Wafer Trimming Device Notch Edge Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wafer trimming methods often result in crack formation during back-grinding due to the inability to remove notch bevels without reducing the good die area, as conventional trimming blades have a large radius that fails to effectively trim the notch bevel, and increasing edge trim width to accommodate notch trimming reduces the good die area and can cause the notch to disappear.
Innovation Solution
A wafer trimming device with separate notch and edge trimmers, where the notch trimmer rotates perpendicular to the wafer surface and the edge trimmer rotates parallel to the surface, allowing for vertical trimming of both areas to remove bevels without reducing the good die area, thereby minimizing trimming width and preventing crack formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional trimming blades with large radius are used, then the blade structure is simple, but the blade cannot remove the notch bevel effectively
Solution Approach 1:
The trimming device is divided into separate notch trimmer and edge trimmer components, each with specialized blades optimized for their specific function. The notch trimming blade has a small radius designed specifically for removing notch bevels, while the edge trimming blade has a larger radius for edge trimming, resolving the contradiction between precision and structural simplicity.
Solution Approach 2:
Different parts of the trimming system have different blade characteristics tailored to local requirements. The notch trimming blade features a small radius optimized for precise notch bevel removal, while the edge trimming blade has a larger radius suitable for edge processing, allowing each component to have optimal local properties for its specific function.
2Manufacturing precision
If edge trim width is increased to include notch area, then notch bevel can be removed, but good die area is reduced
Solution Approach 1:
The trimming operation is segmented into separate notch trimming and edge trimming processes. The notch trimmer with a small radius blade precisely removes only the notch bevel without encroaching on the good die area, while the edge trimmer handles edge trimming independently, preventing overlap and preserving maximum good die area.
Solution Approach 2:
The notch trimming blade is designed with a small radius specifically optimized for the localized notch bevel removal task, enabling precise material removal only where needed without affecting adjacent good die areas, thus maintaining optimal local trimming quality while preserving overall yield.
3Device complexity
If conventional trimming is performed, then the process is simple, but cracks form during back-grinding
Solution Approach 1:
The trimming process is segmented into two distinct operations: notch trimming followed by edge trimming. This sequential segmented approach ensures that the notch bevel is properly removed first to prevent stress concentration points that would lead to cracks during back-grinding, while maintaining a relatively simple overall process structure.
Solution Approach 2:
The notch trimming operation is performed as a preliminary action before edge trimming and before the back-grinding process. By removing the notch bevel in advance, potential crack initiation sites are eliminated beforehand, preventing crack formation during subsequent back-grinding operations.
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 solution effectively prevents crack formation during back-grinding by ensuring vertical trimming cross-sections of edge and notch areas, minimizing trimming width, and maintaining the good die area, thus allowing for the complete removal of bevels without reducing the semiconductor chip's quality.
Implementation Method 1
a chuck table configured to hold a target wafer via suction, thereby fixing the target wafer
Data Source
AI summary
The wafer trimming device includes a chuck table configured to hold a target wafer via suction, thereby fixing the target wafer, a notch trimmer configured to trim a notch of the target wafer, and an edge trimmer configured to trim an edge of the target wafer. The notch trimmer includes a notch trimming blade configured to rotate about a rotation axis perpendicular to a circumferential surface of the target wafer. The edge trimmer includes an edge trimming blade configured to rotate about a rotation axis parallel to the circumferential surface of the target wafer.