Systems and methods for correcting read/write overlay errors in the manufacture of magnetic transducers for storage drives
View Patent ↗Systems and methods for correcting read/write overlay errors in the manufacture of magnetic transducers for storage drives are provided. One such system includes a twisting tool configured to receive and secure a row bar having an elongated rectangular block shape and including a plurality of magnetic transducers spaced apart along a length of the row bar, and where the twisting tool is configured to twist the row bar at a plurality of areas along the length of the row bar.
1. A system for correcting for overlay errors in row bars, the system comprising:
a twisting tool comprising a force applicator, a first planar twisting segment, and a second planar twisting segment, wherein the first planar twisting segment and the second planar twisting segment are configured to receive and secure a row bar having an elongated rectangular block shape and comprising a plurality of magnetic transducers spaced apart along a length of the row bar,
wherein the first planar twisting segment is proximal and the second planar twisting segment is distal relative to an end of the row bar;
wherein the twisting tool is configured to twist the row bar about a longitudinal axis of the row bar at a plurality of areas along the length of the row bar, wherein the force applicator is configured to impart a rotational force on the first planar twisting segment and thereby cause the first planar twisting segment to impart a twisting force on the row bar sufficient to rotate a portion of the row bar about the longitudinal axis, and
wherein the second planar twisting segment is configured to oppose the twisting force.
2. The system of claim 1 , further comprising:
a lapping tool configured to lap a surface of the row bar,
wherein the row bar comprises an overlay error indicative of a variation from a parallel orientation of a reader layer and a writer layer of at least one of the plurality of magnetic transducers, and
wherein the lapping tool and the twisting tool are configured to substantially correct the overlay error in the row bar.
3. The system of claim 2 , further comprising:
an electronic lap guide (ELG) fabricated within the row bar, the ELG configured to provide information indicative of a measurement of a dimension of the row bar;
a controller coupled to the ELG, the lapping tool, and the twisting tool, the controller configured to:
determine the overlay error at a preselected position along the row bar based on the ELG measurement information;
control a degree of twisting performed by the twisting tool at the preselected position to substantially correct the overlay error at the preselected position; and
control a degree of lapping performed by the lapping tool to substantially correct the overlay error at the preselected position.
4. The system of claim 1 , wherein the plurality of areas comprises a preselected number of areas selected from the group consisting of 3 areas, 5 areas, and 19 areas.
5. The system of claim 1 , wherein the twisting tool comprises a plurality of planar twisting segments each configured to impart a twisting force on the row bar.
6. The system of claim 1 , wherein the twisting tool comprises a plurality of planar twisting segments in each of the plurality of areas, wherein each of the plurality of planar twisting segments is configured to impart a twisting force on the row bar.
7. The system of claim 6 , wherein the force applicator is configured to impart a rotational force on each of the plurality of planar twisting segments in one of the plurality of areas.
8. The system of claim 7 , wherein the force applicator comprises an actuator apparatus selected from the group consisting a set screw apparatus, a servo motor apparatus, a voice coil apparatus, a pneumatic apparatus, hydraulic apparatus, a piezoelectric apparatus, and combinations thereof.