Mini etching cuvette
Since I only etch my own boards very rarely and if, only up to the Eurocard at most, I have built a small etching cell. With its dimensions of 250mm x 170mm x 12mm it needs only a maximum of 150ml filling. With 30g of sodium persulfad this is enough for a double-sided eurocard with a useful track layout.
Ventilation is via a built-in air duct, which is provided with some 0.8mm holes at the bottom. The pump is a simple aquarium pump with 3W. The air volume is regulated by a simple screw valve.
I realized the heating via a 3.3Ohm high load resistor, which transfers its heating power to the etching liquid via an aluminum plate.
|4||Frame Seite||250||10||Plexiglas 4mm|
|2||Frame Unten||150||10||Plexiglas 4mm|
|2||Air duct Seite||235||5||Plexiglas 4mm|
|2||Air duct Unten||140||5||Plexiglas 4mm|
|1||Hot plate||170||100||Aluminium 2mm|
If you still want to afford a heating system with controller, here is a simple circuit diagram: