I've never seen an exact number for voiding, but would be interested if anyone
does have one.  As for personal experience, we have seen cases where a single
large void or many small voids aligned at an interface negatively impacted the
reliablility.  Also, we saw a case where some degree of voiding actually
increased the life of BGA's, most likely due to some sort of crack arrest
mechanism.  I would imagine that a good number for max. voiding would need to
include not just % void, but also position in the joint.
My $0.02,
Rod Martens

-----Original Message-----
From: Non-HP-FEiranova
/hp-ftcollins,[log in to unmask]
Sent: Wednesday, October 07, 1998 2:39 PM
To: Non-HP-TechNet /hp-ftcollins,[log in to unmask]
Cc: Non-HP-FEiranova /hp-ftcollins,[log in to unmask]
Subject: [TN] Voiding in BGA

To all:
Is there a specification to address the maximum voiding allowed
for PBGA and CBGA solder joints attached to FR-4 substrate ?
Can anybody share some personal experiences in this matter ?
Thanks

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