With a load of SMT circuit boards (from OSH Park) to build for Bristol Braille project, I decided to finally try using a reflow oven instead of hand soldering. The needle for my solder paste syringe was missing so I had a go at making some disposable stencils using the hackspace’s vinyl cutter. It’s an old Craft Robo 220-20 which is now only available on ebay for about £30.
I pretty much followed Sparkfun’s tutorial, but used sticky back 0.05mm vinyl for the stencil. This worked really well because it was easy to hold in place and I was able to re-use it 3 times with no problems.
The smallest parts I used were sot-23 and so-16 which worked fine.
I was able to do everything with Linux, because one of the hackspace members – Tim Hutt – had previously written RoboCut that drives the cutter from Linux.
I was so happy when it worked out because it reduces the time to build dramatically! Also, the boards look so much neater and professional because as the solder melts in the oven, it pulls the components into place. That means the process is pretty forgiving of slightly off stencil registration or component placement. If you do a lot of SMT soldering you should really try reflow and stencils.
You can get my process writeup over at the Bristol hackspace wiki.
