Thermally Conductive Nanocomposites for Missile Electronics Packaging

The objective of the proposed program is to develop and transition thermally and electrically conductive nanocomposites for improved packaging and thermal control in missile defense electronic modules and systems. During Phase I, NanoSonic would work witha major U.S. military electronics manufacturer to analyze potential improvements in performance and reductions in cost associated with the manufacturing of electronic systems using these materials. Novel randompoly(dimethyl-co-methylhydrido-co-3-cyanopropylmethyl)siloxanes, containing controlled concentrations of pendent crosslinkable sites and functional groups capable of complexing noble metal and metal oxide nanoclusters or carbon nanotubes, would besynthesized. Such highly-filled networks could be crosslinked by platinum-catalyzed hydrosilations or room temperature vulcanizations. Importantly, these novel low modulus nanocomposite adhesives can be used to bond materials having highly mismatchedCTEs, and would 1) offer superior chemical resistance, 2) remain flexible well below subambient conditions, and 3) provide significantly greater adhesive strength than typical polysiloxanes. Recent work by NanoSonic has demonstrated very high electricaland thermal conductivities in polyorganosiloxane-based nanocomposites incorporating Ag and AlN nanoclusters, respectively. Since thermal and electrical conductivity through bondlines depends upon bond thickness, nanosized inclusions lead to highconductivity. Materials would be evaluated by our defense electronics partner for Phase II transition into its current manufacturing systems. Potential Commercial ApplicationsThe primary commercial application of these materials is as low-cost, lightweight polymer-based replacements for high-temperature and environmentally-unfriendly lead-based solders for electronic component, module and system electrical interconnection, andphysically heavy metals for thermal management. Military, industrial and consumer products that are soldered together or that use metal heat sinks and vias could benefit in lower weight and lower cost. Low temperature curing of such conductivenanocomposites would allow the electrical and thermal interconnection of materials and devices that may be damaged by thermal dwell times required for electronic dip solder processing.