Thermal defects generation mechanism in laser precision dressing of metal-bonded micro-groove diamond wheel and their influence on grinding silicon wafer

The metal-bonded diamond grinding wheel demonstrates superior grinding capabilities and has been frequently employed to chamfer the edges of semiconductor wafers by meticulously processing micro-groove on the surface. However, the high hardness of diamond wheel poses challenges to the micro-groove processing task. In response to this issue, this paper adopts the deflection laser method to dress the micro-groove of the wheel using a fiber laser. In this paper, the influence of the deflection angle on contour accuracy was studied. The formation mechanism of the recast layer and spatter layer in the laser dressing process was demonstrated, and the influence of surface defects of the wheel on grinding performance was analyzed. The results demonstrated that the laser deflection dressing method had effectively solved the laser energy dispersion problem, improved the microgroove bevel profile, and arc profile dressing accuracy, the maximum angle, arc radius error values were 0.189 degrees, 0.008 mm. The application of low-power sharpening techniques successfully removed thermal defects, such as hot cracks, recast and spatter layers, which were typically produced during high-power shaping, and this refinement improved the grinding capabilities of the wheel. The dimensions of the silicon wafers after chamfering met the requirements and the surface morphology was found excellent with no cracks.