Homebrew PCBs

> Barry Demers <sdad@...> writes:
> > I have been using a single bulb 12" from a 6 x 9 board, with a 24
> > min exposure.
> 
> A single 15 watt bulb?
> 
> I've been pondering upgrading to two-sided UV exposure, but my LED box
> exposes in only 5 minutes.
> 
> Can you reduce the exposure time by using mirrors to reflect more of
> the UV light to the board?  I.e. something behind the bulbs, or the
> sides of the box.  Or is it just going to mess up the quality of the
> exposure?
>

I have 4 15 Watt 18" lamps and do upto 8" x 12" boards at about 6" from the lamps.   Use to expose about 6 mins. but now have found that 10 mins is better as long as you have a really good transparency.  

Now that I am using Dip Trace instead of the old Ivex Winboard I get a lot better printouts onto the Transparencies.  Seem to get a lot more ink down printing from Dip Trace than I did from Ivex Winboard, even though I would set the amount of ink to max in the printer settings.  With Ivex Winboard I had to always double up or try to print it twice which did not always work.

Ben