Reactive microjoining and packaging - mechanical, thermal and electrical functionalities

The research project investigates the application of reactive metallic multilayer systems in the field of micro-scale interconnections in packaging technology in electronics. The project work focuses on the potential of using reactive multilayers in order to be able to set up a desired interconnection process in this technology area via a predefined layer structure or morphology (Fig. 1). In contrast to all previously published solutions for reactive bonding in the IC area, the proposed project differs in that, in addition to the reactive bonding process, the resulting functional properties of the interconnect (electrical, thermal and mechanical) are also to be precisely determined. The functionality tests will also focus on the long-term stability of these properties and thus on the reliability of such interconnects. This approach enables a fundamental evaluation and validation of the possible applications of a reactive microinterconnection technology for contacting semiconductor devices. From this point of view, the potential use of this interconnection variant for hidden area contact arrangements (e.g. in flip-chip technology) will also be investigated.

With respect to the heat generation and transfer targeted for the reactive micro interconnect process, a new approach is to exploit predetermined morphologies and layer structures of the reactive materials deposited on device surfaces to replicate an "idealized" morphology and microstructure of reactive multilayer structures fabricated by nanotechnologies (e.g. by magnetron sputtering). By optimizing this "application-adapted" morphology-layer structure combination, the temperature profile and the solidification front curve are to be determined for the joining process in the long term in such a way that the desired functional properties can be set without further post-processing steps. Specially constructed measuring equipment will be used to carry out electrical, thermal and mechanical characterizations of the achieved functional properties of the joints in order to be able to establish the relationship between the predefined multilayer structures and the resulting functional properties. The project not only combines the different ways of synthesizing tailored morphologies with attention to scaling for application, but also collaborates with project partners who use simulation to investigate joining compounds to provide further targets for basic research or design and fabrication.

Subproject leader: Prof. Dr.-Ing. Jens Müller

Contact person: Dipl.-Ing. Alexander Schulz

Project duration: 09/2019 - 12/2022

Funding Organisation: German Research Foundation (DFG)

Partner: Saarland University, Department of Systems Engineering, Chair of Microintegration and Reliability