Wafer Dicing via Crack-Aware Cutting Sequence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
During the cutting process of a wafer using a dicing apparatus, cracks within the wafer can grow and damage adjacent devices, especially when the cutting blade approaches the crack at an angle close to its direction of extension.
Innovation Solution
A processing method that includes a crack detection step using illumination and image pickup to identify cracks, followed by a crack direction verification step to determine the direction in which the crack extends, and then performs the cutting in a sequence that first cuts scheduled division lines in a direction farther from the crack's direction, followed by cutting in the direction closer to the crack's orientation, thereby controlling crack growth and minimizing device damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the cutting blade processes along the scheduled division line, then the division accuracy is improved, but cracks may grow and damage adjacent devices
Solution Approach 1:
The patent applies preliminary action by detecting cracks and determining their directions before the cutting process begins. The system irradiates light through the wafer, captures images to identify cracks, and calculates crack directions using image processing. This pre-processing information is then used to plan the cutting sequence, ensuring that cuts are performed in a direction that minimizes crack propagation risk before the actual cutting occurs.
Solution Approach 2:
The patent applies inversion by reversing the conventional cutting approach. Instead of cutting along scheduled division lines in a fixed sequence, the system determines crack directions first and then plans the cutting sequence to cut perpendicular to crack directions. This inverts the traditional workflow by prioritizing crack direction analysis over predetermined cutting paths, thereby preventing crack growth while maintaining division accuracy.
2Ease of manufacture
If the cutting blade approaches the crack at an angle close to its direction of extension, then the cutting process is simplified, but the crack growth is accelerated and device damage increases
Solution Approach 1:
The system performs preliminary crack detection and direction calculation before planning the cutting sequence. By analyzing crack directions in advance using light irradiation and image processing, the system can determine the optimal cutting direction that is perpendicular to crack extensions. This pre-analysis ensures that subsequent cutting operations are performed with the correct orientation to minimize crack propagation, balancing process simplicity with crack prevention.
Solution Approach 2:
The patent applies parameter changes by adjusting the cutting direction parameter based on detected crack directions. The system calculates the angle between the scheduled division line and the crack direction, then modifies the cutting plan to ensure the cutting blade moves perpendicular to the crack. This dynamic parameter adjustment optimizes the cutting process to prevent crack growth while maintaining manufacturing efficiency.
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 method effectively suppresses the further growth of cracks during the cutting process, reducing damage to the devices by ensuring that the crack is divided in a direction that minimizes its propagation, thus protecting the devices from additional damage.
Implementation Method 1
illumination means for irradiating illumination of a wavelength having transparency with respect to the wafer (44)
Data Source
AI summary
A processing method for a wafer including a crack detection step for irradiating illumination of a wavelength transparent to wafer, picking up an image of the wafer, and detecting whether a crack is generated within the wafer, a crack direction verification step for verifying, when a crack is detected, to which one of the first and second directions a direction in which the crack extends is nearer, a first cutting step for positioning the cutting blade to a scheduled division line of a direction decided to be a direction farther from the direction in which the crack extends from between the first and second directions and cutting the scheduled division line, and next a second cutting step for positioning the cutting blade to a scheduled division line of a direction decided to be nearer to the direction in which the crack extends and cutting the scheduled division line.