Settings for K40 to achieve PCB markings


(Scott) #1

I am trying to get some PCB’s serialized using a laser.

I’ve been doing a lot of searching for methods of marking PCB’s from lasers. Most machines are expensive and I cant find much of open sourceness of the topic.

The PCB’s I would be marking would be made of FR-4, any solder mask but white, and would probably be marking an area of 10x50mm.

The questions I have are:

  1. Should I have a large copper pad under the area that will be marked? or make sure it is just the substrate.
  2. Should I treat the material like glass? or like plastic?
  3. is a close to stock K40 capable of doing such a thing?

What kind of setup/ settings should I start with?

Etching/marking/engraving seem to be all appropriate for my purposes.

Thanks in advance!

(Dave) #2

I haven’t tried this yet, but I have some experience with PCBs.

I would suggest no copper under the area to be marked, as it will suck the heat away.
You probably won’t succeed at cutting the glass webbing, but you should be able to mark the epoxy.


The main thing I have seen, and this is going back over 10 years, is to put black spray pain on copper clad, use the laser to remove the pain where you want to etch, and then stick the board in etching solution.

That’s the only thing I can comment on.

To be clear, you have existing, commercially manufactured PCB’s like this, and you want to put serial numbers on them using a laser?

Personally I would not attempt this. Soldermask is a nasty chemical and FR-4 is a resin based material that you should not attempt to laser cut.

(Scott) #4

This is the kind of result I am looking for.
The boards are already manufactured and serializing is the only goal.
It seems like an industry standard to “mark” the material to the point of just barely discoloring the solder mask. after looking at commercial laser markers, they utilize a 3-4W laser to achieve results like above.

Here is a video of it in action

(Dave) #5

The video says 30W, but this should be within our capabilities.
I will definitely try this ASAP, as I design electronics and I have old prototypes hanging around.

(Scott) #6

@dbvanhorn that would be awesome! Ultimately a 2D barcode or QR code would be perfect. I’m not sure how fine it could get with a stock K40, but I would be super grateful to see some testing! :slight_smile:

closed #7