US Patent 8105414 - Lead free solder nanocomposite

http://www.freepatentsonline.com/8105414.html

For environmental reasons lead is being phased out of solder manufacture and being replaced by tin-based composites which require higher processing temperatures. This patent from Lockheed Martin teaches a metal nanoparticle composite solder allowing for lower processing temperatures. Claim 1 reads:

1. A composition, comprising:

metal nanoparticles, said metal nanoparticles comprising copper or aluminum nanocores,

wherein about 30-50% of the metal nanoparticles have a diameter of 20 nanometers or less but greater than zero, and the remaining 70-50% of the metal nanoparticles have a diameter greater than 20 nanometers.