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Subject: Re: [Homebrew_PCBs] Setting exposure with a step gauge

From: Philip Pemberton <ygroups@...>
Date: 2009-06-02

leon Heller wrote:
> Buy the boards from Farnell or Rapid; the resist goes off after six months
> or so, I've found, and they could be old stock. I use sodium hydroxide for
> development - 12 g/litre.

I got the Microtrak and the CPD5 developer from Farnell (they're within
driving distance, and it cost less to drive down there than pay the UPS
hazchem charges) so they should be pretty close to new. If not, I can always
get the boards and developer direct from Mega...

CPD5 is (according to the MSDS) an 11% solution of sodium metasilicate, and
from what I've read is considerably less hazardous than NaOH.

Thanks,
--
Phil.
ygroups@...
http://www.philpem.me.uk/