Homebrew PCBs

> From: Jeff   Sent: Thursday, January 19, 2012 22:55
> I see that some here are using HID mercury lamps for mask/photoresist
> exposure. Where can HID mercury lamps be obtained? Do they give better
> results than black lights or the yellow-housing halogen work lights found in
> home centers?

I've been using a HPW125 for years, 800mm from the pcb and at the focal line of 
a cylindrical parabolic reflector made from aluminium sheet. It gives good 
collimated rays. I expose the precoated negative resist for 90secs with it.

It takes 5-10 mins of warming up for full output.

http://www.lamptech.co.uk/Spec%20Sheets/Philips%20HPW125.htm

>> DO NOT break the outer glass shell of a mercury vapour lamp! It will
> radiate a lot of short wave UV (UV-A) which is dangerous for eyes and skin,
> and it generates lot of ozone (O3). Good results could be obtained without
> breaking the outer glass shell.
>
On 20/01/12 22:02, Boman33 wrote:
 > I bought my HID lamp at eBay.  Remember to buy a socket too.
 >
 > I am not using it for PCB production since I have a 400W UV light source.
 >
 > Always use eye protection!
 >
 > By the way, breaking the protective glass on a regular mercury bulb lowers
 > the UV output, not increases it. (The capsule will run too cold to be
 > efficient.)
 >
 > Bertho