An Experimental Method for Refinement of Solderability Measurement Available to Purchase

An experimental method for measurement system improvement is presented and applied to development of a protocol for solderability measurement with a wetting balance. Protocol development is central to development of reliable monitoring systems for manufacturing. This paper illustrates the method with an experiment in which sets of nearly identical test leads, each with a different solderability, are obtained by steam ageing of hot‐solder‐dipped copper and then measured according to alternative protocols. The protocols entail different flux types and solder bath temperatures. This method can be used wherever solderability measurements are made and thus satisfies the need for in‐house refinement of wetting balance protocols.With the experimental method, one can both compare alternative measurement protocols and estimate the relative solderability of sets of test leads. The results of both depend on what feature of the wetting force curve one selects to portray solderability. The comparison of measurement protocols is based on what is variously called precision, sensitivity, or signal‐to‐noise ratio. The solderability estimates show that different physical properties of the test leads affect different parts of the wetting force curve, and that changes in the steam ageing procedure affect solderability in a generally predictable way.