Experimental Study On Laser Bending Of Silicon Sheet With Different Thickness And Pt Coated Silicon Sheet

During the development of microelectronics and photonics technology, devices in the micro-fabrication field need the manufacturing of plane size as well as complex surface, especially warping micro beam. With the development of science and technology and the change in the demand of silicon sheet with different thickness and Pt coated silicon sheet, it's necessary to break through traditional plane structure with minimum thickness to make further research on the forming of silicon sheet with different thickness and Pt coated silicon sheet. Though the thicker silicon sheet features high hardness while it's still easy to break down by traditional forming method for it belonging to brittle materials and temperature control being more complicated; it takes a long manufacturing cycle and is very difficult to control by chemical means, making environmental pollution inevitably. As a result, laser bending in the micro-manufacturing of brittle material can not only save costs, but shorten the manufacturing cycle and achieve green manufacturing (no pollution). This not only saves a lot of time but also generates direct long-term economic profit. Above all it can be transferred to micro-manufacturing from the traditional manufacturing technology as well as provides good foundation for further development of green manufacturing.Based on the requirement for the silicon sheet with different thickness and Pt coated silicon sheet in MEMS, the main work of the thesis could be summarized as follows:(1) The bending experiments on the silicon sheet with different thickness (100μm,200μm,300μm) are done by millisecond pulse width JK701H-Nd:YAG laser. Based on the existing laser equipment, the relations between the thickness of silicon sheet and bending angle, scanning times and bending angle, cooling time and bending angle, are studied. The changing discipline of silicon sheet bending is investigated.(2) The thermal simulation model is established by Ansys to compute the temperature distribution of silicon sheet with different thickness in the bending process, which is done under the same conditions. The feasibility of forecasting is summarized by comparing with the characteristics of temperature distribution.(3) The electrical property of silicon sheet in the thickness of 100μm after bending is measured by related equipment, optical microscope for silicon surface, semiconductor for IV curves, as well as Hall measuring equipment for carrier concentration and Hall mobility. Based on the bending experiments, the influence on the electrical property is discussed. (4) The temperature field and stress strain field of Pt coated silicon sheet by laser bending are analyzed by simulation of finite element analysis software Ansys. The confirmatory tests are conducted aiming at the simulation results.The laser bending of silicon sheet with different thickness and Pt coated silicon sheet is studied. The combination of bending experiments, measurement and simulation technology creates silicon-bending forming process for high-quality production and opens up a new way for high-performance, environmentally friendly, high-quality silicon material in rapid prototyping manufacturing.