A laser direct-writing magnetic integration process: Low-temperature packaging of magnetic films on on-chip inductive components

• Published in: Journal of manufacturing processes 2025-01, Vol.134, p.904-914
• Main Authors: Wang, Leiyang, Li, Yunfan, Wu, Bang, Liu, Lan, Li, Shifeng, Liang, Kang, Zhou, Yu, Liu, Feng, Liu, Sheng
• Format: Article
• Language: English
• Subjects: Integration; Laser direct-writing; Magnetic film; On-chip inductive component; Radio frequency
• ISSN: 1526-6125
• DOI: 10.1016/j.jmapro.2025.01.014

The integration of functional magnetic films into chips can effectively solve the problem of large area and low performance of radio frequency (RF) on-chip inductive components. However, the lack of low-temperature integration processes compatible with standard semiconductor processes for magnetic films hinders the practical application of on-chip inductive components with magnetic films. In this study, to improve the performance of on-chip inductive components, a laser direct-writing process is proposed for the first time for low-temperature packaging of magnetic films on on-chip inductive components. In this process, an oriented laser is used to heat and solidify a magnetic slurry film composed of thermosetting resin and magnetic nanoparticles, which is coated on on-chip inductive component, thus realizing the low-temperature integration of magnetic film on on-chip component. Furthermore, the laser direct-writing process is applied to integrate ferroferric oxide (Fe3O4) magnetic film onto a meander on-chip inductor. Compared to the same type of air-core meander inductor, the inductance (L) and quality factor (Q) of the meander inductor with Fe3O4 magnetic film are increased by 20.2 % and 7 % at 1 GHz, respectively. The results indicate that the laser direct-writing magnetic integration process is simple, low-temperature, efficient, and fully compatible with standard semiconductor process, and has great application prospects in magnetic material integration of on-chip inductive components. [Display omitted] •A laser direct-writing magnetic integration process for magnetic films packaging on on-chip inductive components.•The laser direct-writing magnetic integration process is simple, low-temperature, efficient, and compatible with IC process.•The laser direct-writing magnetic integration process is applied for improving the RF performance of an on-chip inductor.