Electroplating a magnetic core for micro fluxgate sensor

• Published in: Microsystem technologies : sensors, actuators, systems integration actuators, systems integration, 2009-03, Vol.15 (3), p.413-419
• Main Authors: Kang, Chun-Lei, Liu, Gang, Yang, Jian-Zhong, Liu, Long-Hua, Xiong, Ying, Tian, Yang-Chao
• Format: Article
• Language: English
• Subjects: Applied sciences; Coercivity; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Copper; Domain effects, magnetization curves, and hysteresis; Electrolytes; Electronics; Electronics and Microelectronics; Electroplating; Engineering; Etching; Exact sciences and technology; Ferrous alloys; Fluxgate magnetometers; Instrumentation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Ion beams; Magnetic alloys; Magnetic cores; Magnetic fields; Magnetic properties; Magnetic properties and materials; Magnetic saturation; Magnetization curves, magnetization reversal, hysteresis, barkhausen and related effects; Mechanical Engineering; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Nanotechnology; Oxidation; Permeability; Phase transitions; Physics; Plating; Precision engineering, watch making; Residual stress; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensors; Technical Paper; Thickness; Working conditions
• ISSN: 0946-7076; 1432-1858
• DOI: 10.1007/s00542-008-0736-7

A square-ring shaped micro fluxgate sensor, which was designed for measuring two axes weak magnetic field at the same time, was fabricated using MEMS technologies. To get better magnetic properties, Ni/Fe permalloy was selected to be the materials of magnetic core which was fabricated by DC-electroplating method with several micron thickness. Saccharine was added into the electrolyte to reduce the internal stress, and its influence on magnetic properties was studied. The results show that magnetic properties are related to the crystalline phase transition in the deposition which varied with saccharine content. With 3 g/L saccharine in the electrolyte, a film with low coercive force and high saturation magnetization relatively was obtained and some characters of the sensor were also discussed in the paper.