Research Of The Mechanism Of Polishing Based On Bionic Tin Polishing Pad

Chemical mechanical polishing (CMP) is the most important processing methods for electronic substrate, optical plane and ceramic workpiece and other parts of the ultra-precision machining. The polishing pad in the decision of polishing rate and flatness in the decision as an important component of capacity. It Bears and performs polishing slurry, passing the polishing of the normal force (Normal forces) and shear (Shear forces), and playing a very important role during CMP.At first, this article outlines the background of CMP and prospects, described the role and function of polishing pad in the heart of the CMP system, and the entire CMP process and processing effect. Therefore, Based on the theory of Winkler foundation and phyllotaxis theory a kind of tin pad with bionic surface texture has been designed。And then, the contact mechanism and ANSYS models have been established, Calculated by the finite element method that affect the field uniformity of the wafer surface contact pressure distribution of the key factors ,The phyllotactic parameter k and hemisphere is the most important factors which influence the uniformity of the contact pressure distribution, When the phyllotactic parameter k is 2.2 and the abrasive hemisphere is 2.0, the contact pressure distribution on workpiece surface will be more uniform. The collapse of surface of wafer has been improved.After that, by screen printing method and the reflow processing out of the bionic polishing pad and access to the preparation of processing method of pad. Finally, carrying out comparative experiments with tin pad and general pad on the surface of chip, and considering material removal rate and roughness and surface accuracy of three factors, that the tin pad with bionic surface texture has excellent features than general pad.