Split-window CMP polishing pad and preparation method thereof

Abstract

A preparation method of a split-window CMP polishing pad includes engraving a groove and a window in a backing, attaching the backing with a substrate through an adhesive, punching a hole in the substrate corresponding to the window through a substrate punching mold, forming window support blocks, punching an original window material through a punching machine and a window punching mold, obtaining a formed window material, coating another adhesive on the window support blocks, placing the formed window material into the window portion, and attaching the formed window material to the window support blocks. Compared with the sliced integrated-window, for the split-window provided by the present invention, the materials do not affect each other during the manufacturing process, so that the problem of uneven density distribution of the backing after curing can be solved, and the fluctuation of the tensile strength caused by uneven temperature is reduced.

What is claimed is: 
     
         1 . A preparation method of a split-window CMP (chemical mechanical polishing) polishing pad comprising steps of:
 (S1) preparing a backing and engraving a groove on the backing;   (S2) preparing a substrate and coating a layer of first adhesive on a bottom of the substrate;   (S3) engraving a window portion on the backing engraved with the groove for accommodating a formed window material, wherein the window portion defines a window;   (S4) attaching the backing engraved with the window portion to the substrate coated with the layer of the first adhesive through a layer of second adhesive, forming a hole in the substrate corresponding to the window of the backing by punching through a substrate punching mold, and simultaneously forming two window support blocks at two sides of a bottom of the window portion, respectively, wherein the layer of first adhesive and the layer of second adhesive are respectively coated on the bottom and a top of the substrate;   (S5) punching an original window material through a punching machine and a window punching mold, and obtaining the formed window material;   (S6) coating a layer of primer on the two window support blocks; and   (S7) placing the formed window material into the window portion, attaching the formed window material to the window support blocks, and obtaining the CMP polishing pad.   
     
     
         2 . The preparation method, as recited in  claim 1 , wherein: the window portion is oval with a long side in a range of 35 to 41 mm, an arc radius in a range of 8.6 to 10.6 mm, and a distance between a center of the window portion and a center of the backing in a range of 98.5 to 104.5 mm. 
     
     
         3 . The preparation method, as recited in  claim 2 , wherein: the window portion has the long side of 38 mm, the arc radius of 9.5 mm, and the distance between the center of the window portion and the center of the backing of 101.5 mm. 
     
     
         4 . The preparation method, as recited in  claim 1 , wherein: the substrate punching mold is oval, wherein a diameter of the hole is 2.7-3.3 mm smaller than a window size of the window portion. 
     
     
         5 . The preparation method, as recited in  claim 1 , wherein: a size of the window punching mold is as same as that of the window portion. 
     
     
         6 . The preparation method, as recited in  claim 1 , wherein: the primer is Primer  94 . 
     
     
         7 . A CMP (chemical mechanical polishing) polishing pad, which comprises a backing, a substrate, a first adhesive and a second adhesive, wherein: multiple grooves are provided on the backing, the backing comprises a window portion which defines a window, the substrate has a hole, a window material is accommodated within the window portion, and two window support blocks are respectively located at two sides of a bottom of the window portion. 
     
     
         8 . The CMP polishing pad, as recited in  claim 7 , wherein: both the window and the hole have a same hole center, and a diameter of the hole is smaller than that of the window. 
     
     
         9 . The CMP polishing pad, as recited in  claim 8 , wherein: the diameter of the hole is 2.7-3.3 mm smaller than that of the window. 
     
     
         10 . The CMP polishing pad, as recited in  claim 7 , wherein: the two window support blocks are centrally symmetrically distributed to each other relatively to the window and the hole.