Here is the abstract you requested from the HITEN_2017 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Increased thermal Stability of Sintered Silver Die Attach from 200 °C to 400 °C|
|Keywords: Electronic Packaging,,Aging, Sintering,Bonding, Die Attach|
|Abstract: The surface oxidation of internal pore surfaces of nano-scale sintered silver has increased stability for high temperature applications. Operating temperatures of up to 400 °C have resulted in no or minimal changes in microstructure. By contrast, it is known that the microstructure of untreated pressure-less sintered silver continuously evolves at temperatures above 200 °C. Grain and pore growth occur in this temperature range resulting in coarsening of the microstructure and increased susceptibility to fatigue. Oxidation of the internal pore surfaces, by exposure to steam for example, has the effect of freezing the microstructure when the contact metallization is also silver or chemically inert. Oxidation prevents grain boundary movements by arresting the fast migration of atoms along the internal pore surfaces. Samples exhibited no change in microstructure either through continuous observation through glass, or after cross sectioning. The tested specimens under high temperature storage resisted grain growth for more than 600 h at 300 °C. The only detectable changes in microstructure occurred in a sparse number of isolated grains (1 in 7000 grains), presumably due to non-penetration of oxidising treatment into these closed pore spaces. It is hypothesized that even these can be prevented by minor changes to the sintering paste to slightly increase initial porosity. The oxidising treatment can be performed via many different routes. For example, exposure to steam, or even by dipping in water for 10 min followed by immediate high temperature exposure.|
|khalid khtatba, PhD student
King's college university