ELECTRODEPOSITED MAGNETIC-ALLOYS FOR SURFACE MICROMACHINING

Electrodeposited magnetic materials are of great interest in surface m icromachining as they can be used for transformation of forces in both actuators and sensors. Magnetic alloys of the ferrous metal family wi th different characteristics can readily be electrodeposited. An advan ced lithographic process was performed in order to generate resist mol ds for electrodeposition. By means of standard ultraviolet aligners an d immersion development photoresist layers up to 80 mu m were patterne d in a single shot. Repeated exposure and development were successfull y used for structuring thicker resist layers. High aspect ratios and s teep edges were achieved with a sufficiently high resolution. The resu lting resist patterns were molded via electroplating. For microsystem applications, magnetic alloys such as NiFe and NiCo are of special int erest. The deposited material was characterized in relation to its mec hanical and magnetical properties. Some examples of microsystem compon ents using magnetic properties are given. The active part of a magneti cally driven microvalve containing a membrane with integrated force am plifier from NiFe alloy as well as a microturbine with NiCo rotator we re fabricated and tested.