Investigation of machine vision assisted automatic resharpening process of micro-drills

The micro-drill used in electronic industry is getting smaller in diameter especially for printed circuit board/ball grid array processing; making it is easier to have many defective drills produced in manufacturing process. Defective drills can be resharpened to become conforming products. Focusing on the planar micro-drills less than 0.5 mm in diameter, the paper proposes using machine vision technique to assist the double-wheel grinding mechanism of moving-drill and fixed wheel to achieve resharpening function. First, we find and adjust the posture of micro-drill from vision system for grinding, then detect the line equation of cutting edge of primary facet grinded micro-drill and rotate cutting edge to be horizontal; final we grind the secondary facet of micro-drill. All grinding parameters for resharpening process are found automatically with machine vision technology. As known from the experimental results, the automatic resharpening method proposed by this paper is feasible.