From PICLIST@MITVMA.MIT.EDU Fri Nov 15 07:11:04 2002 Received: from cherry.ease.lsoft.com [209.119.0.109] by dpmail10.doteasy.com with ESMTP (SMTPD32-7.13) id AE8815DA0048; Fri, 15 Nov 2002 07:11:04 -0800 Received: from PEAR.EASE.LSOFT.COM (209.119.0.19) by cherry.ease.lsoft.com (LSMTP for Digital Unix v1.1b) with SMTP id <16.007DC472@cherry.ease.lsoft.com>; Fri, 15 Nov 2002 9:56:57 -0500 Received: from MITVMA.MIT.EDU by MITVMA.MIT.EDU (LISTSERV-TCP/IP release 1.8d) with spool id 3209 for PICLIST@MITVMA.MIT.EDU; Fri, 15 Nov 2002 09:36:10 -0500 Received: from MITVMA (NJE origin SMTP@MITVMA) by MITVMA.MIT.EDU (LMail V1.2d/1.8d) with BSMTP id 0826; Fri, 15 Nov 2002 09:35:32 -0500 Received: from *unknown [47.211.129.137] by mitvma.mit.edu (IBM VM SMTP Level 320) via TCP with ESMTP ; Fri, 15 Nov 2002 09:35:31 EST X-Warning: mitvma.mit.edu: Host *unknown claimed to be znsgs01r.nortelnetworks.com Received: from zwcwc012.europe.nortel.com (zwcwc012.europe.nortel.com [47.160.46.124]) by znsgs01r.nortelnetworks.com (Switch-2.2.0/Switch-2.2.0) with ESMTP id gAFEZUV22223 for ; Fri, 15 Nov 2002 14:35:30 GMT Received: by zwcwc012.europe.nortel.com with Internet Mail Service (5.5.2653.19) id ; Fri, 15 Nov 2002 14:35:31 -0000 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Message-ID: Date: Fri, 15 Nov 2002 14:35:24 -0000 Reply-To: pic microcontroller discussion list Sender: pic microcontroller discussion list From: Michael Rigby-Jones Subject: Re: [PIC]:failed data location? To: PICLIST@MITVMA.MIT.EDU X-RCPT-TO: Status: R X-UIDL: 277600674 X-Evolution-Source: pop://mailinglist%40farcite.net@mail.farcite.net/ X-Evolution: 00000775-0000 > -----Original Message----- > From: Dale Botkin [SMTP:dale@BOTKIN.ORG] > Sent: Friday, November 15, 2002 2:18 PM > To: PICLIST@mitvma.mit.edu > Subject: Re: [PIC]:failed data location? > > How many thousands are you willing to spend on failure analysis to find > out that the chip did indeed fail because either A.) it was flippin' > defective, or B.) you broke it by operating it outside of its safe > operating area? > I guess that would depend on how much you could potentialy lose. In the market I currently work for, where a single product could cost upwards of $4000, even a single failure within a couple of months is bad news, especialy as we thoroughly test everything over voltage and temperature extremes. > If you're using the chip within the power, temperature, humidity, > vibration and other limits specified in the data sheet, you can reasonably > expect the performance specified by Microchip or whatever manufacturer. > Which doesn't explain another posters experience with the duff batch of 16C5x devices. > If you're outside any or all of these limits, all bets are off. QA and > testing data are available on their web site. Using THIS information to > determine what the chances are of the same thing happening to other units > in the field is what "any responsible engineer" should be doing. > > Component failures are a fact of life that we have to deal with, no matter > what we build. Even a good manufacturing lot will have some number of > premature failures. If you get a whole bunch of failures and you know > it's NOT your fault, then it's time to call the manufacturer and > investigate. But excepting very special applications (life support, > spacecraft, weapons systems) a single failure is pretty much a non-event. > That depends entirely on the customer. We have had IC's x-rayed and then decapsulated to try to determine failure mode after a SINGLE failure, at our customers insistance. It would have cost us far more to have not investigated the failure, even though it was apparently a one-off. Mike -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.