J-STD-001C Paragraph 3.6.2 outlines the specifications.  In summary, if the humidity falls below 30%, then proper ESD control needs to be in place.  It also specifies a max of 70%.  We are in the east and find our humidity ranges from as low as 10% in the winter up to 50% or so in the summer.  Even with humidity controls in place we have difficulty maintaining the 30% min in the winter.

Although the spec states a range, other considerations need to be kept in mind.  These include the affect of humidity of MSD's, paste processes, assembly processes, and even reflow.  If paste dries out or absorbs moisture, variation in these processes will be evident.

-Carrie

-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Peter L.
Sent: Wednesday, February 04, 2004 5:46 PM
To: [log in to unmask]
Subject: [TN] Facility Humidity control


Technet,

What is the typical humidity/ temperture (nominal and +/-) for a CEM
production environment?

Is there an industry "acceptable" range?

We are located here in the west coast and have seen relative humidity level
varied from low 30s% (winter) to high 60s in the summer. Under what
conditions should a HVAC control system be introduced and without that,
what would be the potential impact on the overall manufacturing process?


Rgds,
Peter

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
-----------------------------------------------------