Surface micromachined platforms using electroplated sacrificial layers

A technique for the surface micromachining of structures suspended many tens of microns above a substrate surface is presented. Electroplated metal sacrificial layers are used in a standard surface micromachining process to achieve the necessary sacrificial layer thickness. The process is demonstrated using copper as the sacrificial layer and polyimide as the structural material. Surface micromachined bridges 8 mu m thick, 160 mu m long, and 100 mu m wide suspended over the surface from 10 to 50 mu m have been fabricated in this manner. In addition, movable platforms suspended 15 mu m above a surface over an area of 3*3 mm have also been demonstrated.<>