Just my two cents worth with regard to temperature: It is my understanding that for every 10C rise the life of the part is half what it would have been.
- Robert - Robert A. Macy, PE m...@california.com 408 286 3985 fx 408 297 9121 AJM International Electronics Consultants 619 North First St, San Jose, CA 95112 -----Original Message----- From: Grant, Tania (Tania) <tgr...@lucent.com> To: Benoit Nadeau <bnad...@ieee.org>; emc-p...@majordomo.ieee.org <emc-p...@majordomo.ieee.org>; 'jim_bac...@mail.monarch.com' <jim_bac...@mail.monarch.com> List-Post: emc-pstc@listserv.ieee.org Date: Friday, May 12, 2000 7:41 PM Subject: RE: Heat sink temperature rise Benoit, The heatsink is a part;-- whether it is Operator Accessible or only Serviceman Accessible depends upon the cognizant choice of the manufacturer and the design of the PC. If that particular area where the IC and heatsink are located is NOT in an Operator Accessible area, then you shouldn't have to worry about the heatsink temperature. If this area IS accessible to any and all, I would highly recommend that you run some temperature tests of the heatsink to determine just how hot it gets. Depending upon the results, you may discover that you just reclassified this area from Accessible to NON-ACCESSIBLE! Either that, or you are forced with a re-design. For Serviceman only accessibility, and depending upon the heatsink temperature, you might be able to get away with a WARNING label near the heatsink, to protect the Serviceman. However, if he/she have to get their hands in there and will have to touch the heatsink while performing servicing activities and the temperature is still hazardous to the skin, then you will still need to prevent physical access to that heatsink. (Get a bigger heatsink, if you have the room!) My personal opinion is that "hot" heatsinks should NOT be accessible to anyone. If it is too hot to touch, the heatsink is not doing the job, and the IC will probably have a short life. Tania Grant, tgr...@lucent.com <mailto:tgr...@lucent.com> Lucent Technologies, Intelligent Network Unit Messaging Solutions Group ---------- From: jim_bac...@mail.monarch.com [SMTP:jim_bac...@mail.monarch.com] Sent: Friday, May 12, 2000 2:54 PM To: Benoit Nadeau; emc-p...@majordomo.ieee.org Subject: Re:Heat sink temperature rise Forwarding for Benoit Nadeau ____________________Reply Separator____________________ Subject: Heat sink temperature rise Author: Benoit Nadeau <bnad...@ieee.org> List-Post: emc-pstc@listserv.ieee.org Date: 5/12/00 12:55 PM Bonjour de Montréal, Usually, I am more on the EMC side, but I had a question yesterday regarding IEC 950 that I would like to get your advices on: In IEC 60950:, is a metal heat sink, glued on a IC which is soldered on a PC type add-on card installed into a Personal computer chassis should be considered as a "PART in OPERATOR ACCESS AREA" or should it be considered as a component? In particular I would be interested to know what should be the Maximum Temperature-rise limits of this heat sink according to 60950 section 5.1 "Heating". Your comments will be very much appreciated. Regards, ---------------------------------------------- Benoît Nadeau, ing. M.ing (P.eng., M.eng.) Conformity Group Manager Matrox Tel: (514) 822-6000 (x2475) Fax: (514) 822-6275 Chairman 2001 IEEE EMC International Symposium on Electromagnetic Compatibility Montreal August 13 to 17, 2001 ---------------------------------------------- ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org