Integration of Field Sensing in Power Semiconductor Modules for Current Sensing

This work focuses on integrating field sensing giant magnetoresistor (GMR) detectors into power semiconductor modules to be used as integrated current sensors. This work expands on prior work by evaluating the use of GMR detectors in a much smaller and more complex geometry than the bus bar geometries previously evaluated.;When compared to a bus bar structure, a power semiconductor device has current carrying conductors that are near other conducting surfaces. This work uses electromagnetic finite element analysis and experimental evaluation to show that when a current carrying conductor is near another conducting surface, the flat bandwidth (FBW) performance of the conductor is decreases significantly. This configuration cannot be avoided in a module where conducting surfaces will be found due to the ground planes and heat sinks that are required for operation. The work presents a design methodology where placing additional conducting material can be used to improve the FBW performance of the switching device. This work evaluates a round conductor, a thin rectangular conductor, an IGBT device with wirebond interconnects, and an IGBT device with a lead frame interconnect, and a 2-in-1 IGBT module to show how various structures can be used to improve regions of high FBW for sensing.;This work also presents design guidelines for placement for the additional conducting material used to shape the high frequency fields. Using both finite element and experimental results, the sheet conductivity, distance, thickness, and width are evaluated to show the effects of these parameters on the design response.;Other significant contributions of this work include presenting an analytical model to determine the FBW performance of a round conductor near a ground plane, the use multiple detectors to increase the placement tolerances to achieve high FBW performance, evaluating the disturbance rejection properties of the additional conducting sheet, and evaluating how the scaling and geometry of wirebond structures and lead frame structures affect the FBW performance.