Here is the abstract you requested from the hitec_2014 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.
|Uniqueness and Challenges of Sintered Silver as a Bonded Interface Material|
|Keywords: Sintering, Interconnection, Processing|
|The are numerous attributes associated with the use of sintered silver (Ag) as a bonded interface between die and substrate or even between substrate and heat sink in power devices. This is attested to by the relatively large number of studies devoted to it the last several years. Sintered silver has a high temperature capability, high electrical and thermal conductivities, its microstructure is in sustained equilibrium, it predictably responds linearly elastically during thermal cycling, and the time-dependent pore coalescence and pore growth that exists with solders is minimal or even non-existent in it. But sintered silver bonding is a relatively new technology, its solid-state sintering science and its application can be unfamiliar to solder bonding practitioners, concurrent pressure application during process may be needed, and additional considerations of mechanical adhesion with the mating surfaces are involved. Many of the unique issues and challenges mentioned above for silver sintered interconnection will be discussed here, but additional lessons learned during the last several years of ORNL's sintered Ag work will be reviewed in this presentation too. Regarding the latter, overviews associated with the following will be presented: compaction science of the dried Ag powder bed leading up to the activation of sintering, small-area- versus large-area-bonding strategies, surface topography of the mating surfaces that are to be bonded, plating and cleanliness thereof, Ag pad pattern and achievement of uniform thickness in context to pressure application, and stress-concentration development in die (particularly in thin die) during pressure-assisted sintering. It is anticipated the recognition and understanding of these effects will help advance employment of sintered silver technology and the exploitation of its known attributes.|
Oak Ridge National Laboratory
Oak Ridge, TN