Agitator Geometry for Adaptive Electric Field Shielding
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Solution Overview
Problem
Existing electroplating processors for wafer level packaging face challenges in compensating for process variations, such as changes in electrolyte conductivity and wafer patterns, requiring manual adjustments and multiple shield sets, leading to interrupted operations and time-consuming trial-and-error experiments.
Innovation Solution
The electroplating processor employs an agitator with an array of ribs and slots, where the agitator's motion and geometry are used to dynamically adjust electric field shielding around the wafer, allowing for adaptive shielding without the need for manual shield changes, by shifting the agitator's center point, varying slot lengths, and synchronizing with wafer rotation to provide selective edge shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If manual shield changes are used to compensate for process variations, then process control accuracy is improved, but operational continuity deteriorates due to interrupted operations
Solution Approach 1:
The patent applies the dynamics principle by making the agitator geometry changeable during operation. The agitator can be dynamically reconfigured with different slot patterns and rib arrangements to adjust electric field shielding levels in real-time, eliminating the need for manual shield changes and maintaining continuous operation while adapting to process variations
2Adaptability or versatility
If multiple shield sets are manufactured and inventoried for different process conditions, then adaptability to process variations is improved, but device complexity and inventory requirements worsen
Solution Approach 1:
The patent applies universality by designing a single agitator that can perform multiple shielding functions. By changing the agitator's geometric configuration (slot patterns, rib arrangements), one agitator can provide different levels and types of electric field shielding for various process conditions, replacing the need for multiple dedicated shield sets
Solution Approach 2:
The dynamic reconfigurability of the agitator allows it to adapt to different process conditions by changing its geometry during operation, providing the adaptability of multiple shields without the complexity of maintaining an inventory of different shield sets
3Measurement precision
If trial-and-error experiments are performed to determine appropriate shields, then process optimization is improved, but time consumption worsens
Solution Approach 1:
The dynamic agitator allows for rapid geometric changes during operation, enabling quick experimentation with different shielding configurations without the time-consuming manual shield changes. This reduces the time required for trial-and-error optimization while maintaining the ability to achieve process optimization
Solution Approach 2:
The continuous operability enabled by the dynamic agitator allows trial-and-error experiments to be performed without interrupting the electroplating process. The agitator geometry can be changed on-the-fly, maintaining continuous plating operation while optimizing shielding parameters, thus eliminating the time loss associated with stopping operations for shield changes
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 adaptive shielding approach enables continuous operation with improved process control, reducing the need for manual shield changes and inventory, and allows for precise compensation of process variations, enhancing efficiency and reducing trial-and-error methods.
Implementation Method 1
The agitator has an array of ribs and slots, and with a first side of the agitator having fewer slots than a second side of the agitator... moving the agitator horizontally within the vessel... selectively shields a portion of the wafer
Data Source
AI summary
In electroplating apparatus, a paddle or agitator agitates electrolyte in a vessel to provide high velocity fluid flow at the surface of a wafer. The agitator is designed and/or moved to also selectively shield part of the wafer, for example the edge of the wafer, from the electric field in the vessel. Selectively shielding may be achieved by temporally shifting the average position of the agitator towards one side of the wafer, by omitting or shortening slots in the agitator, and/or by synchronizing movement of the agitator with rotation of the wafer.