[Yello]

I have a Chinese CNC drill/router and I like to fix a laser to cut mylar foils. To replace the spindle with a laser is no issue.

Application is mylar foils as solder paste stencils.

The foil thickness is about 0.20mm/200µm/8mil. If mylar doesn't work I would go for kapton.

I wonder if a laser pointer module can do the job? If so, what power and color I should look for?

I know have a 150mW BluRay laser module, haven't tested yet if it can cut. I want to use that to expose photosensitive PCB laminates.

And since we are on that cutting topic, what laser I would need to cut 3mm PMMA/Acrylic? (of course the mill can do that too)

[underthetire]

Isn't Mylar very reflective? Or am I just thinking balloons ? More reflective needs more power. Don't waste your time on anything smaller than 10 watts. Smaller may burn through, but you would have to go so slow it would simply make a mess.

[Yello]

Isn't Mylar very reflective? ... Don't waste your time on anything smaller than 10 watts. Smaller may burn through, but you would have to go so slow it would simply make a mess.

Mylar is a sheet material that melts with heat. There are all sort of colors I guess, mine is white opaque and very shiny.

I have seen images were people cut it with some sort of laser, but the quality looked quite terrible. I believe if the power is too low the Mylar melts and that gives a poor edge. I presume that for a good edge it should instantly evaporate. Right?

Is is an example on Kapton (Polyimide): (However, they talk about 35/45W...???) Laser Information - How to make PCB reflow stencils

I start to think that it may doesn't work at all.

[underthetire]

If I had some, I could test it on a 400watt, but I think your correct, it will probably leave a melted edge, and being that thin the air assist will probably not help.

[underthetire]

Our YAG makes a complete mess of it. The CO2 will cut it, at about 3-5 watts. Bring a sample to a trophy shop, see if they can cut it.