Nice to see there is still a spark of humor in these troubled times...we are entering a new stone age - stone-broke......8-) John Burke (408) 515 4992 -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Whittaker, Dewey (EHCOE) Sent: Tuesday, December 09, 2008 5:59 AM To: [log in to unmask] Subject: Re: [TN] Conformal Coat and Eddy Currents You're in luminous company, though. Dewey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo Sent: Sunday, December 07, 2008 12:27 PM To: [log in to unmask] Subject: Re: [TN] Conformal Coat and Eddy Currents I am in the stone age with a uv lamp. -------------------------- Sent using BlackBerry ----- Original Message ----- From: TechNet <[log in to unmask]> To: [log in to unmask] <[log in to unmask]> Sent: Sun Dec 07 14:20:41 2008 Subject: Re: [TN] Conformal Coat and Eddy Currents Techies Eddy-current testing uses electromagnetic induction to detect flaws in conductive materials. There are several limitations, among them: only conductive materials can be tested, the surface of the material must be accessible, the finish of the material may cause bad readings, the depth of penetration into the material is limited, and flaws that lie parallel to the probe may be undetectable. However, eddy-current testing can detect very small cracks in or near the surface of the material, the surfaces need minimal preparation, and physically complex geometries can be investigated. It is also useful for making electrical conductivity and coating thickness measurements. Useable for conformal coatings? It doesn't seem suitable. I have been experimenting with lasers, but frankly this seems an overkill and reminds me of the Pen v Pencil argument. Russia figured the simplest way to write in space was to use a pencil... Measuring thickness using a readily available micrometer. Granted, measuring thickness on sharp lead ends and component legs os real tough - but coatings have been used to protect electronics since 1940 and they have done a good job. Hope this helps Graham Naisbitt On 4 Dec 2008, at 19:18, Douglas O. Pauls wrote: > Good afternoon all, > > A question for this most excellent forum. Does anyone here use eddy > current methods to measure applied coating thickness on printed > circuit > assemblies? If so, can you share your opinions on the methods and the > equipment? > > There are testers on the market that do this and one of our design > engineers is currently suprised at how we are using "stone age" > technologies (micrometer) to measure coating thickness. > > Doug Pauls > Rockwell Collins > > --------------------------------------------------- > 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 ----------------------------------------------------- --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. 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