Method for manufacturing thin film magnetic heads
View Patent ↗According to one embodiment, a method for manufacturing a thin film magnetic head includes forming on a substrate magnetic head portions having a magnetoresistive element and resistance detection elements for measuring an amount of polishing; slicing the substrate to form at least one row bar; polishing the ABS of each row bar; forming rails on the polished ABS; and cutting each row bar to separate each magnetic head portion. The step of polishing the ABS includes measuring a resistance of each resistance detection element and a resistance of each magnetoresistive element; calculating an offset value between the resistance detection element and the magnetoresistive element; and calculating a final resistance of the resistance detection element by using the calculated offset value. When the resistance of the resistance detection element reaches the final resistance, polishing of the ABS of the row bar is terminated. Other methods are presented as well.
1. 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 bearing surface of the at least one row bar;
forming rails on the polished air bearing 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;
correcting a predetermined final resistance of the resistance detection element using the calculated offset value; and
terminating the polishing when the resistance of the resistance detection element reaches the corrected final resistance.
2. The method for manufacturing a thin film magnetic head according to claim 1 , wherein the calculating the offset value between the resistance of each of the plurality of detection elements and the resistance of each of the magnetoresistive elements is performed in a polishing stage where the resistance of each of the magnetoresistive elements can be measured.
3. The method for manufacturing a thin film magnetic head according to claim 2 , wherein the polishing stage where the resistance of each of the magnetoresistive elements can be measured refers to a polishing stage where the resistance of at least one of the magnetoresistive elements is low.
4. The method for manufacturing a thin film magnetic head according to claim 2 , wherein when the polishing stage is divided into initial, middle, and last substages, the polishing stage where the resistance of each of the magnetoresistive elements can be measured refers to the initial substage.
5. The method for manufacturing a thin film magnetic head according to claim 1 , wherein the polishing the air bearing surface of the at least one row bar includes:
approximating an element height of the magnetoresistive element to a predetermined element height value;
achieving the predetermined element height value of the magnetoresistive element; and
finishing a surface roughness of a surface to be polished to a predetermined value.
6. The method for manufacturing a thin film magnetic head according to claim 1 , wherein the magnetoresistive element is a tunneling magnetoresistive (TMR) element.
7. The method for manufacturing a thin film magnetic head according to claim 1 , wherein the magnetoresistive element is a CPP-GMR element.
8. 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.
9. The method for manufacturing a thin film magnetic head according to claim 8 , wherein the calculating the offset value between the resistance of each of the plurality of detection elements and the resistance of each of the magnetoresistive elements is performed in a polishing stage where the resistance of each of the magnetoresistive elements can be measured.
10. The method for manufacturing a thin film magnetic head according to claim 9 , wherein the polishing stage where the resistance of each of the magnetoresistive elements can be measured refers to a polishing stage where the resistance of at least one of the magnetoresistive elements is low.
11. The method for manufacturing a thin film magnetic head according to claim 9 , wherein when the polishing stage is divided into initial, middle, and last substages, the polishing stage where the resistance of each of the magnetoresistive elements can be measured refers to the initial substage.
12. The method for manufacturing a thin film magnetic head according to claim 8 , wherein the magnetoresistive element is a tunneling magnetoresistive (TMR) element.
13. The method for manufacturing a thin film magnetic head according to claim 8 , wherein the magnetoresistive element is a CPP-GMR element.
14. 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.
15. The method for manufacturing a thin film magnetic head according to claim 14 , wherein the measuring the resistance of the resistance detection element and the resistance of the magnetoresistive element is performed in a region where the difference between a resistance envelope and the resistance of the magnetoresistive element is small.
16. The method for manufacturing a thin film magnetic head according to claim 14 , wherein the magnetoresistive element is a tunneling magnetoresistive (TMR) element.
17. The method for manufacturing a thin film magnetic head according to claim 14 , wherein the magnetoresistive element is a CPP-GMR element.
18. The method for manufacturing a thin film magnetic head according to claim 14 , wherein the polishing the air bearing surface of the at least one row bar includes:
approximating an element height of the magnetoresistive element to a predetermined element height value;
achieving the predetermined element height value of the magnetoresistive element; and
finishing a surface roughness of a surface to be polished to a predetermined value.