Carl, Do not scrap the pad or do any heating or mechanical testing of the surface where the component fell off. Simply do an XRF measurement of the pad surface and see what is left. You can also do an XRF measurement on the component surface. That should give you a first order approximation of what the problem is. My guess is the gold is probably completely dissolved in the solder and the solder is on the component and the failure is at the nickel-tin ICM interface. Regards, George George M. Wenger Senior Principal Reliability / FMA Engineer Andrew Corporation - Wireless Network Solutions 40 Technology Drive, Warren, NJ 07059 (908) 546-4531 Office (732) 309-8964 Mobile E-mail: [log in to unmask] -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Carl VanWormer Sent: Monday, September 19, 2011 3:48 PM To: [log in to unmask] Subject: [TN] large parts falling off finished surface mount board assemblies A surface mount PC board assembly (made by a local assembly house and passed by our outgoing test) was returned from the end user, along with an electrolytic capacitor that they had "knocked off" the board. After looking at the assembly and component under a microscope, I noticed that the "gold plated" PC board (Lead free) had a fine granular solder appearance (much smaller grain than solder paste balls) on the pads newly exposed, with the whole "melted solder" blobs (in the shape of the pads) attached to the capacitor leads (with a similar granular appearance). After minor scraping of various parts, I had come to no brilliant conclusions, so I pressed my finger nail against an inductor that was of similar size to the capacitor. It popped off the board with the same symptoms as the capacitor. After recovering from my surprise, I realized that I have no clue about the causes or cures for my component adhesion problem. Can any of the more experienced members of this fine group direct me to some key words that might lead me to a quick education (and solution)? Thanks, Carl Carl Van Wormer, P.E., AE7GD Senior Hardware Engineer Cipher Systems 1800 NW 169th Place, Suite B-100 Beaverton, OR 97006 Cipher Systems (503) 617-7447 x 5163 Direct Line (503) 425-5163 [log in to unmask] <mailto:[log in to unmask]> This message may contain confidential and/or proprietary information, and is intended for the person/entity to whom it was originally addressed. Any use by others is strictly prohibited. If I sent this to you by mistake, please be nice and delete it, then tell me of my mistake so I can send it to the right person. ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 16.0 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 For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------