Laser Spot Distribution for Crack-Free Optical Device Dicing
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Solution Overview
Problem
Conventional methods for dicing optical devices from substrates, such as glass and silicon carbide, face challenges in maintaining quality due to non-symmetrical thermal or mechanical stress distribution, leading to cracks and chips, especially with complex contours.
Innovation Solution
A method involving a laser machining system that forms multiple sets of laser spots or trenches along a dicing path, with controlled passes and cooling times to optimize stress distribution and reduce cracking, allowing for precise removal of optical devices from the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional single-pass laser dicing is used, then the dicing process is simple and fast, but non-symmetrical stress distribution causes cracks and chips in optical devices
Solution Approach 1:
The dicing process is divided into multiple passes, with each pass creating a set of laser spots at specific positions along the dicing path. Subsequent passes add additional sets of spots at different positions, segmenting the stress application to achieve symmetrical stress distribution and prevent cracking while maintaining productivity
Solution Approach 2:
The laser applies periodic action by creating spots at regular intervals along the dicing path during each pass, and by repeating passes at optimized intervals. This periodic spot formation creates controlled, symmetrical stress distribution that prevents non-symmetrical stress concentrations causing cracks
2Manufacturing precision
If multiple passes with multiple sets of laser spots are used, then stress distribution is optimized and cracking is reduced, but the dicing process becomes more complex
Solution Approach 1:
The method performs preliminary actions by first identifying the complex contour of the optical device, then pre-calculating and storing optimized pass parameters including spot positions, spacing, and timing for multiple passes. This preliminary setup automates the complex multi-pass process, reducing operational complexity while maintaining high manufacturing precision
Solution Approach 2:
The system uses feedback by detecting the actual contour of the optical device and adjusting the dicing path and spot distribution accordingly. This closed-loop control optimizes stress distribution dynamically, achieving high precision while the system manages process complexity through adaptive control
3Manufacturing precision
If laser spots are formed closely along the dicing path, then complete trench formation is achieved, but thermal and mechanical stress concentration increases causing cracks
Solution Approach 1:
The laser spot distribution is segmented into multiple sets along the dicing path, with each set spaced at optimized intervals. Multiple passes create additional segmented sets of spots, ensuring complete trench formation while distributing thermal and mechanical stress across separated locations, preventing stress concentration and cracking
Solution Approach 2:
The laser applies periodic action by forming spots at regular periodic intervals along the dicing path during each pass, and by repeating passes at optimized periodic intervals. This periodic spacing prevents continuous stress concentration while ensuring complete material removal through cumulative effect of multiple passes
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 minimizes non-symmetrical stress distributions, thereby reducing cracks and chips, enhancing the quality and yield of diced optical devices, particularly those with complex contours.
Implementation Method 1
forming a first set of laser spots along a dicing path on a first pass of a laser
Implementation Method 2
a sudden change of the dicing direction can cause non-symmetrical thermal or mechanical stress distribution in the substrate
Data Source
AI summary
Embodiments of the present disclosure relate to methods for dicing one or more optical devices from a substrate with a laser machining system. The laser machining system utilizes a laser to perform methods for dicing one or more optical devices from a substrate along a dicing path. The methods use one of forming a plurality of laser spots along the dicing path or forming a plurality of trenches along the dicing path.