TECHNET Archives

December 2007

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
"Mark F. Focht" <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Mark F. Focht
Date:
Wed, 12 Dec 2007 06:36:49 -0600
Content-Type:
text/plain
Parts/Attachments:
text/plain (35 lines)
I have a design that,due to space constraints, requires stacking microvias (L1-
L2) directly on top of (in line with) drilled buried vias (L2-L7, L2-L11).  I am 
receiving conflicting information about this strategy being reliable (storage 
temp. range -50C to 110C, operating temp. range -40C to 85C) because of 
the different CTE's of the via fill material used in the L2-L7/L2-L11 vias and 
the board material (FR406, 170Tg). While the board shops that will fab this 
admit they prefer the vias be staggered (not very pratical in this design), they 
claim they have produced boards of this type without negative feedback or 
issues.  The CM that will be assembling this is extremely hesitant about using 
this via strategy.  Does anyone have experience using a stack-up similar to 
this?  Would this be reliable?  Is there a plugging paste material that very 
closely matches the CTE of FR406, 170Tg?  Any and all comments are 
welcome.

Thanks,

Mark Focht C.I.D.+
Pole/Zero Corporation
5530 Union Centre Dr.
West Chester, Oh  45069-4821

Voice:  513.870.9060 X173
FAX:    513.870.9064
Email:  [log in to unmask]

---------------------------------------------------
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
-----------------------------------------------------

ATOM RSS1 RSS2