High Temperature Die Interconnection Approaches

High temperature electronics face obvious challenges in terms of high temperature endurance, a wide range of thermal cycling, and fabrication processes. A recent paper demonstrated the stability of 3D printed ceramic substrates with printed gold up to 850 degrees C. The present work addresses approaches to the interconnection of silicon die to such substrates. After screening the materials used to metallize the substrates based on adhesion and the capability of handling high temperatures, three methods of die interconnection were successfully developed: surface mounting, embedding, and flip-chip attach. The resistance of each structure was monitored under high temperature aging up to 500 degrees C and in thermal cycling between -40 degrees C and 300 degrees C, and between room temperature and 500 degrees C. The flip-chip design was shown to operate successfully in the high temperature aging environment and the embedded design was able to handle the harsh thermal cycling tests.