Xiao-Yu Gao

Fabrication of 3D MEMS toroidal microinductor for high temperature application

Based on Microelectromechanical systems (MEMS) technique and thick photoresist lithography technology, a new toroidal-type inductor for high temperature application has been successfully developed. In the fabrication process, heat-resistant materials are used, alumina as insulator and supporting materials instead of polyimide, heat resistant glass for underlay instead of normal glass, and copper for coil. The maximum inductance is 87nH at 0.826GHz and maximum of quality factor (Q-factor) is 4.63 at 0.786GHz, at room temperature. With simulation of thermal deformation, it shows that the developed toroidal inductor can be suitable for high temperature application, from 300 to 700^oC.

Fabrication of ultralow-profile micromachined inductor with magnetic core material

We have fabricated a microinductor with an ultralow profile by a microelectromechanical systems (MEMS) technique. The fabrication process uses UV-LIGA, dry etching, fine polishing, and electroplating to achieve high performance. The dimensions of the inductor are 1500 /spl mu/m/spl times/900 /spl mu/m/spl times/100 /spl mu/m. It has 41 turns, with coil width of 20 /spl mu/m, space of 20 /spl mu/m, and a high aspect ratio of 5 : 1. The inductance is 0.424 /spl mu/H and the quality factor (Q factor) is about 1.7 at a frequency of 1 MHz. The stray capacitance is approximately zero over the frequency range measured.

A Copper/Polyimide Fabrication Process for Fabricating High-Inductance Microinductor

This paper reports on a technological process that combines copper as conductor, permalloy as magnetic core material, and polyimide as insulation material to complete a microinductor on glass with high inductance. The shape of the magnetic core scheme was rectangular, of which the width of the long side and short side were 1.4 and 0.6 mm, respectively. The dimensions of the inductor are 3.86 mm times 3.94 mm times 90 mum with coil width of 20 mum and space of 35 mum. The results show that the maximum inductance is 4 muH at 1 MHz, and the maximum quality factor (Q-factor) is 1.5 at 2 MHz.

An integrated solenoid-type inductor with electroplated Ni-Fe magnetic core

This paper reports a technological process that combines copper as conductor, NiFe film as magnetic core and polyimide as insulation material to complete a solenoid-type inductor. The results show that the inductance is 5.4 muH at 1 MHz and it keeps high inductance of 2 muH at 10 MHz. The quality factor is 1.54 at 1 MHz and up to 1.9 at 7 MHz

A solenoid-type inductor with Fe-based soft magnetic thin film for high frequency application

Soft FeSiBCuNbCr magnetic thin film was deposited by magnetron sputtering as magnetic core for inductor. In the fabrication process, UV-LIGA, dry etching technique, fine polishing and electroplating technique are adopted. The size of the solenoid-type inductor is 3.9 mm times 2.66 mm. Experimental results show that the inductance keeps constant about 0.9 muH in the frequency range from 1 MHz to 10 MHz, and the maximum quality factor is 2.5 at 9 MHz