The specifications offered by Jack Whaley below are typical of several
semiconductor facilities I have built/operated in San Francisco Bay area.
Here, the hardest time is dry winter days when we find ourselves adding
tons of water per day to the air in a medium-size fab. Of course the most
stringent requirement is for photoresist (this has loosened somewhat from
1980's -- when some fabs had really tough +/- 2%RH specs -- due to better
resist, check your manufacturer's requirements) and then secondarily for
static electricity effect reduction. One important thing to remember about
humidity control is that water/humidity can easily pass right through walls
of sheetrock, etc. You may find you are "humidity controlling" adjacent
areas that you did not intend. A proper vapor barrier can be a big help. If
energy costs to maintain temperature/humidity specs gets out of hand then
you might consider subdividing lab space for areas of tighter control using
appropriate humidity seals, doors, etc.
Regards,
Tom
>>Received: from mtl.mit.edu (MTL.MIT.EDU [18.62.0.45]) by email.sjsu.edu
(8.8.8/8.8.8) with ESMTP id JAA02238; Fri, 13 Nov 1998 09:00:17 -0800 (PST)
>X-Sender: whaley@xanadu.ece.ucsb.edu
>Date: Fri, 13 Nov 1998 08:59:05 -0800
>To: labnetwork@mtl.mit.edu
>From: Jack Whaley <whaley@ece.ucsb.edu>
>Subject: RE: Cleanroom temp/humidity
>
>Hi Chris,
>
>Currently, our specs are:
>
>Temp: 68 deg F +/- 1 deg
>RH: 45% +/- 5%
>
>If you are having problems meeting your temp/RH spec in summer, you need to
>do several things. First, make sure the current airhandling system is set
>up correctly, and if it is, then you need to increase you cooling capacity.
>
>To make sure your current air handling system if functioning correctly, you
>need to make sure all the components are operating within specifications.
>This includes air flow rate and temp delta across the coils, water flow
>rate and temp delta through the coils, input and output temp across the
>chiller, correct operation of control valves, etc. If all these things are
>within spec, then you are exceeding the capacity of you chiller. The only
>way to fix that is to add capacity by adding a second chiller, or replacing
>your current chiller with a new one that has higher capacity.
>
>We are in the process of purchasing a new, higher capacity chiller.
>
>Good luck,
>Jack
>
>----------------------------------------------------------------------
>Jack Whaley, Lab Manager Nanofabrication Research Laboratory
>voice 805-893-8174 University of California at Santa Barbara
>fax 805-893-4500 Electrical and Computer Engineering
>whaley@ece.ucsb.edu Santa Barbara, CA 93106
>
>
>
>
`
`
`
-----
Thomas R. (Tom) Boag
-----
J.D. Pinson Process Engineering Chair
and Adjunct Professor
-----
MicroElectronics Process Engineering Program
Department of Chemical/Materials Engineeirng
-----
One Washington Square
San Jose, CA 95192-0082
USA
-----
My Office Phone (408-92) 4-3879
My Fax (ChemMatl) (408) 924-4057
My Cellphone (Emerg.) 1-650-767-8371
My Home Phone 1-650-968-6688
E-Mail: tboag@email.sjsu.edu or trboag@aol.com
-----
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