Magnetic imaging for resistive, capacitive and inductive devices; from theory to piezo actuator failure localization

Abstract

Short circuit is a known defect in electronic devices and several non-destructive techniques have been developed in the last two decades in order to localize them. Magnetic microscopy is very efficient to localize leakage paths inside complex and packaged devices. Nevertheless, when the device under test has a normal inductive or capacitive path, the dynamic current consumption can be considerably higher than the leakage itself challenging the defective path localization.This paper will detail the possibilities given by the magnetic imaging to observe this kind of defect in conditions where the basic use would normally be unable to, since a capacitive and/or an inductive device would blind it. A test vehicle has been realized in order to evaluate this new use of the magnetic imaging. Finally, a piezo-actuator component is then studied in order to prove the concept.