What you are probably observing is data not accurately reviewed by the
fabricator prior to publishing or presenting the information.

This may be due to out-dated information being made available in company
literature, typo, misunderstanding of the information being written, etc
etc.

The Dk may indeed vary from fabricator to fabricator as well as from
lot-to-lot at the same fabricator but not to the degree you posted. This
variance is just inherent to most laminate fabrication processes.

If there is a specific characteristic of the laminate that you just
absolutely need to fall within tight tolerances it is a good idea to have
the specific lot tested prior to use, after fabrication, assembly, etc in
order to determine the actual value of the lot or product at that moment.

Take the literature you receive from the fabricator with a grain of salt,
ask questions, and don't worry if the number varies slightly.

Franklin

---------------------------------------------------
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 847-615-7100 ext.2815
-----------------------------------------------------