A novel technique for MEMS packaging: Reactive bonding with integrated material systems

Considering the demand for low temperature bonding processes in 3D integration and packaging of microelectronic or micromechanical components, this paper introduces a method that uses a specific form of local heat generation, which is based on nano scale reactive material systems. Such systems consist of several layers of minimum two different materials with nano scale thicknesses. These layers generate a self-propagating and exothermic reaction during their intermixing. The resulting heat can be used as the heat source for bonding processes such as solder bonding of micro components. In contrast to other researchers, who focus on relatively thick Ni/Al foils for joining macroscopic parts, we focus on the direct deposition of reactive multilayer systems. The principle of this method is demonstrated by reactive bonding, for which we use different energetic systems. The main part of this paper deals with the preparation and investigation of integrated reactive material systems. (C) 2012 Elsevier B.V. All rights reserved.