By Bob Willis
Most of the industry worldwide has been running no clean processes for many years and often, understandably, neglected important issues like design for cleaning, selecting compatible components and compatibility between cleaning materials and flux residues. With increased miniaturisation and the demands of modern circuits cleaning has come back to eliminate selected failures. Conformal coating is another process which has demanded special levels of surface cleanliness to guarantee coating adhesion and long-term reliability. Although there are high reliability producers that use coating with no clean, others want that extra confidence.