Magnetic Recording Transducer Side Shields Fabrication
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Solution Overview
Problem
Conventional magnetic recording transducer fabrication methods face challenges in controlling the geometry of side shields and main poles due to difficulties in reverse angle trench formation and interference from coils, leading to performance issues.
Innovation Solution
A method involving the formation of separate trenches for side shields and main poles using nonmagnetic layers, allowing for independent control of their geometry and decoupling from coils, with side shields extending from the air-bearing surface to the coil front location.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single trench is formed for both side shields and main pole using reverse angle etching, then fabrication can be completed in fewer steps, but the geometry of side shields and main pole cannot be separately controlled and the etching process is difficult to control
Solution Approach 1:
The patent divides the single trench formation process into two separate trenches: a first trench for the side shield and a second trench for the main pole. This segmentation allows independent geometry control of each component while simplifying the overall fabrication process by eliminating the need for complex reverse angle etching. The side shield and main pole are formed in distinct etching steps, enabling precise dimensional control for each structure.
Solution Approach 2:
The patent introduces a nonmagnetic layer as an intermediary between the side shield and main pole. This nonmagnetic layer is deposited to fill the first trench and provide a platform for forming the second trench. The intermediary layer enables separate geometry control of the side shield and main pole while maintaining their spatial relationship, resolving the contradiction between process simplicity and geometric precision.
2Reliability
If side shields surround the main pole completely (wrap-around shields), then magnetic performance is improved, but the side shields are driven by coil current which degrades performance
Solution Approach 1:
The patent extracts the side shield from the region influenced by coil current by positioning it laterally adjacent to the main pole rather than surrounding it. The side shield is formed in a first trench that is laterally separated from the second trench containing the main pole. This spatial extraction removes the side shield from the harmful electromagnetic field generated by the coil, eliminating the performance degradation caused by coil current while preserving the magnetic benefits of having side shields.
3Ease of manufacture
If reverse angle trench etching is used to form side shields, then the side shields can be formed without trimming the main pole, but the etching process is difficult to control
Solution Approach 1:
Instead of forming the side shield trench with a reverse angle (wider at top than bottom) as in conventional methods, the patent inverts the approach by forming the side shield and main pole in separate trenches with standard etching angles. The geometry control is achieved through the sequential deposition of nonmagnetic layers and selective etching, rather than relying on reverse angle etching geometry. This inversion eliminates the difficult-to-control reverse angle etching process while still allowing side shields to be formed without main pole trimming.
Data Source
AI summary
A magnetic recording transducer is provided. The magnetic recording transducer comprises a main pole including a nose portion, the nose portion terminating at an air-bearing surface (ABS). The magnetic recording transducer further comprises at least one coil having a coil front distal from the ABS, and at least one side shield. The at least one side shield extends from at the ABS to not further than the coil front.