Solderability of lead-free surface finished PCB

This paper deals with results of solderability testing. The wetting balance test is used for the evaluation of wetting performance. Dissolving and removing of oxides and contaminations from the surface of a metal or alloy are the primary purposes of flux. Activated metal surface is easily wetted by the molten solder. However flux is corrosive. Other way of cleaning is the special cleaning liquid, e.g. Decotron F10. The paper presents the comparison of printed circuit board solderability test results measured before and after cleaning. This comparison will be made for several surface finish types. Coupons of printed circuit boards with surface finishes galvanic tin, immersion tin, pure copper, OSP (organic solderability preservative) and ENIG (electro less nickel immersion gold) were tested. The environment of storage can affect the solderability of surface. That is why the solderability was measured before and after ageing also.