Homebrew PCBs

jcarlosmor wrote:
> 
> 
> You should try with a pump that has no-metal parts in the impeller. I
> am very impressed why in this forum almost nobody seems interested in
> building a spray etching system. That is the disadvantage of the "home-
> brew" point-of-view. When you want to go like the pros, nobody seems
> interested. By the way, with a home-build spray ecthing system I was
> able to etch an 30x30 cm double-sided board in 4 minutes with ferric
> chloride at room temperature, with excelent resolution.
> 

I built a spray etcher, admittedly it was a very substantial hobby 
project. It was about 3 years ago when I had my first attempt. You need 
tools like a lathe to fabricate pulley and other rotational parts, and a 
hot air plastic welder to make the tanks. There is lots of plumbing 
involved, hoses, brackets, and depending on how you do the spray arm 
oscillations, you need electronics for control. Learning how to prevent 
corrosion and leaks was another big challenge for me.

I use two paralleled modified 12 volt Shurflo diaphragm pumps, giving 
approximately 2.5 bar at 14L/minute total into 4 fan nozzles positioned 
on opposite sides of the PCB. It is a double sided spray etcher, with 
PCB located vertically at the center of tank. The tank lid has a spray 
proof slot for the PCB to enter.

Before anyone comments on the excessive effort in designing and building 
ones own spray etcher for the purpose of homebrew PCBs, I'll say its 
ultimately just part of a hobby and much like any home project.

Adam