Outgassing is a concern for Space missions. NASA requires that the outgassing meet two requirements,TML Total Mass Loss and CVCM, Collectible Volatile Condensible Material. The TML limit is 1.0% and the CVCM limit is 0.1%. The reason this is important is that in vacumm, the volatiles that are forced out om materials may condense onto critical items such as optics and make them unuseable. Certain conformal coatings may out gas tremendously. NASA tests materials for outgassing and maintains an outgassing data bank of outgassing numbers with test reports for all materials tested. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Lum Wee Mei Sent: Wednesday, March 28, 2007 11:17 PM To: [log in to unmask] Subject: [TN] IPC 6012 : Outgassing Criteria Hello, I was reading this IPC 6012 when I come across Section 3.11.1 Outgassing 1. What actually is outgassing? 2. Why is outgassing critical for PCB? 3. As the PCB consist of so many processes and different materials go into making it, where did the outgassing come from? 4. Is the criteria mandatory for all Class PCB or only specified application? 5. If for only specific application, which application and why? 6. Come to think about it, can the outgassing come also from the coating we use to seal the assembly? Hope someone out there can share with me (novice) on this issue. Thanks and regards, Wee Mei --------------------------------------------------- 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 -----------------------------------------------------