System Packaging for Robust LGA Interconnect Technology in High Performance Computing Applications

Hundreds of millions of Land Grid Array (LGA) contacts currently provide reliable electrical interconnections in thousands of IBM Servers shipped to a multitude of world wide customers. Many of these system designs incorporate both LGA module-to-printed wiring board (PWB) and LGA board-to-board interconnection field upgrade capability for ultimate system flexibility and customer support. The overall scale of this implementation with respect to size and number of LGA modules used, total number of LGA interconnections, and resultant interconnection densities used, along with unique hardware assembly technology, precision tolerances and process controls needed for versatile and reliable assembly integration in both manufacturing and field environments drive a complex and novel set of design, development, and manufacturing challenges. Many engineering solutions developed to successfully address these unique and varied challenges are presented spanning resultant LGA hardware design, assembly process, and field installation requirements.