US 4,229,655 A · Vacuum chamber for treating workpieces with beams

Abstract

Apparatus for directing a beam at a workpiece in vacuum has a special planar sliding multiple seal arrangement that enables repeated scanning movement of the workpiece across the beam. The seal includes a planar slide plate and an opposed relatively movable seal support member, also preferrably a plate parallel to the slide plate. Aligned apertures are in the members, one of which is larger in the direction of relative movement than the other enabling the relative movement while maintaining the alignment. A plurality of concentric resilient seals, which may be of oval race track configuration, bear with a sliding contact against the planar surface, these seals preferably comprising composites of a thin high density polyethylene seal element and a soft and only milding compressed backing element that applies a feather-light seal pressure. Between-seal pumping is provided to reduce the differential pressure across any seal to to remove gas that may leak into the space. The embodiment shown incorporates the seal between a moving target chamber and a fixed ion beam chamber.

Claims24

Dependent claims

Apparatus for directing a beam at a workpiece, said apparatus including a support member for carrying said workpiece and an evacuated region surrounding said support member and the path of said beam, the source of said beam and the support member for said workpiece being relatively movable in a direction transverse to said beam, there being a sealing means accomodating said relative motion while maintaining the evacuated condition,

said sealing means comprising a slide member defining a planar sliding surface extending in said direction of relative motion,
a seal support member generally parallel to and spaced from said surface by a gap,
aligned apertures in said members, one of which is larger in the direction of relative motion than the other enabling said relative motion while maintaining said alignment,
a plurality of resilient seals bearing with sliding sealing contact against said planar surfaces,
said seals each spanning said gap and extending throughout with said contact in successive loops fully around said first and second apertures in all relative positions of said apertures,
said loops being such that outer loops wholly surround inner loops, and
between-seal pumping means for pumping the region radially intermediate two of said seals.

4 more elements

In apparatus for directing a beam at a workpiece, said apparatus including a support member for carrying said workpiece and an evacuated region surrounding said support member and the path of said beam, the improvement comprising

a first vacuum chamber containing said support member,
a second vacuum chamber communicating with said first chamber, said beam travelling through said second chamber and into said first to reach said support member,
means for moving said first chamber relative to said second chamber in a direction generally transverse to said beam,
sealing means for sealing said first chamber to said second chamber, said sealing means comprising
a planar sliding surface extending in said direction of relative motion,
a seal support member generally parallel to and spaced from said first surface by a gap,
said planar surface and support members each including apertures for passing said beam, said apertures being sized to overlap at the location of said beam for any relative position of said first and second vacuum chambers, to thereby provide an uninterrupted path for said beam between said chambers, and
a plurality of resilient seals bearing with sliding sealing contact against said planar surface, said seals each spanning said gap and extending throughout with said contact in successive loops fully around said first and second apertures in all relative positions of said first and second chambers,
said loops being such that outer loops wholly surround inner loops, and
between-seal pumping means for pumping the region radially intermediate two of said seals.

7 more elements

Dependencies are inferred from the claim text.

Vacuum chamber for treating workpieces with beams

Life of this patent

Vacuum chamber for treating workpieces with beams

Life of this patent

Abstract

Claims24