Patent ID: 7975589
Filing Date: 2011-07-12
Classification: B28D,C03B,Y10T

Abstract:
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 a 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 said outer peripheral portion is formed in such a manner as to include inclined surfaces of said two cones, and a central line average roughness Ra of said inclined surfaces is 0.45 μm or less.