Planar Integrated Magnetics Technology — A Review

This article reviews the fundamental design principles and emerging technology trends of planar magnetics and magnetic integration in modern electrification. A physics-grounded overview is presented, establishing a hierarchical taxonomy and examining the role of magnetic integration across automotive, renewable-energy, data-center, and aerospace applications. The review emphasizes the physical intuition and mechanisms governing planar transformer–inductor integration, while evaluating the key geometric and implementation tradeoffs of modern planar architectures using literature-based quantitative benchmarks. Furthermore, key design considerations—including high-frequency distributed effects under wide-bandgap (WBG) excitation, parasitic capacitance, electromagnetic compatibility (EMC), thermal management, insulation coordination, partial discharge (PD), dielectric reliability, and manufacturability—are addressed as coupled constraints inherent to high-density planar structures. Finally, the article outlines current commercial trajectories and future research frontiers, providing design-oriented guidance for the development of more compact, efficient, and reliable power converters.