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Subject: Re: [Homebrew_PCBs] Ammonium Persulfate disadvantages?

From: Markus Zingg <homebrew-pcb@...>
Date: 2008-12-04

The main disadvantages IMHO of ammonium persulfate in adition of what
you say are :

- It does not last long in terms of how many PCBs you can etch up until
it does no longer etch.
- You should return or otherwise savely dispose the used up solution. In
other words you can't reactivate it. At least not that I would know of.
- It is relatively costly to get, and cobined with the above that's a
major thing.

Of course, if you only make one board per year you are probably good.
The advantage it is having is that you can see through it and as such
your able to whatch what's going on. However, once you know the
behaviour of a given setup (no matter what you use), this is no longer
so important.

Just my 2ยข of course

Markus

Jim Miller schrieb:
>
> I just read Adam Seychell's page on various etching solutions.
>
> It seems to me that the only disadvantage to ammonium persulfate is slow
> etch speed at room temp.
>
> Does this result in a poor etch control? Poor etch definition? Other
> problems?
>
> Since my use is for hobby purposes only I'm not sure why slow speed is a
> problem.
>
> Does anyone have any experience with ammonium persulfate that can give
> some
> insight?
>
> tia
>
> jim ab3cv
>
> [Non-text portions of this message have been removed]
>
>