Hi Richard, What you are doing is prudent and there is nothing wrong with your procedure--but, what you are doing is a partial 'burn-in', not a 'stress screening'. 'Burn-In': An operational procedure on all product for 8 to 48 hours at the extreme edge of normal operation or slightly beyond. 'ESS (Environmental Stress Screening)': A screening procedure for product suspected to have some quality deficiencies serious enough to be 'latent defects.' The screening procedure needs to be specific for the suspected latent defects to be brought to failure [without too much damage to good product]--there is no 'generic' ESS. Werner Engelmaier Engelmaier Associates, L.C. Electronic Packaging, Interconnection and Reliability Consulting 7 Jasmine Run Ormond Beach, FL 32174 USA Phone: 386-437-8747, Fax: 386-437-8737 E-mail: [log in to unmask], Website: www.engelmaier.com --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d 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 delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL 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/scripts/wa.exe?S1=technet Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------