Sometimes there are moments when an engineer has to use whatever materials they have to hand in order to complete the job on time. Such a situation arose at the RevSpace hacker space in Den Haag, Netherlands, as they were the assembly venue for a conference badge.
Their problem was that the badge PCB had no solder paste stencil, and the solution was to laser cut one out of an unexpected material. The backing paper for self-adhesive vinyl sheet has properties not unlike those desired of a stencil, so they tried laser-cutting one from that material. The result was a robust stencil that outperformed the Mylar they had previously used, enabled the manufacture of 350 boards.
They think that the polymer layer on top of the paper may be silicone, and found that the laser didn’t unduly melt the edges of the cut. We’re not sure we’d feed random unknown plastics into our cutter, we’re guessing they have good quality ventilation. It’s mounted into a plywood jig in much the same way as a conventional stencil might be.
The badges were destined for WICCON, a Dutch conference from an organisation for women in cybersecurity. Sadly we’ve not seen a completed one so we’re not sure what it does, however we’re pleased to hear they were completed before the event. That’s a hurdle all badge designers will know well.
Long term readers may remember, that RevSpace have something of a history when it comes to assembling badges.
Another option is to build a DIY stencil from…. a beer can like this link shows:
https://electroagenda.com/en/remote-control-car-hacking/#PCB
Please take that sort of garbage elsewhere.
What ‘garbage’ exactly? I understand women are under-represented in IT, sure. I can’t see any reason for a Security Conference to be restricted to female only attendees, I find it genuinely bizarre — doubly so considering how liberal the Netherlands is when it comes to these things usually. Apply the mirror test – if there was a Security Conference that was male-only, would that be OK? This is not a troll, or deliberately provocative – I don’t understand, period.
DIY home-made SMT metal stencil from soda can – the definitive tutorial
https://www.youtube.com/watch?v=JWUJtmgh55M
I have used my vinyl cutter to make a handful of stencils usually out of some type of sticker liner or backer
you might have to fiddle with the corners of finer apertures a little , but it works well enough for even things like soic and qfp’s
It should be noted here (they mention it but barely) that they used the “backing material” of the vinyl and (i hope) did not laser cut the vinyl itself. Hitting a vinyl or any Por any releases chlorine gas which is lethal.
*Por == PVC
Curse my clumsy fingers!
“I just washed my hands and I can’t do a thing with them!”