PCB Power Plane Design Based On Constructal Theory For Power Integrity

Increasing higher frequencies and decreasing devise sizes result in signal integrity andpower integrity problems at any of the chip, package, and printed circuit board levels. Thepower integrity problems mainly involve two issues: increasing voltage drop and theSimultaneous switching noise (SSN) propagating between the power planes and groundplanes. Power-bus has been used for decreasing voltage drops but it cannot isolate SSN.Recently, various planar electromagnetic band-gap (EBG) structures have been proposed andapplied in power/ground plane pairs to mitigate SSN. Steep noise suppression behavior resultsin voltage drop of the power plane.“Fractal” power distribution network (PDN) has beenused to lower the voltage drop of the power plane. But “fractal theory” did not explese how toobtain the data of the size. How can we obtain the network sizes more reasonable?“Constructal theory” given by Bejan gives us the answer.This paper contains:Firstly, based on “Constructal theory” we propose a method to design powerdistribution network for reducing the voltage drop of power plane, such as rectangularnetwork, triangular network and spider-shaped network.Secondly, line up EBG structures between the designd network and obtain theconstructal power plane and reseach their voltage drop performen, noise isolation performenand robustness.Thirdly, the signal integrity is researched in this paper, which shows that SI of designedplane is not worse that tranditional EBG power plane but still needs increasing.