Visualisation of the Contact Area for Different Contact Forces using X-Ray Computer Tomography

The influence of high DC current on printed circuit boards (PCBs) and bolted connectors used in specialist electric vehicles applications is studied. Vehicles under development require higher currents in limited space which may lead to reliability issues at the contact interface. PCB bolted connectors used under high current conditions (250 A) are investigated with a X-Ray computer tomography technique to visualise the mechanical area of contact without disassembling the samples. The mechanical area of contact of the assembled component parts is graphically rendered as a "contact map". For the first time a real contact interface is represented showing the actual asperties which make contact using forces between 0.8 - 4.8 kN. Contact mapping of samples at various contact forces is presented. Samples stressed under vibration tests and high current tests are presented. These are discussed in the context of contact resistance measurements.