Issue link: https://iconnect007.uberflip.com/i/1284035
SEPTEMBER 2020 I SMT007 MAGAZINE 35 electronics packaging. I learned all about what excessive heat, humid- ity, and temperatures can do to an electronic door lock if the PCBAs are not acceptably clean. Through that, I learned a lot about how we can assess the cleanliness at a very detailed level at specific locations on a board assembly and under- stand what chemical residues are going to be acceptable. That whole area for us is something that our customers don't require. Custom- ers demand and expect that things that affect longevity negatively, like cleanliness, are han- dled by CASCO, and we deliver. They need our product to go out there and work for a given length of time at a given performance level, but they don't require us to hit specific clean- liness levels. They leave that up to us to main- tain or to manage, and they trust that we get that right. Johnson: Where do you still struggle to get the kind of reliability from manufacturing that you're looking for? Steiner: Probably that cleanliness area where the industry recognizes that the standard we had used, like the ROSE standard—which mea- sures the bulk electronic assembly gross resi- dues that remain—is almost a useless task to go through. It doesn't give you all the infor- mation that you need. That whole area is not well-controlled by any of the standards organi- zations. I know that ROSE testing as a standard was removed from one of the specs recently, and the intention now is to have a more spe- cific understanding of the residues that are in areas of concern on your board. That proba- bly is the area that we can't just point to a standard and get success. You really have to do your homework and come up with your own standard to follow. Johnson: What do you see on the horizon as upcoming challenges? Where's the industry going with regard to design for manufactur- ability? Steiner: In general, we find that our buyers, as we get to know each other, know what things to look for, such as weaknesses in our design inherently because we have to design a specific way. There are challenges, such as the difficult components to solder. We use heavy copper. Like this 2,000-watt inverter I've mentioned a couple of times has 22 ounces of copper in a six-layer board. That's extremely heavy cop- per. But if you think about what it would take to conduct, for example, 100 amps of current, that's an enormous amount of copper. Getting that kind of learning on how you can pull this off and then reducing that to an acceptabil- ity spec, there's some stuff in there that we pay attention to. But at the end of the day, you have to meet IPC Class 3. That's the goal. Get- ting there is something that somebody needs to focus on, making sure you're maintaining all those things that go into those good sol- der joints and reasonable residues and things. But the lack of a single specification or a single direction to follow makes it a little challenging. Johnson: How does test and inspection equip- ment fit into this process? Does this work reduce the critical nature of the test and inspec- tion, or are you more readily able to design the defect out so that test and inspection finds fewer issues? Steiner: We ask for feedback from our suppli- ers—anything that they can Pareto out and get the heaviest hitters to bubble to the top so we can look for areas we can improve on in the design. We don't get a lot of that feedback, and