Power module for converting DC to AC

• US 9,088,226 B2
• Filed: 10/19/2011
• Issued: 07/21/2015
• Est. Priority Date: 10/19/2010
• Status: Active Grant

• Current Assignee: Electronic Motion Systems Holdings Limited
• Original Assignee: Electronics Motion Systems Holding Limited
• Inventors: Tompkins, James D., Dias, Ryan R., Bolt, Laird R.
• Primary Examiner(s): PERT, EVAN T
• Application Number:
  US13/880,553
• Publication Number:
  US 20130201741A1
• Time in Patent Office: 1,371 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 7/537 using semiconductor devices only, e.g. single switched pulse inverters
• CPC Class Codes: H02M 7/538 in a push-pull configuration H02M7/5375 takes precedence ; with oscillating arrangements H02M7/53832, H02M7/53846

Abstract

A power module for converting direct current to alternating current comprising a semiconductor switching circuit device, a substrate onto which the switching circuit device is physically and electrically coupled without wirebonds, a plurality of leadframe terminals physically and electrically coupled to the substrate, and a cover including an opening exposing a bottom side of the substrate and including a wall portion oriented generally orthogonally relative to the substrate with at least some of the leadframe terminals projecting outwardly from the wall portion. The leadframe terminals projecting outwardly from the wall portion may include an affixed portion coupled to the substrate and an extending segment lying in a plane above the affixed portion with the extending segment projecting outwardly from the wall portion and the cover encapsulating the affixed portion whereby the extending segment is spaced from a plane defined by the bottom side of the substrate.

Claims

1. A power module for converting direct current to alternating current, said power module comprising:

a semiconductor switching circuit device;

a substrate onto which said switching circuit device is physically and electrically coupled without wirebonds;

a plurality of leadframe terminals physically and electrically coupled to said substrate; and

a cover at least partially disposed about said power module, said cover including an opening exposing a bottom side of said substrate and including a wall portion oriented generally orthogonally relative to said substrate with at least some of said leadframe terminals projecting outwardly from said wall portion;

said leadframe terminals projecting outwardly from said wall portion including an affixed portion coupled to said substrate and an extending segment lying in a plane above said affixed portion, said extending segment projecting outwardly from said wall portion with said cover encapsulating said affixed portion whereby said extending segment is spaced from a plane defined by said bottom side of said substrate.

2. The power module of claim 1 wherein said leadframe terminals projecting outwardly from said wall portion further include a vertical segment, said vertical segment being positioned between said affixed portion and said extending segment with said vertical segment positioning said extending segment in a plane above said affixed portion.

3. The power module of claim 2 wherein said affixed portions are connected to said vertical segments by a first bend in said leadframe terminals, and wherein said extending segments are connected to said vertical segments by a second bend in said leadframe terminals.

4. The power module of claim 3 wherein said first bend forms an approximately right angle between said affixed portions and said vertical segments, and wherein said second bend forms an approximately right angle between said extending segments and said vertical segments.

5. The power module of claim 1 wherein said extending segments project generally horizontally from said wall portion relative to the plane defined by said bottom side of said substrate.

6. The power module of claim 1 further comprising at least one secondary substrate with said switching circuit device being physically and electrically coupled to said secondary substrate such that said switching circuit device is formed between said substrate and said secondary substrate.

7. The power module of claim 6 wherein said switching circuit device comprises a high side switching circuit device and a low side switching circuit device and includes a single secondary substrate disposed over both said high side switching circuit device and said low side switching circuit device.

8. The power module of claim 6 wherein said switching circuit device comprises a high side switching circuit device and a low side switching circuit device and includes a pair of secondary substrates, with one of said secondary substrates being physically and electrically coupled to said high side switching circuit device and the other of said secondary substrates being physically and electrically coupled to said low side switching circuit device.

9. The power module of claim 6 wherein said switching circuit device is coupled to said substrate and said secondary substrate by a soldered or a sintered connection.

10. The power module of claim 6 wherein said cover includes at least one cover aperture, said cover aperture exposing a top side of said secondary substrate.

11. The power module of claim 8 wherein said cover includes a pair of cover apertures, with one of said cover apertures exposing a top side of said secondary substrate of said high side switching circuit device and the other of said cover apertures exposing a top side of said secondary substrate of said low side switching circuit.

12. The power module of claim 1 wherein said leadframe terminals projecting outwardly from said wall portion include at least one of a battery terminal and a phase terminal, and wherein said leadframe terminals projecting outwardly from said wall portion further include an upright portion, said upright portion extending generally vertically upwards from said extending portions.

13. The power module of claim 1 wherein said switching circuit device includes either a plurality of insulated gate bipolar transistors and diodes or MOSFETs.

14. The power module of claim 1 wherein said substrate includes a ceramic layer having a top side and a bottom side, a first copper layer coupled to said top side of said ceramic layer, and a second copper layer coupled to said bottom side of said ceramic layer.

15. The power module of claim 1 wherein said substrate includes a copper layer, an aluminum oxide layer, and an aluminum plate, with said aluminum oxide layer being formed on said aluminum base plate and said copper layer being applied over said aluminum oxide layer.

16. The power module of claim 6 wherein said secondary substrate includes a ceramic layer having a top side and a bottom side, a first copper layer coupled to said top side of said ceramic layer, and a second copper layer coupled to said bottom side of said ceramic layer.

17. The power module of claim 6 wherein said secondary substrate includes a copper layer, an aluminum oxide layer, and an aluminum plate, with said aluminum oxide layer being formed on said aluminum base plate and said copper layer being applied over said aluminum oxide layer.

18. The power module of claim 1 wherein said cover comprises a molded cover and is at least partially disposed over a top side of said power module.

19. The power module of claim 18 wherein said cover includes a peripheral raised portion forming said wall portion, and wherein said affixed portions and part of said extending portions are encapsulated within said raised portion.

20. The power module of claim 19 wherein said cover includes said peripheral raised portion and said wall portion on at least two sides.

21. A power module for converting direct current to alternating current, said power module comprising:

a semiconductor switching circuit device;

an underlying substrate and at least one secondary substrate, said switching circuit device being physically and electrically coupled without wirebonds to said underlying substrate and said secondary substrate such that said switching circuit device is formed between said underlying substrate and said secondary substrate whereby said switching circuit device comprises at least one high side switching circuit device and at least one low side switching circuit device;

a plurality of leadframe terminals physically and electrically coupled to said underlying substrate; and

a cover at least partially disposed about a top side of said power module and including an opening exposing a bottom side of said substrate, said cover including an upstanding wall portion at least partially disposed about said opening with at least some of said leadframe terminals projecting outwardly from said wall portion;

said leadframe terminals projecting outwardly from said wall portion including a vertical segment encapsulated within said cover and an extending segment projecting outwardly from said wall portion, said vertical segment being connected to said extending segment and elevating said extending segment above said substrate whereby the portion of said extending segment projecting outwardly from said wall portion is vertically elevated from the connection of said leadframe terminals with said substrate.

22. The power module of claim 21 comprising either (a) a single secondary substrate disposed over both said high side switching circuit device and said low side switching circuit device, or (b) at least one pair of secondary substrates, with one of said pair of secondary substrates disposed over said high side switching circuit device and the other of said pair of secondary substrates disposed over said low side switching circuit device.

23. The power module of claim 21 wherein said cover includes at least one cover aperture, said cover aperture exposing a top side of said secondary substrate.

24. The power module of claim 21 wherein said leadframe terminals projecting outwardly from said wall portion include at least one of a battery terminal and a phase terminal, and wherein said leadframe terminals projecting outwardly from said wall portion further include an upright portion, said upright portion extending vertically upwards from said extending portions.

25. The power module of claim 21 wherein pairs of said high side switching circuit device and said low side switching circuit device are in parallel, and wherein each said high side switching circuit device and each said low side switching circuit device comprises an IGBT and a diode, with the respective IGBTs being arranged in series and the respective diodes being arranged in series.

26. The power module of claim 21 wherein at least one of said underlying substrate and said secondary substrate includes a ceramic layer having a top side and a bottom side, a first copper layer coupled to said top side of said ceramic layer, and a second copper layer coupled to said bottom side of said ceramic layer.

27. The power module of claim 21 wherein at least one of said underlying substrate and said secondary substrate includes a copper layer, an aluminum oxide layer, and an aluminum plate, with said aluminum oxide layer being formed on said aluminum base plate and said copper layer being applied over said aluminum oxide layer.