Non-orthogonal 2.5D PEEC for power integrity analysis

Power distribution network (PDN) of a multilayered PCB is designed to supply low noise and stable power to ICs. Reduced voltage levels, increased current requirements make it challenging to attain the desired PDN impedance profile. It is therefore necessary to have multiple design iterations for optimal performance of the PDN. 3D full-wave electromagnetic solvers like the Partial Element Equivalent Circuit (PEEC) method are time constrained and therefore ill-suited for early stage design. On the other hand, 2.5D tools have lower time and memory requirements and are reasonably accurate for planar power-ground structures. For example, Multilayered Finite Difference Method (MFDM) is a 2.5D formulation suitable for PDN analysis. However, present MFDM techniques are based on orthogonal meshes, such that power-ground planes with irregular shapes and holes require unnecessarily fine mesh at the boundary for a suitable staircase approximation. In this paper, a non-orthogonal 2.5D PEEC formulation is proposed to alleviate this problem. Numerical results using quadrilateral meshes demonstrate good accuracy as compared to 3D full-wave formulation for planar geometries.