Semiconductor Laser Dicing with Adaptive Energy for Seal Ring Protection
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Solution Overview
Problem
Current semiconductor dicing methods, such as mechanical sawing and laser dicing, face challenges in achieving consistent trench depths and avoiding damage to seal rings during the dicing process, leading to reliability issues and reduced packaging yield.
Innovation Solution
A laser system that includes a laser source and a movable laser energy adjusting unit, which adjusts the laser energy based on the material type along the cutting street, and a splitter to generate multiple dicing energies for parallel tracks, ensuring consistent dicing and minimizing damage to seal rings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If mechanical sawing is used to dice wafers, then the dicing process can separate different dies, but the trench depth consistency is poor and damage to seal rings occurs
Solution Approach 1:
The patent replaces the mechanical sawing system with a laser dicing system. The laser beam ablates the wafer material to form trenches and separate dies without physical contact, eliminating mechanical forces that cause inconsistent trench depths and damage to seal rings. This substitution of mechanical action with optical/thermal action resolves the contradiction between manufacturing precision and harmful effects.
Solution Approach 2:
The patent dynamically adjusts laser parameters (energy, pulse duration, frequency) based on the material being processed. By changing these parameters in real-time, the system maintains consistent trench depth across different materials while minimizing thermal damage to seal rings, thus resolving the contradiction between precision and harmful effects.
2Productivity
If laser dicing is used to dice wafers, then the dicing process can separate different dies, but the laser energy must be adjusted for different material types
Solution Approach 1:
The patent incorporates a feedback control system that detects the material type along the cutting path and automatically adjusts laser energy parameters. The system uses real-time information about the wafer structure to modulate laser output, maintaining optimal dicing conditions without manual intervention. This feedback mechanism enables high productivity while managing the complexity through automation.
Solution Approach 2:
The patent employs dynamic adjustment of laser energy parameters during the dicing process. Rather than using fixed settings, the system continuously adapts laser power, pulse duration, and frequency based on the immediate processing conditions and material properties, enabling both high productivity and controlled complexity through real-time optimization.
3Productivity
If high-power laser is used for dicing, then the dicing efficiency is improved, but the risk of damaging seal rings increases
Solution Approach 1:
The patent applies partial action by using ultra-short pulses that deliver high peak power only for brief moments, sufficient to ablate material efficiently. The duty cycle is kept low with long intervals between pulses, allowing heat to dissipate and preventing cumulative thermal damage to seal rings. This partial application of high power achieves both efficiency and safety.
Solution Approach 2:
The patent uses periodic pulsed laser operation rather than continuous wave. The ultra-short pulses are delivered in periodic sequences with controlled duty cycles, providing high instantaneous power for efficient material removal while allowing cooling periods that prevent thermal damage to sensitive structures like seal rings, thus resolving the contradiction between productivity and harmful effects.
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 system achieves consistent laser grooving and trench formation, reducing chip collapse and improving packaging yield by adjusting laser energy according to material types and using multiple dicing energies for parallel tracks.
Implementation Method 1
A laser system for dicing a semiconductor structure includes a laser source configured to generate laser... A trench is formed on the wafer by a laser source along a cutting street
Implementation Method 2
the laser energy adjusting unit is moved to the laser light path between the laser source and the semiconductor structure based on a first determination that the laser source is focused on a first preset region of the semiconductor structure having a first material
Data Source
AI summary
A method for dicing a semiconductor structure is disclosed trench is formed on the semiconductor structure by a laser source along a cutting street. An output energy of the laser source maintains the same when dicing the semiconductor structure along the cutting street. A dicing energy irradiated on the semiconductor structure is adjustable when dicing the semiconductor structure along the cutting street. A mechanical cutting is performed on the semiconductor structure along the cutting street having the trench formed by the laser source.