Chris IPC-A-610 Rev C, covers various inspection criteria for a whole host of solder quality related issues. Most are visual inspections of the board, but in some cases you will need to micro section the joint in question to be sure. But generally you can see a bad joint form the visual inspection or at least get an indication of the over all solder quality. HALT testing can very quickly bring out dry solder joints, but this is expensive and destructive. More mundane environmental testing can be time consuming. With neither methods really being suitable for a 100% screen of all the product.
I have had some success with Thermal Imaging to as a non destructive screen for poor solder joints, but this requires a very high optical and thermal resolution camera. The best initial step to pick up these problems would be a solder quality inspection to IPC-A-610. Then depending on these results decide if micro sectioning or environmental screening is required. Andrew Carson - Senior Compliance Engineer, Xyratex, UK Phone: +44 (0)23 9249 6855 Fax: +44 (0)23 9249 6014 -----Original Message----- From: Chris Chileshe [mailto:[email protected]] Sent: 09 October 2002 09:55 To: [email protected] Subject: Testing for dry joints Hi Group, Probably not the appropriate forum but here goes anyway. A colleague is finding numerous problems with subtle dry joints (partial) between connectors and PCBs and is wondering if there is a way - short of new procedures in process control - that dry joints can be tested for? The specific problem is that the joints appear to be electrically sound to start with, meaning the units are getting through function test, but once exposed to endurance (lengthy) tests or worse still, actual practical use, the gremlins begin to show. The fault analysis almost invariably leads to a connector dry joint. The connectors are rated for 6A DC continuous. Any ideas how these can be picked up early or what measures you have in production to eradicate these problems? Regards - Chris Chileshe - Ultronics Ltd ________________________________________________________________________ This e-mail has been scanned for all viruses by Star Internet. The service is powered by MessageLabs. For more information on a proactive anti-virus service working around the clock, around the globe, visit: http://www.star.net.uk ________________________________________________________________________ ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
