Hi Werner Could you find the cracks by interpolating the known good tolerances program against the tested resistivity variances ? Instead of vibrations ? The intensity required would be high ; with less compact components (most of them comparing to BGA's) quite likely structurally altered . Unless prepared for destructive test . Paul Klasek ResMed >---------- >From: Engelmaier[SMTP:[log in to unmask]] >Sent: Thursday, January 01, 1998 9:39 AM >To: [log in to unmask] >Subject: Re: [TN] Crack detection under BGA? > >Hi Kevin, >The only way you have a chance of finding cracked solder joints in product >with BGAs is to functionally test while subjecting your assemblies to >vibration. This gives you a chance of finding fully fractured solder joints, >as well as use the vibration as a screening test for latent defects. However, >with BGAs, I am not certain that even this method is 100% effective. > >Werner Engelmaier >Engelmaier Associates, L.C. >Electronic Packaging, Interconnection and Reliability Consulting >7 Jasmine Run >Ormond Beach, FL 32174 USA >Phone: 904-437-8747, Fax: 904-437-8737 >E-mail: [log in to unmask] > >############################################################## >TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c >############################################################## >To subscribe/unsubscribe, send a message to [log in to unmask] with following >text in the body: >To subscribe: SUBSCRIBE TECHNET <your full name> >To unsubscribe: SIGNOFF TECHNET >############################################################## >Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional >information. >For the technical support contact Dmitriy Sklyar at [log in to unmask] or >847-509-9700 ext.311 >############################################################## > ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################