Here is the abstract you requested from the imaps_2018 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.
|Low-temperature Sintering IMC-nano-solder for High Temperature Interconnect|
|Keywords: Interconnect, Nanoparticle, Sintering|
|Intermetallic nano-solders like Cu6Sn5 nanoparticles (NPs) are developed as a new generation of joining material enabling nano circuits and nano joints with higher service temperatures than its processing, better interconnection properties, no sintering defects, and super compatibility with the circuit-related substrate, which is impossible for conventional solders or sintered noble metal NPs to provide. An in situ TEM analysis, upon heating, reveals that the two-element intermetallic Cu6Sn5 NPs go through Ostwald ripening, particle migration, atom diffusion, evaporation, creation and disappearance of dislocations. For the first time, the in situ TEM analysis elucidates, upon cooling, coalesced intermetallic NPs experience densification, reorientation, poly-crystallization, polygonization, and twinning behavior, which directly ends up with densely nano-soldered, instead of nano-sintered, microstructure with nano- grains possessing super-plasticity to overcome the initial brittleness of intermetallic. The interesting interaction between nano-Cu6Sn5 and micro-Cu substrate during in situ TEM heating gives first hand atomic lever proof of the formation of Cu3Sn between nano- and micro- material. This work may pioneer a novel strategy of circuit connection: intermetallic nano-soldering and fill up the gap of high temperature solders for the third-generation semiconductors and offer a novel approach toward ultra-high- density, micro/nano circuit, connections in 3-D electronic packaging, flexible and wearable devices, 3-D printing, etc.|
|Ying Zhong, Postdoc
University of California at San Diego
San Diego, CA