You may also be dealing with some delamination issues! Have done any cross sectioning? David A. Douthit Manager LoCan LLC Murulidhara wrote: >Dear Technetters, > >We are facing a peculiar problem. One batch of PC assemblies are behaving in strange way with regard to frequency drift. >The frequency drift noticed is more in the mornings and less in the evenings. > >The PCBs used are of multi layer type with critical components sheilded. > >The same PCBs(from the same PCB manufacturer) assembled in our shop with similar components are passing the test. > >Kindly let us know the reasons for this type of problem. > >What are the possible remedies to over come this? > >Thanks in advance. > >Muralidhara .S >Dy.Chief Engineer, >R&D, ITI Ltd., >Bangalore - 560 016 >INDIA > > > > > > >--------------------------------------------------- >Technet Mail List provided as a service by IPC using LISTSERV 1.8e >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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) >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/archives >Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 >----------------------------------------------------- > > > > --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) 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/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------