Design, modeling and control of a modular contactless wafer handling system

Abstract

In the photovoltaic solar cell industry as in the semiconductor industry, efforts to reduce the thickness of silicon wafers are in progress. Wafer damage and breakage during handling can lead to unacceptable yields and alternative solutions have to be proposed. This paper presents a modular contact-free wafer handling system that responds to the industrial requirements in terms of throughput and flexibility. The system is based on simple unidirectional modules that can be assembled together to form the desired trajectory. A complete and accurate physical model of the modular system describing the motion of the wafer transported by directed airjets is proposed. A decentralized control at the block level is realized to damp the object motion. The experimental results show a great reduction of the response time compared to free motion and a standard deviation of the servo error below the millimeter. In addition, simulations show that a 150 mm wafer could reach a speed up to 2.9 m/s on large conveyors.

Post-prognostics decision making in distributed MEMS-based systems

“…), which can be easily damaged, contaminated or even scratched during conveying. Thus, conveyors based on contact-less air-jet technology, which avoid contact with conveyed objects, can be a solution in this case [23,13,18].…”

Multicriteria optimization in distributed micro-conveying platform

“…), which can be easily damaged, contaminated or even scratched during conveyance. Thus, systems based on air-jet technology [14,3,6] such as smart-surface system avoid contact with conveyed objects and provide safer manipulation conditions. Second, a conveyor usually consists of a single monolithic block dedicated to a specific task in a fixed environment.…”

Optimal Path Evolution in a Dynamic Distributed MEMS-Based Conveyor

“…To study the evolution of the path according to the change of the RUL and transfer time, three types of simulations are done: one source, two sources and several sources. For all simulations only one destination is used, at position (3,4). For one source, the simulation consists in sending objects from the source (0, 0) to the destination (3,4).…”

“…For all simulations only one destination is used, at position (3,4). For one source, the simulation consists in sending objects from the source (0, 0) to the destination (3,4). In Fig.…”

“…), which can be easily damaged, contaminated or even scratched during conveying. Thus, conveyors based on contactless air-jet technology, which avoid contact with conveyed objects, can be a solution in this case [11,3,5].…”