A new method for edge collapse prevention in fixed-abrasive lapping

The flatness affects the performance of the key parts in precision optics processing and Integrated Circuit (IC) manufacturing. Normally, the lapping and polishing process are always employed to achieve the high flatness. However, the edge effect cannot be avoided in lapping and polishing due to the process characteristics. Some methods are proposed to decrease the edge effect, but the current prevention methods are limited by many aspects. In this paper, a new method to prevent the edge collapse by protecting the edge is proposed. In this method, the edge collapse is prevented by enlarging the whole structure, and the edge is transferred to the sacrificial loop. In addition, the sacrificial loop is attached to the workpiece, which makes it become a whole structure. A series experiments are conducted to verify the prevention efficiency. The results show that the depth and width of the edge collapse have been reduced by about 80% and 55% respectively by this method. Hence, this method can achieve the effective prevention of edge collapse.