Substrate-level DC bus design to reduce module inductance

• US 6,845,017 B2
• Filed: 09/20/2001
• Issued: 01/18/2005
• Est. Priority Date: 09/20/2000
• Status: Expired due to Term

• Current Assignee: Continental Automotive Systems, Inc. (Continental AG)
• Original Assignee: Ballard Power Systems Corporation (Superior Plus Corporation)
• Inventors: Maly, Douglas, Flett, Fred, Ahmed, Sayeed, Parkhill, Scott
• Primary Examiner(s): Cuneo, Kamand
• Assistant Examiner(s): DINH, TUAN T
• Application Number:
  US09/957,568
• Publication Number:
  US 20020118560A1
• Time in Patent Office: 1,216 Days
• Field of Search: 361/775, 361/764, 361/728, 361/752, 439/76.1, 439/76.2, 257690-694, 257723-724, 257703-704, 257/678, 363/141
• US Class Current: 361/775
• CPC Class Codes: H01L 2223/665 Bias feed arrangements
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/49175 Parallel arrangements
• CPC Class Codes: H01L 23/50 for integrated circuit devices, e.g. power bus, number of leadsH01L23/482 - H01L23/498 take precedence
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• CPC Class Codes: H01L 25/072 the devices being arranged next to each other
• 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 2924/1305 Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/13055 Insulated gate bipolar transistor [IGBT]
• CPC Class Codes: H01L 2924/13091 Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/19107 off-chip wires
• CPC Class Codes: H01L 2924/30107 Inductance
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H05K 1/0215 Grounding of printed circuits by connection to external grounding means
• CPC Class Codes: H05K 1/0237 High frequency adaptations H05K1/0216 takes precedence
• CPC Class Codes: H05K 1/0306 Inorganic insulating substrates, e.g. ceramic, glass
• CPC Class Codes: H05K 2201/09345 Power and ground in the same plane; Power planes for two voltages in one plane
• CPC Class Codes: H05K 2201/10446 Mounted on an edge soldering edge mounted components H05K3/3405; edge terminals H05K2201/1034
• CPC Class Codes: H05K 2201/10636 Leadless chip, e.g. chip capacitor or resistor
• CPC Class Codes: H05K 2203/049 Wire bonding
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product

Abstract

A DC bus for use in a power module includes a positive DC conductor bus plate parallel with a negative DC conductor bus plate. The positive bus and negative bus permit counter-flow of currents, thereby canceling magnetic fields and their associated inductances, and the positive and negative bus are connectable to the center portion of a power module.

Claims

1. A DC bus bar structure for use in a power module, comprising:

an elongated substantially planar first bus plate, the first bus plate comprising at least an upper surface;

a first insulating layer overlying a portion of the upper surface of the first bus plate and exposing a wire bonding area on the upper surface, the bonding area extending along at least a portion of one edge of the upper surface of the first bus plate; and

an elongated substantially planar second bus plate, the second bus plate comprising at least an upper surface comprising an exposed wire bonding area extending along at least a portion of one edge of the upper surface of the second bus plate, the second bus plate overlying at least a portion of the first insulating layer and positioned parallel to the first bus plate such that the upper surface of the first bus plate and the upper surface of the second bus plate are parallel and face a same direction, and where the second bus plate is spaced from the first bus plate by the first insulating layer; and

wherein the first and second bus plates are physically positioned between a high side and a low side of the power module, a first set of wire bonds electrically coupling the bonding area of the first bus plate to one of the high side and the low side of the power module, and a second set of wire bonds electrically coupling the bonding area of the second bus plate to the other one of the high side and the low side of the power module.

2. The DC bus bar structure of claim 1, further comprising:

a second insulating layer overlying a portion of the upper surface of the second bus plate, exposing the bonding area extending along at least the portion of the one edge of the upper surface of the second bus plate.

3. The DC bus bar structure of claim 1 wherein the bonding area extending along at least the portion of the one edge of the upper surface of the first bus plate and the bonding area extending along at least the portion of the one edge of the upper surface of the second bus plate are opposed to one another across a longitudinal axis of the DC bus bar structure.

4. The DC bus bar structure of claim 1, further comprising:

a first lead terminal electrically coupled to the first bus plate at one end thereof;

a second lead terminal electrically coupled to the second bus plate at one end thereof, the one end of the second bus plate being opposed to the one end of the first bus plate across a lateral axis of the DC bus bar structure such that current flow in the second bus plate is opposite in direction to current flow in the first bus plate.

5. A DC bus bar structure for use in a power module, comprising:

a substantially straight elongated first bus plate comprising a first surface and a second surface opposed to the first surface;

a substantially straight elongated second bus plate comprising a first surface and a second surface opposed to the first surface, the second bus plate positioned parallel and spaced from the first bus plate; and

a first insulating layer interposed between a portion of the first and the second bus plates, wherein the first bus plate, the second bus plate and the first insulating layer are disposed such that a first wire bonding area is exposed extending along at least a portion of the first surface of the first bus plate and a second wire bonding area is exposed extending along at least a portion of the first surface of the second bus plate;

wherein the first and second bus plates are physically positioned between a high side and a low side of the power module, a first set of wire bonds electrically coupling the first wire bonding area to one of the high side and the low side of the power module, and a second set of wire bonds electrically coupling the second wire bonding area to the other one of the high side and the low side of the power module.

6. The DC bus bar structure of claim 5, further comprising:

a second insulating layer overlying a portion of the first surface of the second bus plate, exposing the second wire bonding area of the second bus plate.

7. A power module comprising:

a substrate comprising at least a first surface;

a first set of switches coupled on the substrate to form at least a portion of a high side of the power module;

a second set of switches coupled on the substrate to form at least a portion of a low side of the power module;

an elongated first bus plate comprising at least an upper surface, the upper surface of the first bus plate approximately parallel with and facing a same direction as the first surface of the substrate;

a first insulating layer overlying a portion of the upper surface of the first bus plate, and exposing a bonding area extending along at least a portion of the upper surface of the first bus plate;

an elongated second bus plate comprising at least an upper surface, the upper surface of the second bus plate approximately parallel with and facing a same direction as the first surface of the substrate, the second bus plate overlying at least a portion of the first insulating layer and positioned parallel to and spaced from the first bus plate by the first insulating layer, and disposed over a portion of the upper surface of the first bus plate exposing a bonding area extending along at least a portion of one edge of the upper surface of the first bus plate;

a second insulating layer overlying a portion of the upper surface of the second bus plate, and exposing a bonding area extending along at least a portion of the upper surface of the second bus plate;

a first set of wire bonds electrically coupling the bonding area of the first bus plate to one of the high side and the low side of the power module; and

a second set of wire bonds electrically coupling the bonding area of the second bus plate to the other one of the high side and the low side of the power module;

wherein the high side of the power module is on a first portion of the first surface of the substrate and the low side of the power module is on a second portion of the first surface of the substrate, and the first and second bus plates are both positioned between the first and the second portions of the first surface of the substrate.

8. The power module of claim 7 wherein the bonding area of the first bus plate extends along at least a portion of an edge of the upper surface of the first bus plate and the bonding area of the second bus plate extends along at least a portion of an edge of the upper surface of the second bus plate.

9. The power module of claim 7 wherein the first and the second bus plates extend along an entire length of the substrate.

10. The power module of claim 7 wherein the first and the second sets of switches each comprise a respective row of twelve switches disposed along a length of the substrate, and the first and the second bus plates extend along an entire length of the rows of switches.

11. The power module of claim 7 wherein the first and the second bus plates are straight bars.

12. A power module comprising:

a substrate comprising at least a first surface;

a first set of switches coupled on the substrate to form at least a portion of a high side of the power module;

a second set of switches coupled on the substrate to form at least a portion of a low side of the power module;

an elongated first bus plate comprising at least an upper surface, the upper surface of the first bus plate approximately parallel with and facing a same direction as the first surface of the substrate;

a first insulating layer overlying a portion of the upper surface of the first bus plate, and exposing a bonding area extending along at least a portion of the upper surface of the first bus plate;

an elongated second bus plate comprising at least an upper surface, the upper surface of the second bus plate approximately parallel with and facing a same direction as the first surface of the substrate, the second bus plate overlying at least a portion of the first insulating layer and positioned parallel to and spaced from the first bus plate by the first insulating layer, and disposed over a portion of the upper surface of the first bus plate exposing a bonding area extending along at least a portion of one edge of the upper surface of the first bus plate;

a second insulating layer overlying a portion of the upper surface of the second bus plate, and exposing a bonding area extending along at least a portion of the upper surface of the second bus plate;

a first set of wire bonds electrically coupling the bonding area of the first bus plate to one of the high side and the low side of the power module; and

a second set of wire bonds electrically coupling the bonding area of the second bus plate to the other one of the high side and the low side of the power module,

wherein the bonding area extending along at least the portion of the upper surface of the first bus plate and the bonding area extending along at least the portion of the upper surface of the second bus plate are opposed to one another across a longitudinal axis of the first bus plate.

13. The power module of claim 12, further comprising:

a first lead terminal electrically coupled to the first bus plate at one end thereof; and

a second lead terminal electrically coupled to the second bus plate at one end thereof, the one end of the second bus plate being opposed to the one end of the first bus plate across a lateral axis of the power module such that current flow in the second bus plate is opposite in direction to current flow in the first bus plate.

14. The power module of claim 13, further comprising:

a housing enclosing the substrate, the first and the second sets of switches, and the entirety of the first and the second bus plates except for the first and the second lead terminals.

15. The power module of claim 13, further comprising:

an approximately rectangular housing enclosing the substrate, the first and the second sets of switches, and the entirety of the first and the second bus plates except for the first and the second lead terminals, wherein the first and the second bus plates extend along a longitudinal axis of the housing.