Leland, There are actually several issues you need to be concerned with: The first is actually ESD. Humidity control is also a major component in your ESD program. As the humidity in your facility is reduced, the propensity for charge generation and accumulation increases. As per ANSI 20/20 has the limits set at >30% RH < 70%. The next issue is MSD. From your statement I assume your facility never exceeds 60%. If it does then you have to take actions to correct and derate all of the MSD components you have exposed to the environment. And the third is your primary concern which is the control of your solder paste. This one there is no real industry standard that you need to comply with so it is more results oriented. If you are continuously processing the paste and replenishing your supply you probably will not see much change in your process. If you are having issues with clogging stencils, dry non-tacky paste, shifting components, etc. then you may benefit from the added humidity. Most print machines have an optional humidity control system. If you need help justifying the expense I would suggest you add ESD and MSD to list of reasons. I require my EMS' to monitor and control humidity for ESD and MSD and I recommend it for stencil printers but I am results focused on that. I hope this helps. Good luck. Russell Nowland Alcatel-Lucent Advanced Manufacturing Engineer Address: 14000 Quail Spring Parkway, Suite 300 Oklahoma City, OK 73134 email: [log in to unmask] Desk: 405-302-1660 Cell: 405-203-0034 Fax: 405-302-1622 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Leland Woodall Sent: Wednesday, October 08, 2008 1:11 PM To: [log in to unmask] Subject: [TN] Controlled RH% Versus Screenprinting Results Technetters, A couple of folks in our firm are investigating several different brands of humidification systems for possible installation at our facility. These things aren't cheap, and can run close to 500K. We see seasonal variation within our building of 15-20% in the winter months, and may go as high as 55-60% in the summer. Our paste manufacturer states their optimum printing parameter to be 50-60% RH. Our process engineers think we'll see a vast improvement in our screenprinting process if we pursue this project. I'm trying to understand if this is really going to reap the rewards as anticipated. Does anyone have any prior experience(s) they might share? Thanks in advance for your help! Leland --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 847-615-7100 ext.2815 -----------------------------------------------------