Dual Screw Transfer Apparatus Resolving Substrate Biasing Loads
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Solution Overview
Problem
Conventional transfer apparatuses for semiconductor and liquid crystal display panel manufacturing experience positional deviations and instability due to biasing and moment loads when handling larger substrates, leading to uneven vertical movement and horizontal misalignment.
Innovation Solution
The transfer apparatus incorporates a dual screw-feeding mechanism with synchronized pulleys and a dual slide guide mechanism arrangement, where the screw-feeding mechanisms are spaced apart and driven in synchronism, and the slide guide mechanisms are positioned on the same side of the vertical plane containing the screw shafts, enhancing work-supporting rigidity against biasing and moment loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single screw-feeding mechanism and single slide guide mechanism are used, then the device complexity is reduced, but the stability and precision deteriorate when handling larger substrates due to biasing and moment loads
Solution Approach 1:
The patent divides the single screw-feeding mechanism into two separate screw-feeding mechanisms (first and second), each independently supporting half of the substrate load. Similarly, the single slide guide mechanism is segmented into two, with each guiding one of the screw shafts. This segmentation distributes the biasing and moment loads across multiple independent components, preventing the instability and positional deviations that occur with a single mechanism handling the entire load.
2Adaptability or versatility
If the horizontal transfer distance is increased to accommodate larger substrates, then the adaptability improves, but the biasing and moment loads increase causing positional deviation
Solution Approach 1:
By segmenting the support system into two screw-feeding mechanisms positioned at different locations, the patent enables handling of larger substrates with extended horizontal transfer distances. Each screw-feeding mechanism independently manages the load at its position, preventing the cumulative biasing and moment loads that would otherwise cause positional deviation when handling larger works.
Solution Approach 2:
The patent transitions from a single-point support system to a distributed multi-point support system. The two screw-feeding mechanisms are positioned at different horizontal locations, creating a spatial distribution of support points that accommodates larger substrate dimensions while maintaining vertical position accuracy through independent load management at each position.
3Device complexity
If the screw shafts are positioned close together, then the device complexity is reduced, but the work-supporting rigidity against biasing and moment loads deteriorates
Solution Approach 1:
The patent segments the support function into two independently positioned screw-feeding mechanisms rather than using a single centralized mechanism. This segmentation allows the screw shafts to be positioned at optimal locations that maximize the moment of inertia and resistance to biasing and moment loads, thereby enhancing work-supporting rigidity while maintaining manageable device complexity through modular independent units.
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 configuration ensures stable vertical movement and proper horizontal holding of substrates, reducing the influence of biasing and moment loads, allowing for smooth operation even when the substrate is positioned off-center, thereby maintaining precision and reliability in transferring larger substrates.
Implementation Method 1
The screw-feeding mechanism applies driving force for the vertical movement to the lift base. The screw-feeding mechanism comprises a vertically extending screw shaft rotatably mounted to the stationary base and a nut member provided at the lift base. The nut member is screwed onto the screw shaft. When the screw shaft rotates, the lift base moves vertically with the nut member.
Implementation Method 2
The slide guide mechanisms facilitate the vertical slide movement of the lift base and arranged to be spaced from each other. Each of the slide guide mechanisms is made up of a vertically extending guide rail provided at the stationary base and a guide member provided at the lift base. The guide member is in sliding engagement with the guide rail.
Data Source
AI summary
A transfer apparatus includes a stationary base, a lift base, a lifting mechanism for vertically moving the lift base, a rotary base mounted to the lift base, a rotating mechanism for rotating the rotary base about a vertical rotation axis, a linear moving mechanism supported by the rotary base, and a work hand supported by the linear moving mechanism. The lifting mechanism includes a slide guide mechanism for vertical movement of the lift base, and first and second screw-feeding mechanisms. Each screw-feeding mechanism includes a rotatable vertical screw shaft, and a nut member provided on the lift base and screwed onto the screw shaft. The first and the second screw-feeding mechanisms are spaced from each other, with the rotation axis of the rotary base being located between the first and the second screw-feeding mechanisms.