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For a magnetic MEMS application, the integration of soft magnetic flux guides with high saturation flux density is often needed. A complex form including a trench in substrate was designed to achieve its flux guide function. Electroplating CoFe with followed Chemical-mechanical Polishing (CMP) process was chosen as fabrication technology. Pulse current was selected as power supply for electrodeposition process. Experimental results show, that fine tuned pulse current parameters are necessary for electroplating high magnetic performance, low residual stress CoFe films into a trench form without any formation of cracks and voids. For the further system integration a planarization step is required. Since the CoFe layers show a strong response to the chemical attack causing etching, the mere mechanical polishing process is adequate for the planarization of CoFe. Furthermore, the application of alumina abrasives shows very good results regarding surface quality.

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There are many ways to manufacture Micro Electro-mechanical Systems (MEMS). For thin-film fabrication of integrated MEMS parts, several different techniques (like etching and electroplating) are applied. Typically, the whole fabrication of MEMS devices is conducted on a carrier wafer, which is fixed and bonded on a Printed Circuit Board (PCB). This procedure is complex and time-consuming. Also the system integration of the bonded MEMS faces difficulties. To reduce complexity and time, as well as to facilitate its integration, a new processing approach is investigated at the Institute for Micro Production Technology at the Leibniz Universität Hannover. The approach chosen for fabrication of electro-magnetic MEMS devices is the application of PCB as carrier wafer. After preparation of the PCB, the MEMS components can be structured by thin-film technology directly on the PCB using the laminated Cu layer. This fabrication procedure allows integrating the MEMS components into the system from the beginning.