Issue link: https://iconnect007.uberflip.com/i/390433
12 SMT Magazine • October 2014 a. a. zinn, r. m. stoltenberg, J. beddow, and J. chang LOCkhEEd MArTin SpACE SySTEMS COMpAny, AdvAnCEd TEChnOLOgy CEnTEr FEATurE This article originally published in the proceed- ings of IPC APEX EXPO 2014. abstract The Advanced Technology Center of the Lockheed Martin Corporation has developed a nanotechnology enabled, copper-based elec- trical interconnect material that can be pro- cessed around 200°C. The readily scalable Cu nanoparticles synthesis process uses a low cost solution-phase chemical reduction approach. A pilot plant is fully operational producing one pound per batch of nanomaterial. We have demonstrated assembly of fully functional LED test boards using a copper-nanoparticle paste with a consistency similar to standard solder. Further improvements have led to the assembly of a small camera board with a 48-pad CMOS sensor QFN chip and a 26-pin through-hole connector. In addition, we have a fully func- tional nanocopper assembly line in place for process development using standard industrial off-the-shelf equipment. We are currently work- ing with a commercial assembly house to dial-in the board assembly process. The fused material shows a tensile strength that is already in the range of space qualified solder. Once fully op- timized, the nanocopper-based solder-like ma- terial (CuantumFuse TM ) is expected to produce joints and interconnects with up to 10x the electrical and thermal conductivity compared to tin-based solders currently in use and with a bond strength comparable or better than eutec- tic SnPb. Applications in space and commercial systems are currently under consideration. NanoCopper-Based Solder-Free Electronic Assembly Material