Homebrew PCBs

On Tue, 03 Jan 2006 15:48:13 +0100, Bruno St-Laurent <bsl88k@...>  
wrote:

> Hi guys I'm new using the homebrew mix of HCL 30% and H2O2 3%, and
>
> would like to know what is the best temperature for good etch time??? ,
>
> right now when i do a fresh mix, the etch time is really fast around 5
>
> minutes , but if a week later i want to reuse that mix now clear green
>
> color my etch time goes up to more than 30 minutes!!!!!!
>
>
> Thanks
>
>
> Bruno

It is problematic to heat this etchant because HCL will boil at like 50C  
or something, and already below this temperature the amount of produced  
fumes will increase greatly. So there probably isn't much to heat above  
room temperature before things get nasty.

Use a bubbler.

You do know that you need fresh H2O2 each time, as long as your Cu levels  
are still low?

ST