Laser Etched PCB’s Take 2
UPDATE: I forgot to attach the image file I created to allow for the laser to cut the holes in the PCB. I will attach it later today (5 – 6PM EST).
As promised I was going to continue to research ways of using the laser cutter to make custom PCB’s quickly. The results from the last trial were very good. However, I thought that I could do better by having the laser cut the holes for the components also. The problem with this is epilog c02 lasers (the one at least I have) do not produce high enough energy to “react” with copper. So over every trace I have embeded a small circle that allows during the time of ferric chloride etching will remove some of the copper as well. You can see this here. What this does is make a very small circle that does not have any copper on the top. This will allow the laser to cut the 1/32 silicon PCB board.
CONSTRAINTS:
Alignment, alignment and alignment – I have not come up with a good “template” or “jig” yet to allow for hole cutting once the PCB copper has been removed. Also this precludes me from using double sided designs as well. After talking to Dr. Mark Adams he has proposed an interesting solution to this problem. His idea was to, through eagle regenerate the bottom side of the PCB by changing the rules so that the traces are larger and would allow for higher offset tolerances.
