Design007 Magazine


Issue link:

Contents of this Issue


Page 69 of 87

70 The PCB Design Magazine • August 2016 This month, I'm going to depart from my usual format of providing five essential facts about conformal coatings. Instead, I'm going to provide an account of a customer's problem— no company names mentioned, of course—that brought into question the adhesion perfor- mance of a coating that they had been using successfully for some time. This problem, and its eventual solution, il- lustrates rather well how good record-keeping, batch traceability, and the auditing of suppli- ers for quality control compliance can go a long way to help resolve manufacturing issues. Always up for a challenge, and not wanting to ignore any production-related issue that ap- peared to cast a shadow over the performance of our products, we donned our detective hats and, with spyglasses at the ready, set about to discover the causes of this particularly challeng- ing delamination problem. But first, let's have a little bit of background. Our customer—a multinational firm with sites around the world—contacted us about a coating they had been using without any prob- lems for quite some time, but for some bizarre reason was "no longer sticking" to their boards. They reported that a newly delivered batch of this conformal coating, when applied, could be peeled from the solder mask areas in a single sheet. Our preliminary queries revealed that there had been no changes made to the coating process itself. So, was the coating at fault, or was there something else we were missing? Delving a little deeper, we discovered that our customer was using this batch of coating material at several of its sites, both within the same country as the problem site, as well as sites located in other countries. It turned out these by Phil Kinner ELECTROLUBE CONFORMAL COATINGS DIVISION Conformal Coatings: Beware the Boards that 'Bare' All! SENSIBLE DESIGN

Articles in this issue

Archives of this issue

view archives of Design007 Magazine - PCBD-Aug2016