Visualization of Current Distribution by Subsurface Magnetic Field Imaging System for the Cockcroft-Walton Circuit and Their Components

The miniaturization and high functionality of electrical components have accelerated the development of next generation of electric devices. In particular, power supply circuits have become smaller and more functional. Visualization of electric current distribution using subsurface structural imaging for failure analysis has become increasingly essential to develop smaller and more sophisticated power supply circuits. In this study, we successfully demonstrated the detection of electric current distribution on a Cockcroft-Walton (CW) circuit, and inside a Schottky rectifier and an electric-short circuit spot inside a multi-layered ceramic capacitor (MLCC) using this imaging system equipped with a magneto-impedance (MI) sensor as a highly sensitive magnetic field sensor.