Design And Manufacturing Of Bionic Polishing And Research On Pressure Field Based On Sunflower Seed Pattern

In this article, a kind of the bionic polishing pad with sunflower seed pattern has been designed based on phyllotaxis theory, The sunflower seed pattern will be applied in the designing and making of polishing pad. It is researched that the sunflower seed structure parameter has effect on chemical mechanical polishing of result, the proper parameters could balance the distribution of pressure field on work piece, and making work piece capability uniform, the problem is solved that geometry error in the processing process because the no uniform distribution of contact pressure; and the proper parameters could balance that the distribution of polishing slurry supply and distribution in the chemical mechanical polishing, so that the chemical and mechanical action can get a reasonable match in CMP, and achieve the maximal efficiency of processing.Phyllotaxis arrangement implicates a lot of geometrical and physical characteristics, for example, self-detaching arrangement tightly, maximally absorbing for light radiation and radiating for fluid. Therefore, those geometrical and physical characteristics provide the theoretical basis for obtaining the uniform contact pressure and temperature distribution, and even flow field of the polishing slurry during CMP for wafer.The arrange of the sunflower seed is a typical phyllotactic pattern,leaf patterns of most of advanced plant is spiral fashion. Vogel presented the expanding model that describes the arrange structure of the kernels of the sunflower. Vogel describe the pattern by equation. Base on the model, establish the 3D model of the the bionic polishing pad with sunflower seed pattern.On basis of classical elastic theory, it is established the physical mechanics model on silicon piece of contact form in the CMP. The model of the finite element method(FEM) and the boundary condition are developed based on theory of the FEM, and pressure field is simulated by the ANSYS software which is famous and special for the analysis of the FEM. Base on the result discuss several kinds of the bionic polishing pad parameters effect on contact state and the distribution of contact surface pressure field. The distribution of contact surface pressure field of silicon in CMP and related factors are obtained. Make a simulated analysis for general pad, and contrasting with the bionic polishing pad with sunflower seed pattern.In this article, two types of making the bionic polishing pad are designed. One is pouring, but this method is complicated and expensive. The other is serene printing, this method is relatively simple. Consider the economy, processing condition, working hours and so on. Just make the bionic polishing pad with sunflower seed pattern by serene printing.Finally, going on the experiment of chemical mechanical polishing, abrasive grain blocks and phyllotactic parameters have an effect on removal distribution and roughness of silicon surface which are obtained.