Hi Jim!
Sounds like you have the problem of excessive ball collapse with BGA's solved! I wonder why the OEM's haven't done something like this? It's not like this is an obscure problem...
Silly question; is it possible to replace only the corner balls with Hi-temp balls? See? I told you it was a silly question...
-Steve Gregory-
It just so happens that we build a multi-chip module using a 625-BGA
package. We buy the empty package from Kyocera, install multiple die and
discretes, seal the lid, attach the balls (4 hi-temp in the corners) and
solder the BGA to our PWB.
Jim Marsico
Senior Engineer
Production Engineering
EDO Electronics Systems Group
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631-595-5879
-----Original Message-----
From: Steve Gregory [SMTP:[log in to unmask]]
Sent: Wednesday, September 24, 2003 3:25 PM
To: [log in to unmask]
Subject: Re: [TN] 5Sn / 95Pb Solder Sphere
Jim,
Do you get the devices like that, or do you put the hi-temp balls in
the corners yourself?
Thanks!
-Steve Gregory-
Victor, we use high temp solder balls on the 4 corners of a
625 ceramic BGA.
The main purpose is to prevent the device from collapsing,
causing solder
bridging. Maintaining the stand-off height after reflow
also increases long
term reliability.
Jim Marsico
Senior Engineer
Production Engineering
EDO Electronics Systems Group
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631-595-5879