Hi,
     In response to questions 2 and 3:

     X-ray is the best method for joint inspection, specifically the 5DX
     x-ray laminography system.  Nicolet and Fein Focus also work well.
     Acoustic microscopy is not a good choice due to the long focal length
     and the air gap between the package and the board.

     We have had great success with the SRT rework machine. (I'm sure there
     are others as well.)

     Rod Martens.
     Hewlett-Packard


______________________________ Reply Separator _________________________________
Subject: [TN] Assy: PBGAs
Author:  Non-HP-rblanchet ([log in to unmask]) at HP-ColSprings,mimegw4
Date:    2/4/98 8:46 AM


Hello,

As we hear more and more about BGAs, my perception is that there's some
issues to be improved. From a military/high-end commercial application stand
point, I have the following questions:

1- Do people put a lot of vias under BGAs to perform ICT or do they just
perform functional tests ?

2- How do you guys inspect your BGA solder joints once on the card ?  Are
X-ray practical and reliable in a production mode ?  What about Scanning
Acoustic Microscopy (like a system from Sonoscan) ?

3- And what about repairs ?  Are they easily done with a high success rate ?

I'm trying to learn anything I can about BGAs, so any info is welcome, even
the most basic ones.

You can reach me off-line at [log in to unmask]

Thank you.

################################################################
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
################################################################