Patent ID: 6217423
Filing Date: 2001-04-17
Classification: B24B,Y10S

Abstract:
An apparatus for the mirror surface grinding of a magnetic disc substrate, comprising:a first upper positive electrode metal bond grinding wheel having a horizontal working surface and being rotatable with a first central vertical shaft;a second lower positive electrode metal bond grinding wheel having a horizontal working surface opposed to the working surface of the first grinding wheel, and being rotatable with a second central vertical shaft;a workpiece holder and rotator adapted to hold a magnetic disc substrate to rotate around a vertical axis between first portions of the working surfaces of the upper and lower grinding wheels and shake the magnetic disc substrate in a horizontal direction, said holder and rotator comprising a carrier constructed to carry the magnetic disc substrate, and arranged to be optionally ground by said upper and lower grinding wheels;a negative electrode opposed to second portions of the working surfaces of the metal bond grinding wheels and not in contact therewith, wherein the negative electrode is arranged to allow simultaneous grinding of a work piece and electrolytic dressing of the grinding wheels;a voltage supply arranged to apply a pulsed voltage between the negative electrode and the positive electrode metal bond grinding wheels;a grinding fluid supply arranged to supply grinding fluid between the negative electrode and the grinding wheel to permit electrolytic dressing of the grinding wheel, when the pulsed voltage is applied between the grinding wheel and the negative electrode.