Inductors without Negative Mutual Inductances Based on Self-rolled-up Technology

The self-rolled-up (S-RuM) inductor is typically composed of multiple inductors connected in series. In conventional processes, the current directions of adjacent inductor units are opposite, resulting in negative mutual inductance, thereby reducing the magnetic flux density of the inductor. This paper proposes a novel inductor structure based on S-RuM technology and elaborates on its fabrication process. By altering the connection method of adjacent inductor units, this structure ensures consistent current directions between adjacent inductor units, effectively eliminating negative mutual inductance. Taking a set of six single turn inductors as an example, the new structure increases the quality factor (Q) by 76% and the inductance by 35%, promoting the development of high-performance passive devices.