Scribing wheel for brittle material and manufacturing method for same, as well as scribing method, scribing apparatus and scribing tool using the same

Abstract

A scribing wheel for a brittle material includes a circumferential ridge line in which two truncated cones have connected bottoms so as to share a rotational axis. Alternating notches and protrusions are formed along the circumference ridge line. The protrusion are portions of the ridge line remaining after the ridge line is notched. The length of the notches is less than that of the protrusions so that a catch on the surface is improved while lowering the high penetrability.

1 . A scribing wheel for a brittle material, comprising:
 an outer peripheral portion around which a circumference ridgeline is formed, where two truncated cones have connected bottoms so as to share a common rotational axis; and   a number of alternating notches and protrusions which are formed in the direction of the circumference along said circumference ridgeline,   wherein said protrusions are formed of portions of said circumference ridgeline which remain after said circumference ridge line is notched and have a length in the direction of the circumference so that a scribe line is drawn on said brittle material substrate and a vertical crack extending from the scribe line in the direction of the thickness of a brittle material substrate is formed when the scribing wheel is rotated in such a state as to be pressed against said brittle material substrate,   wherein the length of said notches in the direction of the circumference is shorter than the length of said protrusions in the direction of the circumference, and   wherein a central line average roughness Ra of said circumference ridgeline is 0.40 μm or less.   
     
     
         2 . The scribing wheel for a brittle material according to  claim 1 , wherein the length of said notches in the direction of the circumference is a range from 4 μm to 14 μm. 
     
     
         3 .- 4 . (canceled) 
     
     
         5 . The scribing wheel for a brittle material according to  claim 1 , wherein the scribing wheel for a brittle material is an integrated type wheel which has a hole for an axis through which a pin for supporting said wheel around the axis or is formed integrally with said pin. 
     
     
         6 . The scribing wheel for a brittle material according to  claim 1 , wherein said number of notches are formed in the direction of the circumference around the entire periphery of said circumference ridgeline with different depths. 
     
     
         7 . The scribing wheel for a brittle material according to  claim 1 , wherein said notches are formed around the entire periphery of said circumference ridge line with a pitch of 20 μm to 5000 μm, and the depth of said notches is 0.5 μm to 3.0 μm. 
     
     
         8 .- 12 . (canceled)