Application of a Model-Free Algorithm for the Packing of Irregular Shaped Objects in Semiconductor Manufacture

A Robotic System is being developed to automate the crucible packing process in the CZ semiconductor wafer production. It requires the delicate manipulation and packing of highly irregular shaped polycrystalline silicon nuggets, into a fragile glass crucible. Here an on-line algorithm is presented to plan the packing. It uses a method called Virtual Trial and Error. The on-line algorithm handles large numbers of highly irregularly shaped object of different sizes without requiring the object models. Working with the 3-D range maps of objects, it is computationally fast enough to be applied in real-time to practical industrial applications, such as the CZ wafer manufacture. Simulation results show that it compares well with the human performance. The integrated system is shown to achieve high production rates, required precision and cost effectiveness.