Homebrew_PCBs

> Hi Folks,
> I'm mostly a learning lurker on these tech exchange lists,
> but the recent UV source discussion has stimulated a question
> I've been wondering about. I need a really compact UV source
> for a very portable exposure unit. Anyone know of any success
> using an array of UV LEDs as a UV light source for exposures?
> LEDs are pretty directional, so are fairly well collimated as
> is. And in their visible light forms, bright enough to use in
> traffic lights. But can these UV LEDs put out enough light
> energy to react the photoresist? Anybody have experience or know?
>
> -Karl in Kalifornia

----- Original Message -----
From: "yllawk" <hkwally@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Saturday, September 30, 2006 3:53 PM
Subject: [Homebrew_PCBs] UV LED arrays?


> Hi Folks,
> I'm mostly a learning lurker on these tech exchange lists, but the
> recent UV source discussion has stimulated a question I've been
> wondering about. I need a really compact UV source for a very portable
> exposure unit. Anyone know of any success using an array of UV LEDs
> as a UV light source for exposures? LEDs are pretty directional, so
> are fairly well collimated as is. And in their visible light forms,
> bright enough to use in traffic lights. But can these UV LEDs put out
> enough light energy to react the photoresist? Anybody have experience
> or know?

Elektor had an article on a unit like that, for PCBs up to single Eurocard
size.

Leon

----- Original Message -----
From: "Leon Heller" <leon.heller@...>
> Elektor had an article on a unit like that, for PCBs up to single Eurocard
> size.
>
> Leon

>
> Some of y'all may be interested in this page that concerns using
> UV LEDs to expose PC boards:
>
> http://radikaldesig.blogspot.com/2006/10/insoladora-uv-leds.html
> <http://radikaldesig.blogspot.com/2006/10/insoladora-uv-leds.html>
>
> Dave
>
>

>
> Yep, the LED's they used where: Kingbright L-7113UVC.
> That particular LED has a 20 degree "beam", they put 24 of them in

> ~32mm appart. The distance from the LED to the PCB where 80mm and

> time around 6min. Or so the claim...
>
> /Henrik Olsson.
>
> ----- Original Message -----
> From: "Leon Heller" <leon.heller@...>
> > Elektor had an article on a unit like that, for PCBs up to single

> > size.
> >