Joining of AlN ceramic to metals using sputtered Al or Ti film

A process was developed to improve the joining of aluminum nitride (AlN) ceramic and metals. Radio frequency sputtering was first applied to deposit surface modification aluminum or titanium film on AlN ceramic. Then brazing and diffusion bonding processes were investigated to join the different surface modified AlN ceramics to Cu and FeNi42 metals. The strength of the joints was improved because the interfacial sputtering film improved the wettability of AlN. Based on the results of the microstructure and chemical interactions studies and residual stresses calculations, it is believed that the joining ability of AlN ceramic to metals can be improved further with a functionally gradient material interlayer.