Solderability of Additively Manufactured Pure Copper

Additive manufacturing (AM) holds massive potential and has exhibited its proven capacity to fundamentally change and greatly aid industrial endeavors. New AM technologies have allowed for manufacture of pure copper by Laser Powder Bed Fusion (LPBF), Laser Engineered Net Shaping (LENS), and Bound Powder Extrusion (BPE). The high electrical and thermal conductivity of copper make the possibility of large-scale AM production with this material particularly auspicious. Copper produced by AM will need to be joined to an assembly, likely with solder for electrical applications. Unfortunately, very little data on the solderability of AM copper currently exists. To address this hole in engineering knowledge, the solderability of AM copper was experimentally characterized by the wetting balance technique and pin pull testing. Copper coupons produced by LPBF, LENS, and BPE were tested as built and after surface modification by dry electropolishing. Experiments showed that dry electropolishing enhances the solderability of copper produced by all three AM methods and that BPE is the most promising method for producing highly solderable surfaces.

SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525
This research is based upon work supported by the New Mexico Space Grant Consortium (NMSGC) Space Grant Fellowship through a NASA Cooperative Agreement No. NM-80NSSC20M0034