Wax-bonded NdFeB micromagnets for microelectromechanical systems applications

A microfabrication technique is reported for the fabrication of wax-bonded micromagnets in the 100 mu m-1 mm range. This dimensional size is not typically achievable by thin-film deposition techniques or by conventional macroscale magnet processing, and is of interest for magnetic microelectromechanical systems applications. The magnet fabrication approach incorporates a wax powder binder to lock the magnetic microparticles together to improve the coercivity. In practice, a NbFeB powder and wax powder are packed into pre-etched trenches in a silicon wafer and subsequently heated, allowing the wax to melt and bond the magnetic powder. Using this method, 500x500x320 mu m(3) magnets have been demonstrated with a coercivity of 737 kA/m and a maximum energy product of 16.6 kJ/m(3). (C) 2008 American Institute of Physics.