Thomas Brunschwiler, Jonas Zürcher, et al.
ITherm 2016
Efficient heat removal from integrated circuits arranged vertically in 3-D chip stacks requires thermally conductive underfill materials. The low-heat-transport performance of traditional capillary underfills can be improved by percolating the thermal conductive filler particles. We increased the thermal path by adding quasi-areal contacts using nanoparticle assemblies directed to the contact points of the percolating filler particles. We studied the formation and thermal effect of such nanoparticle neck assemblies in the filler-particle contact points using aqueous suspensions containing nanoparticles of different sizes, size distributions, and concentrations. An optimized binary mixture of small (28-43 nm) and large (200-300 nm) nanoparticles results in dense and defect-free neck assemblies. A neck-enhanced percolating thermal underfill (PTU) with a thermal conductivity as high as 2.4 W/mK was achieved using alumina filler and nanoparticles. Compared to a PTU, the addition of nanoparticle necks resulted in a more than twofold improvement in thermal conductivity.
Thomas Brunschwiler, Jonas Zürcher, et al.
ITherm 2016
Angelos Selviaridis, Brian R. Burg, et al.
CPV 2015
Thomas Brunschwiler, Jonas Zürcher, et al.
ITherm 2016
S. Gerke, Jonas Zürcher, et al.
Flexible and Printed Electronics