Dressing jig for glass substrate polishing pad

Abstract

Dressing treatment of a polishing pad, adjusting a polishing surface of the polishing pad to given flatness and surface roughness without deteriorating productivity, a method for polishing a glass substrate, including polishing a main surface of a glass substrate using the polishing pad adjusted by the dressing treatment, and a method for manufacturing a glass substrate using the polishing method are provided. A dressing jig having arithmetic surface roughness on a surface performing dressing treatment of from 0.10 μm to 2.5 μm is used as the dressing jig for adjusting a polishing surface of the polishing pad to given flatness and surface roughness. A main surface of the glass substrate is polished with the polishing surface of the polishing pad having been subjected to a dressing treatment using the dressing jig.

1 . A dressing jig for a glass substrate polishing pad, having a plate shape and dressing a polishing pad for a glass substrate with a plate surface thereof, wherein the plate surface has a surface roughness of from 0.10 μm to 2.5 μm in terms of arithmetic average roughness Ra. 
     
     
         2 . The dressing jig for a glass substrate polishing pad according to  claim 1 , wherein a material of the plate surface of the dressing jig is at least one kind selected from the group consisting of a glass, ceramics, silicon, a stainless steel, aluminum, an aluminum alloy, titanium and a titanium alloy. 
     
     
         3 . A method for polishing a glass substrate, said method comprising dressing a polishing pad for a glass substrate using the dressing jig according to  claim 1 , and polishing a glass substrate with the polishing pad for a glass substrate. 
     
     
         4 . The method for polishing a glass substrate according to  claim 3 , wherein a polishing surface of the polishing pad after the dressing treatment has a surface roughness of 2.4 μm or less in terms of arithmetic average roughness Ra. 
     
     
         5 . The method for polishing a glass substrate according to  claim 3 , wherein an amount of change of the arithmetic surface roughness Ra of the dressing jig before and after the dressing treatment is 15% or more. 
     
     
         6 . A method for manufacturing a glass substrate, said method comprising the method for polishing a glass substrate according to  claim 3 . 
     
     
         7 . A method for manufacturing a glass substrate according to  claim 6 , wherein the glass substrate is a disk-like glass substrate for a magnetic recording medium and has a circular hole in a central portion thereof. 
     
     
         8 . The method for manufacturing a glass substrate for a magnetic recording medium according to  claim 7 , wherein an average value of micro waviness μWa having a period of from 150 μm to 1,200 um measured using a scanning white light interferometer is 0.12 nm or less at positions of 0°, 120° and 240° in an intermediate portion of recording and reproducing regions of both main surfaces of the glass substrate for a magnetic recording medium, and difference of micro waviness μWa measured at said six sites is 0.020 nm or less. 
     
     
         9 . The method for manufacturing a glass substrate for a magnetic recording medium according to  claim 7 , wherein an average value of micro waviness Wq having a period of from 40 μm to 200 μm measured using laser light having a wavelength of 405 nm at six sites of an inner diameter region, an intermediate region and an outer diameter region in recording and reproducing regions of both main surfaces of the glass substrate for a magnetic recording medium is 2.0 nm or less. 
     
     
         10 . The method for manufacturing a glass substrate for a magnetic recording medium according to  claim 7 , wherein an average value of arithmetic average roughness Ra measured using an atomic force microscope at two sites of 0° and 180° in an intermediate portion in a recording and reproducing region of the glass substrate for a magnetic recording medium is 0.15 nm or less.