Abstract: A substrate for an integrated circuit device includes a low coefficient of thermal expansion material having opposing first and second surfaces with an array of through holes extending from the first surface to the second surface. A high thermal conductivity substrate is adjacent to the second surface of the low coefficient of thermal expansion material and a wettable material bonds the low coefficient of thermal expansion material to the high thermal conductivity substrate while also substantially filling said array of through holes. An integrated circuit device, such as a light emitting diode, may be bonded to the first surface of the low coefficient of thermal expansion material by a compliant die attach material.