A Multi-Function Planar Inductor Based on 3D Printing and Its Optimization

Nowadays, Planar magnetics are being widely used in industry due to its low profile, machine manufacturing accessibility, controllability, and reduction in AC winding loss. There are many ways to manufacture planar magnetics, including printed circuit boards (PCB), thick film, folded copper, etc. However, all the above manufacturing technologies are limited on two-dimensional (2D) plane. This paper proposed a multi-function planar inductor based on 3D printing, which has high efficiency and reliability. The copper winding of the proposed inductor is manufactured by 3D printing technology. The shape of the winding is designed to have dual functions of conducting current and dissipating heat. For PCB planar inductor, the spaces above and below the PCB footprint stretching out of the magnetic core are often wasted. The proposed inductor makes full use of the wasted spaces with winding occupying the spaces, causing a decline of copper loss with no more taking up spaces. One winding is divided into several cooling fins for enlarging heat dissipation area, further reducing maximum winding temperature and increasing reliability. One-dimensional calculation models of both DC resistance (DCR) and maximum temperature rise were established in this paper. Based on the models, the dimension of the winding can be optimized, including the number of fins in finned winding.