Ok, maybe a weird one...

Lasers
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1

Ok, maybe a weird one… anyone tried etching and cutting FR-4 PCB boards? I am curious if a K40 can etch (eat) into the copper far enough to cut out traces, then obviously cut through it to cut out the PCB?

I’ve been wanting to buy a PCB mill, but they are super expensive and i have a laser cutter - surely I can cut my own PCBs?

I’ve seen videos on youtube of people spray painting their copper boards black and engraving the black off, so they can finish the board with Chemical Etching but that’s not what I am wanting to do.

I want to actually cut far enough into the board to remove the copper and leave the fibreglass, kinda like what this video shows as an end product…

I mean I’m happy to buy some board and try… but I am worried that hitting the copper with the laser might be dangerous :frowning:

2

A K40 cannot burn through the copper. The only method that works is spraying with Matt black, burning that off as needed, then etching.

3

All metals reflect the infrared beam, and what little is not reflected gets quickly dissipated by the copper

4

Copper is pretty reflective at this wavelength. They make mirrors from copper for these wavelength lasers.

https://fslaser.com/Applications/Metal

5

Yeah, That’s what I was thinking - bummer, was worth asking though. Thanks everyone for the replies!

6

I’m not an expert, but I know there is something you can place over the copper and when you raster it with the laser you create a super accurate mask and then can etch with some sort of sulfide acid or ferric chloride bath. I used a sharpie with a Radio Shack kit 30 yrs ago. If you’re patient or a small enough board you can use a sharpie or a thin layer of paint, toner or contact paper also ablates under our 35W laser. Your K40 can do a lot more than you think!

7

@Timothy_Rothman Yeah, I know that’s an option, but in my original post I mentioned it wasn’t something I was wanting to do. If I can’t actually cut/etch FR-4 with my laser, I’ll just continue to proto on perf board and send my files to China for PCB manufacture.

or invest in a PCB mill (eventually).

I was just really hoping (against hope) that someone had found a way to actually cut copper with a K40 :wink:

Cheers!

8

My method for pcb.

9

@Timothy_Rothman Yea used the overhead projector sheet in the laser printer trick to make pcbs. Did a pretty good job.

10

@111116 Is this a foiled copper PCB?

11

@Rene_Munsch standard fr4 pcb.