using a laser to print circuit boards?

[tuskiomi]

So, I'm working on a way to produce PCBs for small jobs, and I thought that lasers might be a good way to go, as etching seems to be very difficult from small traces, needed for many microcontrollers.

I started by searching the absobance spectrum of copper, as the metal itself is very reflective. A quick search turned out that the absorbance of copper rests right around 800nm. Thus I came to the conclusion that an 808nm etching diode would probably be best.

My question to you, is weather or not the laser qould actually remove material, or if the copper will take on the heat? 808nm lasers are very focusable,and I plan on having an estimated power of 360KW/cm2 (40W diode at .112mm2 dot)..

I've worked with many lasers before, ranging from IR to UV, and I know enough safety to know that 808 modules are generally focused beasts.

also see: http://laserpointerforums.com/f44/best-laser-melting-copper-powder-80583.html

 

[diachi]

I'm sure you could direct etch just fine - but the easiest way would be to use some sort of coating on the board - either a paint or some sort of photo-sensitive layer. It's been done those ways plenty of times.

Laser etched PCB production | Hackaday

Exposing PCBs with a home made laser printer | Hackaday

Laser-Based PCB Printer | Hackaday

Exposing PCBs with a home made laser printer | Hackaday

https://web.archive.org/web/20120119142047/http://blog.reonarudo.info/

Not sure how well 40W of CW power at 808nm would work, something Q-switched would probably work better - that'd ablate the copper. May run into issues with the substrate/surrounding copper melting if you go too slow with CW.


I take it you're looking at a fibre coupled 808nm diode? Keep in mind a 40W bar isn't going to give you the beam performance you want otherwise.

 

[tuskiomi]

I take it you're looking at a fibre coupled 808nm diode? Keep in mind a 40W bar isn't going to give you the beam performance you want otherwise.

I'm planning on using a lens to focus the laser based on the substrate. I'm reading up on pulsed abalation of copper now, but I'm having no luck on beam abalation.

 

[diachi]

I'm planning on using a lens to focus the laser based on the substrate. I'm reading up on pulsed abalation of copper now, but I'm having no luck on beam abalation.

Could you give us a little more detail on your planned optical setup?

 

[tuskiomi]

Could you give us a little more detail on your planned optical setup?

like a schematic, a technical drawing, a few words? what would be most useful?

 

[diachi]

like a schematic, a technical drawing, a few words? what would be most useful?

A drawing would be good if you have something handy - but words would work too

Which diode? Which Lens(es)?

Might need to fire up the ~20W 808 and see what it does to some blank PCB - fibre coupled so I can get down to a reasonably tight spot with a short FL lens.

 

[Geeker]

I am curious how powerful of the laser you will need in order to etch the copper.