But would you be surprised to know that UL doesn't retest a laminate's CTI after processing? They don't, unless specifically asked by the board mfg., which I'd have to suggest is rare. The CTI for finished boards in UL's RCD is based on those for the base laminate and no assumption should be made to the contrary. If a board house claims otherwise, ask them to provide the test data.
Regards, Peter L. Tarver Nortel [email protected] > ---------- > From: Harold Leipold[SMTP:[email protected]] > Sent: Friday, February 20, 1998 6:04 AM > > > Just to add my "2 cents" to this discussion. CTI etc. after > manufactured > into a finished PCB is actually more important than the CTI of the > basic > laminate itself. That is one reason why one should use PCB vendors who > have > their process UL recognized (and use the recognized logo on the > finished > product for identification). > The PCB fabrication process, solder mask, etc. can affect both CTI and > flammability greatly. > > Comments are personal and do not necessarily reflect corporate > opinion. > > Harold Leipold > Siemens EC > Princeton, IN > Tel 812-386-2161 > Fax 812-386-2616
