Write Head Coil Alignment with Yoke Tip
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Solution Overview
Problem
The challenge in magnetic write head design is to achieve higher data rate and areal density while maintaining signal quality, as increasing data rate leads to poorer media saturation, transition sharpness, and signal-to-noise ratio due to degraded write field magnitude and larger track inflation, which is exacerbated by the reliability issues of side track erasure fields.
Innovation Solution
The design incorporates a write head with a coil structure helically wound around the write pole and yoke, where the first turn of the coil is aligned with the yoke tip, enhancing switching speed and reducing power usage, thus improving high data rate performance by shortening magnetic field rise time and lowering erasure field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the data rate is increased to achieve higher data density, then the writing speed is improved, but the write field magnitude is degraded leading to poorer media saturation and transition sharpness
Solution Approach 1:
The patent changes the geometric parameters of the write head structure, specifically the alignment of the coil first turn with the yoke tip, to optimize the magnetic field generation efficiency and maintain write field magnitude at high data rates
Solution Approach 2:
The coil structure is pre-positioned with its first turn aligned to the yoke tip to prepare the magnetic field path in advance, enabling faster field establishment and improving switching speed for high data rate operation
2Productivity
If the data rate is increased, then the writing speed is improved, but the transition sharpness is degraded due to larger track inflation
Solution Approach 1:
The patent optimizes geometric parameters including the alignment distance between the coil first turn and yoke tip to control track inflation and maintain transition sharpness at high writing speeds
3Device complexity
If conventional coil positioning is used, then the structure is simple, but the switching speed is limited and power consumption is high
Solution Approach 1:
The coil first turn is pre-aligned with the yoke tip to establish the magnetic field path in advance, reducing the time required for field establishment and improving switching speed
Solution Approach 2:
The patent changes the positioning parameter of the coil relative to the yoke, aligning the first turn with the yoke tip to optimize magnetic coupling and reduce inductance, thereby improving switching speed and reducing power consumption
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
This configuration increases write speed, improves driving current-write field efficiency, and enhances reliability by reducing coil power consumption, leading to better HDR performance and track density without degrading the write field cross-track gradient.
Implementation Method 1
A coil is included to generate magnetic signals through the main and return poles in response to a current conducted through the coil
Implementation Method 2
The main pole tip focuses the magnetic flux density such that the magnetic fields interact with the magnetic medium to orient its magnetic moments in an up or down direction
Data Source
AI summary
A write head having a main pole having a pole tip proximate an air bearing surface (ABS), the main pole having a leading side and a trailing side. The write head also includes a yoke having a yoke tip recessed from the ABS, and a helical coil wrapped around the main pole and the yoke. The helical coil has a first turn with its front edge at least substantially aligned with the yoke tip.