Solderability Testing of 95.5Sn-3.9Ag-0.6Cu Solder on Oxygen-Free High-Conductivity Copper and Au-Ni-Plated Kovar

摘要

The solderability of 95.5Sn-3.9Cu solder on oxygen-free high-conductivity (OFHC) copper and Au-Ni-plated Kovar was examined as a function of flux and process temperature. The three solder fluxes included a rosin-based (R) material, a rosin mildly activated (RMA) flux, and a low-solids (LS) flux. The solderability metric was the contact ngle, theta_C, measured by a meniscometer and wetting-balance techniques. The wetting rate and time to maximum force parameters were also documented. In most cases, the contact angles for the 95.5Sn-3.9Ag-0.6Cu solder alloy, regardless of the type of flux or temperature, were higher then those for the 63Sn-37Pb eutectic-solder alloy, indicating a less "solderable" surface.