Homebrew PCBs

Think and tinker has step by step directions for an excellent 
exposure setup. Not expensive either.

Calibration is easy inexpensive, and also described.

Ballendo

--- In Homebrew_PCBs@yahoogroups.com, "mikezcnc" <eemikez@c...> 
wrote:
>
> Les, I agree that that is the ultimate method of making PCBs 
> but...you forgot to mention follwing problems:
> 1. You must have a good UV exposure box-- let's not start another 
> dicussioon today what that means. It is not a trivial issue 
although 
> for some it might be. The issue here is the resolution because I 
have 
> seen a keproo UV box for $500 failing to give a good resolution on 
> TSOP- it was all FUXXY! On quality PCB material, too.I will only 
> state that depending what you are building, the uv light may or 
may 
> not work for some or many applications. And let's not expose to 
sun 
> light for a while either :)
> 
> 2. Once you have the box you need to calibrate the bloody box and 
> depending what light it uses the timing might be all over the map, 
> depending on the preheated condition of the lamp. Depending on 
what 
> you are using. Calibration alone is not for weak people either.
> 
> 3. PCB material: buy ready made (expensive), use negative or 
positive 
> (explain it to a nenwcomer), apply film, make your own secret 
> emulsion, dry, spray, develop (how long, oops, lets strip it and 
do 
> it again, and again... what teh hell is that today...). Then 
finally 
> comes etching which is trivial..
> 
> Now, I am waiting for someone to say that he is happy with scratch 
> and etch or printing directly on copper!
> 
> Overall, I know that UV is best, and I know it works fine because 
I 
> have the whole process prepared when... when I get tired of TT-ing 
> PCBs. So far I don't foresee it. Stick a secret Staples paper in 
the 
> laser printer, hit 'print' and pull the paper out of the printer. 
> etch it and remove the paper. Then you drill.  No adjustment 
process, 
> no secret uv boxes.  Mike
>