TECHNET Archives

March 2001

TechNet@IPC.ORG

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

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

Print Reply
Content-Type:
text/plain; charset="iso-8859-1"
Sender:
Subject:
From:
"Marsico, James" <[log in to unmask]>
Date:
Fri, 9 Mar 2001 07:45:15 -0500
MIME-Version:
1.0
X-To:
Michael Forrester <[log in to unmask]>
Reply-To:
"TechNet E-Mail Forum." <[log in to unmask]>, "Marsico, James" <[log in to unmask]>
Parts/Attachments:
text/plain (76 lines)
All of our present BGA designs incorporate via-in-pad technology.
(Something like a .035" pad with .020" via., 8 layers, .062 thick)  The via
is epoxy filled and plated over with Cu then HASL.  We've been using this
design for many years, even before BGAs, where real estate was a problem.
We had many designs with vias in SMT pads.  It has been tough over the years
to find a supplier who can provide a quality produce consistently.

Jim Marsico
Senior Engineer
Production Engineering
AIL/Electronics Systems Group
An EDO Company
[log in to unmask] <mailto:[log in to unmask]>

        -----Original Message-----
        From:   Michael Forrester [SMTP:[log in to unmask]]
        Sent:   Thursday, March 08, 2001 4:25 PM
        To:     [log in to unmask]
        Subject:        [TN] MicroVia In Pad Vs Silver VIA fill

        We currently have a design with  15 X 15 array BGA patterns a 12
layer 0.62 bd.
        There are 10 mil vias in every BGA pad (22 mil pad) .
        The reason for the Via in pad is keep the runs as short as possible.
Currently
        we fill the vias with conductive silver epoxy and plate E Ni/I Au
        over the entire pad surface.  I would like to try a microvia in pad,
no via
        fill, and OSP.  My questions are:

                  1) Can I get away with not filling the microvia to prevent
solder
        thieving?
                  2) Are there any problems with this approach?  If NG,
other ideas to
        get rid of silver fill?
                  3) Is there any disadvantage/reliability risk, to using
silver via
        fill other than cost and longer lead time?

             Thank you in advance.

        Best Regards,

        Michael Forrester


----------------------------------------------------------------------------
-----
        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 the following message:
SET Technet NOMAIL
        Search previous postings at: www.ipc.org > On-Line Resources &
Databases > E-mail 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

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

---------------------------------------------------------------------------------
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 the following message: SET Technet NOMAIL
Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail 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
---------------------------------------------------------------------------------

ATOM RSS1 RSS2