Design and Fabrication of a Micro Electromagnetic Relay

A new optimization structure for micro electromagnetic relay is introduced based on the research done before. Three-dimensional structure and new fabrication process is adopted accordingly in the improved design. The new structure can decrease the leak of magnetic circuit and increase the magnetic force. An optimization armature is introduced in order to improve the electromagnetic attract force and decrease the rigidity of the armature. A micro electromagnetic relay is fabricated based on the MEMS technology. The size of the micro electromagnetic relay is about 5 mm times 5 mm times 0.4 mm. The micro relay consists a lower magnetic circuit, a planar exciting coil and a permalloy cantilever. Anisotropic etching, electroplating, polyimide film patterning is adopted in the fabrication process. The exciting coil of the micro electromagnetic relay has 16 turns and the resistance of the coil is about 20 Omega. The initial experiments show that the permalloy cantilever displacement can reach 20 mum at a current and voltage of 250 mA and 5 V