Homebrew PCBs

Adam Seychell wrote:

> Hi,
>
> I'm wondering if anyone knows where is a good place to buy >= 100 UV
> LED's for home made PCB exposure box ? There are two sellers on eBay
> that I have found: (all prices below include delivery)
>
> http://stores.ebay.com/Winsome-House-Store 
> <http://stores.ebay.com/Winsome-House-Store>
> They are advertising 100 x 3000mcd(typ.) 20 degree UV LEDs for US$11.
> This sounds almost too cheap.
>
> http://stores.ebay.com/Light-of-Victory-Led-Store-lvehk 
> <http://stores.ebay.com/Light-of-Victory-Led-Store-lvehk>
> They have 100 x UV LEDs 20 degree 7000mcd(typ.) for US$32.
> or 100 x UV LEDs 20 degree 3000mcd(typ.) for US$15.
>
> It would seem I could use half as many of I buy the 7000mcd compared to
> 3000mcd. I'm guessing a 20mm grid spacing would be a good layout for the
> LEDs.
>
> regards,
>
> Adam
>
>  


Hi Adam,

Twelve months ago I bought 50 UV leds from an ebay seller in Homg Kong 
for US$1.99 plusd US$11 postage. One was dead on arrival but the others 
were perfect. My UV light box with 7 strings each of 7 leds in series 
spaced at 20 mm works perfectly for me. But you do need a diffuser to 
get an even light (no hot spots). Believe it or not, I used two sheets 
of baking paper. Lovely even glow. Ten minute exposure times at 60 mm 
above the leds. I mount my sensitied board and the photoartwork inside a 
slide in photoframe with a single sheet of glass in front. Very tight 
package. No undercutting.

I just checked for the seller "jeledhk", but he is "not 
found"...otherwise I would recommend him.

Best of luck.

Regards,

Ross