Yes, Colin. We use 4.5 microinches of Gold over 150 microinches of Nickel
to obtain a flat surface for our 388 pin 1.27mm pitch PBGA's. Owing to the
thick Nickel layer, we have to use a high melting point tin/lead solder
with about 2% silver to get the finish we want from the joints.

Regards

Pete Duncan




                    Colin Weber
                    <colin.weber@VARI        To:     [log in to unmask]
                    ANINC.COM>               cc:     (bcc: DUNCAN Peter/Asst Prin Engr/ST Aero/ST
                    Sent by: TechNet         Group)
                    <[log in to unmask]>        Subject:     [TN] Surface Finish for 1.27mm PBGA


                    05/10/01 09:45 AM
                    Please respond to
                    "TechNet E-Mail
                    Forum."; Please
                    respond to Colin
                    Weber






Could anyone inform me of whether an Electroless Gold surface finish which
conforming to IPC-6012 Class3, is suitable for a 388pin PBGA of 1.27mm
pitch?


Regards,

Colin Weber

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

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