POLISHING ATTACHMENT FOR DISC SUBSTRATE

PURPOSE:To finish a disc substrate so efficiently and accurately, by attaching a pressure head, pressing an abrasive tape to the disc substrate, to a support arm consisting of a parallel-plate spring, forming a pressure member, and constituting this so as to be supported by a reciprocating member. CONSTITUTION:A pressure head 16 being attached to a support arm 18 is pressed to a disc substrate 10, but owing to action of a parallel-plate spring 18a, this pressure head 16 is forcibly pressed in a direction orthogonal with a surface of the disc substrate 10. Therefore, uniform pressurized force is added to the whole contact surface with an abrasive tape 13 of the pressure head 16, whereby its partial contact is prevented from occurring, and surface polishing for the disc substrate 10 by the abrasive tape 13 is efficiently performable, and that grinding irregularities are in no case produced there. In addition, during rotation of the disc substrate 10, even if it is deflected in a plate thickness direction, the pressure head 16 is supported by the parallel-plate spring 18a so that this head 16 prevents it from resonating with this vibration, thus the grinding irregularities are prevented from occurring.