Board separation. It is possible that the BGA is fine but the board fails
during assembly processing. This is a fairly thick board and a large I/O
BGA. I assume a fairly complex board. High aspect ratio PTH? Blind vias,
filled and plated? Food for thought.


-----Original Message-----
From: TechNet [mailto:[log in to unmask]]On Behalf Of Kerry McMullen
Sent: Monday, May 23, 2005 1:10 PM
To: [log in to unmask]
Subject: [TN] BGA Intermittents


Hi Technetters,
I have a 1089 BGA with Sn balls.
Paste is 63/37 SnPb
Board is 14 layer,  .098 thick Immersion Ag.
Ran thermocouples.  Inner balls are seeing 206 degrees C.

What could be causing intermittents at the center and corners of the BGA?

Thanks,

Kerry

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