Transport system including vertical rollers

Abstract

A transport system for conveying articles along conveyance paths including straight, curvilinear, horizontal, inclined and declined conveyance sections. The articles are conveyed between a pair of vertical belts while being supported by protrusions extending from the vertical belts. The vertical belts are guided using a multiplicity of vertical rollers that are configurable into straight, curvilinear and dynamically changing conveyance sections. Multiple conveyance sections can be joined end to end to transport articles over complex paths and over long distances. The articles conveyed may include semiconductor wafers.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The current invention relates to transport systems and methods for conveying articles along a conveyance path, and in some embodiments to conveying semiconductor wafers in a semiconductor fabrication facility. [0003] 2. Related Art [0004] Transport systems are widely employed in industrial manufacturing facilities to convey articles between work stations. Originally, these systems were manual and workers moved articles by hand or by cart. Modern factories have developed specialized equipment to convey articles automatically. In particular, semiconductor fabrication facilities currently use automated transport systems to move semiconductor wafers during the manufacturing process. Typically, a batch of wafers may be conveyed together in a container known as a Front Opening Unified Pod (FOUP). Semiconductor wafer manufacturers have sought to increase manufacturing productivity by using transport systems that efficientl...

AI Technical Summary

Benefits of technology

[0008] The present invention includes, in various embodiments, a transport system for moving articles along a conveyance path that includes straight, curvilinear, horizontal, inclined and / or declined sections. The articles are conveyed between essentially vertical rollers that have circular surfaces that rotate to provide motion in a conveyance direction. Vertically-oriented belts are optionally disposed between the vertical rollers and the articles. In some embodiments, the vertical belts include a long cross-sectional axis approximately parallel to the vertical plane and a short cross-sectional axis approximately perpendicular to an axis of rotation of the vertical rollers. The weight of the articles transported is supported in a direction parallel to the vertical axis. As such, the weight is directed approximately parallel to a vertical rotational axis of the vertical rollers and need not be supported by the circular surfaces of the vertical rollers. This configuration allows the weight of the articles to be decoupled from the uneven circular surfaces.

[0009] In those embodiments including vertical belts, the weight of articles transported is optionally further supported through the long cross-sectional axis of the vertical belts. For example, the vertical belts are optionally stiffer through the weight bearing long cross-sectional axis than they are through their short cross-sectional axis. This results in less variation in the height of the vertical belt between support points (e.g., rollers), as compared to the height of a horizontal belt of the prior art. Systems of the invention, therefore, typically included reduced unevenness in the conveyance path relative to the prior art. In various embodiments, this reduced unevenness allows articles, such as FOUPs including semiconductor wafers, to be transported at greater speeds than in the prior art while still staying within vibration limits.

Problems solved by technology

Existing transport systems employ vehicle-based devices to eliminate vibrations but the capacity of this system is limited by the number of vehicles available.

A common feature of these existing systems is the difficulty of vibrationally isolating the article being conveyed from the surface across which the articles travel.

If the surface across which the articles travel is not flat, the articles experience vibration during the conveyance.

This source of vibration is a known problem in the semiconductor wafer manufacturing industry.

Another problem with existing transport systems used in the semiconductor wafer manufacturing industry is the difficulty of changing or turning the direction of conveyance of an article, such as a FOUP, without momentarily stopping its motion.

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