gnupic: Re: [gnupic] help - DIY PCB manufacture
Subject:
Re: [gnupic] help - DIY PCB manufacture
From:
Alex Holden ####@####.####
Date:
29 May 2005 15:34:55 +0100
Message-Id: <8955A824-E5B5-4E13-86B2-99A02234D280@linuxhacker.org>
On 29 May 2005, at 14:47, David McNab wrote:
> the top side - a 65mm x 65mm board with 0.625mm tracks.
> Is it just me, or is iron-on transfer film simply not up to the
> task for
> fine tracks?
I've never tried transfer film but I've done quite a bit of DIY photo-
etching and in general I try to avoid making tracks as narrow as
that. If I have to pass a track between the pins of an IC I just
narrow the track down where it goes between the pads (using oval
shaped pads helps). It takes a bit of practice to get good results-
some of my early boards were unusable.
> Would I be better off using photo-sensitive boards, printing onto
> transparent film, exposing, developing, etching, developing, cleaning?
I'm not sure what your second developing step is for. I just wash off
the etchant in plain water. Unless you mean using developer to remove
the etch resist? I suspect that would take a few minutes and exhaust
your developer. Apparently many people use acetone to clean it off,
but I just rub it off with a 'PCB rubber' then immediately lacquer it
(be careful not to get fingerprints on the metal between cleaning and
lacquering or they will oxidise the metal under the lacquer).
> Or, is home PCB manufacture more trouble than it's worth? Am I better
> off finding a company who can do it for me at the best price?
If you need lots of very fine tracks close together, PTH, tinning,
solder mask, silkscreen, more than two layers, etc. then it's easier
to get them made for you, but the costs add up and the amount of time
it takes to get the boards back from the low cost overseas board
manufacturers can be frustrating (especially when you find a few
mistakes and need to revise it).
--
------------ Alex Holden - http://www.alexholden.net/ ------------
If it doesn't work, you're not hitting it with a big enough hammer
