Design Of Modular High Power Magnetron Sputtering Bias Power Supply

Miniaturization,high power density and high reliability is Lhe major development trend of high power magnetron sputtering power supply.As a preferred solution of high power switching power supply,modularization is facing the problem of voltage and current sharing.At the same time,efficiency raise and suppression of the parasitic oscillation of modular power supply are more difficult to achieve.For load changes in the process of magnetron sputtering,it is difficult to guarantee current sharing for short term large current by control flow method.This paper designed the high power magnetron sputtering bias supply based on input-parallel-output-parallel phase shifted full bridge converter.Which can realize current sharing via crossed rectification at the secondary side of transformer and the second balance capacitor,without extra control strategy.The operating mode of the main circuit was analyzed and the mathematical derivation was made for principle of current sharing.Secondly,aiming at the lagging arm of ZVS soft switch,duty cycle loss and the parasitic oscillation was analyzed.Further proposed the phase shifted full bridge rectifier cross converter with coupling inductance,which can achieve a wide range of ZVS,reduces the duty cycle loss and the parasitic oscillation,using current enhancement principle of coupling inductance.And these characteristics are verified by simulation.Finally,according to the design index of bias power supply completed parameter calculation and device type selection,a 10kW experimental prototype was designed to verify the characteristics of the effect of current sharing.At the same time it solved the contradiction of lag arm ZVS soft switching and duty cycle loss,can achieve a wide range of ZVS,reduce the duty cycle loss and parasitic oscillation.