If burn-in is included in your Mfg. Test process, would it be common/practical to run a repaired (RMA) unit that has been in the field, through the same burn-in test process? Lester -----Original Message----- From: Craig Hillman [mailto:[log in to unmask]] Sent: Thursday, February 15, 2001 11:33 AM To: [log in to unmask] Subject: Re: [TN] Burn-in Kathy, Burn-in is designed to remove latent defects that can lead to infant mortality. However, burn-in also takes away some lifetime from the products and costs time and money. So, there is a benefit and a disadvantage to burn-in. With a high defect rate in components, burn-in provides a large benefit in comparison to the disadvantage. This primarily because a low stress level is necessary to screen out the defects and a large number of defects are removed. If the defect rate for commercial components is very low, the advantages of burn-in will not outweigh the disadvantages. The stress level necessary to screen for defects increases, which can then lead to reliabilty problems, and very few defects are screened out. Best Regards, Craig -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Kathy Kuhlow Sent: Thursday, February 15, 2001 2:09 PM To: [log in to unmask] Subject: Re: [TN] Burn-in Would that be more when a burn-in cycle takes that components to close to the maximum threshold? If you degraded a componnet through processing then the burn-in would verify this. kathy JF, Due to the increasing reliability of commercial components, some studies suggest that the stress during burn-in (handling, temperature, voltage) will not screen out any latent defects but will instead reduce the reliability of your product. Best Regards Craig -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Bissonnette, Jean-Francois Sent: Thursday, February 15, 2001 1:14 PM To: [log in to unmask] Subject: [TN] Burn-in Are burn-in required on every units that come out of production or is it usually done on a sampling basis? If it has to be done on every unit, why is that so? We're requested to do it on all units, by contract. But some believe that is overkill... I'm among them. Any thoughts??? Thanks in advance! JF WABTEC CORPORATION CONFIDENTIALITY NOTE The content contained in this e-mail transmission is legally privileged and confidential information intended only for the use of the individual or entity named herein. If the reader of this transmission is not the intended recipient, you are hereby notified that any dissemination, distribution, or copying of this transmission is strictly prohibited. ---------------------------------------------------------------------------- ----- 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 the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives 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 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- 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 the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives 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 ---------------------------------------------------------------------------------