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Subject: Re: [Homebrew_PCBs] Re: cheap UV light sources?

From: "otc_friend" <otc_friend@...>
Date: 2007-03-01

Can you describe what makes brass pcb different from copper pcb? I'm wondering if I should switch to brass material.
How good is soldering?

regards -
Henry

www.ehydra.dyndns.info


-----Ursprüngliche Nachricht-----
Von: "garydeal" <garydeal@...>
An: <Homebrew_PCBs@yahoogroups.com>
Gesendet: Dienstag, 27. Februar 2007 11:48
Betreff: [Homebrew_PCBs] Re: cheap UV light sources?


| I use a 500 watt halogen "work light" from the hardware store, $10
| including an extra bulb stashed in the handle. I also use this chinese
| dry-film resist (ebay, $40 for way more than I can use before it dies)
| fed through a $25 laminator from walmart, using the procedures noted at
| thinktink.com. My contact frame is an old glass-faced photo contact
| printer, a couple bucks at a thrift store but generally available cheap
| on fleabay.
|
| With the UV-filtering glass and guard assembly flopped out of the way I
| get a good exposure in about four minutes at ~18 inches. I also avoid
| eyeball exposure, I figure that UV filter is there for a reason.
|
| I generally only do brass, not copper pcb, and I have a darkroom so I can
| go from a good dark inkjet print to litho film without too terrible much
| trouble. I ∗have∗ used an inkjet print as the mask (oil the paper with
| vegetable oil, let soak a while, then keep wiping until dry-ish), takes
| about twice the exposure and requires testing - produces slightly rough
| edges. I'm going to need to make a pcb or two soon, so I expect this
| experience will come in handy.
|
| -Gary
|
| > Can someone please recommend a UV lighting source which:
| > - is cheap
| > - has consistent UV output
| > - is readily available, or easily made up from items from general
| > hardware stores
| > - gives good results with low exposure time (preferably 5-10 mins,
| > I'm not keen on 30 minutes)
|
|
|
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