Low budget lasers

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1

I make PCBs for electronics,

we use ferric chloride usually (we dip the bord in this solution at 50-60° ~).

I baught a regular (diode) 20W laser engraver, it is practicly unsuable, too much time and setup,

but a fiber laser with the same “power” works great.

I was thinking, if using an accelerator (chemical) with that diode laser to make it work decently,

very thin paste or liquid form.

I tried with the ferric chloride , which activates with heat, it kind of started to work, but too much residu accumulates and stops the process.

PCBs are bakelite or mica plates with a 35µm thick copper layer.

I am not a chemist, but if anyone has an idea about a better chemical to use, I will try it.

Regards

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I’m unaware of any easy-to-use laser (light) activated chemicals for etching copper. But not a chemist.

If you are trying to etch the copper directly with a laser the Diode lasers won’t work. Not just because they are ‘20W equivalent’ (eg much lower power but a very fine focus point.) but because the ‘Near UV’ blue light from diodes simply reflects off the copper.

Higher frequency (pure?) UV as produced by the fibre laser is absorbed by the copper and etches it. These machines seem to work quite well for direct copper etching, at least. I’ve seen some good demos of this on YouTube..

The way to use a diode laser with PCB’s is to use it to cut away the mask on pre-masked PCB stock and then do a conventional chemical dip. With good material and technique this can produce superb and repeatable results.

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agreed a 100% , this is why I am proposing,

to acctually create this new procedure, if possible ofc .

a fiber laser does the job like knife-butter, CO² lasers too.

regular diode laser , even 2/3/50W, dont work right away in an efficient way, and yes the copper is problematic for us because of its molecular props. .

like many technical methods in the industry, using a catalyser or an activator is a standard way of doing things, AKA a reaction :slight_smile: ..

In the thing I am proposing, is to find a chemical That will with the energy of the (diode) laser, react with the copper and desintegrate it, we dont even use the laser wave, we use its energy/heat, since ferric chlo… reacts as heat rises.

having ferric chlo… I did a test, and as I explained, this molecule is not the right choice even if on paper it should work, the problem is “mechanical/optical” , the beam weakens in the fluid and residues make it worse.

maybe an ultra thin layer of ferric or other chemical will do the job … .

Regards

4

You will have more success asking about this sort of thing in a chemistry forum.

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If it was doable I’m sure it would have been invented by now. We do have a chemist in the group and he may chime in. @NedMan are you reading this?

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6

I’m not aware of any chemicals that would work with a diode laser like you want. I even did a quick search through the scientific literature and nothing popped up.

I’m not sure what advantage you are trying to get over the regular pcb etching process.

In the past I’ve seen people using lasers to create resist layer patterns. Apply a resist to the whole board and then use the laser to selectively removed the masking resist to create your intended circuitry pattern. Then perform a regular chemical etch.

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7

well,

  1. if one has a diode laser … he could add an extra task to it in his lab.

and like me that laser wont go waste.

  1. speed :slight_smile: and a huge amount of LESS hazard and mess (PCBs labs are a nightmare) .

  2. cost: diode laser setups are 10 times cheaper than fiber laser setups.

  3. patents are a huge source of money, so if a chemist finds the right molecule and form (liquid, paste or pouder),

me and him will do 50/50 .

but helas, it wont be patentable, because it just got into public domain, from this forum :slight_smile:

cheers.

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8

Don’t think enough invention detail has been established to prevent a patent at this point. Also would likely depend on how much time elapses from invention to filling to determine if it would be considered abandoned and there for in the public domain.

You could possible get around the precipitation build up by doing a continuous thin film flow of reagents.

Hmmmm…..