Issue link: https://iconnect007.uberflip.com/i/1000349
28 SMT007 MAGAZINE I JULY 2018 probably would do it myself. You look at when people look at components they look online, which is the Google search. They download the component documentation from the supplier and believe what it says. If you take just an example of QFN, quad- flat no-lead components, the people design- ing these into boards were following what was said to them by the component supplier, until the contract manufacturers and assem- blers said, "Hold on a minute, this isn't going to work. It isn't good practice." Hence, you've had all this work done on stencil thickness and modification to improve processing, but it all stems back. The one thing I'd say to design- ers, if you're going to pick up on a new compo- nent to use, look at the data from the supplier, that's fine. If they've got a few micro sections and if they've got a little bit of other data on their profile, but they've actually got pictures of what they did, you know they've done some technical work. If they've got a spec which is set by the IPC, or this is maximum/minimum temperatures, you've got to query whether they've actually done the work to prove it. I always say look at the data, look for more than the data, and you'll get a better feeling. If we talk about, let's say, wave soldering, it really hasn't changed radically for many, many years. The wave soldering process can still do a good job, but it relies on the people setting it up properly and watching what's actually going on. Wave soldering design is also critical for good yields, and there are so many tricks of the trade in design to improve yield. However much we would like to fully automate the process, that just really won't happen. There was a machine once which was a totally auto- mated, computer-controlled machine made by a company. There's only a handful of those machines that were actually used in the real world because you couldn't actually do very much with them. Selective soldering, we have the ability to control and monitor a lot more. We can control and monitor warpage of boards so we can get better optimization. There's lots of things we can do there. If we talk about reflow soldering, there's been things that have changed to improve on optimization of clean- ing, optimization of gas transfer, and things like that, but the actual fundamental of the machine when we went from infrared technology to convection technology that was the major leap. There wasn't really much that can change with convec- tion technology. You get to a limit, its capability. The machine has to be a certain length to get a certain number of products through in an hour, and that's it. You can look at things like power consump- tion, etc., but then you look at vapor phase process, because you're using a lot less energy with vapor phase, you've got more control of your process. As long as you can run it for the product volume you want to run, that's a much more attractive process. There's lots of toys that us engineers have to play with. We select the best tools to do the job. Really, that's what that best practice is all about. The best tools to do the job and then put in the proce- dures to make sure that people follow and get the best out of their machines. It's not only that, it's listening to people. If I go into a factory and I'm trying to solve a problem. I'll hear all the sort of introductions and listen to what everybody tells me, but I'm going to go down on the shop floor. I'm going