[labnetwork] Light filtering in photolithography bays

[Cohen, Ana N CTR USARMY DEVCOM ARL (USA)]

Hi Travis,

A couple years ago we switched our lithography bay fluorescents (T8) to
amber tube LEDS from Super Bright LEDs. The light is more orange than yellow
so took a little adjusting (many users first thought it was darker than
usual), but visibility has actually been much better since we these bulbs
are more stable and we don't end up with dark patches from dead
fluorescents.
https://www.superbrightleds.com/t8-uv-blocking-led-tube-clean-room-18w-1800-
lumens-single-end-dual-end-ballast-bypass-type-b-32w-equivalent-1800k+packam
t-30-Pack 

Our fume hoods are still fluorescent bulbs with filters. I've definitely
noticed a degredation over time, but our facilities also have purchased
different filters over the years, so I can't provide much comparison to your
situation. However, it may be that your LEDS are emitting higher wavelengths
than the fluorescents. UV Process has UV filters along with the color tubes
which could be useful
https://www.uvprocess.com/c3/1790-gamtube-and-supertube-filters.html

We don't filter our computer screens because don't notice much light
pollution and we don't keep anything photosensitive nearby long-term, but
you can definitely turn down the brightness and blue saturation on the
monitors. We also have not needed to replace the darker pigment filters on
our doors' windows, but similar to the monitors they are placed sufficiently
distant from the photoresists/coated substrates.

Good luck!
Ana

--
Ana N. Cohen [she/her/hers]
Photolithography Cleanroom Technician
Contractor | General Technical Services, LLC
US Army Research Laboratory
2800 Powder Mill Road, Adelphi, MD 20783
Tel: 301-394-1527
Email: ana.n.cohen.ctr at army.mil

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