Hi Chris, It does happen (the same way - cracking in parallel to the surface when rough paper is used to grind down and it touches the die). Also if too much pressure is applied to the nugget while polishing (even on finer grids) it will cause the same problem. Regards, Vladimir ------Original Message------ From: Chris Mahanna To: TechNet E-Mail Forum To: Vladimir Igoshev Subject: RE: [TN] Die cracks Sent: Feb 12, 2010 14:59 Hi Vlad, Thanks Trust me, this is what we want the answer to be. And yes we do approach with 180 or 320. But why do we see it in only 0.1% of our BGA sections? And is it our process that grouped the observations with these samples? And, just to be clear, do you know the signature? We know the edge grinding damage signature: https://robisan.sharefile.com/d-s441418b99d34882b Chris -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Vladimir Igoshev Sent: Friday, February 12, 2010 2:18 PM To: [log in to unmask] Subject: Re: [TN] Die cracks Chiris, 99.999999% the cracks are due to the sample preparation. Most probably, the die was approached (touched) with a low drig SiC paper (like 180), -- Best regards, Vladimir mailto:[log in to unmask] SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 ----------------------------------------------------- SENTEC 11 Canadian Road, Unit 7. Scarborough, ON M1R 5G1 Tel: (416) 899-1882 Fax: (905) 882-8812 www.sentec.ca ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________