New deformation prediction of micro thin-walled structures by iterative FEM

The machining of micro thin-walled parts constitutes a key process in the microelectronic field. Deformations and machining errors easily occur, due to the low stiffness of micro thin walls. In this paper, a new iterative finite element method (iterative FEM) was proposed for the deformation predictions based on previous conducted works in the authors' laboratory. The new method, with aim at the effect of low radial immersion milling, was improved in three aspects compared to the traditional predicted methods: interaction calculation between the deformation extent and the cutting force; the grid division was significantly intensive; the cutting force was dispersed on certain nodes similarly to real cases. Firstly, the static deformation analysis and iterative FEM were introduced. Following, a diamond-coated micro milling tool was utilized to machine the micro thin-walled structures of 30 to 105 mu m in thicknesses. Subsequently, several tungsten steel-coated milling tools were also utilized. Various tool diameters and edge radii were selected for comparison to the diamond-coated micro milling tool. The experimental results demonstrated that the deformations were approximately consistent with the simulation results, although certain errors still existed.