POWER MODULE FOR INVERTER SWITCHING DEVICES HAVING GATE COILS SHIELDED FROM EDDY CURRENTS

• US 20180198378A1
• Filed: 01/12/2017
• Published: 07/12/2018
• Est. Priority Date: 01/12/2017
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: XU, ZHUXIAN, LEI, GUANGYIN, CHEN, CHINGCHI
• Granted Patent: US 10,622,909 B2
• Time in Patent Office: Days
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/40245 the item being metallic
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 25/07 the devices being of a type provided for in group H01L29/00
• CPC Class Codes: H01L 25/072 the devices being arranged next to each other
• CPC Class Codes: H01L 2924/00012 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H05K 7/1432 specially adapted for power drive units or power converters
• CPC Class Codes: H05K 7/14329 specially adapted for the configuration of power bus bars
• CPC Class Codes: H05K 7/20927 Liquid coolant without phase change
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/72 : Electric energy management in electromobility

Abstract

An inverter for an electric vehicle drive has a bridge configuration using power transistors packaged in actively cooled power modules. Control electrodes in the power modules carrying gate signals to drive the transistors contain inductive coils to increase a common source inductance in order to reduce power losses. Each inverter power module comprises a pair of transistor dies with output electrodes defining a power loop. The control electrodes with inductive coils carrying respective gate signals are arranged to be magnetically coupled with the power loop. For active cooling, a heat conductive plate underlies the dies. A magnetic interrupter is disposed at the heat conductive plate. A localized eddy current preventer is interposed at the heat conductive plate in alignment with the inductive coils to avoid eddy currents that could otherwise reduce the coupling of the inductive coils with the power loop.

Claims

1. An inverter power module comprising;

a pair of transistor dies with output electrodes defining a power loop;

a pair of control electrodes carrying respective gate signals and having inductive coils magnetically coupling with the power loop;

a heat conductive plate underlying the dies; and

a localized eddy current preventer interposed at the heat conductive plate in alignment with the inductive coils.

2. The power module of claim 1 wherein the preventer is comprised of a magnetic shielding sheet.

3. The power module of claim 2 wherein the magnetic shielding sheet is comprised of silicon steel.

4. The power module of claim 1 wherein the preventer is comprised of an open slot in the heat conductive plate creating an electrically non-conducting region so that eddy currents are displaced laterally away from the inductive coils.

5. The power module of claim 1 wherein the heat conductive plate is comprised of a fluid heat exchanger shell having planar top and bottom walls and an internal channel, wherein the preventer is comprised of an open slot in the walls partially bisecting the shell, and wherein the internal channel provides a coolant flow path extending between both sides of the open slot.

6. The power module of claim 1 wherein the heat conductive plate is comprised of a heat spreader having two discontinuous sections separated by an electrically non-conducting region.

7. The power module of claim 1 wherein the dies and electrodes are mounted to a direct bonded copper (DBC) substrate, and wherein the heat conductive plate is comprised of a DBC backing layer having two discontinuous sections separated by an electrically non-conducting region.

8. The power module of claim 1 wherein the inductive coils are connected to gate terminals of the transistor dies.

9. The power module of claim 1 wherein the inductive coils are connected to emitter terminals of the transistor dies.

10. The power module of claim 1 wherein the transistor dies each comprise an insulated gate bipolar transistor (IGBT).

11. An electric drive system for a vehicle, comprising:

a DC link between a pair of buses receiving a DC supply voltage from a power supply;

a plurality of power modules coupled between the buses in a bridge configuration to provide alternating power to a drive motor, each power module comprising;

a pair of transistor dies with output electrodes defining a power loop;

a pair of control electrodes carrying respective gate signals and having inductive coils magnetically coupling with the power loop;

a heat conductive plate underlying the dies; and

a localized eddy current preventer interposed at the heat conductive plate in alignment with the inductive coils.

12. The drive system of claim 11 wherein each preventer is comprised of a magnetic shielding sheet.

13. The drive system of claim 12 wherein each magnetic shielding sheet is comprised of silicon steel.

14. The drive system of claim 11 wherein each preventer is comprised of an open slot in the respective heat conductive plate creating an electrically non-conducting region so that eddy currents are displaced laterally away from the inductive coils.

15. The drive system of claim 11 wherein each heat conductive plate is comprised of a fluid heat exchanger shell having planar top and bottom walls and an internal channel, wherein each preventer is comprised of an open slot in the respective walls partially bisecting the shell, and wherein each internal channel provides a coolant flow path extending between both sides of the respective open slot.

16. The drive system of claim 11 wherein each heat conductive plate is comprised of a heat spreader having two discontinuous sections separated by an electrically non-conducting region.

17. The drive system of claim 11 wherein the dies and electrodes are mounted to a respective direct bonded copper (DBC) substrate, and wherein each heat conductive plate is comprised of a respective DBC backing layer having two discontinuous sections separated by an electrically non-conducting region.

18. The drive system of claim 11 wherein the inductive coils are connected to gate terminals of the respective transistor dies.

19. The drive system of claim 11 wherein the inductive coils are connected to emitter terminals of the respective transistor dies.

20. The drive system of claim 11 wherein the transistor dies each comprise an insulated gate bipolar transistor (IGBT).