New Laser Curvature Adjust Technique (LCAT) For Precise Adjustment of the Crown and Camber of Magnetic Head Sliders

One difficulty hindering the continuing reduction in the slider flight heights (and hence the increase in storage density) is that the control of slider curvature parameters (particularly crown) by classical lapping method has become inadequate. In addition, low-flying sliders should preferably have positive camber for improved tribological performances, and conventional slider fabrication methods do not always produce positive camber. We have developed and introduced into manufacturing a new process called Laser Curvature Adjust Technique (LCAT). This process utilizes suitable laser scribing of microscopic patterns on the back side of the slider to produce corresponding curvature changes of the front (ABS) side of the slider. The laser scribing is done using a compact diode-pumped laser, and is performed in installments as controlled by an in-situ optical monitor of curvature integrated inside the LCAT tool. This closed-loop microscopic laser-shaping process can produce desired slider curvatrues, particularly, crown and camber, to accuracies of a few nanometers.