Yes, I would be interested in more information on SIR for BGA's.
     Rod Martens
     Hewlett-Packard


______________________________ Reply Separator _________________________________
Subject: Re: [TN] BGA SIR Patterns
Author:  Non-HP-SIRGuru ([log in to unmask]) at HP-ColSprings,mimegw4
Date:    3/16/98 10:14 AM


In a message dated 98-03-16 06:34:35 EST, you write:

>  I would like to know if we are any nearer to having IPC SIR combs designed
>  to go under BGA devices?
>  Do the IPC have any recommendations for dealing with the situation in the
>  absence of these coupons?

I would say no.  Considering that BGAs are an array of balls designed to
contact the board surface, comb patterns under BGAs is not practical.  Most
SIR testing that I have done relative to BGAs has involved daisy chaining the
pads together, such that alternating rows of balls form the cathode and anode
of the SIR test pattern.  There are various ways to approach designing such an
SIR test pattern, depending on what you are looking for.  My own preference is
to take the two center rows of balls, daisy-chain them together, and do SIR on
the two parallel lines.  It should give worst case.

As far as I know, the IPC does not have any efforts at this time to examine
SIR under BGAs.  Not to say we couldn't, but right now we are focusing on test
environment levels (temperature and RH for various tests).

Out of curiosity, is there many others out in TechNetLand that are interested
in doing SIR under BGAs?

Doug Pauls
Chairman, SIR Task Group

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text
 in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional inform
ation.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-97
00 ext.311
################################################################

################################################################
TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c
################################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body:
To subscribe:   SUBSCRIBE TechNet <your full name>
To unsubscribe:   SIGNOFF TechNet 
################################################################
Please visit IPC web site (http://jefry.ipc.org/forum.htm) for additional information.
For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311
################################################################