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Subject: Re: [Homebrew_PCBs] PCB Etching Solution Amount

From: Hermod Pedersen <hermod.pedersen@...>
Date: 2005-04-26

Leon Heller wrote:
>I use a relatively small amount of etchant in a plastic food container. It
>works very well.

That was my aim -- alas, I failed at my first attempt with photo resist.
Being unsure whether the board was exposed long enough, I got another
board, fired at it a lot longer with the bulb, only to get the same result:
very little in way of etching.

Mixing a new brew of etchant solved that -- it all etched in a few minutes.
Proves what Jan Rowland wrote:

>Now the total NUMBER of boards you etch with that same etchant in whichever
>container is a function of the TYPE of etchant, the "ounce value" of the
>board (copper-thickness), how much copper is removed for the
>particular pattern
>works very well.involved, and the temperature of the liquid. This is a
>matter you will have
>to learn via your own experience.

To err on the "big hammer" side, this time I put the tiny board into a big
bucket of etchant...
I am confident, thanks to all your enlightening comments, that I will be
able to scale down towards my newly bought food container turned etch bowl.
By the way, for the time being I think I'll stick to natriumperoxidisulfat
(forgot to mention that). Even though it seems to wear out faster, to me it
feels somewhat nicer than ferric chloride or hydrochloric acid.

Best of all, I made two boards on the same piece. All this chemical stuff
may seem messy (it kept me away for a looong time), but it really isn't
that difficult once you get started. A lot of your postings here have been
of great help and encouragement.

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Hermod Pedersen, HCDX Web Editor
<http://www.hard-core-dx.com/>