Advanced PCB Etching Tank Control

I’ve consistently had inconsistent results from etching PCBs. My best luck has been with PCB developing using a laser printer and transparency sheets. I was whiping up a batch of PCBs for my 6 meter amplifier when I decided I was really getting annoyed with figuring  out how to keep the etchant hot, but not too hot. This PLC modulates the temperature at a predefined setpoint. It switches a relay on and off to a heating element I scrapped out of a 10$ coffee maker and I used a little fountain water pump that cost me $8. The rest of the materials I had laying around. I kept my etchant at 125 deg F. A probe within the 5 gallon bucket monitored the temperature. Because of the staged heating the temperature varied about 5 degrees total. The heat of the water pumping transferred through the plastic container and heated the etchant so I didn’t have to directly heat the etchant.

I still have the bones of this project though I haven’t etched a board in a solid two years so I re-purposed some of the items.

Controls Cabinet
Controls Cabinet
MG Chemicals PCB enchant container with the 5gal bucket that is filled with heater water.
MG Chemicals PCB enchant container with the 5gal bucket that is filled with heater water.
The hole system... the laptop isn't needed I just had it hooked up to "tune the PID loop".
The whole system… the laptop isn’t needed I just had it hooked up to “tune the PID loop”.
I heat the water by circulating water through this coffee maker heater.
I heat the water by circulating water through this coffee maker heater.
the display panel, pretty simple but gets the job done.
the display panel, pretty simple but gets the job done.

 

 

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