Hans, All, We use both AR and UR in different applications on Class 3. It really depends on your end use and fitness for use, and in particular the unit or requirement specification you are trying to meet. AR is easier to rework etc, bit that also means it can be less effective when it comes to protection... tougher coating = generally harder to remove. If you have a requirement to protect against aircraft fluids etc, then AR will be a poorer choice. If you want to use it in a telephone box, AR will do a great job. AR does however have better moisture properties than UR. None of course are truly hermetic, but they will do well in a condensation/evaporation scenario. AR may be good for rework (if/when it is needed), but it also needs to be good for service, which may be decades. Clive ff. -----Original Message----- From: Hinners Hans M Civ WRALC/LUGE [mailto:[log in to unmask]] Sent: 09 March 2004 15:00 To: [log in to unmask] Subject: Re: [TN] Pros and Cons on Type UR vice Type AR Conformal Coating *** WARNING *** This mail has originated outside your organization, either from an external partner or the Global Internet. Keep this in mind if you answer this message. I've approved switching from UR to AR at the request of the repair line. The assemblies are IPC-A-610 Class 3, on aircraft,crew accessible cargo area. Hans ~~~~~~~~~~~~~~~ Hans M Hinners AC-130 Systems Engineer WR-ALC/LUGE Special Operations Forces / Combat Search & Rescue System Program Office 226 Cochran St Robins AFB, GA 31098 DSN Prefix: 468 Com: (478) 926 - 5847 Fax: (478) 926 - 4911 mailto:[log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Dehoyos, Ramon Sent: Tuesday, March 09, 2004 8:15 AM To: [log in to unmask] Subject: Re: [TN] Pros and Cons on Type UR vice Type AR Conformal Coating One thing to know is that AR can be coated to patch UR but not the other way around. Patching AR with UR creates a mix that takes too long to dry, stays soft. So to switch from UR to AR is recommended. Regards, Ramon > -----Original Message----- > From: - Bogert [SMTP:[log in to unmask]] > Sent: Monday, March 08, 2004 4:55 PM > To: [log in to unmask] > Subject: [TN] Pros and Cons on Type UR vice Type AR Conformal Coating > > As a Class 3 customer we are considering mandating transition from > Type UR to Type AR conformal coating, to make it easier to replace failed components. Are there any Class 3 users of Type AR coating? What is track record for using Type AR? Are there any compatibility issues with certain types of solder masks? Any input you have would help. Another advantage with AR would be for returned equipment. The OEM could remove all the coating from an assembly using alcohol, then perform > --------------------------------------------------- > 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 > ----------------------------------------------------- > bed-of-nails testing to quickly identify failed components. --------------------------------------------------- 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 ----------------------------------------------------- ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. 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