It is best to make the stencil holes a little larger to make it easier to lift the stencil off cleanly - mine are specified as 2.6mm I use 2.5mm stainless steel dowels - these are cheap and have chamfered ends. Drill the holes with a drill press - they have to be perpendicular! I’ve found that two holes are fine for a small board. If this is a one off, you could easily use a spare board to align and drill a couple of holes on a wooden board or similar. I then arrange the mounting/alignment holes on a10mm grid on my pcb. If that’s worth doing, whats the best way to do it? Draw a circle in the edge cuts layer on the PCB and then draw another circle in the mask layer?Īs I use this technique a fair bit, i made an alignment jig consisting of a thick slab of Delrin with 2.5mm holes drilled at 10mm centres on a CNC. If I get a solder paste stencil supplied with my boards, is it a good idea to have a couple of locating holes in the pcb and the stencil so they can both be aligned easily on a couple of dowel pins? Location holes for solder stencil Manufacturing I’d be curious to know if it works for you though. In this case you will pull the mylar from the pins.īut it’s your project, so do as you wish. You can pull quite hard on a piece of tape (sideways), but you can not do that when the mylar is just held with some pins. Standard method is then to fix the stencil itself with a piece of tape along one long edge too, and then hold it under tension while pasting so it does not flop around. If you do not have a SMT Stencil printer then laying the PCB flat on a table, putting some PCB pieces around it (both for making a bigger flat surface and for preventing the PCB from moving is a reasonable method. If you have a decent SMT stencil printer, it has adjustment knobs and you do not need this method in the first place. What sort of pins do you plan to put though this in the first place?.Mylar is floppy, It will not stay put very well when you move your squeegee.It gets easily contaminated with paste.It will hinder movement of your squeegee.In a more general sense, I also have doubt whether it’s a good idea to do this for several reasons. If this does not work (which seems unlikely) you can also add an “SMT Aperture” pad type to your footprint, and then only use the Paste layers for that pad. To make holes in the solder stencil, you also have to enable the F.Paste and B.Paste layers.īut do check your Gerbers. It looks like a NPTH pad has the F.Mask and B.Mask layers enabled.
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