Hazen L. Hoyt - Costa Mesa CA John D. Sanders - Tustin CA Jon C. Goldman - Orange CA William R. Mello - Huntington Beach CA
Assignee:
Thermco Systems, Inc. - Orange CA
International Classification:
B65B 2102
US Classification:
414416
Abstract:
Semiconductor wafers in plastic cassettes are loaded into (and later unloaded from) an input/output station serving a CVD furnace and thereafter the cassettes are non-manually transported by a programmable elevator to and from a flat-finder, a wafer transfer machine (where the wafers are transferred to a boat) and in-process storage. The boats are non-manually transported by a second programmable elevator to and from the wafer transfer machine, in-process boat storage and a boat loader (or process chamber directly). The cassettes can be loaded or unloaded while one or both of the elevators are operating. Up to eight human assisted steps are reduced to only two such steps. Furnaces having more than one processing chamber have a loading station, in-process cassettes and boat storage and boats dedicated to each processing chamber so that there is no cross contamination between processing chambers caused by the boats and the cassettes in which wafers are delivered to the process are the same cassettes in which process wafers are returned to the input/output station so that there is no cross contamination of the wafers caused by the cassettes.
Electrophotographic Exposure And Development Arrangement
In the embodiment disclosed in the specification, an electrophotographic exposure and development arrangement has a flexible transparent photoreceptor belt driven between two support rollers and along four printing stations at each of which the photosensitive surface of the photoreceptor is charged, exposed to a light image corresponding to a selected color, and developed with toner of the corresponding color to produce a composite multicolor image which is transferred to a substrate and subsequently fixed on the substrate. At each printing station an exposure unit has a curved belt support surface which is engaged by the photoreceptor belt passing through the printing station between the exposure location and a development location with a curvature and length selected to minimize the effect of ripples or irregularities in the position of the photosensitive surface of the photoreceptive belt resulting from a set taken by the photoreceptor belt when held stationery against a supporting number.