Nondestructive detection of current in power modules by means of magnetic measurements

A new measurement technique for the nondestructive check of the current distribution within a generic power module is presented. It is based on the detection of the two-dimensional spatial distribution of the magnetic field arising from the loaded power modules at a proper distance from its bottom. The paper demonstrates that the magnetic field is particularly sensitive to the currents flowing through the interconnections between the chips. Moreover, the measurement of such distributions allows us to individuate differences among the currents through the chips with a good resolution.