Influencing Factors of Inductance for 3D Micro-PCB Rectangular Coil

The main constraint that restricts wireless charging technology successfully applied in miniature medical electronic equipment is that the volume of the transmission coil is difficult to reduce. The printed circuit board (PCB) coil can take advantage of multi-layer wiring space to achieve the coil stack, achieving the purpose of increasing the relative magnetic flux, so that it could replace the traditional spiral coil to become the medium of wireless power transmission in the mini-medical electronic device. In this paper, we analyzed several electrical parameters that could affect the 3D PCB rectangular coil inductance value based on the 3D PCB rectangular coil inductance computing method. Then we sort these influencing factors so that these results can help designers to design the 3D PCB coil. The conclusions are as follows: (1) number of layers, total number of turns have positive correlation with the self-inductance; metal width, substrate thickness, the pitch between adjacent turns have negative correlation with the self-inductance. (2) The sorting of influencing factors of the inductance is as follows: total number of turns>number of layers, the pitch between adjacent turns>substrate thickness>metal width.