Issue link: https://iconnect007.uberflip.com/i/1000349
JULY 2018 I SMT007 MAGAZINE 27 Las Marias: What do you think, Bob? Willis: Well, you could spend a day talking about each one of those issues, so I think we've got to be general about it. I mean, exactly what Steve has said that, unfortunately, when you delve back into the information based on a new product, so much information is never available. It's never been documented, it hasn't been evaluated, if we talk about cleanli- ness and corrosion and things like this. Like I said a moment ago, I've just been looking on some failures on automotive specif- ically on corrosion. When you then ask the questions to get the information, "Was testing done?" "How was it done?", all of that informa- tion is just like a fluid sand bath. It just melts away because it hasn't been done. The steps in any process need to be considered. I like to do things on a very practical level to start off with. I like to get something in my hands, I want to feel it, I want to touch it and I want to test it in that right. Then I decide, how can we test this so it meets an IPC/IEC standard? What's the methods we can use? If we look at something I have been involved with recently looking at condensation testing for PCB, for cleanliness and conformal coating compatibility with NPL. The existing tests really don't give you perfect consistency on results and the test developed particularly for the automotive industry, the Dewing Test, which was being conducted for many years in Germany really again gives more failures than positives. Prob- ably because of the way the test is done. There is no control and repeatability over the amount of moisture introduced onto a surface. Even a pretty clean surface can actually have fail- ures, but not because of what we've handled. Not because of what flux we've used. It's liter- ally the material condensing on a surface, and because you're getting a large amount relatively speaking, droplets, in certain areas, that's why we're starting to see issues. I think that the way in which we do test needs to be continu- ally reviewed, and that's what IPC does. They continue to review tests to see how they can get better and better and better. I started off my career testing components for cleaning compatibility with water and solvent. If we look at cleaning as a subject, if you look at most components today, if you look at speci- fications, because many engineers have grown up in a no clean environment, you ask them about testing components and they look at you blankly. You ask a designer, "Have you tested this component and is it compatible?" Because you want to have this product cleaned by your contract manufacture, and they'll look at you blankly. Another thing, and it's no disrespect, I