Substrate Conveying Robot Blade Elevating Unit
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Solution Overview
Problem
Conventional substrate conveying robots with edge grip systems face challenges in shortening tact time due to positioning errors and deviations in substrate handling, particularly when switching between substrate placing and receiving operations, leading to inefficiencies in semiconductor manufacturing processes.
Innovation Solution
A substrate conveying robot with a pair of vertically arranged blade members, each equipped with a fixed and movable gripping portion, and a blade elevating unit, allowing for independent control of the blade members to optimize substrate placement and reception timing, and the ability to switch between vertical and non-vertical arrangements to accommodate different substrate placing structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the fixed gripping portion is exactly fitted to the position of the edge portion on the distal side of the wafer, then the positioning precision is improved, but the robot arm deflection or teaching error causes the fixed gripping portion to be positioned in front of the edge portion, leading to failed wafer reception
Solution Approach 1:
The blade member is advanced below the wafer before the fixed gripping portion reaches the edge portion position. This preliminary positioning allows the wafer to be properly engaged by the movable gripping portion before final gripping occurs, preventing failed reception due to positioning errors
Solution Approach 2:
The blade member is designed to be movable in the vertical direction, allowing dynamic adjustment of the gripping portion position. This enables the system to adapt to positioning variations by adjusting the blade member height rather than relying on absolute positioning precision
2Productivity
If a robot conveys a plurality of wafers at the same time by one hand, then the tact time upon conveying wafers is shortened, but the robot is not suitable for single-wafer processing steps where processed and un-processed wafers need to be conveyed one by one
Solution Approach 1:
The substrate holding device is divided into a pair of independent hands (upper hand and lower hand), each capable of holding substrates independently. This segmentation allows the system to convey multiple substrates simultaneously when needed while also being able to operate with a single hand for single-wafer processing steps
Solution Approach 2:
The substrate holding device with a pair of hands can perform multiple functions: conveying multiple substrates simultaneously for batch processing, conveying single substrates for single-wafer processing, and coordinating between hands for synchronized operations. This multi-functionality provides adaptability across different processing requirements
3Productivity
If the vertical interval between hands is widened when the lower hand holds a wafer and the upper hand is in a non-holding state, then the wafer can be placed onto an empty lower stage and the empty upper hand can receive a wafer from an upper stage simultaneously, but the device complexity increases
Solution Approach 1:
The vertical interval between the pair of blade members is made adjustable rather than fixed. The blade elevating unit allows dynamic change of the vertical position of one blade member relative to the other, enabling the system to optimize the vertical interval for different operational modes (simultaneous placement and reception vs. single operation) without increasing structural complexity
Data Source
AI summary
A control device is configured to make a robot arm and a substrate holding device execute a blade member advancing operation for advancing a pair of blade members into a substrate placing structure, a substrate receiving operation for receiving a substrate placed on an upper stage of the substrate placing structure by the blade member in a substrate non-holding state, and a substrate placing operation for placing the substrate on the blade member in a substrate holding state onto a lower stage. A timing of receiving a substrate by the substrate receiving operation is shifted from a timing of placing a substrate by the substrate placing operation. A substrate conveying robot capable of shortening the tact time upon conveying substrates regardless of the kind of substrate fixing method in the substrate holding device can be provided.