Pivoting Tab End Effector for Wafer Positioning Stability
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Solution Overview
Problem
Robots in semiconductor processing struggle to maintain semiconductor wafers in a proper position during high-speed transport, leading to wafers moving or falling out of the wafer blade pocket, which can damage equipment and require downtime.
Innovation Solution
A robot with a surface region equipped with levers or tabs that pivot or move from a first position to a second position when a wafer is placed, pressing against the wafer to secure it, and return to the first position when the wafer is removed, using beveled sidewalls and elastomeric materials to prevent displacement and damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If robots transport wafers at high speed, then productivity is improved, but wafers may move or fall out of the wafer blade pocket causing damage and downtime
Solution Approach 1:
The end effector employs dynamic tabs that automatically pivot from a first position to a second position in response to wafer placement, and return to the first position when the wafer is removed. This dynamic adaptation allows the system to maintain reliability across varying transport speeds without requiring manual adjustment or complex control systems.
Solution Approach 2:
The tabs are configured to self-activate through weight-activated mechanisms that detect wafer presence and automatically engage the securing function. The system serves itself by using the wafer's own weight to trigger the securing action, eliminating the need for external actuators or control systems while maintaining secure positioning during high-speed transport.
2Reliability
If levers or tabs press against the wafer to secure it, then wafer positioning stability is improved, but the wafer may be damaged due to applied force
Solution Approach 1:
The tabs utilize elastomeric materials that change their mechanical properties based on applied load. When the wafer is placed, the elastomeric material deforms to provide securing force, then returns to its original shape, maintaining consistent securing pressure without exceeding damage thresholds. This parameter change allows the same component to provide both gentle contact and secure retention.
Solution Approach 2:
The elastomeric material acts as an intermediary between the rigid tab structure and the wafer surface. It distributes the securing force evenly across the contact area and absorbs shock or impact forces, preventing direct transmission of harmful forces to the wafer while maintaining positioning stability during transport.
3Reliability
If traditional securing mechanisms are used, then wafer positioning is maintained, but the system requires contact with the wafer's top surface which may contaminate or damage it
Solution Approach 1:
The securing mechanism transitions from vertical contact (top surface) to lateral contact (side surface). The tabs engage the wafer's side surface perpendicular to the top surface, maintaining positioning stability while eliminating contact with the contamination-sensitive top surface. This dimensional change allows securing without compromising wafer integrity.
Solution Approach 2:
The invention extracts the securing function from the top surface contact mechanism and relocates it to the side surface. By removing the need for top surface contact, the design eliminates the associated contamination and damage risks while preserving the essential positioning function through lateral engagement by the pivoting tabs.
4Device complexity
If simple wafer holding structures are used, then device complexity is reduced, but wafers cannot be securely held during high-speed transport
Solution Approach 1:
The end effector is segmented into multiple independent tabs that can pivot and engage individually. This segmentation allows each tab to independently respond to wafer placement and provide localized securing force, achieving reliable retention during high-speed transport while maintaining a relatively simple overall structure that can be manufactured and maintained easily.
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 secures wafers in place during transport at higher speeds, reducing the risk of damage and downtime by maintaining proper positioning without requiring contact with the wafer's top surface and applying minimal force, and is applicable to various article shapes and robot types.
Implementation Method 1
a second protrusion comprising an elastomeric material
Data Source
AI summary
An end effector blade (201) is provided which has a region (203) defined thereon for receiving an article. The end effector blade is also equipped with a plurality of tabs (213) disposed about the periphery of said region. Each tab moves from a first position when no article is present in the region, to a second position when an article is disposed in the region, and each tab pressingly engages the article when it is in the second position.