What caused the mechanical damage to the solder mask surface? Can we see a photo of a mounted heat sink. How many leads are attached to the PWB? Can the upward motion cause tensile pull on the lead? Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory Sent: Thursday, February 01, 2007 11:35 AM To: [log in to unmask] Subject: Re: [TN] Mechanical Stress on solder joints Hi Gary! I have your picture posted. It's at: http://stevezeva.homestead.com/files/Broken_Pin.jpg It sure looks like something has pulled or stressed that pin. I'm trying to visualize the heatsink, but I can't form a mental picture of it, so I can't say for sure if it was the heatsink or not. But from your description, it seems pretty probable that the stress that you describe damaged that pin. -Steve Gregory- -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Bremer, Gary Sent: Thursday, February 01, 2007 10:02 AM To: [log in to unmask] Subject: [TN] Mechanical Stress on solder joints Gentlemen, I have a device that failed in the field, the part is a DC/DC converter that is first soldered to the circuit board then a massive heatsink is screwed to the converter pulling the device upward because of an air gap not covered by a thermal conductive pad. Could this be the cause of damage to the component pins as shown in the attached photo? The solder used is Sn63 on the circuit board side and the mass of the board solder joint appears to be twice that of the component. Gary Bremer Senior Manufacturing Engineer, CIT Curtiss-Wright Controls Inc. Embedded Computing -Subsystem 28965 Avenue Penn Santa Clarita, CA 91355-4185 Main: 661.257.4430 extension 2170 Fax: 661.257.4782 e-mail: [log in to unmask] Web: www.cwcembedded.com NOTICE: This e-mail communication is private and confidential and is intended for the addressee only. The email may only be used for conducting business with VISTA Controls Inc., dba Curtiss-Wright Controls Embedded Computing Subsystems. If you are not the intended recipient, please notify us by replying to this email followed by deleting the email and all attachments from your system. Anyone other than the intended recipient or those with a need to know within the recipient's organization is strictly prohibited from using, printing, distributing or disseminating the email or any information or attachment contained therein. --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 1.8e 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 1.8e 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 -----------------------------------------------------