TFLC Photonics Double-Blade Dicing for Low-Loss Singulation
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Solution Overview
Problem
Existing methods for singulating thin film lithium-containing (TFLC) photonics devices face challenges in achieving low optical losses, high yield, and minimizing chipping or other issues during the separation of individual devices from a wafer.
Innovation Solution
A dicing system and method that uses a blade to make precise cuts through the TFLC layer and silicon substrate, forming grooves with low surface roughness and overhanging edges, followed by additional cuts to separate the devices, ensuring smooth sawn edges and reduced insertion losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional singulation methods are used to separate TFLC devices from wafer, then manufacturing speed can be maintained, but optical insertion losses increase due to high surface roughness and chipping
Solution Approach 1:
The singulation process is divided into two distinct stages: a roughing cut that removes the majority of material to separate devices, followed by a finishing cut that creates the final smooth edge. This segmentation allows each cut to be optimized for its specific function, resolving the contradiction between speed and precision.
Solution Approach 2:
The roughing cut is performed first as a preliminary action to remove bulk material and create initial separation between devices. This preliminary removal of material reduces the workload for the subsequent finishing cut, enabling it to focus on creating the smooth optical edge without the time penalty of removing large amounts of material.
2Productivity
If aggressive cutting is used to increase singulation speed, then productivity improves, but device reliability decreases due to chipping and cracking
Solution Approach 1:
The cutting process is segmented into roughing and finishing passes, where the roughing pass handles material removal for speed, and the finishing pass handles precision cutting for reliability. This segmentation allows aggressive cutting parameters in the first pass without compromising final device integrity.
Solution Approach 2:
The roughing cut performs an excessive action by removing more material than strictly necessary for separation, creating a groove that extends beyond the final device boundary. This excessive material removal enables faster cutting parameters while the subsequent finishing cut removes the excess and creates the precise final edge.
3Device complexity
If single-blade cutting is used to simplify the process, then device complexity is reduced, but manufacturing precision deteriorates due to inability to achieve low surface roughness
Solution Approach 1:
The single cutting operation is segmented into two sequential passes with different blade configurations or parameters. The first pass creates the groove with relaxed precision requirements, while the second pass refines the edge to the required smoothness specification.
Solution Approach 2:
The dicing blade is designed to perform multiple functions: first as a roughing tool for material removal, then as a finishing tool for precision edge creation. This multi-functionality allows a single blade type to handle both operations, reducing overall system complexity while maintaining high precision.
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
The method results in TFLC photonics devices with low optical insertion losses, improved manufacturing yield, and enhanced performance by reducing chipping and cracking, facilitating efficient optical coupling and alignment with fibers.
Implementation Method 1
A dicing system and method that uses a blade to make precise cuts through the TFLC layer and silicon substrate, forming grooves with low surface roughness
Data Source
AI summary
A singulated thin film lithium containing (TFLC) photonics device, as well as a method and system for singulating the device are described. The TFLC photonics device includes a device layer and a silicon substrate. The device layer includes a TFLC layer having a depth. The device layer also has a first sawn edge. The silicon substrate has a second sawn edge and includes an upper portion and a lower portion. The upper portion has the second sawn edge that is mutually aligned with the first sawn edge. The upper portion overhangs the lower portion.