Today I made the pilgrimage to Brighton again, this time not for a Mini Maker Faire but to Build Brighton, the Brighton Hackspace, who as part of the Brighton Digital Festival are running some workshops including the one I attended today ‘Making your own PCBs‘.
The workshop was run by Chris, one of the members who started the day with general introductions, followed by an introduction to some freeware design software called Express PCB, however not being a PC user and not being interested in learning that software I opted for EAGLE which I already know to a degree. After 13:30 another member came along who was more familiar with EAGLE and started showing me some of the more advanced techniques that I was missing previously such as buses and creating new components.
As the day wore on we printed our circuit board designs onto PCB transfer paper using a laser printer, which using a few passes in the laminator was transfered over to the blank copper board, prepared by sanding the surface to increase the surface area for the etching to act on and the toner to stick to. There were a few patches left over which were blotted with a permanent marker.
The copper was then washed under cold running water to cool it to a safe handling temperature, at this point we then peeled off the backing of the transfer paper to leave behind only the the toner which would protect the copper from the etchant.
The copper boards were then put into a solution of about two table spoons of ferric chloride crystals and warm water, to a thick brown (not yellow or orange) consistency. The boards are left in the solution whilst being agitated, until all the copper is removed.
The boards are then washed and dried to remove the remaining etchant and the sink must be throughly washed to ensure no concentrated amounts of etchant are left that would damage the pipework or surface of the sink.
Finally using a small 0.8mm drill bit the board is drilled and the board is ready for use, there are instructions on Hack A Day on producing a DIY solder mask for those who want a bit more of a professional finish.
The design we produced was a kit designed by Build Brighton’s own members, my design had an error in it but etched perfectly, I now feel much more confident about etching my own boards in future, here is the botched build of the kit using Build’s PCB design rather than mine…