Laser Diode Submount Trenches for EAMR Alignment
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Solution Overview
Problem
Conventional energy-assisted magnetic recording (EAMR) disk drives face challenges in properly aligning and coupling laser diodes with sliders due to rough and chipped sidewalls of submounts, leading to misalignment and performance issues.
Innovation Solution
A method involving the creation of silicon islands with trenches and controlled facets, where metallization and solder pads are applied for improved alignment and thermal management, using silicon reactive ion etching to form precise trenches and insulating layers for accurate laser diode submounts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional dicing method is used to create submounts, then manufacturing simplicity is maintained, but sidewalls become rough and chipped causing misalignment
Solution Approach 1:
The patent changes the manufacturing parameter from conventional dicing to reactive ion etching, which fundamentally alters the sidewall formation mechanism. This process parameter change produces smooth, vertical sidewalls with precise dimensions, directly resolving the sidewall quality issue while maintaining manufacturing feasibility through standardized semiconductor processing techniques.
Solution Approach 2:
The patent replaces the mechanical dicing process with a chemical etching process (reactive ion etching). This substitution eliminates the mechanical contact that causes chipping and roughness, producing clean, precise sidewalls. The chemical process provides better control over sidewall morphology while remaining compatible with existing semiconductor manufacturing infrastructure.
2Manufacturing precision
If laser diode is affixed to conventional submount, then assembly is simple, but alignment is challenging due to rough sidewalls
Solution Approach 1:
The patent changes the geometric parameters of the submount by creating controlled facets at specific angles (e.g., 45 degrees) through reactive ion etching. These precise angular parameters provide self-aligning features that guide laser diode placement, improving alignment accuracy without requiring complex external alignment mechanisms.
Solution Approach 2:
The patent introduces metallization layers and solder pads as intermediary elements between the submount and laser diode. These intermediaries provide precise positioning features and electrical connections, facilitating accurate alignment while maintaining relatively simple assembly procedures. The metallization patterns act as alignment references that simplify the bonding process.
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 enhances the alignment of laser diodes, reduces chipping, and improves thermal and electrical connectivity, leading to better performance and reliability of EAMR disk drives.
Implementation Method 1
A method involving the creation of silicon islands with trenches and controlled facets, where metallization and solder pads are applied for improved alignment and thermal management, using silicon reactive ion etching to form precise trenches
Data Source
AI summary
A method and system for providing a laser diode submount for use in an energy assisted magnetic recording disk drive are described. A portion of a silicon substrate is removed, forming trenches therein. Each trench has sidewalls, surrounds a silicon island corresponding to a laser diode submount, and corresponds to a thickness of the laser diode submount. The silicon island has a top surface and a facets corresponding to the trench sidewalls. Insulator(s) for the top surface and facets of the silicon island are provided. Metallization is provided on the top surface and facets of the silicon island. A first portion of the metallization on the top surface corresponds to under bump metal (UBM) for solder pad(s). A second portion of the metallization corresponds to electrical traces. Solder pad(s) are provided on the UBM. The silicon island is released from the silicon substrate.