Hi Ken,
Have you considered delamination (popcorn effect) ?
TBGA are known to be highly moisture sensitive.
I am assuming that proper moister handling procedures were followed.
You may want to contact Sonoscan about their analysis lab, if you wish to do
non-destructive failure analysis from this angle.
Charles.


-----Original Message-----
From: Ken Patel [mailto:[log in to unmask]]
Sent: Tuesday, January 23, 2001 12:22 PM
To: [log in to unmask]
Subject: Re: [TN] Urgent...Open underneath the BGA


Werner,
Package looks visual fine on the reflowed boards hence my comment. Perimeter
joints visually look fine too. Per our test folks, it passes when they apply
the thump pressure on the BGA. This package is TBGA package.

re,
ken patel

-----Original Message-----
From: Werner Engelmaier [mailto:[log in to unmask]]
Sent: Monday, January 22, 2001 3:09 PM
To: [log in to unmask]
Subject: Re: [TN] Urgent...Open underneath the BGA


Hi Ken,
When you say "BGA package looks sturdy to handle the heat", what to you
mean?
BGAs with Cu heat spreader sure look sturdy, but can warp like potato chips
when heated.
Werner Engelmaier

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