[labnetwork] LED lights in photosensitive areas - yellow lens needed?

Fri Jul 7 20:16:55 EDT 2017

LEDs are being used and can be use as replacements to the mercury arc lamps to expose photoresists, from 365nm out to the 400s... filtering is needed...

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On Saturday, July 8, 2017, 5:06 AM, Dennis Grimard <dgrimard at mit.edu> wrote:

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Frank:

LED’s do emit in the UV … see spectral response below … thus they need filters …

These are for 4000K and 5000K LED’s.

The lower the temperature the broader the spectral output in the visible range and the lower the peak output is in the 400 to 450 nm range.  There is also a shift to the visible for the lower temperatures towards higher wavelengths (toward 500 nM).

D

4000K

5000K

Dennis S Grimard, Ph.D

Associate Director of Operations

MIT.nano

School of Engineering

Massachusetts Institute of Technology

60 Vassar Street, Bldg 39-559

Cambridge, MA 02139

C:   (734) 368-7172

EM:  dgrimard at mit.edu

From: labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu]On Behalf Of Nava Ariel-Sternberg
Sent: Friday, July 07, 2017 3:07 PM
To: 'Frank Gavin' <fgavin at wafabintl.com>; labnetwork at mtl.mit.edu
Subject: Re: [labnetwork] LED lights in photosensitive areas - yellow lens needed?

Hi Frank,

We have installed LED lights in our litho area and heard the same claim but we checked with photoresist manufacturers and their recommendation was to have amber filers and block all wavelength below 500nm.

Although LED lights do not emit in the UV, some of the photoresists are sensitive to the lower part of the visible range.

We ended up purchasing amber plastic filters and installed them on top of the LED lights.

Hope this helps,

Nava

Nava Ariel-Sternberg, Ph.D.

Director of CNI Shared Facilities

Columbia University

530 w120th st., NY 10027

Room 1015/MC 8903

Office: 212-854-9927

Cell: 201-562-7600

From:labnetwork-bounces at mtl.mit.edu [mailto:labnetwork-bounces at mtl.mit.edu]On Behalf Of Frank Gavin
Sent: Friday, July 7, 2017 12:58 PM
To: labnetwork at mtl.mit.edu
Subject: [labnetwork] LED lights in photosensitive areas - yellow lens needed?

Hello everyone

We are suppliers of wet process equipment and one of our vendors of HEPA and ULPA fan/filter units tells us that we do not need to add yellow lens covers over LED light because such lights do not emit ultraviolet light.  I am always suspicious of simple convenient solutions so I want to put this statement out to this learned community and learn if this statement is true.  Perhaps some members have experience using LED lights in photosensitive areas of their fab and would care to comment?

Best Regards,

FRANK GAVIN, Sales Eng.

6161 Industrial Way, Livermore CA 94551
(925) 455-5252 ext 2420  Fax: (925) 455-5351
http://www.wafabintl.com

direct dial: 925-800-5551

cell (408) 314-6199

Please visit us at:

July 11th –13th

Moscone Center, San Francisco   Booth: 7817 (West Hall)

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