I have not seen acoustic microscopy successfully used to detect solder cracks (not enough of a gap in the crack). Perhaps you may want to contact the CSAM folks to see if they've successfully accomplished it. Jeff Perkins Photocircuits -----Original Message----- From: Jim Marsico 516-595-5879 [SMTP:[log in to unmask]] Sent: Tuesday, September 29, 1998 7:48 AM To: [log in to unmask] Subject: Re: [TN] ASSY: BGA FAILURES Well, how about it! Does anyone have any experience using ultrasound to detect cracked solder joints? Does anyone know of a testing lab that can perform this function? Thanks again... Jim Marsico Mark wrote: Dear Jim This may be a very stupid idea, but what about using ultrasound? I believe they use ultrasound to detect microscopic fractures in mechanical assembly's and the joint between the CBGA and the solder ball is mechanical. I don't know what the ultrasound would do to the chip or the wire bonds but it may be worth some more inquiries to the component manf. I would be very interested to read how you got on. ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################