DC-DC converter assembly, method of manufacturing a DC-DC converter assembly and method of manufacturing an output inductor for a DC-DC converter assembly

• US 9,892,851 B2
• Filed: 05/26/2017
• Issued: 02/13/2018
• Est. Priority Date: 10/28/2013
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Todorov, Emil, Molloy, Brian
• Primary Examiner(s): NGUYEN, TUYEN T
• Application Number:
  US15/606,321
• Publication Number:
  US 20170263378A1
• Time in Patent Office: 263 Days
• Field of Search: 336200, 336232, 336 65, 336192
• CPC Class Codes: H01F 17/06 with core substantially closed in itself, e.g. toroid
• 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 41/0246 Manufacturing of magnetic circuits by moulding or by pressing powder magnetic cores made by moulding or by pressing powder H01F27/255; soft magnetic particles H01F1/20, H01F1/36
• CPC Class Codes: H01F 5/00 Coils superconducting coils H01F6/06; fixed inductances of the signal type H01F17/00
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H02M 3/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H05K 1/18 Printed circuits structurally associated with non-printed electric components H05K1/0201, H05K1/023, H05K1/0243, and H05K1/16 take precedence
• CPC Class Codes: Y10T 29/49075 including permanent magnet or core
• CPC Class Codes: Y10T 29/49128 Assembling formed circuit to base

Abstract

A DC-DC converter assembly a power stage die of a DC-DC converter attached to a board, an output inductor attached to the board and electrically connected to an output of the power stage die, the output inductor accommodating the power stage die under the output inductor, a plurality of input capacitors attached to the board and electrically connected to input terminals of the power stage die, an output capacitor attached to the board and electrically connected to the output inductor, and a plurality of decoupling capacitors attached to the board and electrically connected to power terminals of the power stage die. A total footprint of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors is at least a third of the combined surface area of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors.

Claims

1. A DC-DC converter assembly, comprising:

a power stage die of a DC-DC converter attached to a board;

an output inductor attached to the board and electrically connected to an output of the power stage die, the output inductor accommodating the power stage die under the output inductor;

a plurality of input capacitors attached to the board and electrically connected to input terminals of the power stage die;

an output capacitor attached to the board and electrically connected to the output inductor; and

a plurality of decoupling capacitors attached to the board and electrically connected to power terminals of the power stage die,

wherein a total footprint of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors is at least a third of the combined surface area of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors.

2. The DC-DC converter assembly of claim 1, wherein a magnetic core of the output inductor is positioned over and spaced apart from the power stage die.

3. The DC-DC converter assembly of claim 2, wherein the magnetic core has a thinner inner region and a thicker outer region so that a gap exists between the thinner inner region and the board, and wherein the gap accommodates a thickness of the power stage die.

4. The DC-DC converter assembly of claim 3, wherein the thickness of the power stage die and the gap are both less than 1 mm.

5. The DC-DC converter assembly of claim 2, wherein the magnetic core has a planar side facing the board, and wherein first and second terminals of the output inductor extend from a periphery of the magnetic core beyond the planar side by a distance corresponding to at least a thickness of the power stage die to realize a gap between the planar side of the magnetic core and the board that accommodates the power stage die.

6. The DC-DC converter assembly of claim 2, wherein first and second terminals of the magnetic core are secured to the board by first and second blocks at a periphery of the magnetic core, and wherein the first and second blocks each have a thickness corresponding to at least a thickness of the power stage die to realize a gap between the magnetic core and the board that accommodates the power stage die.

7. The DC-DC converter assembly of claim 1, wherein the DC-DC converter is a multi-phase converter and the power stage die provides one phase of the multi-phase converter.

8. The DC-DC converter assembly of claim 1, wherein the output inductor also accommodates the input capacitors under the output inductor.

9. The DC-DC converter assembly of claim 1, wherein the output inductor completely covers the power stage die.

10. The DC-DC converter assembly of claim 1, wherein the total footprint of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors is at least half the combined surface area of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors.

11. A method of manufacturing an output inductor, the method comprising:

forming first and second sections of a magnetic core, the second section having a thinner inner region and a thicker outer region, the thinner inner region being thin enough to accommodate a power stage die of a DC-DC converter positioned under the second section of the magnetic core without the power stage die contacting the thinner inner region and the thicker outer region of the second section;

placing an electrical conductor on the second section; and

attaching the first section to the second section so that the magnetic core secures the electrical conductor and the electrical conductor has contactable terminals.

12. The method of claim 11, wherein forming the second section of the magnetic core comprises molding a magnetic material in a mold shaped to form the thinner inner region and the thicker outer region of the second section.

13. A method of manufacturing a DC-DC converter assembly, the method comprising:

attaching a power stage die of a DC-DC converter to a board;

attaching an output inductor to the board, the output inductor being electrically connected to an output of the power stage die and accommodating the power stage die under the output inductor after being attached to the board;

attaching a plurality of input capacitors to the board, the input capacitors being electrically connected to input terminals of the power stage die;

attaching an output capacitor to the board, the output capacitor being electrically connected to the output inductor; and

attaching a plurality of decoupling capacitors to the board, the decoupling capacitors being electrically connected to power terminals of the power stage die,

wherein the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors are attached to the board so that a total footprint of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors is at least a third of the combined surface area of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors.

14. The method of claim 13, wherein attaching the output inductor to the board comprises positioning a magnetic core of the output inductor over and spaced apart from the power stage die.

15. The method of claim 14, wherein the magnetic core has a thinner inner region and a thicker outer region so that a gap exists between the thinner inner region and the board, and wherein the gap accommodates a thickness of the power stage die after the output inductor is attached to the board.

16. The method of claim 14, wherein attaching the output inductor to the board comprises positioning the magnetic core so that a planar side of the magnetic core faces the board and first and second terminals of the output inductor extend from a periphery of the magnetic core beyond the planar side by a distance corresponding to at least a thickness of the power stage die to realize a gap between the planar side of the magnetic core and the board that accommodates the power stage die.

17. The method of claim 14, wherein attaching the output inductor to the board comprises positioning the magnetic core so that first and second terminals of the magnetic core are secured to the board by first and second blocks at a periphery of the magnetic core, and wherein the first and second blocks each have a thickness corresponding to at least a thickness of the power stage die to realize a gap between the magnetic core and the board that accommodates the power stage die.

18. The method of claim 13, wherein the plurality of input capacitors are attached to the board before the output inductor, and wherein the output inductor also accommodates the input capacitors under the output inductor after being attached to the board.

19. The method of claim 13, wherein the output inductor is attached to the board so that the output inductor completely covers the power stage die.

20. The method of claim 13, wherein the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors are attached to the board so that the total footprint of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors is at least half the combined surface area of the power stage die, the output inductor, the input capacitors, the output capacitor and the decoupling capacitors.