Hexagonal BGA Patterns for Power-Via Resonance Minimization and Common-Mode Suppression

A power-via resonance minimization and common-mode suppression approach is proposed for hexagonal high-speed differential signals and power via ball-grid-array patterns. Power-vias are assigned to shift power-via resonance from odd-mode to even-mode. The vias are excited in even-mode so that they can function as common-mode filter which has around 7 dB common-mode suppression at 10 GHz or higher. The effect of asymmetric and symmetric power-via pattern is also studied. Different high frequency signal combination and hexagonal patterns are given to investigate the resonance and common mode suppression. Signal integrity performance is presented in terms of insertion loss, crosstalk, and common-mode response.