Stacked Coil Architecture for Magnetic Write Head Yoke Length Reduction
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Solution Overview
Problem
Conventional write heads face challenges in reducing yoke length due to difficulties in insulating material fill processes, which hinders the development of high data rate performance in perpendicular magnetic recording systems.
Innovation Solution
A stacked coil architecture for magnetic write heads is introduced, utilizing thin film thicknesses and atomic layer deposition for better process control, allowing for a shorter yoke length and more efficient current concentration near the main pole tip, enhancing high data rate writing capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional helical coil structures are used, then the coil can be manufactured with traditional filling processes, but the yoke length cannot be reduced due to insulator fill process difficulties
Solution Approach 1:
The patent transitions from a conventional helical coil winding approach to a stacked coil architecture where coil turns are arranged in multiple layers stacked vertically. This dimensional reorganization allows the coil structure to achieve shorter yoke length while maintaining manufacturability through thin film deposition processes rather than traditional gap-filling methods.
Solution Approach 2:
The patent changes the manufacturing parameters by using thin film deposition thicknesses and atomic layer deposition techniques instead of conventional insulator fill processes. This parameter change enables better process control and allows for the realization of shorter yoke lengths that were previously unachievable with traditional manufacturing methods.
2Productivity
If yoke length is reduced for high data rate performance, then writing speed increases, but manufacturing complexity increases due to aspect ratio challenges
Solution Approach 1:
By stacking coil turns in multiple vertical layers, the patent redistributes the coil structure in the vertical dimension rather than relying on horizontal winding. This dimensional change reduces the horizontal aspect ratio challenges and enables shorter yoke lengths that improve data writing speed while keeping manufacturing complexity manageable through thin film processes.
Solution Approach 2:
The patent replaces the mechanical helical winding and filling process with a thin film deposition-based manufacturing approach. This substitution uses atomic layer deposition and thin film thickness control instead of mechanical gap-filling, thereby reducing manufacturing complexity associated with high aspect ratio structures while enabling shorter yoke lengths for faster data writing.
3Productivity
If current is concentrated near the main pole tip, then high data rate performance is achieved, but conventional coil structures cannot deliver sufficient current density
Solution Approach 1:
The stacked coil architecture enables different regions of the coil structure to have optimized local properties. By arranging coil turns in multiple stacked layers, the design concentrates current density specifically near the main pole tip region while maintaining appropriate current distribution in other areas. This local optimization of current density achieves high data rate performance that conventional helical coils cannot deliver.
Solution Approach 2:
The patent uses the vertical stacking dimension to control current density distribution. By positioning multiple coil layers at different vertical heights, the design concentrates current pathways near the main pole tip, achieving the required current density distribution for high data rate performance. This dimensional approach provides precise control over where current is concentrated, achieving manufacturing precision for current density distribution.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The stacked coil architecture enables faster data bit writing and higher data rate performance by concentrating more current density closer to the main pole tip, overcoming the limitations of conventional coil structures.
Implementation Method 1
Write heads make use of the electricity flowing through a coil 202 in the write head 200, which produces a magnetic field
Implementation Method 2
A strong, highly concentrated magnetic field emits from the write pole in a direction perpendicular to the magnetic disk surface, magnetizing the magnetically hard top layer
Data Source
AI summary
Approaches for a magnetic write head having a stacked coil architecture. Embodiments utilize the better process control capability available with thin films' thicknesses, compared to the control capability of vertical gap-filling processes, which provides for better scalability to shorter yoke length magnetic write heads, which are faster at writing data bits than are magnetic write heads having a longer yoke length.