EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Electroless nickel immersion gold (ENIG) layers are widely applied in the electronics industry and the quality of interconnections is directly related to its thermal stability, which in turn has a direct impact on the processes occurring at elevated temperatures during the soldering process or later during use of the final product (heating/cooling cycles). The additives such as W, Mo, Co, Re can be used to improve the thermal stability.
The main goal of the research was to determine the quality of the joint, the width of the newly formed zones, and the presence of the intermetallic phases, formed as a result of the reaction with tin. The addition of rhenium to Ni-P coatings inhibited the formation of the Ni2SnP phase in each of the tested phosphorus content ranges, also after the thermal cycles. Thus, no undesirable phenomenon of intermetallic phase detachment from the layer/solder interface was observed. Studies have shown that the corrosion resistance of samples increases as the pH of the solution from which the test coatings are deposited decreases, and the addition of rhenium to Ni-P coatings always improves their corrosion resistance.