Research on low-temperature anodic bonding using induction heating

A novel low-temperature anodic bonding process using induction heating is presented in this paper. Anodic bonding between silicon and glass (Pyrex 7740) has been achieved at temperature below 300 °C and almost bubble-free interfaces have been obtained. A 1 kW 400 kHz power supply is used to induce heat in graphite susceptors (simultaneously as the high-voltage electrodes of anodic bonding), which conduct heat to the bonding pair and permanently join the pair in 5 min. The results of pull tests indicate a bonding strength of above 5.0 MPa for induction heating, which is greater than the strength for resistive heating at the same temperature. The fracture mainly occurs inside the glass or across the interface other than in the interface when the bonding temperature is over 200 °C. Finally, the interfaces are examined and analyzed by scanning electron microscopy (SEM) and the bonding mechanisms are discussed.