A Zero X‐Y Shrinkage Low Temperature Cofired Ceramic Substrate Using Ag and AgPd Conductors for Flip‐chip Bonding*

A zero X‐Y shrinkage low temperature cofired ceramic(LTCC) substrate was developed, which was applied to flip‐chip bonded chip‐size packages (CSPs) and multichip modules (MCMs). The Ag internal conductor, the AgPd external conductor and the newly developed Ag via conductor could be used by matching the sintering shrinkage behaviour with that of the zero X‐Y shrinkage LTCC substrate. Flip‐chip bonding using the stud‐bump ‐bonding (SBB) technique could be performed on this substrate without Au plating on the external conductor. Stable flip‐chip bondability was obtained.