Laser cut CMS stencil
This afternoon I tested the laser cutting CMS stencil technique at Lyon’s FABLab (Fabrique d’Objets Libres), that will be used to build the development modules. These stencils will be part of the development module kit I’m working on: an autonomous module allowing you to test your boards before building them.
The plastic stencils (rhodoïd – 150 micrometers thick) work great, at least as good as steel ones and are perfect for laser cutting. Tin sticks well to the PCB once the stencil if removed and transparency makes positioning easier.
You need to watch your pad size though, due to the cutting width: as much as 40% smaller for CMS components in CMS 0402 boxes, SOT-363 boxes or even LQFP boxes like the LPC1224′s otherwise you’ll get shot circuits.
And now, the pictures: