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 -----------------------------------------------------