Study of influences on the changes of the surface tension

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.). In measurements we changed conditions such as temperature of the molten solder, oxygen concentration and surface finish of part of the sample, which is immersed under molten solder. Together with the change of these conditions we ware able to measure changes of the wetting force, which is given by the change of the surface tension.