Solderability of Additively Manufactured Metals and the Effect of Surface Modification

The enhanced geometrical design freedoms enabled by additive manufacturing (AM) are of particular interest in producing components for electrical and thermal applications. Copper (Cu) is an excellent conductor, but it is relatively unexplored in AM. For effective use in electrical and thermal assemblies, AM Cu requires further study. In the present work, the bulk and surface properties as well as the solderability of AM Cu produced by laser powder bed fusion (LPBF), directed energy deposition (DED), and bound powder extrusion (BPE) has been characterized. Additionally, the surface properties, effect of electroplating, and the solderability of AM 17-4 PH stainless steel are explored. LPBF Cu and nickel plated 17-4 PH wet very well with eutectic Tin-Lead (SnPb) solder, but BPE Cu was determined to have the best overall solderability. Surface modification by dry electropolishing is shown to decrease the surface roughness and improve solderability.