Sorry to re-start a previous discussion, but I'm still dealing with a board
failure and I'm trying to learn fast.

I received a higher-resolution picture of a board problem we are having

http://www.frontdoor.biz/PCBportal/corequestion.jpg<http://www.frontdoor.biz/PCBportal/corequestion.jpg>

and if I look at it closely, I can see the dividing line between all ten
layers of dielectric.

By looking at which way the copper is located from each dividing line, I can
tell which are cores and which are prepreg (because the prepreg layers will
flow "around" the copper features)
For example, the thin pinkish layer is a core. Am I on the right track so
far?

So, our problem is a 120V end-of-line test frying two out of every hundred
boards right through the pinkish core material with the white streak through
it
(3.2 mils, which should handle a few kilovolts at least, right?)

So here's the question:
Should I be questioning the material quality rather than the bare-board
manufacturing process itself?

I realize you guys have already been generous with helping me on this, so I
hope I'm not pushing your patience...

onward thru the fog,
Jack (aka "the new guy")

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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
-----------------------------------------------------