Evaluation of the Determination of Soldering Flux Resistance Using Rectangular and Circular Test Cells

The increasing use of critical solid state components working on very small operating currents and the tendency towards high density packaging of these components on printed boards place greater importance on the cleanliness of the assemblies. Some of the components used cannot be subjected to total immersion solvent cleaning; consequently flux residues will remain on the boards during service. Flux residues under this condition can be objectionable either because they are overactive and chemically corrosive or because they degrade the insulation resistance of the printed board laminate.