Thanks Mel, I hear ya about the conformal coating & CTE - good info. The conformal coating is a substitute since the original used injected foam. I'm considering a double conformal coat - polyurethane for the first layer and silicone over that. It's what the US Army uses on some of the assemblies in the M1A tank. Hans Integrity First - Service Before Self - Excellence in All We Do ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Hans M. Hinners Electronics Engineer Warner Robins - Air Logistics Center (WR-ALC/LUGE) 226 Cochran Street Robins AFB GA 31098-1622 mailto:[log in to unmask] <mailto:[log in to unmask]> Com: (478) 926 - 5224 Fax: (478) 926 - 4911 DSN Prefix: 468 -----Original Message----- From: Mel Parrish [mailto:[log in to unmask]] Sent: Tuesday, January 08, 2002 1:33 PM To: [log in to unmask] Subject: Re: [TN] Staking compounds Hans Recommend looking very closely at the Z, CTE characteristics of the RTV also. I had some hardware reliability issues in defense products years back where the PTHs were partially extracted from the board due to RTV staking under the components. More specifically these were PGAs. Also recommend keeping in mind that the conformal coating is a limited environmental barrier at best for moisture. Mel Parrish -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Hinners Hans M Civ WRALC/LUGE Sent: Tuesday, January 08, 2002 6:44 AM To: [log in to unmask] Subject: Re: [TN] Staking compounds Hi All, This is great information. I've had an Assembly supplier suggest using an RTV to stake discrete components to FR-4. Graham confirmed that it wasn't a good combination with a silicone based conformal coating. (Thanks Graham.) The last thing I or the customer needs is dewetting of the conformal coating. My applications are hi-rel military avionics - in a rather harsh environment: high vibration, high humidity and some salt water. Is there some cutoff point when it's better to go with mechanical staking? I'm new to staking. Hans Integrity First - Service Before Self - Excellence in All We Do ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Hans M. Hinners Electronics Engineer Warner Robins - Air Logistics Center (WR-ALC/LUGE) 226 Cochran Street Robins AFB GA 31098-1622 mailto:[log in to unmask] <mailto:[log in to unmask]> Com: (478) 926 - 5224 Fax: (478) 926 - 4911 DSN Prefix: 468 -----Original Message----- From: Dieselberg, Ron [mailto:[log in to unmask]] Sent: Tuesday, January 08, 2002 7:28 AM To: [log in to unmask] Subject: Re: [TN] Staking compounds Doug, we have used CONAP K-20 for a long time with good results. We have also used Loctite 416 with 18580 activator. The Loctite is easier to use since it "sets" more quickly. All depends on how you want to use it and how much time you have available for curing. In either case be sure the materials that you are going to stake to are "sqweekey" clean! Ron Dieselberg Trainer/Auditor CMC ELECTRONICS CINCINNATI [log in to unmask] BM__MailData-----Original Message----- From: [log in to unmask] [ mailto:[log in to unmask] <mailto:[log in to unmask]> ] Sent: Monday, January 07, 2002 14:41 PM To: [log in to unmask] Subject: [TN] Staking compounds Good day all, I am curious as to what all y'all use for staking compounds (to fix wires or components in place) on your assemblies, especially if you are in the high-rel area or aerospace sector. Thanks. Doug Pauls Rockwell Collins ---------------------------------------------------------------------------- ----- 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 e-mail to [log in to unmask]: SET Technet NOMAIL To recieve ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest 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 <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 ---------------------------------------------------------------------------- -----