Only when required. As long as the part is UL certifiable I don't see an issue with putting it on when it isn't required. We don't because we have to do extra things to UL product(like matching prepreg vendors) and more failure opportunities(98% of what we do isn't UL).
-----Original Message-----
From: IPC-600-6012 [mailto:[log in to unmask]] On Behalf Of Jose A Rios
Sent: Tuesday, November 03, 2009 7:29 PM
To: [log in to unmask]
Subject: [IPC-600-6012] UL marking on pwb's
is UL code marking a requirement on all pwb's by default??
or only when procurement documentation requires it ??
Joey Rios
PWB & Process Quality Eng'r
Endicott Interconnect Technologies
1093 Clark St.
Endicott, NY 13760
Office: 607-755-5896