We used to have this requirement when we were using a type ER conformal coating. It was a royal pain in the butt!! It cost us a lot of extra time and money, and the coating we were using at the time was only marginally reworkable. After using this coating for about 2 years we gave up on these coatings and used only type AR and UR after that. With those coatings there was no sleeving required and the ability to rework was greatly enhanced. Keith S. Calhoun Product Engineer SoPark Corporation 3300 South Park Avenue Buffalo, New York 14218 Phone: 716-822-0434 Ext. 237 Fax: 716-822-5062 email: [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Lee Whiteman Sent: Tuesday, June 09, 2009 8:22 AM To: [log in to unmask] Subject: [TN] CONFORMAL COATING ON GLASS BODIED COMPONENTS We have the following requirement on one of our space programs: All glass-bodied electronic parts which are bonded, encapsulated or conformally coated shall be sleeved with sleeving that remains resilient over the temperature range specified for the equipment. Surface mount, non-axially leaded, glass-bodied diodes that are conformally coated do not require sleeving if the coating Tg is below all application and test temperatures. I am confident that this came from NASA STD 8739.1A as well as the IPC Space Addendum. The question is why? Have there been documented failures of glass-bodied electronic parts without sleeving which failed when conformal coating was applied? Should glass-bodied components be masked from conformal coating? Thanks again... Lee Whiteman, PMP Senior Member Engineering Staff L-3 Communications East Telephone: (856) 338-3508 FAX: (856) 338-2906 E-Mail: [log in to unmask] --------------------------------------------------- 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 -----------------------------------------------------