This specific application doesn't warrant a Teflon substrate, I think it is FR-4. Let me clarify one thing, It's assumed that the material is cold flowing, causing ground interruptions (this is an RF Engineer's assumption). The fact is that, after time in service, the main complaint from the test guys is electrical problems associated with a degenerated ground. It could be associated with moisture entering the housing causing the tin-lead plating on the ground plane, which is in direct contact to the housing via screws, to become slightly oxidized. This is not a hermetically sealed housing. In fact, there is a hole in it to allow for a pot adjustment. Which leads to another question... are there bulk-mounted pots available, mounted directly to the housing wall, which would eliminate the hole? Jim Marsico Senior Engineer Production Engineering EDO Electronics Systems Group [log in to unmask] <mailto:[log in to unmask]> 631-595-5879 -----Original Message----- From: Crepeau, Phil [SMTP:[log in to unmask]] Sent: Tuesday, December 09, 2003 4:47 PM To: [log in to unmask] Subject: Re: [TN] GOOD RF GROUND hi, is the fastener loosening up because the laminate is teflon based (which is common in rf applications)? phil --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 847-509-9700 ext.5315 -----------------------------------------------------