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

• US 10,304,615 B2
• Filed: 03/20/2014
• Issued: 05/28/2019
• Est. Priority Date: 10/05/2005
• Status: Active Grant

• Current Assignee: Altera Corporation (Intel Corporation)
• Original Assignee: Enpirion, Inc. (MediaTek, Inc.)
• Inventors: Lotfi, Ashraf W., Wilkowski, Mathew A., Liakopoulos, Trifon M., Weld, John D.
• Primary Examiner(s): Enad, Elvin G
• Assistant Examiner(s): Hossain, Kazi S
• Application Number:
  US14/220,478
• Publication Number:
  US 20140203903A1
• Time in Patent Office: 1,895 Days
• Field of Search: 336221, 336192, 336200
• 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 magnetic device, comprising:

a magnetic core, including;

a first surface continuously spanning an end-to-end boundary of said magnetic core and facing a first conductive substrate; and

an opposing second surface continuously spanning said end-to-end boundary of said magnetic core;

a first u-shaped conductive clip facing said second surface and continuously spanning said end-to-end boundary of said magnetic core to form a first portion of a winding of said magnetic device; and

a second u-shaped conductive clip facing said second surface and continuously spanning said end-to-end boundary of said magnetic core to form a second portion of said winding of said magnetic device, wherein said first u-shaped conductive clip is coupled by a first solder area to said first conductive substrate, and said second u-shaped conductive clip is coupled by a second solder area to a second conductive substrate separate from said first conductive substrate, and wherein a first location on said first conductive substrate where said first u-shaped conductive clip is coupled to said first conductive substrate by the first solder area and a second location on said second conductive substrate where said second u-shaped conductive clip is coupled to said second conductive substrate by the second solder area are separated by a gap, wherein the gap comprises an air gap between the first solder area and the second solder area.

2. The magnetic device as recited in claim 1 wherein ends of said first and second u-shaped conductive clips are electrically coupled to said first and second conductive substrates to cooperatively form said winding therewith about said magnetic core.

3. The magnetic device as recited in claim 1 wherein ends of said first and second u-shaped conductive clips are bent toward said first and second conductive substrates about ends of said magnetic core.

4. The magnetic device as recited in claim 1 wherein said first and second conductive substrates also form an electrically conductive interconnect layer for a component coupled thereto.

5. The magnetic device as recited in claim 1 wherein said first and second conductive substrate also form an electrically conductive interconnect layer for a component wire bonded thereto.

6. The magnetic device as recited in claim 1 wherein said magnetic device is an inductor.

7. The magnetic device as recited in claim 1 wherein said first and second conductive substrates comprise a conductive leadframe.

8. The magnetic device as recited in claim 7 wherein said conductive leadframe includes leadframe fingers that form terminals for external electrical connections.

9. The magnetic device as recited in claim 1 further comprising an additional gap between said second surface of said magnetic core and said second u-shaped conductive clip.

10. The magnetic device as recited in claim 1 wherein said first surface of said magnetic core is adhered to an adhesive on said first conductive substrate.

11. The magnetic device as recited in claim 1 wherein said first surface of said magnetic core is soldered to said first conductive substrate.

12. The magnetic device as recited in claim 1 wherein said first or second u-shaped conductive clip is about 8 to 12 millimeters (mils) in thickness.

13. The magnetic device as recited in claim 1 wherein said magnetic core is formed from manganese zinc ferrite.

14. The magnetic device as recited in claim 1 wherein said magnetic core is formed from a bar of magnetic material.

15. The magnetic device as recited in claim 1 wherein said magnetic core is a single piece magnetic core.

16. The magnetic device as recited in claim 1 further comprising an encapsulant about said magnetic device.

17. A magnetic device, comprising:

a magnetic core, including;

a first surface continuously spanning an end-to-end boundary of said magnetic core and facing a first conductive substrate; and

an opposing second surface continuously spanning said end-to-end boundary of said magnetic core;

a first u-shaped conductive clip facing said second surface and continuously spanning end-to-end boundary of said magnetic core to form a first portion of a winding of said magnetic device;

a second u-shaped conductive clip facing said second surface and continuously spanning said end-to-end boundary of said magnetic core to form a second portion of said winding of said magnetic device, wherein said first u-shaped conductive clip is coupled by a first solder area to said first conductive substrate, and said second u-shaped conductive clip is coupled by a second solder area to a second conductive substrate separate from said first conductive substrate, and wherein a first location on said first conductive substrate where said first u-shaped conductive clip is coupled to said first conductive substrate by the first solder area and a second location on said second u-shaped conductive substrate where said second u-shaped conductive clip is coupled to said second conductive substrate are separated by a gap, wherein the gap comprises an air gap between the first solder area and the second solder area; and

a plurality of wire bonds coupled between said first conductive substrate and a semiconductor die.

18. A magnetic device, comprising:

a magnetic core, including;

a first surface continuously spanning an end-to-end boundary of said magnetic core and facing a first conductive substrate; and

an opposing second surface continuously spanning said end-to-end boundary of said magnetic core;

a first conductive clip facing said second surface and continuously spanning said end-to-end boundary of said magnetic core to form a first portion of a winding of said magnetic device;

a second conductive clip facing said second surface and continuously spanning said end-to-end boundary of said magnetic core to form a second portion of said winding of said magnetic device, wherein said first conductive clip is coupled by a first solder area to said first conductive substrate, and said second conductive clip is coupled by a second solder area to a second conductive substrate separate from said first conductive substrate, and wherein a first location on said first conductive substrate where said first conductive clip is coupled to said first conductive substrate and a second location on said first conductive substrate where said second conductive clip is coupled to said second conductive substrate are separated by a gap, wherein the gap comprises an air gap between the first solder area and the second solder area;

a plurality of wire bonds coupled between said first conductive substrate and a semiconductor die; and

at least one wire bond coupled between said first conductive substrate and second conductive substrate.