Workpiece carrier with suction slot for a disk-shaped workpiece
AssigneeBalzers Aktiengesellschaft
InventorsRudolf Wagner, Hans Hirscher
Life of this patent
Estimating the term…
Abstract
For the transmission of heat under vacuum conditions to a workpiece, a carrier is used with gas outlets and gas return openings distributed on its surface. A dynamic gas layer is thus formed between the carrier and the workpiece wherein the gas effects thermal conduction between the carrier and the workpiece. The gas outlets terminate in a distribution space implemented as a groove and has at least on slot shaped aperture extending substantially around most of the carrier periphery.
Claims7
In a workpiece carrier for a disk-shaped workpiece, subjected to a surface treatment in a vacuum installation and having a workpiece support forming a support surface with an outer periphery and for supporting the workpiece, at least one exit aperture terminating in the support surface, a gas feed connected to said at least one exit aperture for supplying a gas to said exit aperture to form a heat transferring gas layer between said support surface and said workpiece, the improvement comprising:
- the support surface including, in addition to said exit aperture, at least one suction aperture, said suction aperture being formed as at least one slot extending along a substantial portion of the periphery of said support surface and;
- gas suction means connected to said at least one slot for suctioning gas from said slot which comes from said at least one exit aperture, so that a dynamic gas seal is formed at said periphery, said slot having a cross-sectional area and communicating with said suction means along a communication path with a cross-sectional area not smaller than that of said slot considered in a flow direction of gas suctioned through said slot by said gas suction means.
In a workpiece carrier for a disk-shaped workpiece, subjected to a surface treatment in a vacuum installation and having a workpiece support forming a support surface with an outer periphery and for supporting the workpiece, at least one exit aperture terminating in the support surface, a gas feed connected to said at least one exit aperture for supplying a gas to said exit aperture to form a heat transferring gas layer between said support surface and said workpiece, the improvement comprising:
- the support surface including, in addition to said exit aperture, at least one suction aperture, said suction aperture being formed as at least one slot extending along a substantial portion of the periphery of said support surface;
- gas suction means connected to said at least one slot for suctioning gas from said slot which comes from said at least one exit aperture, so that a dynamic gas seal is formed at said periphery, said slot having a cross-sectional area and communicating with said suction means along a communication path with a cross-sectional area not smaller than that of said slot considered in a flow direction of gas suctioned through said slot by said gas suction means;
- said gas suction means defining a distribution space formed by a groove, and including a covering plate covering the groove and forming the workpiece support, the groove being directly connected to said at least one slot;
- said at least one exit aperture extending through said covering plate;
- said gas suction means including means for suctioning gas from said slot at a mass fluid rate per unit time which is at least equal to a mass fluid rate per unit time of gas supplied by said gas feed;
- and
- a heating coil in the groove.
Dependencies are inferred from the claim text.