Flux from ‘No Clean’ solder processes can cause reliability problems in the field due to aggressive residues, which may be electrical conducting or corrosive in humid environments. The solder temperature during a wave solder process is of great importance to the amount of residues left on a PCBA[a]. ‘No Clean’ fluxes typically contain about 2 wt%[b] solids, 96 wt% alcohol, 1 wt% water and 1 wt% additives.