Impedance Optimization of the Power Distribution Network in a Three-Dimensional Microassembly with Back Side Commutation

This article examines the resistance of the power distribution network (PDN) in a microassembly manufactured using three-dimensional integration technology, namely in a microassembly with back side commutation. Simulation was performed to obtain the Z-parameters of the PDN of a microassembly prototypes with 74 back side traces, 150 μm wide, located around the perimeter of the microassembly (15 back side “ground” traces on each side and 14 power traces on one side). For comparison, modeling was performed in a microassembly with a wide back side “ground” conductor on one side and a power conductor circuit on the other. A decrease in the resistance of the power bus was found when using multiple small back side conductors compared to one wide conductor. Graphs of the Z-parameters of the power bus were obtained for a microassembly with back side, in which the method of placing back side “ground” conductors between signal conductors and power conductors was used.