Partitioned Air Slots in Electrical Lead Suspension
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Solution Overview
Problem
The reduction in size and weight of hard disk drive components leads to issues with electrical lead suspension (ELS) due to increased write-to-read cross-talk and signal loss, primarily caused by the continuous air slots under the read and write traces, which result in mechanical stiffness loss and interference between voltage-sensitive read and write traces.
Innovation Solution
The implementation of an electrical lead suspension with partitioned air slots, where the first plurality of signal traces is supported by a first set of air slots and the second plurality of traces is supported by a second set of air slots, either aligned or offset, to reduce cross-talk and signal loss, while maintaining structural rigidity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If continuous air slots are used under read and write traces to provide mechanical stiffness, then structural support is improved, but write-to-read cross-talk increases and signal quality deteriorates
Solution Approach 1:
The continuous air slots in the base-metal layer are divided into separate first and second sets of air slots. The first set supports the first plurality of signal traces while the second set supports the second plurality of traces. This segmentation prevents differential return currents from coupling between adjacent trace pairs, thereby reducing write-to-read cross-talk while maintaining mechanical stiffness through the distributed slot structure.
2Object-generated harmful factors
If air slots are placed directly under signal traces to reduce cross-talk, then signal isolation is improved, but mechanical stiffness is reduced
Solution Approach 1:
Air slots are strategically positioned only in specific regions where cross-talk mitigation is most needed, rather than uniformly across the entire base-metal layer. The first and second sets of air slots are located to support specific groups of signal traces, providing localized electrical isolation while preserving mechanical stiffness in other critical areas of the ELS structure.
3Volume of moving object
If ELS size is reduced to meet miniaturization requirements, then device compactness is improved, but write-to-read cross-talk increases due to reduced voltage margins
Solution Approach 1:
By segmenting the air slots into separate first and second sets that independently support different groups of signal traces, the patent reduces electromagnetic coupling between adjacent traces. This segmentation allows for reduced ELS size while maintaining adequate voltage margins and minimizing cross-talk, as the isolated slot structures prevent current interference even in compact geometries.
Data Source
AI summary
An electrical lead suspension (ELS) having partitioned air slots. The ELS includes a laminate. A first plurality of signal traces and a second plurality of traces are in a first formed layer of the laminate. The second plurality of traces may be signal traces or power traces. The laminate has a dielectric layer between the first formed layer and a second formed layer. A plurality of partitioned air slots is in the second formed layer of the laminate. The portion of the ELS having a plurality of partitioned air slots supporting the at least the first plurality of signal traces and the portion of the ELS having a second plurality of partitioned air slots or patterns supporting the second plurality of traces. The supporting of the first plurality of signal traces separate from the second plurality of traces reduces write-to-read cross talk and signal loss. Offsetting the first plurality of air slots from second plurality of air slots further reduces cross talk and signal loss and restores some of the structural rigidity lost due to in line (e.g., aligned) slots.