Segmented Trailing Shield for High Data Rate Perpendicular Recording

The trailing shield structure is segmented into three distinct layers: a first trailing shield layer with high magnetic saturation (16-24 kG) for efficiency, a low magnetic saturation layer (8-16 kG) positioned at the air bearing surface to contain fields, and a second trailing shield layer (16-24 kG) providing structural support. This segmentation allows each layer to perform its specific function, resolving the contradiction between efficiency and field leakage.

Different magnetic saturation properties are assigned to different regions of the trailing shield structure. The first layer uses high saturation material for overall efficiency, while the second layer uses low saturation material specifically at the air bearing surface where field containment is critical for preventing adjacent track erasure. This local differentiation of material properties resolves the contradiction.

The trailing shield is divided into multiple layers with different width configurations. The first and second trailing shield layers can have reduced widths compared to full width coverage, while the low saturation layer provides the necessary magnetic containment. This segmentation enables faster write response while maintaining manufacturability through standardized layering processes.

The solution moves from a single-dimensional full width layer to a multi-layered structure where width varies through the thickness dimension. This allows optimization of write response speed by reducing the effective width of high saturation layers while maintaining adequate field containment through the stacked configuration.