In a message dated 7/24/00 11:09:14 AM EST, [log in to unmask] writes:

<< Hey all.

 How should one go about inspecting PGAs after wave soldering?  I've checked
the archives, but can't find anything.  I would imagine that you'd have to
use X-ray equipment, but are there specific angle to take shots from?

 Thanks,


 Eric Kalgren
 BFGoodrich Aerospace
 Space Flight Systems
 [log in to unmask]
 (505) 938-5139 >>

Hi again Eric!

I put a couple of pictures of some PGA solder joints up at:

http://www.driveway.com/share?sid=4eced0a4.94f42&name=Pictures

Actually, it's of a PGA socket, PLCC to PGA. I couldn't find any boards
around here that had a PGA device soldered directly in the board. The first
picture (PGA.jpg) is of a joint that's on the outside row of pins. The second
picture (PGA1.jpg) is of the joints on inner row pins. You need to position
the board a little to see the areas that will tell you whether or not you've
got good wetting and a decent fillet...you won't be able to see the whole
joint like you do on an outside row of pins, but you can see enough of it to
tell whether things are good or not. You do that by focusing the lense inward
toward the center of the device. The inner joint picture looks a little dark
(hard to get good lighting in there) but it's much clearer on the monitor
than what the picture shows.

BTW, these pictures were looking underneath the socket body that was maybe
1-2mm off the board...

-Steve Gregory-

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