Method of burnishing a burnishable rear pad slider in a disk drive

Abstract

A method of burnishing a rear pad of a slider within a disk drive. The rear pad is formed of a burnishable material and maintains elements for reading and writing. The disk drive further includes a spindle motor rotatably driving a disk and an actuator assembly positioning the slider over a surface of the disk. With this in mind, the method includes rotating the disk. The slider is moved in a radial fashion relative to the disk surface in a reciprocal fashion, causing the rear pad to rock. As the rear pad rocks, contact between the rear pad and the disk surface burnishes the rear pad. As a result, a positive camber is imparted in the rear pad relative to the MR element. The above-described method can be practiced following initial manufacture of the disk drive, or at various times over the life of the disk drive. Regardless, the method is practiced in-situ and is therefore very fast, cheap, and adapts quickly to the particular disk in which the slider is flying.

What is claimed is:  
     
         1 . A method of burnishing a rear pad of a slider within a disk drive, the rear pad being formed of a burnishable material and maintaining an element for reading and/or writing, the disk drive further including a spindle motor rotatably driving a disk and an actuator assembly positioning the slider over a surface of the disk, the method comprising: 
 rotating the disk;    radially moving the slider relative to the disk surface in a reciprocal fashion, causing the rear pad to rock; and    burnishing the rear pad via contact between the rear pad and the disk surface;    wherein the rear pad is burnished as the rear pad rocks, imparting a positive camber in the rear pad relative to the reading and/or writing element.    
     
     
         2 . The method of  claim 1 , wherein the rear pad defines a height, and further wherein burnishing the rear pad includes reducing the height.  
     
     
         3 . The method of  claim 1 , wherein the rear pad defines a leading surface, a trailing surface, opposing side surfaces, and a bottom surface opposite a support body of the slider, and further wherein radially moving the rear pad includes alternately contacting the opposing side surfaces against the disk surface.  
     
     
         4 . The method of  claim 3 , wherein imparting a positive camber includes forming at least a portion of each of the opposing side surfaces to be non-perpendicular relative to the bottom surface.  
     
     
         5 . The method of  claim 4 , wherein imparting a positive camber includes blending each of the opposing side surfaces relative to the bottom surface.  
     
     
         6 . The method of  claim 4 , wherein a width of the rear pad is defined by a distance between the opposing sides, and further wherein imparting a positive camber includes establishing a minimum width of the rear pad at the bottom surface.  
     
     
         7 . The method of  claim 3 , wherein following burnishing the opposing side surfaces are non-symmetrical.  
     
     
         8 . The method of  claim 1 , wherein radially moving the slider relative to the disk surface includes radially accelerating the slider relative to the disk surface.  
     
     
         9 . The method of  claim 1 , further comprising: 
 moving the slider tangentially relative to the disk surface, causing the rear pad to rock longitudinally.    
     
     
         10 . The method of  claim 9 , further comprising: 
 correlating radial slider movement and tangential slider movement to optimize a shape of the rear pad following burnishing.    
     
     
         11 . The method of  claim 1 , wherein radially moving the slider includes operating the actuator assembly in a first operational state when a height of the rear pad is relatively large and in a second operational state when the height is reduced, and further wherein the first operational state differs from the second operational state by at least one of radially slider velocity, radial slider acceleration, radial slider travel distance, and tangential slider velocity.  
     
     
         12 . The method of  claim 11 , wherein the first operational state is characterized by an initial stage of burnishing and the second operational state is characterized by a final stage of burnishing, and further wherein the slider is moved a shorter radial distance in the second operational state as compared to the first operational state.  
     
     
         13 . The method of  claim 12 , further comprising: 
 establishing parameters of the first operational state and the second operational state prior to radially moving the slider.    
     
     
         14 . The method of  claim 1 , wherein the rear pad is burnished in-file.  
     
     
         15 . A method of shaping a rear pad of a slider within a disk drive, the rear pad being formed of burnishable material and maintaining an element for reading and/or writing, the disk drive further including a spindle motor rotatably driving a disk and an actuator assembly positioning the slider over a surface of the disk, wherein during normal operation of the disk drive, rotation of the disk at a normal operational speed generates an air bearing between the slider and the disk surface, the air bearing dictating a fly height, the method comprising: 
 initially forming the rear pad to an increased height such that at the normal operational speed, the rear pad is loaded against the disk surface and the fly height is zero;    rotating the disk such that the rear pad rubs against the disk surface; and    radially moving the slider relative to the disk surface in a reciprocal fashion during a first burnishing mode, causing the rear pad to rock;    wherein during the first burnishing mode, contact between the rear pad and the disk surface causes the height of the rear pad to decrease and imparts a positive camber into the rear pad.    
     
     
         16 . The method of  claim 15 , wherein a radial velocity and a radial travel distance of the slider during the first burnishing mode is predetermined.  
     
     
         17 . The method of  claim 15 , wherein the first burnishing mode includes an initial burnishing stage and a secondary burnishing stage, the method further comprising: 
 establishing an initial wear level value for the rear pad; and    transitioning from the initial burnishing stage to the secondary burnishing stage once the rear pad has been burnished to the initial wear level value;    wherein a radial velocity of the slider and the secondary burnishing stage is less than a radial velocity of the slider in the initial burnishing stage.    
     
     
         18 . The method of  claim 17 , wherein the first burnishing mode further includes a final burnishing stage, the method further comprising: 
 establishing a final wear level value for the rear pad; and    transitioning from the secondary burnishing stage to the final burnishing stage once the rear pad has been burnished to the final wear level value;    wherein a radial travel distance of the slider in the final burnishing stage is less than a radial travel distance of the slider in the secondary burnishing stage.    
     
     
         19 . The method of  claim 15 , further comprising the steps of: 
 a) operating the disk drive at a normal operational speed following completion of the first burnishing mode, the slider flying above the disk surface at a fly height;    b) determining that a fly height correction is necessary;    c) operating the disk drive in a second burnishing mode, the second burnishing mode including: 
 temporarily decreasing a spacing between the rear pad and the disk surface;  
 radially moving the slider relative to the disk surface in a reciprocal fashion, causing the rear pads to rock;  
 wherein sides of the rear pad are burnished by the disk surface during the second burnishing mode; and  
   d) operating the disk drive under normal operational conditions, wherein the fly height has been altered by the burnishing in the second burnishing mode.    
     
     
         20 . The method of  claim 15 , wherein a radial acceleration of the slider in the first burnishing mode is greater than a radial acceleration of the slider under normal operational conditions of the disk drive.