Electroplated soft magnetic materials for microsensors and microactuators

Abstract

A number of micromachined magnetic sensors and actuators require materials with desirable magnetic properties as well as thicknesses in the range of several microns. Materials with appropriate magnetic properties have been reported for magnetic storage applications, but often in thickness ranges insufficient for other sensors and actuators. We report the development of an electroplating bath for the deposition of a high permeability, low coercivity material, a NiFeMo alloy. Using this bath, the NiFeMo alloy may be electrodeposited up to 5 microns in thickness. In addition we report the use of a NiCo soft magnetic alloy, and the use of NiCo and NiFe layered films for improved magnetic performance.