Analysis of SMT decoupling capacitor placement in electronic packages using hybrid modeling method

An efficient hybrid modeling method is presented for analysis of the surface-mount technology (SMT) decoupling capacitor placement in the power distribution network (PDN) of an electronic package. The PDN includes the multilayered power-ground (P-G) planes, the P-G vias, and the decoupling capacitors to provide a low-impedance path between the printed circuit board and the die. The SMT decoupling capacitors are commonly used to mitigate the resonant phenomenon of the electronic package in cavity-like structure and provide the additional return paths for the signal traces. Applying the modal decomposition of the waves propagating inside the P-G planes and the traces, the electro-magnetic fields can be decomposed into the parallel-plate mode and the transmission-line mode. The former is analyzed by using the scattering matrix method for the finite P-G planes with multiple vias. The multiconductor transmission-line theory is applied to model the micro-striplines and striplines in the package. The method has been experimentally validated.