Thermal Resistance and Temperature Cycling Endurance of DCB Substrates

Automotive ignition modules are constructed employing power transistors which are soldered to metallised ceramic substrates to achieve electrical insulation and good heat dissipation. Research activities were aimed to substitute potentially hazardous BeO ceramics by means of DCB substrates using non toxic Al2O3. To fulfill reliability requirements as well as thermal conductivity specifications, the DCB compound has to be optimised with regard to thermal stresses, material properties and interconnection technology. Complementary, appropriate test criteria have been established to characterise the performance of DCB substrates in the ignition module.