Containing emissions from a microprocessor module

Based on the Faraday cage principle a solution to contain noise at the modular level of a microprocessor (μP) is presented. This solution builds a conductive enclosure around the module. Using a metallic skirt the enclosure is connected to the ground structure of the motherboard to complete a six-sided box. For the shield design to be implement-worthy, it had to be ensured that neither the thermal solution of the μP nor the design of the bus on the motherboard is broken by the enclosure design. This solution showed good suppression of emission at all frequencies (including the high frequencies) generated by the μP. Otherwise, the high bandwidth emissions demand costly and difficult chassis enhancements to meet strict regulatory requirements. This investigation focused on different flavors of vertically standing Pentium(R) III Xeon^TM processors from Intel