An Integrable High-Frequency 3-D Magnetic Field Scanning Method for Power Module

As one of the key parameters of power modules, the high-frequency magnetic field not only reflects their switching characteristics and spatial distribution, but also plays a crucial role in electromagnetic compatibility evaluation, reliability design, and chip selection. Because of the presence of multiple field sources and strong coupling within the device, existing magnetic field scanning techniques, however, face challenges in meeting the demands for high bandwidth (BW), compact size, and cost-effectiveness. This article introduces an integrable 3-D magnetic field scanning method based on air-coil. By capturing magnetic field distribution (MFD) along the (x, y, z) axes, the 3-D magnetic field map inside the power device can be reconstructed. An integrable 3-D magnetic field probe (MFP) was designed, taking into account packaging characteristics and current distribution, enabling real-time monitoring. Finally, a multipulse generation platform was developed to validate the feasibility of the proposed method. The experimental prototype achieved a bandwidth limit of up to 30 MHz and a sensitivity of approximately 10 V/T (or 0.01 V/(A/m) in 0.2 mm).