Laser attachment for reprap to cut circuit boards

Guys tell me where I am going wrong.

A Lasers cutter would be perfect tool for reprap as it does not create any vibration. Unfortunately they are expensive and probably not a good tool for
a hobbyist due to cost and the ability to blind yourself.

However a Laser is nothing special. It simply delivers an intense beam of parallel light to a small spot which gets very hot and then vaporises the material.

Could we achieve the same thing with a lens which focuses the light into a single point? The beauty of this is the setup would be relatively harmless outside of the focus point and therefore some thing we could use.

I am currently thinking of taking 3 x 500 watt bulbs and trying to focus each on a single point using a few high quality magnifying lens. i.e. one from above and one on each side. Each one lined up to exactly the same spot.

I do appreciate that this is a waste of time for cutting something with any sort of thickness as you would not be able to focus the light.

But would this be enough to burn a track into a blackened blank copper circuit board? or could be used for etching?

Grin

Stephen

P.s. Apologies if this is obviously flawed idea or something someone else is working on.

Copper reflects Infrared C02 Laser light.

We need a CNC router for that. But Viktor et. al. are working on laser cutter stuff.

it's a neat idea, but won't work. too much of the light will cancel out other light beams.

The reason lasers are used is coherence and collimation, which together allow most of the optical power to actually arrive at the target.

you cannot get coherent, collimated light from a bulb because they emit a range of frequencies in a range of directions, so you would have to compensate with raw power. I guess you would need about 1KW of heat lamps to do the work of a 50w laser for these reasons.

Even a 50W C02 laser will reflect off that thin film of copper.

I'd go with a CNC router, or a tiny bench-mounted mini metal shear and brake:
[www.micromark.com]
[www.northerntool.com]
[www.wttool.com]

... beside lasers there are some comercial optical heads for soldering/sintering with light too.

They use special bulbs with very small light/IR(heat)-emitting wire-windings in the power-ranges about 300 Watts.

The focussing unit is a extreme precise and smoth polished concave mirror with maybe 50 to 80mm in diameter and the resulting light-spot is between 3 and 5mm in diameter.

A laserspot is much smaller - typically 0.3mm or smaller (i have 0.06mm@1Watt and 0.02mm@50Watts), so a laser has much more energy-density per area, so it can solder/melt/sinter too but is much better usable for cutting or engraving ...

Viktor

But would this be enough to burn a track into a blackened blank copper circuit board? or could be used for etching?

Sorry. I was distracted, and didn't realize your question was about masks, etching, etc.

Yeah, I think someone with a generic, common laser cutter did it in the hobby community. Check makeblog. I think the process is unwieldy for even small prototyping runs, though.

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There are ooooooodles of ways to make pcbs.

You might be interested in doing up a lens system and UV led to carefully expose the unpolymerized mask on a 'Pre-sensitized PCB'. And then etch in FeCl, etc.

Also, you should establish whether you are interested in reseaching new processes, or just getting things done and making stuff. In which case there's lots of cookbook recipes for getting things done.