Slider Contact Pad Isolation for Lapping Measurement Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the manufacturing of hard disk drives, existing technologies face challenges in accurately locating and isolating electronic lapping guides (ELGs) on slider bodies during the lapping process, leading to potential errors due to non-uniform air bearing surfaces and interference from ground connections, which can affect the precision of slider element dimensions.
Innovation Solution
The implementation of co-located electronic lapping guides along the cross-track axis, electrically isolated from ground, allows for improved accuracy in determining height differences and reducing interpolation errors, with additional contact pads dedicated for lapping operations to prevent damage and enhance measurement precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electronic lapping guides are located on slider bodies during lapping, then measurement capability is provided, but ground connections cause electrical interference that reduces measurement precision
Solution Approach 1:
The patent extracts the harmful ground connection from the electrical circuit by implementing electrical isolation. The lapping guide circuit is separated from ground potential through insulation techniques, removing the source of electrical interference while maintaining the measurement function. This allows precise electrical measurements during lapping without ground loop interference.
Solution Approach 2:
The patent introduces an intermediary isolation mechanism between the lapping guide and ground. Insulating materials and isolated circuit pathways act as mediators that block electrical interference from ground connections while still allowing the lapping guide to function. This intermediary layer prevents harmful electrical signals from affecting measurements.
2Measurement precision
If additional contact pads are added for lapping operations, then measurement capability is enhanced, but device complexity increases
Solution Approach 1:
The patent implements multi-functionality by designing contact pads that serve dual purposes: they are used both for operational electrical connections during hard drive function and for lapping guide connections during manufacturing. This universal design allows the same structural elements to fulfill multiple functions, adding measurement capability without proportionally increasing device complexity.
Solution Approach 2:
The patent merges the operational contact pad structure with the lapping guide contact requirements. By combining these functions into a unified contact pad design, the patent avoids duplicating structures and minimizes the increase in device complexity while still providing enhanced measurement capability during lapping operations.
3Manufacturing precision
If slider bodies are lapped to achieve uniform air bearing surfaces, then surface uniformity is improved, but interpolation errors occur due to non-uniform surfaces during the lapping process
Solution Approach 1:
The patent applies preliminary action by positioning multiple lapping guides at different locations across the air bearing surface before the lapping process begins. These pre-positioned guides provide reference points that enable accurate height measurements and interpolation calculations throughout the lapping process, compensating for surface non-uniformity as it develops.
Solution Approach 2:
The patent implements feedback through real-time height measurements taken by multiple lapping guides during the lapping process. These measurements provide continuous feedback about surface uniformity, allowing for interpolation error calculation and correction. The system uses this feedback to maintain measurement precision even as the surface evolves during lapping.
Data Source
AI summary
The present disclosure involves a row bar that includes a plurality of slider bodies to be lapped. At least one slider body includes at least a first row of a plurality of electrical contact pads; and a second row of a plurality of electrical contact pads. The first row of electrical contact pads extends along the cross-track direction at a first position in a lapping direction. The second row of electrical contact pads extends along the cross-track direction at a second position in the lapping direction. The second row of electrical contact pads are electrically isolated from ground. The present disclosure also involves related methods of locating electrical contact pads on a slider body.