US Patent 7303599 Manufacture of lapping board

A method for manufacturing a lapping board having abrasive grains fixed on its surface, which is performed by the steps of: preparing a rotatable metal board having a surface of soft metal, an abrasive slurry-supplying tool arranged over the surface of the metal board, an abrasive-pressing tool which is placed on the metal board and has a hard surface, and a ultrasonic oscillation-generating tool attached to either or both of the abrasive-pressing tool and the metal board; rotating the metal board while supplying an abrasive slurry onto the surface of the metal board and while supplying electric power to the ultrasonic oscillation-generating tool to generate and apply ultrasonic oscillation to either or both of the abrasive-pressing tool and the metal board, whereby introducing the supplied abrasive slurry between the metal board and the abrasive-pressing tool and partly embedding some abrasive grains onto the metal board; and removing unfixed abrasive grains from the metal board.