Unfortunately, we do not have the tools to do this type of analysis. My best guess is that when the board is separated from the breakaway with the rotary blade, the action is one of displacement rather than material removal. While the material is being displaced with a squeezing move, the forces to push the material toward the components. If the cap is too close to the edge I think the cap actually flexes as the material pushes toward the cap. If someone has a high speed camera, this may be a great project for an intern next summer! -----Original Message----- From: Blair K. Hogg [mailto:[log in to unmask]] Sent: Thursday, August 28, 2003 10:01 AM To: [log in to unmask] Subject: Re: [TN] Cracking Ceramic SMT Capacitors Carrie, We have also seen cracking caps after this type of depanelization. I just can't seem to grasp the forces during this process that would cause a capacitor to crack. Do you have any further insight into this? Thanks, Blair >>> [log in to unmask] 08/28/03 09:54AM >>> We have seen an increase in cracking. The root cause for us is depanelizing using a rotary style blade cutter. Caps and some filters too close to the edge are most subject to damage due to the forces imparted on the board when depanelizing. Often we can eliminate the problem by flipping the board over during depanelize, but, that does not always work and since we do not have the tools to analyze the forces during the depanelize process, any changes like flipping the board over is essentially a bit of a gamble. -Carrie -----Original Message----- From: Bob Perkins [mailto:[log in to unmask]] Sent: Wednesday, August 27, 2003 7:42 PM To: [log in to unmask] Subject: [TN] Cracking Ceramic SMT Capacitors Cracking Ceramic SMT Capacitors " Is anyone else seeing an increase in the number of cracked and shorting ceramic chip capacitors? In our experience as a contract manufacturer we have, in the past, seen the occasional instance of ceramic capacitors cracking and shorting out. The cause of this problem is generally obvious, as it is isolated to components situated in areas of the PCB that are subject to flexing. Recently however we have seen more frequent instances of this problem; very often in areas of the board that should not be experiencing any appreciable flex. Our process has not changed and neither have our sources of these components. Have chip capacitors themselves become more fragile?" Rod Lafond Manager, Quality Assurance and Technical Training APEX-Micro Manufacturing Corporation [log in to unmask] ********************************************************************** This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This footnote also confirms that this email message has been swept for the presence of computer viruses. www.hubbell.com - Hubbell Incorporated ********************************************************************** --------------------------------------------------- Technet Mail List provided as a free 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 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free 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 847-509-9700 ext.5315 -----------------------------------------------------