A novel technique for the fabrication of herringbone grooves in a dynamic thrust bearing combining UV-LIGA with electro-discharge machining

This paper presents a novel technique for the fabrication of herringbone grooves in a dynamic thrust bearing by combining both UV-LIGA (the German words for lithography, electroplating, and molding) and electro-discharge machining (EDM) processes. A negative photoresist is used to fabricate an electroforming mold from which a microelectrode for the EDM process is electroformed. The last step is to employ the microelectrode in the EDM process to fabricate the herringbone grooves in the dynamic thrust bearing. Through the processes of UV-lithography, micro-electroforming and EDM, the accuracy of pattern transfer from the photo mask in UV-lithography to the herringbone grooves on the stainless disk is within 5%. A complex but planar microstructure can be fabricated by this combined technique quickly and accurately.