Vacuum Transport Hand Inertia Control for Substrate Alignment
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Solution Overview
Problem
In semiconductor manufacturing, substrate positioning accuracy is compromised during the photolithography process due to misalignment caused by the inertia of a transport robot's hand moving downward and differences in downward movement between low and high hands, affecting the precision of seating substrates on spin chucks.
Innovation Solution
A substrate transport apparatus with transport hands that clamp substrates by vacuum pressure, featuring a controller that synchronizes the turning off of vacuum pressures at the same height from the substrate support member, ensuring equal downward movement distances and improved alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the transport robot hand moves downward to load the substrate onto the spin chuck, then the substrate can be transferred to the processing unit, but the substrate position becomes misaligned due to inertia
Solution Approach 1:
The vacuum pressure is turned off in advance before the hand completes its downward movement, so that the substrate remains clamped during the motion but is released at the optimal moment to minimize inertia-induced misalignment while maintaining transfer efficiency
Solution Approach 2:
The controller monitors the hand's position and movement state, and based on this feedback, dynamically controls the vacuum pressure supply timing to optimize both transfer speed and positioning accuracy
2Ease of operation
If the low hand and high hand move downward different distances to load substrates, then each hand can reach its target position, but the positioning accuracy decreases due to inconsistent downward movement
Solution Approach 1:
Each transport hand is equipped with an independent vacuum pressure control system that can be adjusted according to its specific movement characteristics, allowing the low hand and high hand to compensate for their different travel distances and achieve consistent positioning accuracy
Solution Approach 2:
The vacuum pressure turn-off timing is adjusted as a controllable parameter for each hand based on its starting position and movement trajectory, ensuring that both hands release substrates at the optimal moment despite different downward movement distances
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 solution enhances substrate positioning accuracy and uniformity by minimizing misalignment and maintaining consistent downward movement after vacuum pressure interruption, thereby improving the precision and efficiency of substrate seating.
Implementation Method 1
a transport hand that clamps a substrate by vacuum pressure
Implementation Method 2
The position of the substrate may be misaligned by inertia when the hand moves downward
Data Source
AI summary
A substrate transport apparatus includes transport hands that clamp substrates by vacuum pressures, respectively, and that are located at different heights, a vacuum pressure supply unit that supplies the vacuum pressures to the transport hands, and a controller that controls the vacuum pressure supply unit to supply the vacuum pressures to the transport hands or interrupt the supply of the vacuum pressures to the transport hands. The controller controls the vacuum pressure supply unit such that the vacuum pressures of the transport hands are turned off at the same height from a substrate support member.