Printed Circuit Boards (PCB) using the Laser Cutter

This is a new twist on an existing process, which allows you to make super accurate PCBs. It basically involves spray painting copper board, laser cutting off the paint and then putting the board in a bath of Ferric Chloride to remove the unwanted copper. This method is particularly good when using large chips as they need very accurate pin spacing.

Step 1 Spray copper board

Cut your copper board to the required size and spray paint it with a nice even coating

Comments

[o0mouse0o]

Is that PCB photoresist paint you're using?

[mashorter]

No I'm just using standard spray paint, I've never heard of photoresist paint, where can you buy it, is it any good?

[TechShopJim]

I've tried a lot of spray paints for this with our 60-watt Epilog laser cutters at TechShop to create resist layers on copper clad board, but the laser etching seems to leave a very thin invisible water-resistant coating on the copper, even though it looks like the spray paint has been removed.

The ferric chloride will not reach the copper because of this invisible layer.

Did you encounter this in your experiments, and if so, what did you do to get past it?

[sblaszak]

Jim,

Do you use the "air assist" on your Epilog? I haven't tried this yet, but I'm wondering if the film you're seeing could be paint vapors that are re-settling on the piece after the laser moves away. If so, and if mashorter is using the "air assist" and you aren't, then the "air assist" may be blowing his vapors away before they have a chance to settle. Just a shot in the dark but I figured I'd throw it out there.

[ZrvZ]

how precise  are you able to do a pcb with this? Is trace width of 15mil possible or maybe even less? How much clearance do  you have between traces?

[josheeg]

where can someone get a low cost lazor cutter or access to one to do this?

[frugalguy]

http://www.techshopdurham.com
or another TechShop near you.

[unwiredben]

I wonder if you should use artwork like that prepared for a CNC PCB milling system for this; in those setups, they just mill lines in the copper to separate conductive areas.  It seems like that would require a lot less laser time, since you're removing less of the copper.  If you're paying for laser time by the minute, this could really save some money.

[jeff-o]

Cool! What laser cutter did you use? What settings?

[mashorter]

Hi Jeff-o, its an ILSM 30W laser with the settings SPEED 30 and POWER 100.