A low temperature co-fired ceramic land grid array for high speed digital applications

A Land Grid Array (LGA) package was designed and fabricated to utilize specific materials and design concepts for high speed operation. The performance of this LGA was compared with that of a functionally and dimensionally equivalent Pin Grid Array (PGA) that is currently being used to package high speed silicon ECL gate arrays. Two structures that were sources of signal degradation in the PGA, the pins and a layer of plating lines, were eliminated in the design of the LGA. The package was fabricated out of DuPont Green Tape low temperature co-fired ceramic (LTCC) with gold conductors and vias. This combination of an improved LGA structure and materials with superior high speed properties resulted in a package with improved performance and decreased signal degradation when compared with conventional high temperature co-fired ceramic (HTCC) PGAs. The LGA has a heatsink made from a new Metal Matrix Composite (MMC) of Al in a sintered silicon carbide matrix.<
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