Francis ; You also must be aware that lower humidity also means more potencial ESD events, when you solve one problem you must check if the solution will not create another one ... Thanks -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Francois Monette Sent: Friday, April 13, 2001 7:11 AM To: [log in to unmask] Subject: [TN] Humidity and temperature specification Francis, Your SMT support group is right to be concerned with popcorn if you are assembling MSDs, however this does not mean that your environment should be less than 30%. The proper guidelines for storage and handling of moisture-sensitive components are clearly defined in the joint IPC/JEDEC standard J-STD-033 : Standard for Handling, Packing, Shipping and Use of Moisture/Reflow Sensitive Surface Mount Devices. Take note that all MS components are qualified and classified based on worse case conditions of 30C/60%RH. The maximum floor life that is specified on the MS labels represents the safe limit within this range of temperature and humidity. If your environment is significantly different this will have a significant effect on the maximum floor life. If the RH is less than 60% the floor life will be longer, if it is above 60% then it will be shorter. You can actually compensate for your actual production conditions by using table 5 in J-STD-033 : Derating due to factory environmental conditions. This de-rating varies based on the actual MS level and component body thickness of each component. Francois Monette Cogiscan Inc. 50 De Gaspe, Suite A5 Bromont, Quebec, Canada, J2L 2N8 Tel : (450)534-2644 Fax: (450)534-0092 www.cogiscan.com Date: Thu, 12 Apr 2001 12:16:34 -0400 From: Francis Sun <[log in to unmask]> Subject: Re: Humidity and temperature specification I thank everyone for their replies. 30% to 70% seems to be the general guideline. However, the SMT support group is concern that humidity level over 30% will cause 'popcorn effect' on the plastic package components. I believe that it is a valid concern, but is the 30% level limit legitimate? I would appreciate any feedback from learned colleagues. Best Regards; Francis Sun Mark IV Industries ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------