Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, Daniel Johnson <a3v03v0@...> wrote:

>
> I switched from ferric chloride to sodium persulphate (MG Chemicals).  It is a much easier to handle are requires somewhat less care. 
>
> I often etch single PCBs in a glass bread pan sitting on a foam rubber block while read mail.  A slight rocking of the pan is enough to keep the etchant moving.   I heat the etchant to about 130 degrees prior to starting.  Depending on how worn out the etchant is I may have to reheat.
>
> One of these day I should make a real etching tank.
>
> The heavier the copper is the more you will have undercutting. This post on Electrotech has some images of a PCB I was working on a while back.  Compare the edges to what you are getting.
>
> http://www.electro-tech-online.com/chit-chat/86683-cricut-2.html#post674243
>

How are you heating the etchant?


Have you tried "sponging" the surface or not bothered with
trying it?


Also, do you keep your boards etching copper up, or copper down.