Issue link: https://iconnect007.uberflip.com/i/869081
18 SMT Magazine • September 2017 Automation in Rework Will there be some form of automation coming in to replace an element in rework/ repair? "Replace is a strong word," Patten says. "But to assist, for sure; [but] not replace." Still, it will not eliminate the need for all those years of ex- perience. According to Patten, it will require the op- erator to have even more experience. Although it will allow them to do higher quantities of re- work/repair. "You might have some pick and place type, not for a bare board but for a popu- lated board or touchless removable solder, dif- ferent things like that. You still need the highly skilled, highly trained tech to run it. With the fight of keeping rework costs as low as possible, and to keep a tech in such a glamorous position at the rates that they would re- quire at that position, is chal- lenging." How to find such people? Most of the time, the same people with previous contract manufacturing experience. "We have a work force that has been with us for many years," says Price. "People retire and you have to draw from the talent base that's in the area. We're not re- cruiting from across the country, so we're draw- ing from people that have previous contract manufacturing experience who have worked at a bench. Then, it's incumbent upon us to focus their efforts in certain areas to get them started so they're able to help us in certain ways. Then just expand their exposure to different things. It takes more than a couple of weeks, believe me. It's a long-term training cycle." "The skillset is just not on the market so we have to find somebody with the right mind- set and the right capability, and bring them in. But maybe not experience, so that we can train them." The Future of Rework/Repair The trend toward miniaturization continues to pressure the electronics manufacturing in- dustry to create products with finer pitch and spacing. Where does this lead the rework/repair process? "We have been approaching the limits of what we can repair for the last 20 years," says Patten. "So, we'll continue to evolve as they keep getting smaller. But, wow, we are really small, 2mm packages, 40mil balls are very diffi- cult to work with." "Sometimes it's a matter of context," ex- plains Freedman. "Some of the packages we use routinely can be put down easily and repeated- ly if the board is designed for it. Going back to a server board for instance, you have micro BGAs and you have a lot of through-hole devices and thick power and ground planes which compli- cates the matter. If I had a board that was nothing but QFNs, I could probably come up with a formula to do that all day and all night with no is- sues at all. When you have oth- er things in the context of the board, that's what makes it dif- ficult. If we were to reduce re- liance on through-hole devic- es, that would go a long way to helping things out. A cou- ple other things that I'd like to mention is that one of the things that I've seen done very poorly in the original assembly and in repair is thermal profiling. I don't see peo- ple taking the time or expending materials to do a thermal profile for initial assembly of the board or for its repair. I see people winging it on both sides." "I want to make a point of that," says Pat- ten. "They don't want to spend the time or the money to test it and make sure that the repair goes right. They're winging it." "Yet, another thing on my list is automat- ed or semi-automated repair methods," says Freedman. "I hate to see people taking hand- held hot air tools to boards; it's such an uncon- trollable process. You don't know what you're getting; you don't know what damage you're doing to the board, to the joints, to the things around it. I like to see more controlled methods and metrology so that we know what tempera- tures are being reached locally, and what's go- ing on with the board. With a programmable A LOOK INTO PCBA REWORK AND REPAIR Andy Price