The Thermal Stress Analysis Of Silica (Si) Irradiated By Laser

Processing silicon materials by laser can ensure the accuracy and efficiency and increase the processing's environmental performance. It's being paying attention and accepting by people. When the laser touch the face of Si material, there are a lot of problems appeared such as Shape changes or damage caused by thermal stress. The object of this study is the thermal stress analysis of Silicon irradiated by laser.About the Si material's temperature distribution and thermal stress distribution when they are under the laser's irradiation, this study analyzed and found the solutions that under the steady-state temperature field of silicon material's temperature distribution and stress distribution. Otherwise, we also theoretical analyzed and solved the temperature distribution and stress distribution of laser irradiation of silicon material under the three-dimensional unsteady temperature field by using the initial conditions and boundary conditions and thermo-elastic equations.Based on the heat conduction equations, we found the model about the temperature distribution and thermal stress distribution. Then We simulated and analyzed with a wavelength of 1064nm, energy 100mJ, pulse width of 10ns, gaussian distribution of laser energy was irradiated crystal structure of (110) face of silicon material and the edge of laser irradiation zone heat distribution and thermal stress distribution. Through the result, we analyzed the laser energy, laser spot size's inflations on the thermal distribution and thermal stress distribution.The result tells us, the temperature's increase is very fast in range of the spot, but it is not so clearly in outside. The same node's temperature changes with the laser energy's change increases with the laser radius decreases. Stress increases as the temperature increases, but the circumferential and radial distribution of the situation is more complicated. In the range of the spot, the thermal stress on the ring direction is negative. Closing the centre of the spot, the increasing of the temperature is fast, the value becomes positive. After reaching the maximum, the value decline toward slowly.This research work will be silicon experimental study of laser damage mechanism to provide theoretical guidance for the silicon laser processing technology improvements and the improvement of laser systems provide a theoretical basis.