Solder magnetic materials

Researchers at Carnegie Mellon University and Intel have developed a new class of materials called solder magnetic nanocomposites that could help improve the process of electronic packaging.

The Carnegie Mellon research team, led by Prof Michael McHenry in collaboration with Intel senior packaging materials engineer Raja Swaminathan, devised the RF heating technique for solder magnetic nanoparticle (MNP) composites that can sufficiently heat solders to cause reflow without placing computer chips in conventional ovens.

At present, techniques for making computer chips during the electronic packaging process involve use of hot-air convection or the use of infrared ovens.

Because heating the chips in these ovens requires significant energy costs and also poses the risk of chip warpage, Prof McHenry’s team worked collaboratively with Intel’s Swaminathan to develop a system that could use radio frequency coils to heat specially designed magnetic particles that are mixed with solder pastes.

‘By varying the concentration and composition of these magnetic particles we can control the time it takes to heat them, which ultimately helps improve the speed of processing them and potentially lowers the cost,’ said Prof McHenry.

‘Though we have a long way to go in implementing a locally melting solder in actual applications, the concept of local heating opens up many opportunities,’ said Swaminathan.

Research funding for the project came from a number of sources, including chip-making giant Intel and the US National Science Foundation.