Would it be so severe in normal ambient cycle Werner ? Even 90'C span over 24 hours seems (likely mistakenly?) pretty mild ? I came across this as well ; is there any average daily span ? in say average Alaskan warehouse ? Could you elaborate a bit also on that 20'C cross line significance I noted in the 785 standard ? Could it be said storage forms equal part of the product life & warranty considerations ? Thanks ahead Paul Klasek http://www.resmed.com. > ---------- > From: Werner Engelmaier[SMTP:[log in to unmask]] > Sent: Friday, 5 February 1999 7:47 > To: [log in to unmask] > Subject: Re: [TN] Storage of assembled boards at - 50 degrees Celcius > > Hi Daan, > Your problem is not storage at -50C, but storage from -50C going up to > maybe > +40C and back down again. That is a rather severe thermal cycle, which if > repeated too often may cause failures, especially of solder joints. > > Werner Engelmaier > Engelmaier Associates, L.C. > Electronic Packaging, Interconnection and Reliability Consulting > 7 Jasmine Run > Ormond Beach, FL 32174 USA > Phone: 904-437-8747, Fax: 904-437-8737 > E-mail: [log in to unmask] > > ################################################################ > TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c > ################################################################ > To subscribe/unsubscribe, send a message to [log in to unmask] with > following text in the body: > To subscribe: SUBSCRIBE TechNet <your full name> > To unsubscribe: SIGNOFF TechNet > ################################################################ > Please visit IPC's web site (http://www.ipc.org) "On-Line Services" > section for additional information. > For technical support contact Hugo Scaramuzza at [log in to unmask] or > 847-509-9700 ext.312 > ################################################################ > ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################