Compliant Mesoscale Grinding of 3-Dimensional Free Form Shapes in Silicon Wafers

This paper presents a new approach to create three-dimensional free form shapes in silicon wafers by compliant grinding. Instead of requiring high rigidity in traditional ultra-precision grinding systems, the proposed compliant grinding method requires relatively low rigidity. It achieves the required surface roughness, form accuracy and surface integrity by utilizing grinding force feedback and adaptive control. Compliant grinding mitigates microfractures, chipping, and defect formation in the silicon substrate, so that both electronic and mechanical properties of the Si are not degraded. A prototype silicon die grinder has been built and initial rough grinding results are promising.