TBGA bond process for ground and power plane connections

The general construction of the TBGA developed at LSI Logic Corp. is discussed. Ground/power plane connections are typically provided in double metal tape for Tape Ball Grid Array (TBGA) by using plated vias for connections. A unique process which allows ground connections for TBGA package in assembly, rather than in tape is discussed. It further discusses a novel way to provide power plane connections also during assembly of a TBGA package, instead of providing it in the tape. Providing such interconnections in the assembly makes the product more cost effective and TBGA tape becomes more manufacturable. Both equipment and process for this unique “down bond” technique are discussed. Such an interconnection technique is currently being used in manufacturing at LSI Logic Corp