ALEXANDRIA, Va., June 9 -- United States Patent no. 12,285,835, issued on April 29, was assigned to DISCO Corp. (Tokyo).
"Hard wafer grinding method" was invented by Daisuke Akita (Tokyo), Makoto Saito (Tokyo) and Takashi Yamaguchi (Tokyo).
According to the abstract* released by the U.S. Patent & Trademark Office: "A hard wafer grinding method includes a rough grinding step of forming a section along the diameter of a hard wafer into a centrally recessed shape by roughly grinding the hard wafer such that a central part of the hard wafer is thinner than a peripheral part of the hard wafer, a finish grinding step of expanding a ground area of the hard wafer from the peripheral part in an annular shape to the central part while dressing lowe...