Joining Mechanism of Static Bonding Between β"-Al₂O₃ and L₂-Aluminum

Electrostatic bonding, as a special method of solid-state diffusion bonding for the ceramics and the metals, can be performed at low temperature quickly and conveniently. And It’s suitable for making micro electromechanical system (MEMS), such as micro-devices, solar cell and micro-sensors. So Electrostatic bonding process mainly is used to bond the fast-ion conductivity materials and the metals. The bonding technique of functionally materials and metals had a significant role in the manufacture of MEMS. In this paper, the L2 aluminum film and β"-Al₂O₃ sheet were bonded by the electrostatic bonding process. SEM, EDX, XRD were applied to investigate the interfacial structure and composition of the samples, and the bonding mechanism and technical condition were characterized precisely. The experimental results showed that the electrolyte ceramics and aluminum can be bonded very well. The bonding area was composed of Al metal, transition area and aluminum oxide. The successful bonding was achieved due to the formation of the oxide in the interface. The main factors that influenced the bonding process were voltage, temperature and the electrical conductivity of the materials.