Wafer Alignment Solution: Marking for Precision After Reinforcement Removal
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Summary
Problems
The existing method for removing the annular reinforcing portion from a wafer results in the loss of the notch, making subsequent wafer alignment difficult due to the absence of a reference point.
Innovation solutions
A wafer processing method that forms a mark corresponding to the notch radially inside the boundary between the device area and the annular reinforcing portion before or after separating the annular reinforcing portion, allowing for proper alignment post-removal.
TRIZ Analysis
Specific contradictions:
General conflict description:
Principle concept:
If the annular reinforcing portion is removed from the wafer using laser processing, then the device area is separated from the reinforcing portion, but the notch on the annular reinforcing portion is also removed, making subsequent alignment difficult
Why choose this principle:
A mark corresponding to the notch position is formed on the wafer before the annular reinforcing portion is removed. This preliminary marking ensures that alignment information is preserved on the wafer itself, allowing subsequent alignment operations to proceed accurately even after the reinforcing portion and its notch are removed.
Principle concept:
If the annular reinforcing portion is removed from the wafer using laser processing, then the device area is separated from the reinforcing portion, but the notch on the annular reinforcing portion is also removed, making subsequent alignment difficult
Why choose this principle:
The notch information is copied from the annular reinforcing portion to the wafer substrate by forming a mark at the corresponding radial position. This copying process transfers the alignment reference from the removable reinforcing structure to the permanent wafer body, ensuring alignment information survives the removal process.
Application Domain
Data Source
AI summary:
A wafer processing method that forms a mark corresponding to the notch radially inside the boundary between the device area and the annular reinforcing portion before or after separating the annular reinforcing portion, allowing for proper alignment post-removal.
Abstract
Disclosed herein is a wafer processing method for removing an annular reinforcing portion from a wafer having a device area, the annular reinforcing portion being formed around the device area. The wafer processing method includes the steps of supporting the wafer through an adhesive tape to an annular frame, forming a mark corresponding to a notch at a position radially inside a boundary portion between the annular reinforcing portion and the device area, cutting the boundary portion together with the adhesive tape to thereby separate the annular reinforcing portion from the device area, and moving the annular reinforcing portion supported through the adhesive tape to the annular frame away from a holding table to thereby remove the annular reinforcing portion from the wafer.