Research On High Current Fast Recovery Diode For New Energy Vehicles

The direct current of the battery output of the new energy vehicles is inverted through IGBT,converting the direct current into alternating current to drive the motor,and each IGBT needs to match a fast recovery diode for the freewheeling.Through this study,we should design a product that can replace imported fast recovery diode chip and realize localization.Based on the basic theory,the device simulation is carried out by Silvaco software.The influence of buffer layer thickness,buffer layer concentration and P junction concentration on static and dynamic parameters is studied.As the buffer layer thickness increases,the forward voltage drop and the reverse recovery time increase,but the reverse recovery overshoot current peak decreases.With the increase of P junction concentration,the forward voltage drop and the reverse recovery time remain unchanged,but the reverse recovery overshoot current peak increases.The change of the buffer layer concentration of the device does not affect the static and dynamic losses of the device,but the breakdown voltage will decrease when the buffer layer concentration increases.Based on theoretical analysis and simulation research,the product design and wafer process.This topic will be tested and imported products of the same conditions,25 degrees the product of static and dynamic loss are imported products 98% and 96%,125 degrees this paper products of the static and dynamic loss respectively is 84% and 90% of the imported products.This product has low reverse recovery overshoot voltage,so it has higher robustness.The high temperature leakage of the device is only 45% of the imported device,so it has higher reliability.The above test results can meet the requirements of the imported products.Usually that reverse recovery softness decided to reverse recovery voltage overshoot peak,through the research,the viewpoint that the charge release rate in the last stage of the reverse recovery process determines the peak value of reverse recovery overshoot voltage is put forward,which provides a new technology for the research of fast recovery diode support,the research content of this paper has theoretical significance and engineering significance research and development of power devices.