Microfabrication of Sm2Co17 micromagnets for MEMS and micromotors using ultrashort pulsed hydro laser micromilling process.

Micromagnets have wide applications in MEMS and micromotors but there are still miniaturization limitations in current microfabrication processes for permanent magnets. A novel damage-free ultrashort pulsed laser machining process to manufacture complex shapes of Sm2Co17 micromagnets is proposed in this work. Laser process permits to further miniaturize the size of the resulting micromagnets achieving very small micromagnets. This can be achieved as micromagnets are submerged in a refrigerant fluid which is especially beneficial for magnets that are materials very sensitive to high temperature. The heat effect of laser cutting on the hard magnetic materials is drastically reduced thanks to the fluid. The detailed description of the manufacturing process is hereby presented. Results of several machining processes like milling and cutting and the magnetic characterization of the resulting micromagnets are shown. Complex segment shapes, with 65-μm thickness made in high-quality Sm2Co17 material, with good accuracy are achieved. It is demonstrated that no permanent degradation of the magnetic properties appears after laser machining. [ABSTRACT FROM AUTHOR]