Methods for forming and positioning moldable permanent magnets on electromagnetically actuated microfabricated components

Abstract

A low temperature batch method for forming and positioning permanent magnets on electromagnetically actuated micro-fabricated components, such as electrical switches employs a first adhesive, such as a Siltem/epoxy blend of an epoxy resin and a siloxane polyimide polymer, to releasably attach a mold layer of Kapton polyimide to a substrate, which may be the movable portion of a micromechanical structure, or a precursor to such movable portion. A well-shape cavity is formed in the mold layer, and filled with a slurry of rare earth NdFeB magnetic particles suspended in a second adhesive, which is cured to form the body of a magnet. The second adhesive is an SPI/epoxy blend, also of an epoxy resin and a siloxane polyimide polymer, but with a greater adhesion strength and a higher temperature softening point compared to the Siltem/epoxy blend. The entire structure is heated, and the mold layer is pulled off the substrate, while the body of magnetic material remains firmly attached. Selective etchants may be subsequently employed to remove metal sacrificial layers, while the NdFeB magnetic particles are protected from attack by the etchant by being effectively encased in plastic.

Dependencies are inferred from the claim text.