Variable Pressure Brush/Pad

Abstract

A brush for cleaning a workpiece is provided. The brush includes a rigid core having first and second portions affixed to each other. The rigid core has an aperture defined around an axis of rotation of the rigid core. A fluid channel is defined between opposing surfaces of the first and second portions. The fluid channel extends radially from a surface defining the aperture. First and second membranes are affixed to outer surfaces of the first and second portions, wherein movement of the first and second membranes is controlled through introduction of a fluid through the fluid channel. In one embodiment, the membrane is porous and the fluid is a cleaning fluid that contacts the workpiece, such as a magnetic disc or semiconductor substrate for cleaning.

1 . A brush for cleaning a workpiece, comprising:
 a rigid core   first and second membranes affixed to outer surfaces of the rigid core; and   brushes affixed to outer surfaces of the membranes, wherein movement of the first and second membranes, and movement of the brushes, is controlled through introduction of a fluid between the membranes.   
     
     
         2 . The brush of  claim 1 , wherein the first and second membranes are porous and the fluid contacts the workpiece during the cleaning. 
     
     
         3 . The brush of  claim 1 , wherein the first and second membranes have a pad material affixed thereto. 
     
     
         4 . The brush of  claim 1 , wherein the rigid core consists of first and second portions affixed to each other, the rigid core having an aperture defined around an axis of rotation of the rigid core, a fluid channel defined between opposing surfaces of the first and second portions, the fluid channel extending radially from a surface defining the aperture. 
     
     
         5 . The brush of  claim 4 , wherein the first and second portions include a plurality of extensions extending from a surface defining the aperture to a peripheral rim concentric with the aperture. 
     
     
         6 . The brush of  claim 5 , wherein cavities are defined between each of the plurality of the extensions, the peripheral rim and a surface defining the aperture. 
     
     
         7 . The brush of  claim 6 , wherein fluid delivery to each of the cavities is independently controllable. 
     
     
         8 . The brush of  claim 4 , wherein the aperture of the rigid core is disposed over a shaft, the shaft delivering the fluid to the fluid channel. 
     
     
         9 . An apparatus for cleaning a workpiece, comprising:
 a plurality of spaced apart cleaning elements disposed along a length of a shaft, the plurality of spaced apart cleaning elements each having a rigid core with an aperture accommodating the shaft, the rigid core defining a fluid channel extending from the aperture, the rigid core having a flexible membrane extending radially to a perimeter of the rigid core, wherein the fluid channel enables access for a fluid to cause the flexible membrane to expand and contract.   
     
     
         10 . The apparatus of  claim 9 , wherein the shaft includes a fluid delivery channel aligned with the fluid channel. 
     
     
         11 . The apparatus of  claim 9 , further comprising:
 first and second anchors affixed to respective ends of the shaft, the plurality of spaced apart cleaning elements being disposed between the first and second anchors, each of the first and the second anchors having the rigid core with the flexible membrane extending over a single side of the rigid core.   
     
     
         12 . The apparatus of  claim 9 , wherein the flexible membrane is porous and wherein the fluid contacts the workpiece to clean the workpiece. 
     
     
         13 . The apparatus of  claim 9 , wherein the flexible membrane has a layer composed of polyvinyl alcohol disposed thereover. 
     
     
         14 . The apparatus of  claim 9 , wherein the rigid core is compartmentalized by a plurality of extensions radially extending from a surface defining the aperture to an outer rim of the rigid core and wherein the flexible membrane is affixed to a surface of each of the extensions and the outer rim. 
     
     
         15 . The apparatus of  claim 9 , wherein the rigid core is defined by a first and a second member, and wherein the fluid channel is partially formed in the first and second members. 
     
     
         16 . The apparatus of  claim 14 , wherein expansion and contraction of each compartmentalized section independently controllable. 
     
     
         17 . A workpiece cleaning apparatus, comprising:
 a rigid cylindrical core having a surface with a plurality of openings, the rigid cylindrical core rotatable about an axis, wherein a fluid plenum is defined within inner walls of the cylindrical core; and   brushes spaced apart and extending outward from each of the plurality of openings, the brushes having a flexible inner tube in fluid communication with corresponding openings, the flexible inner tube surrounded by a brush material, wherein the flexible inner tube expands and contracts according to a fluid introduced from the fluid plenum, thereby adjusting a gap between the brushes.   
     
     
         18 . The workpiece cleaning apparatus of  claim 17 , wherein the flexible inner tube is curved in a direction opposing a direction of rotation for the rigid cylindrical core and wherein the flexible inner tube extends through the cylindrical core into the fluid plenum. 
     
     
         19 . The workpiece cleaning apparatus of  claim 17 , wherein the flexible inner tube is porous. 
     
     
         20 . The workpiece cleaning apparatus of  claim 17 , wherein an outer surface of the brush material has a groove defined thereon, the groove extending along a length of the brush material. 
     
     
         21 . The workpiece cleaning apparatus of  claim 17 , wherein the apparatus is included with a second workpiece cleaning apparatus proximately located therewith, the second workpiece cleaning apparatus rotating in an opposite direction to the workpiece cleaning apparatus, and wherein workpieces of varying sizes are cleaned contemporaneously when inserted into gaps between the brushes of the workpiece cleaning apparatuses.