KNIFES BLADES HAVING ULTRA-SHARP CUTTING EDGES AND METHODS OF FABRICATION

摘要

Knifes blades having exceptionnally sharp cutting edges (19) are formed from wafers (10) of monocrystalline silicon using known semiconductor processing technology. In one embodiment, an elongated ridge (18) having a flat top (20) covered by an etchant mask (15) is etched to undercut the mask (15) and to shape the ridge side walls (17) to inwardly converge towards the ridge tip (19). The mask (15) is removed and a sharp ridge apex (19) is provided by a series of oxide forming and oxide stripping processes. Individual knife blades of silicon, each comprising a ridge (18) having a sharp cutting edge (19), are shaped from the wafer (10). In another embodiment, the silicon wafer (50) is etched entirely through between top (52) and bottom (54) surfaces to form a tapered etched wall (87) intersecting the bottom wall (54) at a highly acute edge (91). The edge (91) is sharpened by the oxide forming and oxide stripping process to form a cutting edge (91) in the completed blade. In both embodiments, various etch masks and etching procedures are used for providing blades of various shapes.