Deadlock Detection in Semiconductor Multi-Piece Transport
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Solution Overview
Problem
Current deadlock determination methods are inadequate for semiconductor apparatuses that transport multiple pieces of material in a single step, as they are designed for single-piece transportation and fail to prevent scheduling deadlocks in systems with complex resource sharing.
Innovation Solution
A deadlock determination method that constructs a new Wait Relation Graph (WRG) by combining resources across process steps, allowing for the determination of deadlock occurrence in systems transporting multiple pieces of material, by altering the total capacity of each process step to accommodate multi-piece transportation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the existing deadlock determination method is used, then deadlock detection is possible for single-piece transportation systems, but it cannot detect deadlocks in multi-piece transportation systems
Solution Approach 1:
The patent modifies the parameters of the Wait Relation Graph by changing the total capacity of each process step to reflect multi-piece transportation capabilities. Specifically, the total capacity is updated to account for multiple workstations and parallel transportation paths, enabling the deadlock determination algorithm to accurately analyze systems that transport multiple materials simultaneously.
2Productivity
If resources are combined to support multi-piece transportation, then transportation capacity increases, but the complexity of deadlock determination increases
Solution Approach 1:
The patent creates a universal deadlock determination method that works for both single-piece and multi-piece transportation systems. By formulating the Wait Relation Graph construction and analysis in a generalized manner that accommodates variable transportation capacities, the method maintains algorithmic simplicity while supporting enhanced productivity through multi-piece transportation.
Data Source
AI summary
A deadlock determination method includes constructing a new WRG and determining a deadlock. At least a process step that includes a plurality of resources is selected from process steps in a WRG that supports transporting a single piece of material. The plurality of resources corresponding to the selected process step are combined. A total capacity of each of the process steps is changed according to a combination result to construct the new WRG that supports transporting a plurality of pieces of material. The plurality of resources include apparatuses for performing the process steps. The total capacity is a sum of a number of workstations of resources corresponding to each process step. Determining a deadlock includes determining whether a piece of material scheduling deadlock occurs based on the new WRG. The plurality of resources include apparatuses for performing the process steps.