You are right FR4 should not be punched. You will see the cracking of the edges but mostly what I believe you are seeing is the first 100 or so panels probably looked OK. After that, the glass content in FR4 dulled the tool and this is where you get the cracking of the edge. Joe J. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of cguitar Sent: Wednesday, February 16, 2005 11:09 PM To: [log in to unmask] Subject: Re: [TN] Cracking FR4 FR4 should never be punched, I believe At 11:54 AM 2/17/2005, you wrote: >Hopefully someone in the forum may have had experience with cracking >along edge of FR4 as per attached photo. The profile of this pcb was >punched and subsequently the edge has fine cracks through the >soldermask and glass. We have had a large quantity of this part made in >China and are concerned that this cracking could compromise the board function. > > > >--------------------------------------------------- >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 -----------------------------------------------------