Ultra-Stable Sintered Silver Die Attach for Demanding High-Power/Temperature Applications

A novel and simple processing step has been demonstrated to produce thermally stable sintered silver nanoparticles structures. Sintered silver has been investigated as a die attach to resolve the long-standing demand for a reliable material to enable high-power/temperature electronics operating above 300 °C. However, it is now a well-known fact that such materials undergo massive microstructural evolution at 250 °C and above, creating doubts about their long-term reliability. Here, an additional processing step utilizing oxidizing treatment is demonstrated to immobilize the silver atoms through formation of Ag2O. This technique stabilizes sintered silver up to 400 °C, taking advantage of the open-pore network to facilitate treatment deep in the material interior.