Title: Development of new copper-based brazing filler metal for dissimilar material welding

Award winners^*2: Shun Takano, Yuya Kurihara, Mizuki Endo, Genya Nogawa, Proterial, Ltd.

The research project led to the successful development of new copper-based brazing filler metal enabling dissimilar material welding at lower temperatures than the conventional material, silver(Ag)-based brazing filler metal, by adding varied elements to alloy based on copper (Cu). The following welding applications have been suggested based on the compositional design guide of the new copper-based brazing filler metal and assessment results of its bondability: welding for electronic components including insulating heat-radiating substrates for power modules and submounts for LEDs, working tools including diamond tools, and heat exchangers. Prototyping for welding is underway in anticipation of practical application. The material is expected to be used in multiple fields.

Multi-materialization is advancing for electronic components, including power modules and LEDs, working tools, and heat exchangers, with a view to optimizing thermal efficiency and power consumption in each component and reducing mechanical loss. Dissimilar material welding is drawing attention as a technology for supporting multi-materialization. Active brazing filler metal based on silver/copper/titanium (Ag-Cu-Ti)^*3 has found widespread application, especially as a material for jointing ceramics and metal. Nevertheless, new materials needed to be developed, given the increased resource risk due to the recent surge in silver prices and the growing need for lower bonding temperatures. However, there were few reports on effective substitute materials.

The new copper-based brazing filler metal that Proterial developed is mainly based on copper, which is less expensive than silver. Additionally, it permits a wide range of applications because the melting point is lower than Ag-Cu-Ti-based active brazing filler metal. The material is expected to exhibit excellent properties especially in applications for insulating heat-radiating substrates for power modules requiring high reliability and heat dissipation, working tools requiring a longer life, and high-luminance LEDs and lasers requiring thicker films in the wiring layers.

Proterial will flexibly continue to respond to changes in customer needs to contribute to the realization of a sustainable society through innovative material development and social implementation.

The award goes to particularly excellent talks among the research reports at the Technical Commission on Solid Phase Welding and Brazing or those with remarkable achievements recognized so far.