Subject: | |
From: | |
Reply To: | |
Date: | Fri, 16 Sep 2005 10:03:54 EDT |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
In a message dated 9/16/2005 9:10:09 AM Eastern Daylight Time,
[log in to unmask] writes:
Yep, they're buried vias and I think they're filled with resin. If they
weren't filled they would look darker and the copper plating in the hole would
look a lot rougher from the grinding & polishing.
I think the hole fill was a separate operation (there's not enough pre-preg
each side to fill the hole with resin). All the delam is on one side only,
maybe there was some contamination of the layer during the filling.
Geoff Layhe
This seems to be Resin Coated Copper construction. The 1+4+1 construction
is interesting - the four layer core is pretty standard (thick), but the added
outer layer dielectric is quite thin. Definitely, there is not enough resin
to fill the buried vias. It is hard to see from the magification here for
sure that there is no glass in the surface dielectric.
Check to be sure this is RCC construction. The treatment for RCC adhesion
will be per the vendor's recommendation, and I suspect the board fab shop
knows there were some shortcuts taken for them to give you the baking
recommendations. If they also took shortcuts in pressing the parts to add the RCC
layers, I doubt any procedure at this point will be sure to give you good boards
after assembly.
Denny Fritz
MacDermid, Inc
---------------------------------------------------
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
-----------------------------------------------------
|
|
|