Multi-Grinder Wafer Re-Grinding for TTV Flatness Control
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Solution Overview
Problem
Existing grinding technologies fail to adequately address the deterioration of substrate flatness (TTV) due to changes in device and environmental characteristics during standby or grinding condition changes, requiring additional substrates for inclination adjustment and discarding them.
Innovation Solution
A processing method involving re-grinding processes using multiple grinding units to adjust the relative inclination based on thickness distribution measurements, eliminating the need for additional substrates and ensuring uniform thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If inclination adjustment is performed using additional substrates, then manufacturing precision is improved, but loss of substance increases due to discarding wafers
Solution Approach 1:
The substrate itself is used to detect and correct inclination errors through the thickness measurement process. The substrate undergoes re-grinding based on its own thickness distribution data, eliminating the need for separate calibration substrates. This self-service approach allows the processed substrate to correct its own flatness issues without requiring additional sacrificial wafers for inclination adjustment.
Solution Approach 2:
The system implements a feedback loop where thickness distribution measurements are taken, inclination adjustments are calculated based on these measurements, and re-grinding is performed accordingly. This closed-loop feedback mechanism enables continuous correction of substrate flatness without needing external calibration standards or additional substrates for adjustment.
2Manufacturing precision
If multiple grinding processes are performed, then manufacturing precision is improved, but productivity decreases due to additional processing time
Solution Approach 1:
Thickness distribution measurements are performed at intermediate stages during the grinding process, allowing inclination adjustments to be made before the final grinding step. This preliminary detection and correction approach prevents the accumulation of errors and reduces the need for extensive post-processing, thereby maintaining productivity while improving precision.
Solution Approach 2:
The grinding process is divided into multiple stages with intermediate measurement and adjustment points. By segmenting the process into rough grinding, intermediate measurement, inclination adjustment, and finishing grinding, the system optimizes each stage independently, achieving high precision without excessive total processing time.
3Manufacturing precision
If inclination adjustment is performed frequently, then manufacturing precision is improved, but loss of time increases due to adjustment operations
Solution Approach 1:
The system uses real-time thickness distribution feedback to determine when inclination adjustments are actually needed, rather than performing adjustments at fixed intervals. This demand-driven adjustment approach minimizes unnecessary adjustment operations while maintaining precision, reducing time loss compared to frequent scheduled adjustments.
Solution Approach 2:
The system replaces manual or mechanical inclination adjustment operations with automated calculation and control based on thickness measurement data. The inclination adjustment amount is computed from measurement results and executed through automated control, reducing the time required for adjustment operations compared to traditional manual methods.
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
Improves substrate flatness by minimizing TTV without discarding wafers for inclination adjustment, maintaining parallelism, and optimizing grinding conditions.
Implementation Method 1
a first grinding processing on the substrate in a first grinder; performing a second grinding processing on the substrate in a second grinder; performing a first re-grinding processing on the substrate in the first grinder; and performing a second re-grinding processing on the substrate in the second grinder
Data Source
AI summary
A processing method of processing a substrate in a processing apparatus includes performing a first grinding processing on the substrate in a first grinder; performing a second grinding processing on the substrate in a second grinder; performing a first re-grinding processing on the substrate in the first grinder; and performing a second re-grinding processing on the substrate in the second grinder. The substrate is ground to a final thickness in the second re-grinding processing.