Architecture for power modules such as power inverters
View Patent ↗Power converters such as power modules configured as inverters employ modularized approaches. In some aspects, semiconductor devices are thermally coupled directly to thermally conductive substrates without intervening dielectric or insulative structures. Additionally, or alternatively, semiconductor devices are thermally coupled to thermally conductive substrates with relatively large surface areas before heat transferred from the semiconductor devices encounters a dielectric or electrically insulating structure with correspondingly high thermal impedance.
1. A power module, comprising:
a first switch module comprising a first base plate and a first number of switches, the first base plate comprising a first surface and a second surface opposed to the first surface, the switches of the first number of switches each comprising a first active terminal, a second active terminal, and a control terminal, one of the active terminals of each of the first number of switches surface mounted to the first surface of the first base plate;
a second switch module comprising a second base plate and a second number of switches, the second base plate comprising a first surface and a second surface opposed to the first surface, the switches of the second number of switches each comprising a first active terminal, a second active terminal, and a control terminal, one of the active terminals of each of the second number of switches surface mounted to the first surface of the second base plate; and
a housing comprising an electrically insulative material forming an interior of the housing separated from an exterior of the housing, the first and second base plates received by the housing such that the first surfaces of the first and second base plates are disposed in the interior of the housing and the second surfaces of the first and second base plates are exposed to the exterior of the housing to transfer heat thereto, the housing further comprising at least a first rib of electrically insulative material extending at least partially between the first and the second base plates to electrically isolate the first and the second base plates from one another.
2. The power module of claim 1 wherein the first surface of the first base plate is thermally coupled to the second surface of the first base plate without an intervening thermally resistive material.
3. The power module of claim 2 wherein the first base plate consists of a conductive material selected from the group consisting of copper and aluminum.
4. The power module of claim 1 wherein each of the first and the second base plates consist of a respective plate of a metal.
5. The power module of claim 1 wherein the first switch module further comprises a first insulating substrate carried by the first surface of the first base plate and a first conductive pattern carried by the first insulating substrate, the first insulating substrate electrically insulating the first conductive pattern from the first base plate, and wherein the second switch module further comprises a second insulating substrate carried by the second base plate and a second conductive pattern carried by the second insulating substrate, the second insulating substrate electrically insulating the second conductive pattern from the second base plate.
6. The power module of claim 5 , further comprising:
a first set of wire bonds electrically coupling the first conductive pattern to the control terminals of the first set of switches; and
a second set of wire bonds electrically coupling the second conductive pattern to the control terminals of the second set of switches.
7. The power module of claim 5 wherein the first insulting substrate and the first conductive pattern comprise two layers of one of a direct bond copper substrate and a direct bond aluminum substrate.
8. The power module of claim 1 , further comprising:
a first conductive member;
a first number of wire bonds electrically coupling the first conductive member with the first base plate;
a second conductive member; and
a second number of wire bonds electrically coupling the second conductive member with the one of the active terminals of the second set of switches;
a conductive interconnect;
a third number of wire bonds electrically coupling the conductive interconnect with the second base plate; and
a fourth number of wire bonds electrically coupling the conductive interconnect with one of the active terminals of the first set of switches.
9. The power module of claim 8 wherein the conductive interconnect partially overlays the first conductive member, exposing a sufficient area of the first conductive member to attach wire bonds thereto, and the second conductive member partially overlays the conductive interconnect, exposing a sufficient area of the conductive interconnect to attach wire bonds thereto.
10. The power module of claim 9 wherein the first conducive member, the second conductive member and the conductive interconnect are elongated members positioned between proximate edges of the first and the second base plates.
11. The power module of claim 1 wherein the first set of switches comprises a number of unpackaged bare silicon die transistors.
12. The power module of claim 1 , further comprising:
a circuit board overlying the interior of the housing to isolate the interior of the housing from the exterior of the housing.
13. The power module of claim 1 , further comprising:
a cooling header thermally coupled to at least one of the first and the second base plates.
14. A power module, comprising:
a housing of an electrically insulative material comprising a perimeter wall forming an interior compartment and at least a first rib;
a first base plate comprising a first surface and a second surface opposed to the first surface, the first base plate coupled to the housing such that the first surface of the first base plate is disposed in the interior compartment and at least half of the second surface of the first base plate is exposed to an exterior of the housing;
a second base plate comprising a first surface and a second surface opposed to the first surface, the second base plate coupled to the housing such that the first surface of the second base plate is disposed in the interior compartment and at least half of the second surface of the second base plate is exposed to the exterior of the housing, the first rib extending at least partially between the first and the second base plates to electrically isolate the first base pate from the second base plate;
a first conductive member coupled across the housing;
a second conductive member coupled across the housing;
a conductive interconnect received in the housing;
a first number of bare die transistors each comprising a first active terminal, a second active terminal, and a control terminal, one of the active terminals of each of the first number of bare die transistors electrically and thermally surface mounted to the first surface of the first base plate and the other one of the active terminals electrically coupled to conductive interconnect by a first set of wire bonds;
a second number of bare die transistors comprising a first active terminal, a second active terminal, and a control terminal, one of the active terminals of each of the second number of bare die transistors electrically and thermally surface mounted to the first surface of the second base plate and the other one of the active terminals electrically coupled to the second conductive member by a second set of wire bonds;
a third set of wire bonds electrically coupling the first base plate to the first conductive member; and
a fourth set of wire bonds electrically coupling the second base plate to the conductive interconnect.
15. The power module of claim 14 wherein the conductive interconnect is disposed between at least a portion of the first and the second conductive members.
16. The power module of claim 14 wherein the conductive interconnect partially overlays the first conductive member, exposing a sufficient area of the first conductive member to attach wire bonds thereto, and the second conductive member partially overlays the conductive interconnect, exposing a sufficient area of the conductive interconnect to attach wire bonds thereto.
17. The power module of claim 14 , further comprising:
a first insulating substrate carried by the first surface of the first base plate;
a first conductive pattern carried by the first insulating substrate, the first insulating substrate electrically insulating the first conductive pattern from the first base plate;
a second insulating substrate carried by the second base plate;
a second conductive pattern carried by the second insulating substrate, the second insulating substrate electrically insulating the second conductive pattern from the second base plate;
a fifth set of wire bonds electrically coupling the first conductive pattern to the control terminals of the first number of bare die transistors; and
a sixth set of wire bonds electrically coupling the second conductive pattern to the control terminals of the second number of bare die transistors.
18. The power module of claim 14 , further comprising:
a first direct bond copper substrate carried by the first surface of the first base plate;
a fifth set of wire bonds electrically coupling the first direct bond copper substrate to the control terminals of the first number of bare die transistors;
a second direct bond copper substrate carried by the first surface of the second base plate; and
a sixth set of wire bonds electrically coupling the second direct bond copper substrate to the control terminals of the second number of bare die transistors.
19. The power module of claim 14 , further comprising:
a plurality of fasteners coupling the first and the second base plates to the housing.
20. The power module of claim 14 , further comprising:
a circuit board overlying the interior compartment of the housing to isolate the first and the second number of bare die transistors from the exterior of the housing.