Semiconductor Laser Alignment via Dual-Surface Markers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing semiconductor laser device structures in thermally assisted magnetic heads face challenges in achieving precise attachment accuracy, leading to errors in the relative positional relationship between the semiconductor laser device and the slider, which affects the precision of magnetic recording.
Innovation Solution
A semiconductor laser device structure with a light source supporting substrate and an optical waveguide supporting substrate, where a first alignment mark member is exposed on both the mounting and bonding surfaces, allowing for accurate alignment and attachment from different directions, ensuring precise optical coupling and reducing attachment errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the magnetic fine particles are made smaller to enhance recording density, then the recording density is improved, but the thermal stability in magnetization deteriorates
Solution Approach 1:
The patent applies thermal assistance by changing the temperature parameter of the magnetic recording medium during writing. Heat is applied to lower the coercivity of the medium, enabling writing with smaller particles while maintaining thermal stability through the KUV/kBT index management.
Solution Approach 2:
The patent utilizes thermal phase transition effects where heating temporarily changes the magnetic properties of the recording medium. The heat applied during writing creates a temporary phase state that allows lower coercivity, and the system relies on the cooling phase to restore stability.
2Reliability
If the coercivity is increased to improve thermal stability, then the thermal stability is improved, but the writing magnetic field intensity becomes insufficient
Solution Approach 1:
The patent employs periodic thermal action where heat is applied during the writing process to temporarily reduce coercivity, allowing the writing magnetic field to be effective. The thermal assistance is applied periodically during writing and then dissipates, creating a cyclic process of heating for writing and cooling for stability.
Solution Approach 2:
The patent dynamically changes the coercivity parameter by applying heat during writing operations. The thermal assistance temporarily modifies the magnetic properties, allowing writing with higher coercivity materials while maintaining the ability to write with sufficient magnetic field intensity.
3Ease of manufacture
If two securing operations are used to attach the semiconductor laser device to the slider, then the attachment process is completed, but the attachment accuracy deteriorates due to cumulative errors
Solution Approach 1:
The patent merges the mounting and bonding processes into a single integrated operation. The alignment mark members are designed to be exposed at both surfaces simultaneously, allowing both the semiconductor laser device mounting and the substrate bonding to be performed in one securing operation, eliminating cumulative alignment errors.
Solution Approach 2:
The alignment mark members serve as intermediary reference elements that are exposed at both the mounting surface and the bonding surface. These intermediaries provide a common reference framework that enables accurate alignment during the single securing operation, mediating between the two surfaces that would otherwise require separate alignment operations.
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 solution enables precise magnetic recording by ensuring accurate alignment and attachment of the semiconductor laser device to the optical waveguide, allowing for high-precision irradiation of the recording area with laser light, thereby enhancing the thermal stability and accuracy of magnetic recording.
Implementation Method 1
a semiconductor laser device (3); a light source supporting substrate (2A) mounting the semiconductor laser device (3); and an optical waveguide supporting substrate (1A), bonded to the light source supporting substrate (2A), having an optical waveguide (4) for introducing therein light from the semiconductor laser device (3)
Implementation Method 2
an optical waveguide (4) for introducing therein light from the semiconductor laser device (3)
Data Source
AI summary
A first alignment mark member is exposed at both of a mounting surface and a bonding surface, and thus can be seen from two directions by image sensors. While a semiconductor laser device is mounted on the mounting surface of a light source supporting substrate with reference to the first alignment mark member observed from the direction of the image sensor, the first alignment mark member can also be observed from the direction of the image sensor. With reference to the first alignment mark member observed from the latter direction, the light source supporting substrate is bonded to the slider substrate. Namely, though observed from different directions, the alignment mark member is used for a common reference for two securing operations, whereby attachment errors can be suppressed.