PCB材料与电源/地层谐振阻抗关系

为降低多层高速PCB(Printed Circuit Board)电源/地谐振阻抗,根据平行平面腔体谐振模型理论推导出PCB电源/地谐振阻抗、谐振频率、谐振品质因数与构成PCB板的导体材料和绝缘材料的电磁参数的之间的函数关系式,并根据此关系式得出了从PCB材料选取角度减小电源/地谐振阻抗的两种途径,即采用高磁导率、低电导率的导体材料代替普通导体材料;采用高介电常数和损耗正切的平面间绝缘体材料.随后PCB电源/地平行平面结构的全波仿真结果证实了这两种途径的有效性.

Relationship between PCB material and power/ground impedance

To mitigate PCB(printed circuit board)power/ground impedance,which is a great negative influential factor to signal and power integrity of high-speed multilayer PCB,the relation functions among PCB power/ground resonant impedance,resonant frequency,resonant quality factor and the electromagnetic parameters of power/ground planes structure were deducted based on cavity resonant model.According to the deductions above,two main ways to reduce PCB power/ground resonant impedance from the aspect of selecting conductive and insulating materials whose electromagnetic parameters are more helpful to reduce power/ground impedance were developed.These two ways include using conductive material with high permeability and low conductivity and adopting insulating material with high permittivity and loss tangent.The latter full-wave simulation results prove the effectiveness these two ways.