Write Head Resistor Network for Coil Current Split and Heat Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in achieving higher recording densities in magnetic recording devices is the degradation of write heads due to increased temperature from high currents, which limits writing field effectiveness and performance reliability, and the difficulty in accurately tuning current distribution.
Innovation Solution
A resistor network is coupled to the write head, comprising a first path for the primary coil and a second path for an assistive write element, with a preamplifier diverting current into these paths individually, allowing precise tuning of current distribution through auxiliary resistances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If higher currents are applied through the write head to increase writing field strength, then writing field effectiveness is improved, but temperature of the write head increases causing degradation and reliability issues
Solution Approach 1:
The patent divides the current path into two separate parallel paths: a first current path through the primary coil and a second current path through the assistive write element. This segmentation allows independent control of current through each element, enabling the system to achieve the required writing field strength while distributing the thermal load to prevent overheating and degradation of the write head.
Solution Approach 2:
The patent introduces a resistor network as an intermediary component between the preamplifier and the write head elements. This resistor network includes auxiliary resistances that can be tuned to precisely control current distribution between the primary coil and assistive write element, allowing optimization of both writing field strength and thermal management.
2Power
If higher currents are applied through the write head to increase writing field strength, then writing field effectiveness is improved, but temperature increase causes degradation at the media facing surface
Solution Approach 1:
By segmenting the current path into parallel paths through the primary coil and assistive write element, the patent distributes the current load and resulting heat generation across multiple elements. This reduces the temperature increase at the media facing surface while maintaining the required writing field strength for effective data recording.
Solution Approach 2:
The resistor network with tunable auxiliary resistances acts as an intermediary that precisely controls current distribution. By optimizing the resistance values, the system can limit current through elements that would otherwise overheat at the media facing surface, preventing degradation while still achieving sufficient writing field strength.
3Reliability
If currents are lowered to prevent overheating, then write head reliability is improved, but writing field strength is limited
Solution Approach 1:
The patent merges the functionality of the primary coil and assistive write element by connecting them in parallel through the resistor network. This combination allows both elements to contribute to the writing field simultaneously, achieving sufficient field strength while operating at lower individual current levels that prevent overheating and improve reliability.
Solution Approach 2:
The resistor network serves as an intermediary that enables precise current distribution between the primary coil and assistive write element. By tuning the auxiliary resistances, the system can optimize current split to maintain reliable operation at lower temperatures while still generating the required writing field strength through the combined effect of both elements.
4Device complexity
If a single preamplifier is used to drive both primary coil and assistive write element, then device complexity is reduced, but current distribution control becomes difficult
Solution Approach 1:
The patent introduces a resistor network with tunable auxiliary resistances as an intermediary between the single preamplifier and the two write head elements. This intermediary component enables precise control of current distribution between the primary coil and assistive write element, providing current tuning capability comparable to dual preamplifiers while maintaining the simplicity of a single preamplifier configuration.
Solution Approach 2:
The patent utilizes adjustable resistance values in the auxiliary resistors as a parameter control mechanism. By changing the resistance values in the resistor network, the system can precisely tune current distribution between the primary coil and assistive write element, enabling flexible operation with a single preamplifier while maintaining ease of current control.
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 enables precise control of current flow to the primary coil and assistive write element, enhancing magnetic field generation at the main pole tip without overheating, thus improving write head performance and reliability.
Implementation Method 1
a primary coil wrapped around the main pole
Implementation Method 2
an assistive write element
Data Source
AI summary
The present disclosure generally relate to a magnetic recording device comprising a write head and a resistor network coupled to the write head. The resistor network comprises a first path comprising a primary coil of the write head and a second path in parallel with the first current path, the second path comprising an assistive write element of the write head. A preamplifier coupled to the resistor network is configured to apply current to the first and second paths, where the current diverts into the first and second paths individually. The resistor network is coupled to the preamplifier by a single lead. The first path is configured to apply current to a primary coil of the write head. The second path is configured to apply current from a leading shield, via the assistive write element, to a trailing shield at a media facing surface.