# Anybody built UV light source for making printed circuit boards?



## Karlik (Nov 16, 2012)

I have been thinking about making a LED light source for developing printed circuit boards.

I wonder what UV LEDs will be best. An array of small ordinary UV LEDs or few (2-3) power LEDs? I am not planning making big boards. Not bigger than 100x150 mm.

What wave length should I look for?

Do I need some sort of diffusor?

I wanna build it cheap. 

Anybody made something like this already?


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## AnAppleSnail (Nov 16, 2012)

Medium wavelength UV LEDs still cost a couple hundred apiece last time I looked. It's just hard to get such high-energy photons out. It appears any UV-ish LED works, though. Behold: Google:

Instructable


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## bshanahan14rulz (Nov 16, 2012)

Back in my day, us hobbyists just used the kind where you mask it with a sharpie or transfer toner from a sheet to the board, like this: http://www.dr-lex.be/hardware/tonertransfer.html

Can you just use the sun?


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## Norm (Nov 16, 2012)

Have you looked at UV nail dryers on ebay? Not LED.

Norm


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## Karlik (Nov 17, 2012)

Thank you for your suggestions, guys. I really appreciate it.
I will probably try the array of LEDs.

The toner transfer method is also very interesting and looks very straightforward.


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## jspeybro (Nov 27, 2012)

my brother bought a face tanning setup for a few dollars to make PCB's. not sure if he ever finished it. The setup used a flatbet scanner glass and uv fluorescent tubes I think.


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## dt3830 (Dec 27, 2012)

Salutations to all,

I used to use this setup, about twenty years ago.
Single six or four inch (black) fluorescent tube with
(Inverted or reversed) paper print out of the PCB track with
the desired sized, photo resist PCB.

I will normally print out the track (reversed) and wrap the PCB board with it.
I will then place the (Photo resist PCB side) on top of the tube for 5 minutes.

I will the wash it off with Sodium Hydroxide (diluted) and
finally etch the design with Feric Chloride solution.

I have not used the UV LED design yet. The theory is similar, but I worry that it might not give out enough UV illumination to leave the tracks on the (photo resist) PCB.

No need for diffusor, just leave a small gap of about an inch or so, between the UV tube and the PCB.

~ChamHoongLoong


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