Slider having independently controlled crown and cross curvature and method of controlling curvature

A method of adjusting cross and crown curvatures on a bearing surface of a disc head slider, which has a back surface opposite to the bearing surface with leading and trailing edges, first and second side edges, a longitudinal axis and a transverse axis, the method comprising:

• (a) obtaining a measure of the cross and crown curvatures;
• (b) selectively forming a first number of laser scan lines on the back surface, parallel to the transverse axis and within each of first and second rectangular cross curvature adjust bands as a function of the measure of the cross curvature;
• (c) defining the first and second rectangular cross curvature adjust bands along the leading and trailing edges, respectively, of the working surface and peripheral to a central area of the working surface;
• (d) selectively forming a second number of laser scan lines on the back surface, parallel to the longitudinal axis and within each of first and second rectangular crown curvature adjust bands as a function of the measure of the crown curvature;
• and
• (e) defining the first and second rectangular crown curvature adjust bands along the first and second side edges, respectively, of the working surface and peripheral to the central area of the working surface.

A method of controlling cross and crown curvatures of a substrate material, the method comprising:

• (a) obtaining a measure of the cross and crown curvatures;
• (b) selectively altering material stresses in a working surface of the substrate material within an independent cross curvature adjust area based on the measure of the cross curvature;
• (c) defining the independent cross curvature adjust area such that step (b) induces a change in the cross curvature while inducing substantially no change in the crown curvature;
• (d) selectively altering the material stresses in the working surface within an independent crown curvature adjust area, which is isolated from the independent cross curvature adjust area, based on the measure of the crown curvature;
• and
• (e) defining the independent crown curvature adjust area such that step (d) induces a change in the crown curvature while inducing substantially no change in the cross curvature.