Whether or not cleaning is actually necessary to prevent any of the above described failure patterns has to be verified from product to product based on the expected quality requirements, i.e. product life cycles. The susceptibility of assemblies to failure can range from delamination of conformal coatings to electrochemical migration, and even the circuit design. It has been demonstrated however, that the removal of contamination prior to conformal coating provides significant improvements in the adhesion of conformal coatings and at the same time reduces the possibilities of contamination induced failures. Furthermore, it was shown that with the onset of lead-free products, the level of contamination and its respective impact with furthermore add to the complexity of adequate process control. In light of this ongoing transition, the authors are currently extending this investigation to provide even greater insight of lead-free initiated phenomena. This in turn will lead to more adequate analytical tools for detection and complementary know how for coating materials and their respective performance. Due to the complexity of the topic, the authors highly recommends to consult with your precision cleaning expert to avoid costly retrofits for cleaning processes or even potential product liability concerns.
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