Segmented wafer polishing pad

Abstract

Working plate ( 10 ) is formed of forty-eight sections ( 10 ′), with groove ( 12 ) extending through the majority of the thickness of the plate. In one form, dovetail grooves are machined to the back of the sections of the plates ( 10 ′) attached to the base plate ( 19 ). In an alternative arrangement, fixing rails are attached to the backs of the sections and the dovetail grooves are in the base plate ( 19 ).

1 . Lapping apparatus for flat lapping application using multi-groove slurry distribution, the apparatus comprising means to rotate a lapping plate, the lapping plate comprising a base plate having detachably mounted thereon a working plate for abutment against material during the lapping operation, the working plate being rigid and having a cross-hatch arrangement of grooves on the surface for abutment against a semi-conductor wafer in the lapping operation, the cross-hatch arrangement of grooves comprise two sets of continuous grooves.  
     
     
         2 . Lapping apparatus for the manufacture of semi-conductor wafers, the lapping apparatus comprising means to rotate a lapping plate, said lapping plate comprising a base plate having detachably mounted thereon a working plate for abutment against a semi-conductor wafer during the lapping operation, the working plate being rigid and having a cross-hatch arrangement of grooves on the surface for abutment against a semi-conductor wafer in the lapping operation, the cross-hatch arrangement of grooves comprising two sets of continuous grooves.  
     
     
         3 . Lapping apparatus according to  claim 1  or  2  wherein the working plate is segmented to form a plurality of equi-planar sections.  
     
     
         4 . Lapping apparatus according to any preceding claim wherein the working plate is segmented in strips.  
     
     
         5 . Lapping apparatus according to any preceding claim wherein the working plate is segmented in columns and rows.  
     
     
         6 . Lapping apparatus according to any preceding claim wherein the sets of grooves are mutually orthogonal.  
     
     
         7 . Lapping apparatus according to any preceding claim, comprising two lapping plates each having a base plate with a working plate detachably mounted thereon, the working plates abutting opposing faces of a semi-conductor wafer during the lapping operation.  
     
     
         8 . Lapping apparatus according to any preceding claim comprising at least one fixing rail attached to the base plate.  
     
     
         9 . Lapping apparatus according to  claim 8  wherein the fixing rail has a dovetail profile.  
     
     
         10 . Lapping apparatus according to  claim 8  wherein the fixing rail has an ovoid profile.  
     
     
         11 . Lapping apparatus according to  claim 9  or  10  wherein the at least one rail comprises a load distribution strip to effect clamping of the rail at the edges.  
     
     
         12 . Lapping apparatus according to any preceding claim wherein the or each working plate is formed of a plurality of sections.  
     
     
         13 . Lapping apparatus according to  claim 12  wherein the sections of a plate are joined at lines which are groove lines of the working plate when complete.  
     
     
         14 . Lapping apparatus according to  claim 1  wherein the working plate includes one or more further grooves extending generally diagonally relative to the arrangement of grooves.  
     
     
         15 . Lapping apparatus according to any preceding claim, wherein the base plate is formed of one of the following materials: 
 Stainless steel, treated aluminum, treated mild steel, gray cast iron, Kevlar/epoxy composite, carbon/epoxy composite, glass/epoxy composite, glass/polyester composite.    
     
     
         16 . Lapping apparatus according to any preceding claim wherein the working plate is formed of one of the following materials: 
 spheroidal cast irons, ceramics.    
     
     
         17 . Lapping apparatus according to any preceding claim wherein the working plate is detachably mounted on a base plate by means of one or more of the following: 
 Magnetic clamping;    Male/female arrangements incorporating the plate as one of the attachment;    Male/female arrangements with other mechanical fixings;    Other mechanical means of attachment e.g. cotter of dowel pins, taper pins, circlips;    Advesively bonding the working surface to the base plate other fastening media, e.g. Velcro (RTM) or adhesive tapes. Hydraulic or Pneumatically operated retention methods.    
     
     
         18 . A working plate for lapping apparatus according to any preceding claim.  
     
     
         19 . A working plate according to  claim 14  being rigid and having means to attach the plate onto a base plate of a lapping apparatus and working plate has a cross-hatch arrangement of grooves on the surface for abutment against a semi-conductor wafer in the lapping operation the cross-hatch arrangement of grooves comprise two sets of continuous grooves.  
     
     
         20 . A working plate according to  claim 19  wherein the attachment means comprises one or more of the following: 
 Magnetic clamping;  
 Male/female arrangements incorporating the plate as one of the attachment;  
 Male/female arrangements with other mechanical fixings;  
 Other mechanical means of attachment e.g. cotter of dowel pins, taper pins, circlips;  
 Advesively bonding the working surface to the base plate other fastening media, e.g. Velcro (RTM) or adhesive tapes.  
 Hydraulic or Pneumatically operated retention methods.  
 
     
     
         21 . A working plate according to  claim 18  or  19  wherein the working plate is formed of a plurality of sections.  
     
     
         22 . A working plate according to  claim 20  wherein the working plate is formed of sections for joining at lines which are groove lines of the working plate when complete.  
     
     
         23 . A working plate according to any of  claims 18  to  22  wherein the working plate has a cross-hatch arrangement of grooves on the surface for abutment against a semi-conductor wafer in operation.  
     
     
         24 . A working plate according to any of claims  20  or  21  wherein the working plate is formed of one of the following materials: 
 spheroidal cast iron, ceramics.