Bus bar interconnection techniques

• US 7,888,601 B2
• Filed: 06/01/2007
• Issued: 02/15/2011
• Est. Priority Date: 12/29/2006
• Status: Active Grant

• Current Assignee: Cummins Power Generation IP, Inc.
• Original Assignee: Cummins Power Generation IP, Inc.
• Inventors: Medina, Paul, Bax, Randall L., Elayed, Karim
• Primary Examiner(s): Norris; Jeremy C
• Application Number:
  US11/809,607
• Publication Number:
  US 20080160840A1
• Time in Patent Office: 1,355 Days
• Field of Search: 174/252, 174/261, 361/702, 361/709
• US Class Current: 174/252
• CPC Class Codes: H01R 4/30 utilising a screw or nut clamping member H01R4/50 takes precedence; utilising a clamping member acted on by screw or nut H01R4/38; for coaxial cables H01R9/0521

Abstract

One system of the present application includes an electronic assembly with a heat dissipating device, printed wiring board with electronic circuitry, bus bar, insulative grommet, and fastener. The board defines a bus with an interconnection pad and a board opening. The bus bar connects with the interconnection pad and defines a bar opening with a beveled shoulder portion that align with the board opening to define a passage to a fastening site of the heat dissipating device. The grommet defines a distal end portion opposite a proximal end portion shaped with a flange. The distal end portion is inserted into the passage with the flange abutting the beveled shoulder portion. The fastener extends through the grommet to provide a mechanical connection of the board and bar to the site and maintain thermal coupling between the board and device while the grommet electrically insulates the fastener from the bar.

Claims

1. An apparatus, comprising:

a heat dissipating device defining a fastening site;

a printed wiring board with electronic circuitry defining a bus with an interconnection pad and a board opening through at least a portion of the pad, the board opening being aligned with the fastening site;

an electrical bus bar connected to the interconnection pad and defining a bus bar passageway that extends from a first side to a second side, the bus bar passageway is aligned with the board opening to define at least a portion of a passage to the fastening site and includes a bevel to provide a larger opening on the second side than the first side, the second side being closer to the interconnection pad than the first side;

an electrically insulative grommet defining a first end portion opposite a second end portion, the second end portion being shaped with a flange, the first end portion being inserted into the passage with the flange abutting the bus bar about the bus bar passageway on the first side, the bevel and the grommet cooperating to define a clearance space therebetween; and

a fastener extending through the grommet to provide a mechanical connection of the printed wiring board and the bus bar to the fastening site and maintain thermal contact between the printed wiring board and the heat dissipating device while electrically insulating the fastener from the bus bar with the grommet.

2. The apparatus of claim 1, wherein the bus bar includes a contact foot soldered to the interconnection pad and an elevated connection site extending above the printed wiring board.

3. The apparatus of claim 2, wherein the bus bar has a Z-shaped or S-shaped profile, and the printed wiring board includes an electrically insulating layer extending between the interconnecting pad and the grommet to at least partially bound the clearance space.

4. The apparatus of claim 1, wherein the bus bar is metallic and includes a contact foot soldered to the interconnection pad, the contact foot defining a number of apertures to permit passage of solder therethrough.

5. The apparatus of claim 1, wherein the printed wiring board and the bus bar define another passage with another grommet and another fastener to fasten the printed wiring board and the bus bar to another fastening site of the heat dissipating device.

6. The apparatus of claim 1, wherein the heat dissipating device includes means for flowing a cooling fluid therethrough.

7. The apparatus of claim 1, wherein the fastening site defines a threaded cavity and the fastener is a screw with a threaded stem opposite a head, the head engages the flange, and the stem is at least partially threaded into the threaded cavity.

8. The apparatus of claim 7, wherein:

the bus bar includes a contact foot soldered to the interconnection pad and an elevated connection site extending above the printed wiring board, the contact foot defining a number of apertures therethrough to facilitate solder flow; and

the heat dissipating device includes a plate with a passage to flow a cooling fluid therethrough.

9. An apparatus, comprising:

a heat dissipating device defining a fastening site;

a printed wiring board with electronic circuitry defining a bus with an interconnection pad and a board opening through at least a portion of the pad, the board opening being aligned with the fastening site;

an electrical bus bar including a first electrical contact portion connected to the interconnection pad and a second electrical contact portion, the bus bar being sized and shaped to extend the second contact portion a predetermined distance away from the printed wiring board, the first electrical contact portion defining a bus bar opening aligned with the board opening, the bar opening defining at least a portion of a passage to the fastening site and being shaped to provide a clearance space between the bus bar and the printed wiring board;

an electrically insulative grommet defining a distal end portion opposite a proximal end portion, the proximal end portion being shaped with a flange, the distal end portion being inserted into the passage with the flange of the proximal end portion abutting the bus bar about the bar opening; and

a fastener extending through the grommet to provide a mechanical connection of the printed wiring board and the bus bar to the fastening site and maintain thermal coupling between the printed wiring board and the heat dissipating device while electrically insulating the fastener from the bus bar with the grommet.

10. The apparatus of claim 9, wherein the bus bar has a Z-shaped or S-shaped profile and first contact portion and the second contact portion each extend along different planes that are generally parallel.

11. The apparatus of claim 9, further comprising means for fixing the bus bar to the interconnection pad.

12. The apparatus of claim 9, wherein the printed wiring board and the bus bar define another passage with another grommet and another fastener to fasten the printed wiring board and the bus bar to another fastening site of the heat dissipating device.

13. The apparatus of claim 9, wherein the heat dissipating device includes a plate with a passage to flow a cooling fluid therethrough.

14. The apparatus of claim 9, wherein the fastening site defines a threaded cavity and the fastener is a screw with a threaded stem opposite a head, the head engages the flange, and the stem is at least partially threaded into the threaded cavity.

15. The apparatus of claim 9, wherein a number of different bus bars are soldered to the printed wiring board.

16. The apparatus of claim 9, wherein the bus bar opening is beveled to present a larger dimension of the opening on a first side of the bus bar that a second side of the bus bar opposite the first side and at least partially defines the clearance space, the first side being placed closer to the interconnection pad than the second side.

17. The apparatus of claim 9, further comprising an electric power generation system including the heat dissipating device and the printed wiring board with electronic circuitry connected thereto with the grommet and the fastener.

18. An apparatus, comprising:

an electric power generation system including an inverter assembly, the inverter assembly including;

a cold plate defining a plurality of threaded cavities;

a printed wiring board defining a number of interconnection pads and a plurality of board openings through the pads, the board being positioned to align each of the board openings with a corresponding one of the threaded cavities;

a number of metallic bus members each including a contact foot, the contact foot defining one or more holes therethrough, the holes each aligning with a respective one of the board openings and the corresponding one of the threaded cavities to collectively define a number of passageways, the holes each being shaped with a larger opening on a bottom side than a top side to define a corresponding one of a number of clearance spaces;

a number of washers each having a barrel-shaped portion opposite a respective flange portion, the washers each being positioned with the barrel-shaped portion being received in a respective one of the passageways with the respective flange portion abutting the contact foot about a corresponding one of the holes; and

a number of fasteners each including a head opposite a stem with threading, the stem of each respective one of the fasteners extending through a respective one of the washers with the threading engaged to the corresponding one of the threaded cavities, the head of each of the fasteners bearing against the respective flange portion to exert a force to mechanically and thermally couple the bus bars and the printed wiring to one another and the cold plate.