Improved mechanical and thermomechanical properties of alumina substrate via iron doping

 We present a method to improve the overall properties of sintered alumina substrate via iron doping that has a higher fracture toughness, lower thermal conductivity, lower thermal expansion coefficient and comparable dielectric constant than pure alumina. Such properties are beneficial for harsh environment electronic packages. X-ray and electron probe microanalyses concluded that toughening is likely caused by multiple phase strengthening and ruled out crack bridging or grain boundary strengthening.