Method for manufacturing thin film magnetic heads

A method for manufacturing a thin film magnetic head, the method comprising:

• forming, on a substrate, a plurality of magnetic head portions, each magnetic head portion having a magnetoresistive element and at least one resistance detection element for measuring an amount of polishing;
• slicing the substrate to form at least one row bar;
• polishing an air hearing surface of the at least one row bar;
• forming rails on the polished air hearing surface;
• and
• cutting the at least one row bar to separate each of the plurality of magnetic head portions,
• wherein the polishing the air bearing surface of the at least one row bar further includes:
• measuring a resistance of each of the plurality of resistance detection elements and a resistance of each magnetoresistive element;
• calculating an offset value between the resistance of each of the plurality of detection elements and the resistance of each of the magnetoresistive elements from the measured resistance of each of the plurality of resistance detection elements and the measured resistance of each magnetoresistive element;
• and
• calculating a final resistance of the resistance detection element by using the calculated offset value,
• wherein when the resistance of the resistance detection element reaches the final resistance, polishing of the air hearing surface of the at least one row bar is terminated,
• wherein the measuring the resistance of each of the plurality of resistance detection elements and the resistance of each magnetoresistive element is performed in a region where the difference between a resistance envelope and the resistance of each of the magnetoresistive elements is small.

A method for manufacturing a thin film magnetic head, the method comprising:

• forming, on a substrate, a plurality of magnetic head portions, each magnetic head portion having a magnetoresistive element and at least one resistance detection element for measuring an amount of polishing;
• slicing the substrate to form at least one row bar;
• and
• polishing an air bearing surface of the at least one row bar, wherein the polishing the air bearing surface of the at least one row bar further includes:
• measuring a resistance of one of the resistance detection elements during a final stage of the polishing;
• measuring a resistance of the magnetoresistive element of the head portion having the resistance detection element being measured during the final stage of the polishing;
• calculating an offset value between the measured resistances;
• and
• calculating a final resistance value of the resistance detection element using the calculated offset value;
• monitoring the resistance of the resistance detection element for determining when the resistance thereof reaches the calculated final resistance value;
• and
• terminating the polishing when the resistance of the resistance detection element reaches the final resistance value.