Evaluation of the Cold Atmospheric Plasma Metallization of Bare Dies with Copper Through Life Cycle Assessment

The cold atmospheric plasma metallization (CAPM) with copper is an alternative coating process to electroplating for applying a thermo-mechanical buffer onto bare dies to enable more powerful top-side interconnection technologies for power electronics. A complete life cycle assessment (LCA) is to be performed in order to evaluate improvements to increase sustainability of the copper metallization. Since life cycle assessment results strongly depends on the set system boundaries and availability of primary data, the scope of this study is determined by the availability of the latter. Since the coating properties are dependent on the plasma spray parameters, a variation of set parameters is assessed, which are currently used for the coating of the bare dies. The evaluation showed that electricity, plasma gas and powder production have major impacts on the sustainability. The necessary heat treatment is responsible for on third of the emissions if bare die production and plasma coating are included into the assessment. Potential improvements are the reduction of total conveyed powder and carrier gas, as well as increasing the number of bare dies treated in one annealing process.