There was a time when reflow soldering was an impossibly unique course of at our stage, one thing that solely probably the most superhuman of hackers might even dream of trying. But a demystification of the method plus the prepared availability of inexpensive PCB and stencil manufacture has rendered into the vary of virtually all constructors, and it’s probably that a lot of you studying this may have carried out it your self.
Screen-printing solder paste onto a single board presents a light alignment problem, however how about doing it with many boards directly? [Eric Gunnerson] had this drawback with a small-volume board he’s promoting, and never being within the pleased place of getting his PCBs provided on a panel, needed to create his own multi-board alignment jig and stencil. His write-up gives a complete and interesting introduction to the method whether or not you’re an occasional dabbler or embarking on a manufacturing run as he’s.
The drawback dealing with any would-be stenciler is that the board needs to be held in place reliably in the identical alignment because the stencil. With a single board, it’s simple sufficient to do the same old factor of taping scraps of PCB board to constrain its edges and maintain it in place as a rudimentary jig, then decrease the stencil onto it. Perhaps you’ve used a kind of industrial stencil jigs, through which a set of magnets maintain the stencil in place, or possibly you utilize pins to line all the pieces up.
[Eric] takes us by way of the method of making a laser-cut alignment jig for twelve boards, and slicing an identical twelve-board stencil. This consists of all of the software program aspect utilizing Inkscape, the choice of supplies to match PCB thickness, and a few of the points with slicing Mylar sheet for the stencil with out shrinkage on the corners. He’s utilizing pins for alignment, and he even finds a helpful provide of these within the type of shelf assist pins.
We’ve visited the world of reflowing many instances earlier than. If you’d like a primer, here’s our Tools of the Trade piece on it, and should you aren’t daunted by bigger initiatives, right here’s an account of a prototype run of a significantly complex board.