STOCK REMOVAL MONITOR DEVICE OF THIN-FILM MAGNETIC HEAD

PURPOSE: To easily detect the stock removal of the medium-facing surface of a thin-film magnetic head with high accuracy by increasing the change rate of the resistance value with the prescribed stock removal with monitors which detect the stock removal as a change in the resistance value. CONSTITUTION: Series circuits of the first thin-film resistors 1a (18a-1 to 1a-4) including the front ends 1a-3, 1a-4 which are disconnected when polished down to the prescribed distance S from a polishing surface P and the second and third thin-film resistors 2a, 3a which are two layers of higher resistance and are not affected by polishing are formed on a substrate (not shown in Fig.) to be formed with the thin-film head. The series circuits and the resistors 1a are connected in parallel by contacts 4 to 6. The resistance value between the legs 1a-1 and 1a-2 is increased largely stepwise by the high-resistance series circuits of the two-layered structure when the front ends are disconnected by polishing to the prescribed quantity, by which the polishing made to the specified quantity is detected. The plural monitors successively deepened in the position S to be disconnected are installed in parallel, by which the resistance value with the stock removal is changed stepwise.