Ivp limited offer direct bonded copper substrate. The reason al_2_o_3_ and ain-dbc have become the preferred industry power substrates is their performance and competitive pricing. The high thermal conductivity of al_2_o_3_ [24 w/mk] and ain [180 w/mk] combined with the high thermal capacity and the thermal spreading of thick pure copper [typically 0.2 mm or 0.3 mm thick copper] make dbc the most popular material choice for power substrates. The thermal coefficient of expansion of al_2_o_3_ @ 7.1 ppm and ain @ 4.1 ppm closely matches that of silicon @ 4.0 ppm. This minimizes the mechanical stress in the bare silicon die which is attached to the substrate since the thermal coefficient of expansion of dbc al_2_o_3_ and ain are much closer to that of silicon than other materials [pcb typically > 30 ppm]. Multilayer dbc circuits are possible, and can be interconnected using power vias. Curamik electronics have developed a range of hermetic power packages suitable for aerospace applications using their multilayer technology. In europe and increasingly in the u.S.A., ain is preferred to beo for environmental reasons. The restriction on the use of beo does not apply to ain.
