How to Etch a Printed Circuit Board



So you made it to the first few steps, well its easy going from here on. Time to break out the chemicals, please refer to the first page for the list of stuff needed, you can get those chemicals at your pharmacy or chemical store. There are few more ways to etch a PCB, but this is the only one where you do not need to heat the liquid, so no need to buy expensive equipment to do that.

When making a cold etching bath, please be careful dealing with chemicals, even though these aren’;t the strongest around they will leave nasty irremovable stains on your clothing. remember you only have one set of eye’;s and limbs, they don’;t grow back, so wear protection! When dealing with chemicals wear rubber gloves and safety glasses. If u happen to spill some solution on your hands rinse it with water immediately, and if a white spot develops on your skin, simply cover the spot with a thick layer of moisturizing hand cream.

Right now, get a little plastic container or glass bowl and add about 3 to 4 bottle caps of Hydrochloric Acid (10%). To the Hydrochloric Acid we need to add the Hydrogen Peroxide, put about 1 to 1.5 bottle caps into the bowl, and stir with your plastic tweezers to properly mix the two chemicals. You have now just made your own cold etching bath, wasn’;t that hard was it ;).



Etching in progressClick here for a larger image



There are a few things you need to know, when Hydrogen Peroxide is mixed with an acid it will react with it. The reaction will not be harmful tough, all you get is pure oxygen. This process will continue until the Hydrogen Peroxide is gone, leaving you with the water it contained. By doing this the Hydrochloric acid will lose its strength because its slowly getting diluted with water. If the etching goes really slow add some more Hydrogen Peroxide and if that doesn’;t help, you will need some new Hydrochloric acid. You can store the solution in a plastic coke bottle or a glass jar, but don’;t fully close the lid because the pressure will build up and your bottle or jar could explode, the best way to prevent this from happening is to puncture the cap or lid with a nail, so the buildup air can escape.

Now get your developed board and place it in the solution, be sure the whole board is submerged. You will notice that it will fizzling a lot, this is due to the chemical reaction the mixture has on the copper. Continue wiggling the board every so often, for approximately 1 to 5 minutes.


Particaly Etched

Click here for a larger image Click here for a larger image

After about 1 or 2 minutes you’;ll notice that you can see some board through the copper. Frequently check until all of it is gone, when your artwork is clean and clearly visible get it out of the bowl and rinse it with water. Remember we don’;t want to leave it in the solution for too long or it will begin dissolving the protected copper. Congratulations, you just made your own Printed Circuit Board.