Research On The Packaging Technology Of Press-pack IGBT

Press pack IGBT(PPI)has a through-flow capacity of large,no welding points,lead-free,high reliability,double-sided cooling,low thermal resistance,wide safe operating area(SOA),high power density,the unique short circuit failure mode and other characteristics,can be widely used in HVDC systems(HVDC),railway traction,wind power,high-voltage power-driven industrial equipment and many other areas.The difference between the PPI module and the welded IGBT in the package structure lead to the difference in the packaging technology and implementation.Firstly,the second chapter has introduced the pressure distribution of the PPI under no-deviation force field and thermo-mechanical coupling by comsol simulation,and focuses on the contact pressure of the chip in two physical fields.In some cases of PPI packaging,the contact pressure in the center chip is 0N.In order to avoid this worst-case package,we require the overall tolerance must be less than 6?m in the PPI packaging.Secondly,the PPI are stacked by many components,and the contact layer between the components lead to the proportion of the contact thermal resistance is very high.Nano-silver sintering technology is used to sinter the chip and the molybdenum.The chips and the un-sintered chips were loaded into a single-bump FRD module for thermal resistance testing.After the thermal resistance test,the t est data can be used to set simulation boundaries,finally through comsol simulation to get the contact thermal resistance size in each contact thermal layer.Finally,this paper has proposed two methods to improve pressure uniform distribution among the chips: It can be increase the internal module height during the packaging process.