Thermally-Assisted Magnetic Recording Head Light Source Alignment
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Solution Overview
Problem
Current methods for aligning light sources with sliders in thermally-assisted magnetic recording heads face challenges in achieving high accuracy and efficiency, particularly in the composite slider structure, where active alignment is time-consuming and passive alignment lacks precision due to reliance on markers and positional errors.
Innovation Solution
A method involving image recognition to align the light source unit with the slider by irradiating the waveguide and light source with specific lights to form images of the light-receiving and light-emitting ends, allowing for precise alignment without markers or additional recognition means, enabling high accuracy and reduced processing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If active alignment is used to align the light source unit with the slider, then alignment accuracy is improved, but manufacturing time and processing complexity increase significantly
Solution Approach 1:
The patent replaces the mechanical active alignment process with an optical imaging-based alignment method. By using a light source to illuminate the waveguide structure and capturing images with a detector, the system substitutes mechanical adjustment and probing with optical field interaction, enabling automated image recognition and processing to determine alignment positions without time-consuming mechanical iterations
Solution Approach 2:
The patent creates an optical copy or image of the waveguide structure by illuminating it with light and detecting the transmitted or reflected light patterns. This optical copy contains positional information about the light-receiving end surface, which can be processed to determine alignment without physically manipulating the components, thereby reducing alignment time while maintaining precision
2Productivity
If passive alignment with markers is used to align the light source unit with the slider, then alignment speed is improved, but alignment precision deteriorates due to marker positional errors
Solution Approach 1:
The patent extracts the alignment information directly from the waveguide structure itself by illuminating the light-receiving end surface and detecting the optical response. This eliminates the need for separate alignment markers, as the waveguide's own optical properties provide the positioning data, thereby achieving both speed and precision without marker-related errors
Solution Approach 2:
The patent introduces light as an intermediary medium to transfer positional information from the waveguide structure to the detector. The light acts as a carrier that conveys spatial data about the light-receiving end surface without requiring physical contact or visible markers, enabling precise and rapid alignment through optical field interaction
3Device complexity
If conventional alignment methods are used in composite slider structure, then manufacturing simplicity is maintained, but alignment precision and efficiency deteriorate
Solution Approach 1:
The patent makes the waveguide structure serve multiple functions: it not only guides light for thermal assistance but also acts as its own alignment reference by having its light-receiving end surface illuminated and imaged. This multi-functionality eliminates the need for separate alignment features, maintaining process simplicity while achieving high precision through the waveguide's inherent optical properties
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 achieves high alignment accuracy within ±1 μm in a shorter time compared to conventional methods, reducing manufacturing load and eliminating the need for power supply probes, thereby enhancing the efficiency of thermally-assisted magnetic recording head production.
Implementation Method 1
a waveguide (31) provided in an element-integration surface (2202) adjacent to an opposed-to-medium surface (2210) of a slider substrate (220), the waveguide having a light-receiving end surface (430) extending to a back surface (2211) of the slider on the side opposite to the opposed-to-medium surface (2210)
Implementation Method 2
a light source unit (23) provided with a light source (40) on the back surface (2211) of the slider (220), the light source having a light-emitting end surface (4000) on the joining surface (2300) side
Data Source
AI summary
Provided is a method for manufacturing a thermally-assisted magnetic recording head with “composite slider structure”. In the method, the waveguide is irradiated with a first light from opposed-to-medium surface side, and the passing first light is detected on back surface side to obtain an image of the light-receiving end surface, and a light-receiving center position is determined from the image. Further, the light source is irradiated with a second light from opposite side to joining surface, and the passing second light is detected on the joining surface side to obtain an image of the light-emitting end surface, and a light-emitting center position is determined from the image. Then, the slider and the light source unit are moved based on the determined positions of the light-receiving and light-emitting centers, aligned and bonded. As a result, alignment can be performed with high accuracy in a short process time under simplified process.