Alumina-Copper Eutectic Bond Strength: Contribution of Preoxidation, Cuprous Oxides Particles and Pores

Abstract

Abstract. The in uences of cupric oxide layer thickness, cuprous oxide particles and pores on the mechanical properties and microstructure of an alumina-copper eutectic bond have been investigated. The furnace atmosphere in the rst stage was argon gas with 2 10????6 atm oxygen partial pressure. In the second stage, the furnace atmosphere was the same as the rst stage except that the cooling interval was between 900-1000 C and the hydrogen gas was injected into the furnace atmosphere. Finally, in the last stage, a vacuum furnace with 5 10????8 atm pressure was chosen for the bonding procedure. The peel strength of rst stage specimens shows that a cupric oxide layer with 320 25 nm thickness generates maximum peel strength (13:1 0:3 kg/cm) in the joint interface. In the second stage, by using hydrogen gas, a joint interface free from any cuprous oxide particles was formed. In this case, the joint strength has increased to 17:1 0:2 kg/cm. Finally, the bonding process in the vacuum furnace indicates that the furnace gas does not have a considerable e ect on joint interface pores. Furthermore, the bonding process in the vacuum furnace reduces the peel strength of the joint due to the formation of more pores. A thorough study of pore formation is presented.