Hi Gary,
A couple of issues.
First, Class 3 is "High Quality", which does not necessarily translate to
"High Reliability." Reliability issues are not addressed in an direct form by
the 3 Classes.
Second, regarding the nonfunctional lands, the answer is: "It depends." If
you cannot produce your thick PWBs with small-diameter vias to good quality,
than obviously your PWBs will be less reliable. However, many board shops
have that capability and their PWBs may show an improved PTH/PTV reliability
depending on the assembly processes used and the severity of the use
environment.

Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL  32174  USA
Phone: 386-437-8747, Fax: 386-437-8737
E-mail: [log in to unmask], Website: www.engelmaier.com

---------------------------------------------------------------------------------
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 e-mail to [log in to unmask]: SET Technet NOMAIL
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/html/forum.htm for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315
---------------------------------------------------------------------------------