Project:PCB Making/Cupric chloride etchant

From London Hackspace Wiki
Jump to: navigation, search

Note : see Pcb for other references

Ferric Chloride is convenient for small projects, but it is used up by the etching process and disposal is a pain. An alternative is an etchant that can be regenerated by adding HCl and bubbling air through it.

I understand from some sources that adding HCl to Ferric Chloride will also regenerate it and eventually the etchant changes to CuCl as above. I don't know how carefully that procedure needs to be managed, or whether it's better to start directly with the CuCl bath.

I've set up a bath using this system and made the first pcb. Results are quite encouraging - I kept it at the low end of possible concentrations and ran it it 35 C (the tank will go to about 50), so fumes are acceptably low. It did a decent etch in 15 minutes. I used liquid developer from Mega, which takes about 1 minute.--Artag 16:49, 6 September 2010 (UTC)

  • The hackspace tank has now been changed to this system. It was set up using HCl and copper wire, left to disolve for several days. More HCl was added to reach the parameters described in the texts above. It's working well and we have found it occasionbally convenient to accelerate the rejuvenation by adding a litle peroxide.

  • I have plenty of syringes, bought from acuflow. These work very well for measuring, I will bring some in. Although a flask is best for watching the titration, I have used a glass measuring cylinder and found it convenient for both measuring the water (diluting the etchant) and mixing in the NaOh. They can be obtained from wine / beer making shops. - artag