Dear Ms. Ramos:

I doubt there is any standard. The yellow light intensity is determined by the
requirement for the operators to have adequate illumination so they can do their
jobs and also not to have the photo bay be gloomy. With a yellow filter you cut
out some intensity.

Usually in fab design they put the same number of fluorescents in the photo bay
as the other bays and just sleeve them with yellow filters made to go over
flourescent lights.

The thing you need to make sure about with yellow light is that you filter
sleeves on your fluorescent tubes are not leaking blue, violet or uv light
through. In slang terms it isn't leaking white light. However, the sleeves are
standard and you just need to change them out annually or some such time period
like that. Some bleach out, and probably some don't.

Ed

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On
Behalf Of Laura Oropeza Ramos
Sent: Wednesday, October 15, 2008 11:29 AM
To: MEMS-talk@memsnet.org
Subject: [mems-talk] light type and intensity for a clean room lithographyarea

Hello all,

We are planning the construction of a clean room for MEMS polymer fabrication in
Mexico City. I can not find information about if there is a standard way to
determine the yellow light intensity in the lithography clean room areas. If
somebody could give me an advice on this, it would be highly appreciated.

Thanks so much

Laura A. Oropeza Ramos, Ph.D.