DIY PCB UV-Box

[microc]

Hi,
I'm currently working on a UV-box for making my own PCB's. I've got an old scanner and I'm about to deside what kind of UV-media to lay down. The price range is huge.

From a regulare electro shop the prices are as following:
1. UV- fluorescent tude,  prices from €60
2. UV- Diodes, prices from €12,5

On the otherhand, if I go to a computer store to get "case mods" equipment, for pimping your computer(!!!) the price is really cheap:
1. UV - diodes from €2,25
2. UV - cold cathode fluorescent light (from Sunbeam), 30cm glass tube from €3.5

Any idea why the pricerange is so significant? Can I use the light from a computershop or is the glass eliminate the UV energy and only showing the colour?

I thought making a "bed" of cheap diodes would do the trick..

Any thougts?

 

[abbey road d enfer]

You need a tube that is specifically made for the purpose, with the correct radiation wavelength. You want to go to a dedicated DIY shop specializing in PCB equipment.
UV diodes just do not have enough power to produce the photochemical reaction.

 

[detonator]

Try to find an old scanner. It has basicly all that you need

 

[hobiesound]

just get a second hand face tanner + a broken scanner... put in box .....hey presto...

i made mine for less than 10 euro.

greetz,

Thomas

 

[microc]

Cheers guys!

I've got an old scanner. I just need to rigg the light inside.

Thank you for your time=)

BR

 

[Apache5]

I read somewere that the fly killer lamps can do, that they have the appropriate wavelength to be used for that. I sometimes use an old 400W face tanner lamp that I found someday and it takes like 3min standing 50cm far from the photo pcb face... I have an old scaner waiting to be an UV-box in future. I think it depends on the speed of pcb production that you need... if you need to be fast maybe you need to look for the specialized UV-lamps

Arnau

 

[gemini86]

I've been doing mine with a full spectrum tube, from walmart... It takes longer, but works... I only made 4 pcbs last year so it's nothing to wait 15 minutes for a pcb to be exposed.

 

[mobyd]

I use a 175 watt mercury vapour discharge lamp. It is necessary to break off the outer envelope and use a ballast choke but it gets the job done in 2 minutes (after warmup) for boards coated with KPR.
M

 

[livingnote]

Whoa - do you have a picture of how you got that vapor discharge lamp mounted?

(that's what they use in the industry)

The wavelength you need is UVA (320-400nm). This is common in tanners and insect
lamps like they say. My stuff is sensitive between 350 and 400 nm - most everything is.

Peak sensitivity iirc is actually 400nm, so if you happen to build one out of very many
Aculed 1W UVLEDs you can't be more on target. And (cough) out of money.

But tubes rock more than anything. Philips Actinic BL & co. "gets Sh*t done™"

It's worth looking into getting a face tanner off ebay because one small tube runs around 9€.

"Blacklight" fluorescents work too, they're the same tubes painted purple.

Watch out for specialty bulbs or tubes that are made to emit UVB or UVC, they're way
less efficient. And they'll hurt your eyes (they generally have clear glass).

LEDs - needs complicated solder-together-grid of them, and like...

CCFLs - not enough power. Well, yeah, enough power, but takes 6-12 minutes to expose
if you stuff a scanner chock full of them. So yeah, I guess, works too...just takes longer.

I built one with CCFLs and used it happily for a long time myself - only caveat - needs lots
of DC amps, so you end up designing an extra PSU for it with a big trafo somewhere.


But what's really useful: Install an amperemeter.

That way, you know how many photons are coming out, and you can measure individual
tubes when you're setting it up so you can be sure they're all emitting about the same.

Also, as they slowly degrade, you'll know by how much.

 

[microc]

I built one with CCFLs and used it happily for a long time myself - only caveat - needs lots
of DC amps, so you end up designing an extra PSU for it with a big trafo somewhere.

Neat!

Thanks! I found a used face tanner on ebay! Looks great. 4 tubes =)