try this one , Ryan

Take whatever you have (be it 1mm) drill in between (and measure four >::<
balls instead of one = gives actually more balanced readings ) .
After you have this 1mm hole ; somewhere around the BGA where you have room
drill another hole for a retaining screw .
Bend the thermo wire end 1/4" 90 degrees ; clamp the wire under the screw ;
let the end clip into the 1mm hole with a smear of paste ; make sure you
have not too much of the spring > it would lift the BGA .
I think the balls should retain seat on pads for a No. of reasons during the
profiling ; not just drill them out ;
also the wire influence is bit more balanced on 4 balls (or 2 on 0.6)

See you                  paul


-----Original Message-----
From: Ryan Jennens [mailto:[log in to unmask]]
Sent: Tuesday, 4 May 1999 1:47
To: [log in to unmask]
Subject: [TN] uBGA profiling


Hey Everybody!

How can I attach a thermocouple to a uBGA with .325 mm diameter balls and
.75 mm pitch?  The narrowest thermocouple I could find has 1 mm diameter
wire.  My plan to drill through the bottom of the board and into the BGA
ball is foiled. The board also has BGAs with .6 mm diameter balls.  How are
these done?

-Ryan Jennens
TelGen Corporation

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