Column grid arrays:  are more expensive, the soft solder columns (typically Pb-10Sn) are much more easily damaged than solder balls, are generally used for larger substrates ( typically > 28mm substrates), most commonly used on ceramic substrates, provide significantly greater thermal cycling life vs BGA.  CGA solder columns do not melt at SMT temperatures so the only solder available for self-alignment comes from printed paste.  This is likely to may the CGA more sensitive to bond pad design/solder mask opening geometry and placement accuracy.  BGAs are a more widely available package option than CGAs - manufacturing CGAs and PCB assembly of CGAs is well known, but vastly more assembly know-how and literature is available for BGAs.

-----Original Message-----
From: Louis, Edwin @ CSE [mailto:[log in to unmask]]
Sent: Monday, September 23, 2002 2:54 PM
Subject: Pros and Cons of BGAs v.s. CGAs

Which PWA attachment method is more appropriate, CGAs or BGAs from the
folloeing perspective:
(1) manufacturing producibility
(2) Solder joint longevity with thermal cycling from -65 degrees C to +125
degrees C
(3) Placement registration
(4) Other parameters

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