The Process Research Of Grinding Monocrystalline Silicon Slice With Constant Force Using Single Abrasive Brick

Monocrystalline silicon is widely used in such as integrated circuits, optoelectronic areas aerospace and defence technology as a kind of excellent substrate material. For the demands of subsequent processing technology and device performance, the surface of monocrystalline silicon substrate has a very high geometric accuracy and surface integrity requirements. The important process of monocrystalline silicon slice processing is the ultra-precision grinding using the diamond grinding wheel. Through the effect of brush, scratch, and plow of the diamond grits, the material of the monocrystalline silicon is removed. This process will no doubt cause scratches crush on monocrystalline silicon surface, also can cause micro cracks on the sub-surface. The normal pressure of the grinding has a very big effect on silicon surface and subsurface damage. As the measurement process of high frequency micro force is complex in the grinding wheel grinding process, and the experimental process is difficult, the experiment research under the constant force control of diamond grinding wheel grinding is less. Considering the effect of changes of speed and force between silicon surface and diamond wheel on the surface and sub-surface damage in the process of high-speed grinding monocrystalline silicon, experimental workbench with a force measuring device is designed to realized the single abrasive brick high-speed wipe silicon slice.Using more abrasive grains instead of single abrasive grain amplifies the load value, and facilitates the measurement and control. The high-speed wipe experiment is designed under different speeds and the normal pressure on the surface of single crystal silicon using 40?m grain diameter of resin bond diamond grinding block. The effect of grinding linear velocity and the positive pressure on the grinding efficiency and surface/sub-surface damage under the condition of constant force control of grinding is studiedThe main research contents of this paper are concluded as follows:Based on the rotary platform the integration machine tool of ultra-precision lapping/polishing, the single grinding block constant force control experiment platform is designed with flexible loading system. Platform can realize transverse and longitudinal feed, which is easy to adjust position and dress grinding wheel. A the load knob is set, and the single grinding block constant force control is achieved using the NC3DT60 three-axis force sensor.(1) Grinding experiment is designed using the single grinding block constant force grinding experiment platform, the grinding experiment under constant pressure is completed about the impact of different parameters on the material removal efficiency, and the grinding depth is detected by the LJ-V7060 ultra-high speed contour measuring instrument. The results show that:under constant normal pressure, the single removal depth of abrasive brick increases first, then decreases with the linear velocity increasing. Under the condition of the same linear velocity, the single removal depth increased 2.3-3.1 times with normal pressure is 2 times than before, which effectively improves the removal efficiency.(2) Through the section polishing method for silicon surface/subsurface damage experiment, and using optical microscope to make a contrast of the surface/subsurface damage under different grinding parameters. The results show:under the condition of same normal pressure, the subsurface damage decreases with the linear velocity increasing. And the grinding surface grain becomes fine and homogeneous, the surface defects reduce. Under the condition of same linear velocity, the surface/subsurface damage are improved obviously with the normal pressure increasing.