OK, I have a conformal coating question being debated internally related to
the wavelength of light used for black light inspection of conformal
coating.  Fluorescent lights tend to emit more around 365 nm, which is
where you get the most fluorescence from the dye.  I would like to use some
of the new LED black lights, lower power, longer life, much brighter, but
they emit in the 395-410 nm wavelength.  Seems to illumine the coating just
as well, but am getting pushback from some areas of the company.  So, here
is my question:

Are there coating features or defects which you can see at 365 nm, which
you cannot see at 395-410 nm?

Doug Pauls
Principal Materials and Process Engineer
Rockwell Collins