Wafer bonding with intermediate Parylene layer

In this paper, wafer bonding using Parylene as the adhesive layer is investigated. The experiments are carried out under various conditions in two approaches: Parylene-to-Parylene and Parylene-to-Silicon. By heating at 230°C and applying a bonding force in vacuum environment, both Parylene-Parylene and Parylene-Silicon are successfully bonded. The bonding quality is characterized by the joint area and the bonding strength. The results show that there is no significant difference on the bonding qualities between the two bonding approaches. Process parameters, such as film thickness, bonding force, are evaluated. The maximum bonding strength is 2.38 MPa, which is adequate for certain applications.