Development of Sn Solder Plating Containing Cellulose Nanofiber

Abstract

We focused on low-cost and high-strength cellulose nanofibers (CNFs) as a substitute for Ag used for lead- free solder material. In this study, Sn/conductive CNF composite plating film was formed on a Cu plate after the CNFs were given electrical conductivity by sulfide reduction treatment. After plating, two Cu plates with the Sn/conductive CNF composite plating film were heated and joined to investigate the microstructure of the solder joint. It was found that conductive CNFs were incorporated into Sn plating films, while after joining, the conductive CNFs were agglomerated due to the melting of Sn.