Diamond disc and method for manufacturing same

Abstract

A diamond disc includes: a shank base; a bonding layer formed on a surface of the shank base; and a plurality of boron-doped diamonds (BDD) disposed in the bonding layer to be exposed. At least some of the plurality of boron-doped diamonds are disposed in the bonding layer in a posture in which an uppermost surface thereof meeting a long axis of the boron-doped diamond is inclined downward from an upper end of the major axis.

What is claimed is: 
     
         1 . A diamond disc comprising:
 a shank base;   a bonding layer formed on a surface of the shank base; and   a plurality of boron-doped diamonds (BDD) disposed in the bonding layer to be exposed,   wherein at least some of the plurality of boron-doped diamonds are disposed in the bonding layer in a posture in which an uppermost surface thereof meeting a long axis of the boron-doped diamond is inclined downward from an upper end of the major axis.   
     
     
         2 . The diamond disc of  claim 1 , wherein the boron-doped diamonds are disposed in the bonding layer in a posture in which the long axes of the boron-doped diamonds have an angle more than 50° and equal to or less than 90° with respect to the shank base. 
     
     
         3 . The diamond disc of  claim 1 , wherein a wetting angle at which a surface of the bonding layer and a surface of each of the boron-doped diamonds meet is maintained at 0° or more and 60° or less. 
     
     
         4 . The diamond disc of  claim 1 , wherein a ratio of a thickness of the bonding layer to an average diameter of the boron-doped diamonds is in a range of 30% to 65%. 
     
     
         5 . The diamond disc of  claim 1 , wherein an amount of boron doped in each of the boron-doped diamonds ranges from 1 ppm to 2000 ppm. 
     
     
         6 . The diamond disc of  claim 1 , wherein a magnetic susceptibility per unit volume of each of the boron-doped diamonds is in a range of 20 to 800 per unit volume. 
     
     
         7 . The diamond disc of  claim 1 , wherein a ratio of a density of the boron-doped diamonds to a density of the bonding layer is maintained in a range of 0.4 to 0.6. 
     
     
         8 . The diamond disc of  claim 5 , wherein each of the boron-doped diamonds is an octahedron diamond, and
 a lower end of the boron-doped diamond is in point or line contact with the surface of the shank base or is spaced apart by a predetermined distance from the surface of the shank base when the boron-doped diamond is erected on the bonding layer.   
     
     
         9 . The diamond disc of  claim 1 , wherein in a pad cut rate (PCR) test equipment, when a CMP Pad conditioner made of the boron-doped diamonds is rotated at 100 rpm to 120 rpm and a polishing pad is rotated at 80 rpm to 95 rpm, it takes more than 13 hours until a PCR by the boron-doped diamond lowers to 2 to 10 μm/hr range for pad conditioning in a state in which the CMP Pad conditioner made of the boron-doped diamonds presses the polishing pad at 4 to 9 lbf. 
     
     
         10 . A diamond disc manufacturing method, comprising:
 a bonding material application step of applying a bonding material to a surface of a shank base;   a pre-sintering step of heating the bonding material applied to the surface of the shank base to a first temperature range to form a pre-sintered bonding layer;   a diamond providing step of providing a plurality of boron-doped diamonds (BDD) to the surface of the pre-sintered body; and   a heat treatment step of performing heat treatment in a second temperature range so that at least some of the plurality of boron-doped diamonds are disposed in the bonding layer in a posture in which an uppermost surface meeting a long axis of the boron-doped diamond is inclined downward from an upper end of the major axis.   
     
     
         11 . The diamond disc manufacturing method of  claim 10 , wherein in the heat treatment step, the boron-doped diamonds are disposed in the bonding layer, in a posture in which the long axes of the boron-doped diamonds have an angle more than 50° and equal to or less than 90° with respect to the shank base, to be exposed. 
     
     
         12 . The diamond disc manufacturing method of  claim 10 , wherein in the pre-sintering step, the first temperature range is 600° C. to 900° C., and in the heat treatment step, the second temperature range is 1000° C. to 1300° C. 
     
     
         13 . The diamond disc manufacturing method of  claim 10 , wherein in the heat treatment step, a wetting angle at which a surface of the bonding layer and a surface of each of the boron-doped diamonds meet is maintained at 0° or more and 60° or less. 
     
     
         14 . The diamond disc manufacturing method of  claim 10 , wherein in the heat treatment step, a ratio of a thickness of the bonding layer after the heat treatment to an average diameter of the boron-doped diamonds is in a range of 30% to 65%.