By the deposition of metallic sealing frames on the active side of ASICs, they can directly be connected with micro sensors. The deposition of frame structures or, if needed, of vertical contacts is made on the entire wafer. The Fraunhofer ISIT has specific know-how regarding the metallization across an elevated wafer topography, the selection of adhesion promoters and barrier layers, and the sealing process technology. For metallic joints, e.g. eutectic gold-tin (Au-Sn) bonding, the wetting control of the formed liquid phase is of crucial importance for the bonding result.
Further Information: