Reading time ( words)
In a recent SMT007 survey, we asked the following question: "What are your greatest challenges when it comes to soldering?" Here are just a few of the replies, slightly edited for clarity.
Gebhard Neifer, Delphi: “Customer acceptability criteria regarding void level, in particular for bottom terminated components (BTCs). Odd form components meant to be mounted in a THR/PiP process are limited in size due to constraints in pick-and-place equipment and clearance in reflow ovens. Component mix leads to compromises regarding stencil thickness. We keep pushing the boarder regarding stepped stencils, but still face issues with providing sufficient paste for PiP and have, on the other side, solder bridges under BTCs.”
Allen Bennink, VAL Engineering Sciences Inc.: “Soldering and inspection of leadless parts; BGAs on both sides of flex circuits; and large ground planes on outside layers of boards. I am able to use and prefer OSP finishes. I also use SN100C chemistry almost exclusively—I really dislike SAC.”
Michael Lynn, Colt Tech LLC: “High temperature required for lead free; reworking lead free; and quality of lead free. Our customers are unwilling to pay for the much higher cost of a lead-free process. We need lead in our solder for a reliable solder joint.”