circuitry includes forming a magnetic device by placing a magnetic core proximate a conductive substrate with a surface thereof facing a conductive substrate, and placing a conductive clip proximate a surface of the magnetic core. The method of forming the magnetic device also includes electrically coupling ends of the conductive clip to the conductive substrate to cooperatively form a winding therewith about the magnetic core. The method of providing the power conversion circuitry also includes providing at least one switch on the conductive substrate. The method of forming the power module also includes depositing an encapsulant about the power conversion circuitry.

Claims

1. A method of forming a power module located on a conductive substrate, comprising:

providing power conversion circuitry, including;

forming a magnetic device by;

placing a magnetic core proximate said conductive substrate with a surface thereof facing said conductive substrate,

placing an entirely unencapsulated conductive clip having a bare horizontal lower surface facing and directly above a horizontal upper surface of said magnetic core, and

electrically coupling ends of said conductive clip to said conductive substrate to cooperatively form a winding therewith about said magnetic core, and

providing at least one switch on said conductive substrate; and

depositing an encapsulant about said power conversion circuitry.

2. The method as recited in claim 1 wherein a lower surface of said magnetic core faces said conductive substrate.

3. The method as recited in claim 1 wherein said conductive clip is about 8 to 12 mils in thickness.

4. The method as recited in claim 1 wherein said conductive substrate is a leadframe.

5. The method as recited in claim 1 further comprising adhering said magnetic core to said conductive substrate.

6. The method as recited in claim 1 wherein said ends of said conductive clip are bent toward said conductive substrate about ends of said magnetic core.

7. The method as recited in claim 1 further comprising soldering said conductive clip to said conductive substrate.

8. The method as recited in claim 1 further comprising providing a gap between said conductive clip and said magnetic core.

9. The method as recited in claim 1 further comprising forming terminals that protrude from sides and a lower surface of said power module.

10. The method as recited in claim 1 wherein portions of said power module are formed from integrated circuits or surface mount components.

11. The method as recited in claim 1 wherein said magnetic core is a single piece magnetic core.

12. The method as recited in claim 1 wherein said ends of said conductive clip are surface mounted to said conductive substrate.

13. The method as recited in claim 1 wherein said conductive clip spans an end-to-end length of said magnetic core.

14. A method of forming a power module located on a patterned, conductive leadframe, comprising:

providing power conversion circuitry, including;

forming a magnetic device by;

adhering a magnetic core formed from a bar of magnetic material to said conductive leadframe,

locating at least one entirely unencapsulated conductive clip having a bare horizontal lower surface facing and directly above a horizontal upper surface of said magnetic core,

soldering ends of said at least one conductive clip to said conductive leadframe to cooperatively form a winding therewith about said magnetic core, and

providing at least one switch on said conductive leadframe; and

depositing an encapsulant about said power conversion circuitry.

15. The method as recited in claim 14 wherein said bar of magnetic material is formed from manganese zinc ferrite.

16. The method as recited in claim 14 further comprising forming terminals by creating leadframe fingers in said conductive leadframe that protrude from sides and a lower surface of said power module.

17. The method as recited in claim 14 further comprising electrically coupling portions of said conductive leadframe with at least one wire bond.

18. The method as recited in claim 14 wherein said ends of said at least one conductive clip are bent toward said conductive leadframe about ends of said magnetic core.

19. The method as recited in claim 14 further comprising providing a gap between said magnetic core and said at least one conductive clip.

20. The method as recited in claim 14 further comprising providing a gap between said magnetic core and said at least one conductive clip and further comprising substantially filling said gap with said encapsulant.

21. The method as recited in claim 14 wherein said encapsulant is an epoxy encapsulant.

22. The method as recited in claim 14 further comprising providing a controller and a driver.

23. The method as recited in claim 14 wherein portions of said power module are formed from integrated circuits or surface mount components.

24. The method as recited in claim 14 wherein said magnetic core is a single piece magnetic core.

25. The method as recited in claim 14 wherein said ends of said at least one conductive clip are surface mounted to said conductive leadframe.

26. The method as recited in claim 14 wherein said at least one conductive clip spans an end-to-end length of said magnetic core.