Metal-assisted hermetic wafer-level packaging

Abstract

This work main focus is the use of Gold thermocompression and gold-tin transient liquid phase bonding to achieve a hermetic wafer-level packaging. Herein, we describe the major advantages and difficulties that characterized these two bonding processes at design and materials levels. We also provide detailed in- and ex- situ studies of morphological and thermal stabilities of the multi-layer stacks utilized to prepare the wafers to be bonded. These investigations also set the ground to optimize the bonding conditions in order to enable high-quality bonding interfaces.