Patent ID: 7182116
Filing Date: 2007-02-27
Classification: B29C,B29L,G11B

Abstract:
1. An apparatus for joining together substrates, which have an inner hole, to form a substrate disk, comprising: an expandable element that is introducible into an inner hole of at least two superimposed substrates, wherein said expandable element is expandable to such an extent that it can come into contact with said inner holes of both of said substrates to close off an intermediate space formed between said substrates relative to the environment; a substrate support that is rotatable about an axis of rotation perpendicular to a support surface thereof; a centering means that is rotatably coupled with said substrate support and is movable relative thereto in the direction of said axis of rotation, wherein said expandable element is disposed, and is compressible, between said substrate support and said centering means.