Apparatus and method for abrading a workpiece
AssigneeNovellus Systems, Inc.
InventorsAleksander Zelenski, Sergey Cheprasov
Life of this patent
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Abstract
An apparatus for abrading a workpiece comprises a first plate assembly having a first surface for supporting a workpiece and a second plate assembly having a second surface for engaging the workpiece to abrade a portion thereof. A displacement shaft is mounted for movement with respect to the upper and lower plate assemblies and has a first end configured to engage the upper plate assembly. A feedback assembly is coupled to the displacement shaft for moving the displacement shaft to substantially maintain a predetermined load exerted on the displacement shaft by the upper plate assembly.
Claims37
An apparatus for abrading a workpiece, the apparatus comprising:
- a first plate assembly having a first surface for supporting a workpiece;
- a second plate assembly having a second surface for engaging the workpiece to abrade a portion thereof;
- a displacement shaft mounted from movement with respect to said second plate assembly and said first plate assembly and having a first end configured to engage said second plate assembly;
- and
- a feedback assembly coupled to a second end of said displacement shaft for moving said displacement shaft to substantially maintain a predetermined load exerted on said displacement shaft by said second plate assembly.
An apparatus for abrading a workpiece, the apparatus comprising:
- a frame;
- a carriage slidably mounted on said frame;
- a drive mechanism coupled to said carriage for moving said carriage substantially vertically;
- a lower plate assembly having an upper working surface for supporting the workpiece;
- an upper abrading plate assembly having a lower working surface for abradingly engaging the workpiece;
- a displacement shaft having upper and lower ends and slidingly mounted for vertical movement with respect to said upper plate assembly and said lower plate assembly, said upper end configured to engage said upper plate assembly;
- a feedback assembly coupled to the lower end of said displacement shaft for sensing the load between said lower plate assembly and said displacement shaft, and in response thereto, moving said displacement shaft to substantially maintain a predetermined load;
- and
- a displacement measuring assembly coupled to said feedback assembly for measuring the movement of said displacement shaft.
A method for abrading a workpiece to a desired thickness using an abrading apparatus of the type having a vertically stationary lower plate assembly and an upper, vertically moveable and rotatable abrading plate assembly, the method comprising the steps of:
- measuring a first position of a displacement shaft in contact with the upper abrading plate assembly when the upper abrading plate assembly is in contact with the lower plate assembly and a substantially predetermined load exists between said displacement shaft and said upper abrading plate assembly;
- placing the workpiece between the upper abrading plate assembly and the lower plate assembly to abrade the workpiece;
- sensing increases in load on the displacement shaft as the workpiece is abraded;
- lowering the displacement shaft to maintain the predetermined load;
- and
- terminating the abrading of the workpiece when the displacement shaft has been sufficiently lowered to achieve the desired thickness.
Dependencies are inferred from the claim text.