Conveyors: power-driven – With means to facilitate working – treating – or inspecting... – Means to convey a palleted load back and forth between an...
Patent
1986-12-08
1989-02-21
Valenza, Joseph E.
Conveyors: power-driven
With means to facilitate working, treating, or inspecting...
Means to convey a palleted load back and forth between an...
198493, 981152, 15301, B65G 4700
Patent
active
048057592
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to handling (transport and storage) of objects during manufacture.
2. Description of the Prior Art
Efforts are being increasingly directed to automating the manufacture of all kinds of objects as completely as possible with a view to reducing production costs while achieving enhanced reliability of the products obtained.
Certain stages of manufacture have in fact been largely automated for the mass production of some types of objects. This is the case, for example, in operations involving assembly of simple component parts which are relatively sturdy and little affected by environmental conditions. Where parts of this type are concerned, the automation problems presented by operations involving cutting, bonding, welding, screwing and so on have been fairly satisfactorily solved.
In most installations, the objects being produced are transported from one workstation to another by a belt conveyor (traveling band) on which the objects rest. When an operation on a first object is completed at one workstation, the object is re-taken by the conveyor. The following object arrives and is thrust forward to the workstation in order to undergo the same treatment. In the meantime, the first object is transported by the conveyor to the following workstation a which it is subjected to another treatment operation without delay or after a waiting period which is as short as possible since the parts are processed in the order of arrival on the conveyor. If the individual workstations are correctly automated, it is possible to achieve a very high degree of automation. This presupposes, however, there is a waiting line at the input of a workstation, by the often abrupt displacement of the conveyor as it moves in front of a stationary workstation and conversely, order of successive workstations along the conveyor, approximately identical time-durations.
On the contrary, automation presents particularly difficult problems under circumstances in which: are very different from each other, different objects or batches of objects to be manufactured.
An additional difficulty arises when the objects have to remain in a controlled clean atmosphere (in particular a dust-free environment), not only during successive processing operations but also between these operations.
The fabrication of integrated circuits accumulates these difficulties in its first production stages or in other words throughout all the processing steps carried out on semiconductor layers before they are cut into individual chips and encapsulated within a sealed package. It is for this reason that many difficulties are encountered when automating these initial processing steps whereas it proves much easier to control the automation of the following steps and in particular the assembly of an integrated circuit in a package.
However, automatic processing of semiconductor layers on an industrial production basis is a particularly desirable objective. Although it is true that, in practice, the atmosphere of production workshops is maintained in a highly controlled state of cleanliness, the coming and going of operating personnel represents an inevitable source of pollution which considerably reduces production yields.
Various specific systems for handling semiconductor wafers have been proposed. These systems are not built on the general principle of conventional belt conveyors for at least three reasons which arise from the foregoing remarks. In the first place, semiconductor wafers are too delicate. Secondly, processing times are too long and too variable from one processing step to the next (from several tens of minutes to several hours). Furthermore, a requirement to be met is that the semiconductor wafers should not all follow the same series of treatments. It is also desirable to ensure that the batches can subsequently return to a machine through which they have already passed. For example, it may be necessary to perform several ion implantations with other operations such as pho
REFERENCES:
patent: Re28909 (1976-07-01), Holbert
patent: 3803556 (1974-04-01), Duffy
patent: 3958682 (1976-05-01), Martin
patent: 4306646 (1981-12-01), Magni
patent: 4616594 (1986-10-01), Itho
patent: 4649830 (1987-03-01), Tanaka
patent: 4682927 (1987-07-01), Southworth et al.
Dubois Guy
Faure Louis
Lalanne Alain
Rochet Andre
Societe pour l'Etude et la Fabrication de Circuits Integres Spec
Valenza Joseph E.
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