New Type Side Shield Head for Ultrahigh Density Recording

In magnetic writing heads, one of the most important factors for ultrahigh recording density is the skirt width of write field along cross track direction without degradation of head field and field gradient. The side shield design is known to be the most powerful design for reducing the skirt width. However, the side shields make write field and field gradient weak. By FEA simulation, we propose the shell type side shield to reduce skirt width without field degradation. As a result, we could reduce track width from 255 to 190 nm with no head field degradation, at 7060 Oe. We used design of experiment (DOE) tools, especially response surface method (RSM), to optimize the design. In the simulation, we took into account all soft magnetic materials (write head and soft magnetic underlayer). To verify the results, we checked the correlation between the head field of each shape and ATE.