New Supersolder with High Elasticity Developed


Solder on spool / Photo by Wikimedia Commons


In electronics, solders are metal alloys that permanently bind metal workpieces. The materials are also responsible for transferring heat away from crucial electronic components, however, the advances in technology make it difficult for conventional solders to dissipate heat properly. Engineers at Carnegie Mellon University developed the supersolder to solve the heat issue in electronics.

The supersolder is the result of a four-year research of the Department of Mechanical Engineering at CMU and the National Renewable Energy Laboratory. The engineers produced copper-tin nanowire arrays as the supersolder, with twice as much thermal conductance than current state-of-the-art thermal interface materials.

"The nanowires are grown from a template, like a mold, using small pores. It's chip technology using electroplating, grown one layer at a time, like how you coat an electrical cord by dipping it into electrolyte," said Sheng Shen, an associate professor of mechanical engineering at CMU, quoted

While the arrays showed efficient performance in thermal management, the engineers discovered that the nanowires exhibited excellent elasticity, which matches the elastic properties of rubber or some other polymers. In soldering electronic components, elasticity can be a highly useful property since the material expands and contracts when exposed to heat. If compared to standard solders, the supersolder has up to three orders of magnitude of elasticity.

In an experiment, the engineers compared the supersolder to a conventional solder made of tin. The conventional material started to degrade after less than 300 hours of cycling, while the supersolder continued to perform even after more than 600 hours. The team did not know yet the exact limits of the new arrays.

The engineers are still working on the supersolder after observing that the material is a conductor, a property of a solder undesired in some applications. They are planning to create a non-conductor variant of the material.