Prototyping and Production of High-temperature Power Electronic Substrates through Additive Manufacturing Processes

This paper reveals a study on Selective Laser Melting (SLM) as an alternative technology for producing power electronic substrates, and shows the possibility of producing a stable interface between alumina and copper through SLM technique. Additive Manufacturing (AM) has not yet been established in the manufacturing of electronic devices. The prevalent benefits of the generative manufacturing sector such as material efficiency, product customization/–flexibility, elimination of the usage of tools, constructional freedom and less process steps in contrast to the conventional fabrication methods of ceramic substrates for power electronic applications like DBC or AMB, are pointed out. Moreover, AM reduces energy costs due to the elimination of the necessary firing, etching and washing processes. The realized study focuses on the examination of adhesion strengths of copper structures, melted on different Al2O3 ceramics with and without pre-copper and -glass paste coating. The melting process was categorized for different laser parameters (1–3) based on the same energy input. Maximum shear values of the substrate probes reached were at about 30 N/mm2 for copper coated ceramic, and at 20 N/mm2 for conventional and glass paste coated substrates. All results were determined in a full factorial design of experiment (DoE) with 54 combinations and a sample size of six samples per parameter combination. Furthermore, several cross sections of the probes produced were illustrated to better understand the melting and joining behavior of the copper powder applied on the ceramic substrates. For improved mechanical adhesion, the ceramic substrates were roughened by laser radiation, with roughness values measured, and the cracking behavior of the exposed ceramics explained.