Homebrew PCBs

> > andrewm wrote:
> > 
> > Data sheets for most of the positive
> > resist I have seen would indicate that
> > black light (long wave UV) bulbs are
> > faster at exposing than germicidal bulbs
> > (short wavelength).
> > <SNIP>

> jpanhalt wrote:
>
> Do the datasheets really show 600nm is the
> best wavelength?

They show just below 400 as the best.  This
is closer to BL[B] bulbs (350 - 370nm) than
GE/GT bulbs which put out UV-C at 250nm

> 
> What in the datasheet for the positive
> resist shows that longer wavelength UV
> will be more effective, i.e., faster,
> given the same intensity of light at each
> wavelength one compares?

If you look on duponts website for Riston
9000 - it states in textual format that the
peak sensitivity is 350-380 nanometers.

This is actually different from the
datasheet I remeber being given for another
brand that showed a graph of sensitivity
and the peak being a bit lower than 400
and rapidly dying off below 300.

> <SNIP>

> Can you give a link to the data sheet for
> the positive resists?
> 
> Thanks. John

Can't find the one with the graphs though
if you google for 

"Riston 9000 datasheet"

The PDF for it comes up as hit number 1.

Page 4 of this data sheet is where it
says "peak sensitivity of 350 to 380nm".

I have both BLB and GE bulbs at my house
if you think it is worth doing some side
by side tests.  I am happy using the
safer BL[B] bulbs myself though.