I will soon have to solder a bunch of circuit boards and I’m looking to laser-cut the solder stencils for them. This would require the use of mylar foil on the laser-cutter, which I think no one has done before here.
@petra this is the project I was talking about today
Mylar is BoPET and seems to be fairly popular for laser-cutting.
- The Chicago art institute bans it saying it releases ammonia and Hydrogen cyanide, but I think that’s wrong? https://sites.saic.edu/aoc/laser-cutting/lasermaterials/
- Cutlasercut and others offer it as a material for laser cutting.
- Glowforge lists it as a safe material: https://glowforge.com/materials
- ATX Hackerspace lists it as a safe material: http://atxhackerspace.org/wiki/Laser_Cutter_Materials
- Trotec also lists Mylar under materials suitable for laser cutting: https://www.troteclaser.com/en-gb/applications/film-foil-cutting/ (but they also say polycarbonate foil is safe.)
If the material is safe to use, the other question would be how to cut stencils with extremely small holes into extremely thin foil.
The smallest holes in the solder stencil are 0.25mm away from each other and 0.25mm wide. The material is 0.075mm thin. Apparently the trick to good results is raster engraving the holes instead of cutting the outline, because that gives the material more time to cool (though to me it seems like just using a very low speed setting should also work?)
I’m finding wildly varying suggestions for settings, ranging from “use very little power and go slow” to “use 100% power and go slow”. The idea with high power seems to be that it leaves the edges much cleaner, but i’d be worried it just spends a lot of time cutting the honeycomb. Here are some example settings I’ve found, which illustrate how wildly recommendations vary:
For reference, this is what the laser would have to cut for this project, the grid size is 1x1mm:
Here’s the only local source of the material I’ve found so far:
I’d love to know what people think about this! I’m hoping it’s safe to use this material on the laser cutter, and if it is - is anyone up for helping me dial in the settings for this?