Dissolution of copper on Sn-Ag-Cu system lead free solder

Purpose - The paper's purpose is to provide a solution to a problem on dissolution and disappearance of copper electrodes in solder bath in lead free soldering on printed circuit board (PCB). Design/methodology/approach - The influence of the copper concentration, temperature, and flowing velocity of molten solder on the copper dissolution have been estimated, and it has been found that the dissolution rate of copper electrodes in Sn-3.0Ag-xCu solder alloys is defined by temperature and copper concentration in solder. Findings - It was found that increasing the copper concentration to 1.5 mass% in Sn-3.0Ag-xCu solder could lower the rate of copper dissolution to the equivalent level as that of the conventional Sn-Pb eutectic alloy at the temperature of 560 K. Research implications/implications - In this paper, a dissolution phenomenon has been studied on Sn-Ag-Cu system alloys. it is interesting about the effect of other elements for controlling the dissolution. Practical implications - The method to control the copper electrode dissolution in wave soldering is clarified. The copper dissolution rate for Sn-3.0Ag-1.5Cu solder can be lowered to the equivalent level as that of conventional Sn-Pb eutectic solder, even at 560 K. Originality/value - In this paper, a dissolution phenomenon has been evaluated by flowing molten solder which is close to one in a practical soldering. It is the most different point from earlier study.