Ken, From the limited amount of information given, I can only assume that there was a fabrication process problem. All the HALT and HASS in the world will not make "bad" product "good". You MAY learn that the problem is better or worse than expected by performing HALT/HASS, but only if you have a control group of "good" product. If you have a "bad" fabrication process, HALT/HASS may only weaken the product and not actually precipitate the failure. If you decide to ship the product, it may fail even earlier in the field than if no HALT/HASS were performed. I have been asked to perform the exact type of screen in the past (different company then I work for today). I was given evidence that the fabrication process was out of control and told to screen out the "bad" product so that the "good" product could be shipped. I could not do it.....As I stated earlier, HALT/HASS cannot make "bad" product "good". Brent Reliability/Quality Engineer >>> [log in to unmask] 07/20/00 03:29PM >>> John, We have seen the PTH via crack (circumferential) which results into open during ICT. At that moment our boards are gone thr' two reflow cycle (225c max) and one wave cycle. How can I select chamber profile so that it will weed out bad one? Is there any guide lines? My boards are loaded with components and need resolution ASAP. re, ken patel At 12:03 PM 7/20/2000 -0400, you wrote: >Ken mentions: > >> Reliability/Quality Expert, >> How can I select the thermal stress/shock profile for loaded board if I >want >> to precipitate the fab problem. Boards are functionally passed but belongs >> to suspect date code. >> >> I am looking for a profile in the following format. > >Hi Ken, > >Before you do any testing, a good, root cause failure analysis is >required before specifying a failure acceleration method. > >Once you've conclusively identified the specifc cause of your >module failure, you can tailor a stress test to weed out that >specific problem (or fix the root cause failure reason, better yet!) > >Without the root cause failure identified, you may end >up spending a lot of money, and potentially ruining a lot >of good modules doing accelerated life/reliability testing, >with minimal return. > >Rgds >John > > >-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- >John Brewer >Supervisor, Component Engineering >Raleigh, NC >(919)-266-8870 >[log in to unmask] >-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > >############################################################## >TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional >information. >If you need assistance - contact Keach Sasamori at [log in to unmask] or >847-509-9700 ext.5315 >############################################################## > > ______________________________________________________ Ken Patel Phone: (408) 490-6804 1708 McCarthy Blvd. Fax: (408) 490-6859 Milpitas, CA 95035 ############################################################## TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################