Minimum power required for PCB etching?

So I finally upgraded my generic laser engraver from its stock "2.5W" which turned out to be 1W. I replaced the diode with an nubm47 and am successfully
etching into aluminum with the aid of black marker @5.5W.

I would love to be able to etch PCB's by burning off the copper clad and avoid toner transfer and acid baths, or router dust. So my question is how
much power do I need at minimum to get into the area of diy laser etched pcbs?

I know that a co2 laser is ideal for such a project, but ive got time and diodes!

Im thinking 4x nubmo8's paralleled and some expansion optics to reduce spot size. Any thoughts?

Forgot to add and will reserve this spot for pics; I bought a block of nubm08's where I plan to remove a row of 4
and use the remaining four in their mounts to knife edge and focus the combined to a fine point just deep enough to breach the
copper layer on PCB clad.

Would 20W be sufficient, or should I try this with something a little more exotic like the 90W nubm31? I dont want to be entering into
the realm of overkill, so if I can pull this off with four 08's, id prefer that.

As copper reflects 450nm pretty well, even 200W of blue isn't enough or will char the FR4 underneath the copper.

Pulsed dpss lasers are used.

farbe2 said:

As copper reflects 450nm pretty well, even 200W of blue isn't enough or will char the FR4 underneath the copper.

Pulsed dpss lasers are used.

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Damn, I knew that would have been too easy. Though at least one step can be skipped and that is the toner transfer by using black
paint and engraving the layout then directly into the acid bath.

Some neat systems out there, this guy showcases one with appealing results.

Cool vid, neat watching. Couldn't help thinking of dot matrix printers evolved they'd now be laser-dot matrix printers and print something like that.

It sounds like you etched PCBs before, I've never but always wanted to try image etching.

Thorsteenster said:

Cool vid, neat watching. Couldn't help thinking of dot matrix printers evolved they'd now be laser-dot matrix printers and print something like that.

It sounds like you etched PCBs before, I've never but always wanted to try image etching.

Click to expand...

I etched boards for a few years but got lazy. Its a tedious endeavor. I got quite good at it, but hated the toner transfer part.
Finding the right paper was a pain in the rump, Even tried the special made clear transparencies from the local electronics shop.
Just such a pain lol

Something as point and shoot as a laser would motivate me back into some of my hobbies.

We used a paint back in the 80s. Then a uv light, rinse, etch