Laser etching SMT stencils tutorial

etchedstencils_main

Felix Rusu of LowPowerLab has posted a detailed tutorial on how to laser etch SMT stencils:

In this blog post I want to show you my new method that I’ve been using since I’ve purchased a laser cutter from china. It’s using the laser to etch stencils out of transparency plastic (mylar). Chances are that you already have membership or access to a local workshop or hackerspace where a laser cutter is available, so you can give this a try. The trick is to balance the power vs speed of the laser at that sweet spot where it won’t burn the plastic or over/under etch the pads. And for those really wondering why in the world I don’t order from OSHStencils (not affiliated with OSHPark) or similar affordable online services – some of it is explained in the video but mainly because instead of waiting a few days I can do it in 5 minutes, and the flat mylar allows making letter sized stencils. Don’t get me wrong, I support and use the OSHPark PCB service but I prefer to etch my own stencils on the fly on my laser, it’s really convenient and allows for errors and retries without another few days of waiting. Plus, I can do in mylar what they can’t in thin curvy kapton.

Check out the video after the break.

Join the Conversation

4 Comments

  1. Hi,
    you can improve the flatness and quality by engraving not cutting the holes.
    The power need to be adjusted as high to engrave a hole at high speed.

  2. I have been using this method for a while now, it works well. I use 3M CG 3700 transparency film which is more readily available for me (5mil).

    Yes, engraving is the only way to go here. With my 50W laser I set .3mm Y step, 200mm/s speed and 12.5% power which gets me the best result, i.e. the least amount of burring and clean holes. Experimentation is key as every laser is different.

    It really helps to add alignment holes to your PCB and stencil if you have the room. I usually go for 3mm holes which tend to be a nice and tight fit with common M3 bolts.

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.