Reliability Analysis Of Bonding Wire Based On Novel Power Module With Stacked DBC Hybrid Packaging Structure

High power density of the power module becomes one of the most critical specifications for power electronics applications.In order to increase the power density of the power module,the switching frequency of the semiconductor switching device should be increased,so that the volume of the passive device can be reduced.However,due to material limitations,silicon-based devices can not achieve high switching frequencies,so the SiC device provide new options for high power density application.The SiC device inherit faster switching speed,higher breakdown voltage and lower conduction resistance.But it will lead to high di/dt,which is the strong challenge for parasitic control.The new hybrid packaging structure based on SiC device adopts the mutual inductance cancellation rule,which can effectively reduce the parasitic inductance of the power module.Its fabrication process is simpler and more mature than the flat structure,so it can be said that it is an ideal high power density packaging structure.Nevertheless,the hybrid packaging structure still has reliability problems,like bonding wire lift up and so on.Therefore,it is very important to study and optimize the reliability of this new structure.This thesis focuses on the influence of five shape parameters of the bonding wire based on the novel stacked DBC hybrid packaging structure on the reliability of the bonding wire.Firstly,through the transient structure module of ANSYS Workbench platform,the simulation method of temperature cycling for the new stacked DBC hybrid package structure is proposed,and the reliability of the bonding wires is compared by the maximum Von-mises equivalent stress value and plastic strain amplitude in the simulation results.Then,building the temperature cycle experimental platform,and put forward the specific experimental method and detection method for the temperature cycling of the new stacked DBC hybrid packaging structure,and the reliability of the bonding wires is compared by the bonding wire tensile test results.Finally,through the double verification of the temperature cycle simulation results and the temperature cycle test results,it is found that if the bonding wire is bonded to the center of the upper DBC ceramic substrate,the bonding wire reliability will be higher;the thicker the copper layer of the upper DBC ceramic substrate,the thinner the ceramic layer of the upper DBC ceramic substrate,the higher the reliability of the bonding wires;the smaller the diameter of the bonding wire,the higher the reliability of the bonding wire;the greater the horizontal distance between the top of the bonding wire and the front end of the first solder joint,the higher the reliability of the bonding wire;when the vertical distance between the top of the bonding wire and the front end of the first solder joint is 2.5mm,the bonding wire has the highest reliability.The optimal shape parameters improves the reliability of the bonding wire,provides a reference for the wire bonding process of the module,and provides a reference for the reliability research of other parts of the structure.