A New Alumina Multi-Layer Ceramic Substrate for ECU with Low Resistance Conductor

We have developed a new alumina multi-layer ceramic substrate material, whose properties of low resistance conductor and excellent mechanical and thermal characteristics, providing a new and unique substrate solution for automotive ECU applications. Unique to this material is the circuit conductor which is made from a composite material of tungsten and copper, providing low electric resistance and high thermal diffusivity. This material system (AO600) utilizes a low-temperature, co-fireable alumina with a low resistance metal conductor composite. Electric current path is made by copper in the composite to effectively reduce the resistance. Thick film on the alumina substrates surface is also effective for the resistance reduction. Using this material system, substrates with miniaturized design, high strength and high thermal diffusivity have been realized. We have also tested reliability by temperature cycle tests between -40 and 150 degrees centigrade. We confirmed that no resistance change and no damage in the adhesive strength were observed. This material system can be effectively used for ECU's in automotive engines, transmissions and other applications.