Re: [CAD_CAM_EDM_DRO] PC board making

I think thats the same PCB material I used to make my stepper drives. I got
the board from www.oceanstateelectronics.com
I used a floodlight style grow light from Lowes and it seemed to work fine.
It did have a bit of a learning curve, the boards were taking a long time to
etch and I thought they needed more exposer when in fact the developer was
getting weak. I ended up with 2 usable PCB's from 5 attempts. I'd sure try
again though - the parts that came out ok look really good. The
pre-sensitized board is pretty resonable too. I hadn't thought about
doubling the transparencies, sounds like a great idea...

Joel

----- Original Message -----
From: Ian Wright <Ian@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Saturday, April 21, 2001 9:11 AM
Subject: [CAD_CAM_EDM_DRO] PC board making


> Hi,
>
> I struggled for a long time trying to make decent PC boards by all sorts
of
> different techniques but I now have the problems cracked. I can now make
> good small boards every time.
> What I do is draw the board out in Eagle, Corel draw or some other
graphics
> package and print out two copies onto clear overhead projector film (I use
a
> normal inkjet printer). One of the copies I print in reverse (just tell
the
> graphics prog to flip it) and I then tape these together with the printed
> surfaces touching. This doubles the density of the print and seems almost
as
> good as a litho film for this purpose. I then use commercially coated,
light
> sensitive PC board from the local surplus electronics shop. I have found
> that there are (at least) two distinct types of this board about and you
> need to understand the type you have. The one I use is a fibreglass based
> board which develops with Sodium Hydroxide. I sandwich the board and the
> double 'negative' between a sheet of glass and a piece of wooden board and
> expose it to the light from a 35mm projector for about 8 minutes. It then
> gets developed in ordinary Caustic Soda drain cleaner, washed in water,
and
> etched in Ferric Chloride.
> The board says you should use ultra-violet light for exposure but I have
> found that, if you give it a strong enough blast of ordinary light from
the
> quartz halogen projector lamp, it works just as well. You could probably
get
> a similar effect using a car headlight lamp with a bit longer exposure. I
> would always try a narrow 'test strip' cut from the edge of any new type
of
> board to verify timings first. HTH,
>
> Ian
> --
> Ian W. Wright
> Sheffield UK
> www.iw63.freeserve.co.uk
>
>
> Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
discussion of shop built systems, for CAD, CAM, EDM, and DRO.
>
> Addresses:
> Post message: CAD_CAM_EDM_DRO@yahoogroups.com
> Subscribe: CAD_CAM_EDM_DRO-subscribe@yahoogroups.com
> Unsubscribe: CAD_CAM_EDM_DRO-unsubscribe@yahoogroups.com
> List owner: CAD_CAM_EDM_DRO-owner@yahoogroups.com, wanliker@...
> Moderator: jmelson@... timg@... [Moderator]
> URL to this page: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO
> bill,
> List Manager
>
> FAQ: http://www.ktmarketing.com/faq.html
>
> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>