Influence of the reduced oxygen concentration on the wetting force

The knowledge of actual value of surface tension is important for the understanding to several soldering aspects, such as wetting, joint shape, fluxing action and, particularly, for the quantification of solderability testing. High surface tension is required for wave soldering.Values of surface tension are mainly caused by measurement conditions (temperature, ambient -air, inert atmosphere of the different composition etc.). We have measured influence of the reduced oxygen concentration on the wetting force. The change of the wetting force is related to the change of the surface tension. We used a wetting balance technique to measure the wetting force change which depends on the changing oxygen concentration. The measurement was carried out on two different types of solders (Sn63Pb37 and Sn95,5Ag3,8Cu0,7) and on non-wetting measurement specimen (teflo-non-stick cylinder).