Magnetic Read-Write Head Lapping Mount Tool for Stripe Height and Wedge Angle Control
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Solution Overview
Problem
The challenge in hard-disk drive manufacturing is achieving precise control of magnetic core width and wedge angle in magnetic read-write head sliders, as existing methods struggle to accurately align and dimension these components due to inherent variations in thin-film manufacturing processes, affecting areal density and overall performance.
Innovation Solution
A lapping process using a lapping mount tool with actuation pins and flexible wedge angle flexures to set and maintain target stripe height and wedge angle for each head slider within a row-bar, applying pressure gradients through a compliant elastomer to ensure precise material removal and alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional lapping methods are used for head sliders, then manufacturing throughput is maintained, but precise control of magnetic core width and wedge angle is lost due to inherent variations in thin-film manufacturing processes
Solution Approach 1:
The lapping tool is segmented into multiple independently actuated pins, each capable of applying force to specific regions of the head slider. This segmentation allows different zones of the slider to be lapped with different pressures and angles, enabling precise control of magnetic core width and wedge angle while maintaining a manageable process structure
Solution Approach 2:
The lapping process employs dynamic force application through actuated pins that can independently adjust their position and applied force. This dynamic control allows real-time adjustment of lapping parameters during the process, compensating for variations in thin-film manufacturing and achieving precise dimensional control without requiring overly complex static tooling
2Manufacturing precision
If individual head sliders are lapped separately to achieve precise dimensions, then manufacturing precision improves, but productivity decreases due to the time-consuming nature of discrete processing
Solution Approach 1:
Multiple head sliders are merged onto a single lapping tool fixture, allowing simultaneous lapping of multiple sliders in one operation. The tool applies forces through multiple actuated pins that can independently control each slider's lapping parameters, achieving precise wedge angle control for all sliders on the fixture at the same time, thereby maintaining high productivity while improving precision
3Productivity
If higher lapping forces are applied to achieve target dimensions faster, then productivity improves, but manufacturing precision deteriorates due to increased variability in material removal
Solution Approach 1:
The lapping tool applies different force levels to different regions of the head slider through independently actuated pins. High forces can be applied where material removal is needed to meet dimensional targets, while lower forces are applied in regions requiring precise finishing. This local differentiation of force quality enables fast productivity without sacrificing dimensional control accuracy
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 approach allows for simultaneous and precise lapping of multiple head sliders to target dimensions, reducing undesirable offsets and improving areal density by achieving more accurate and consistent magnetic core width and wedge angle, thereby enhancing the performance and stability of hard-disk drives.
Implementation Method 1
a lapping process involving fixing the row (or 'row-bar') of sliders to a lapping mount tool fixture, actuating each of a plurality of stripe height actuation pins to set each head slider for lapping to a respective target stripe height, and simultaneously lapping each head slider according to each respective target stripe height
Implementation Method 2
applying pressure gradients through a compliant elastomer to ensure precise material removal and alignment
Data Source
AI summary
A lapping mount tool and a process for lapping a row of head sliders involves affixing the row to a lapping mount tool fixture, actuating each of multiple first actuation pins to set each head slider for lapping to a respective element target stripe height, and simultaneously lapping accordingly. The process may further involve actuating each of multiple second actuation pins to set each head slider for lapping to a respective target wedge angle, and simultaneously lapping accordingly. Each target wedge angle may be achieved by applying a respective angular force to a compliant elastomer adhered to the fixture and to the row, where such angular forces may be applied through at least two flexures interconnecting a rotatable first structural member and a second structural member of the lapping mount tool, wherein the flexures virtually intersect at and define an axis of rotation about which the angular forces are applied.