Design Of High Precision Micro-machining System Based On Compact Excimer Laser

Laser micromachining technology refers to a technology that irradiates laser on the surface of a material,causing the change of surface shape or structure of the material,and is also the technology that has the fastest growing application demand in the field of material processing.At present,the laser wavelength used in common laser micromachining is mainly concentrated in the infrared and visible bands.Although using the thermal effect of laser to achieve micromachining possesses advantages like fast processing speed and low cost,there are some shortcomings such as low processing accuracy,large thermal effect,and not suitable for semiconductor materials and high polymer materials.Excimer laser has attracted extensive attention in the field of high-precision micromachining because of its advantages such as extremely short wavelength,narrow pulse width,large single-photon energy,uniform laser energy distribution and small thermal effect.In this paper,a high precision micromachining system based on compact excimer laser was designed.The system used 193 nm excimer laser in the deep ultraviolet band for micromachining.It overcome technical difficulties such as deep ultraviolet laser transmission and shaping,focusing spot adjustment and control,and stable control of the whole machine under discharge interference environment,and realized the integration and effective control of the four parts of the laser light source,the deep ultraviolet laser light transmission system,the host computer and the processing pattern,and the target material.Micro-machined topography with adjustable spot size,adjustable spot overlap rate and different processing patterns was obtained in this system.The optical resin lens was processed using this system,and the characteristics and laws of the interaction between different laser parameters and the optical resin lens were explored.The main contents are:1.A high-precision all-optically isolated laser light source control system was designed.The system transmitted the switch-type control signal through the optical fiber,and the control signal drove the DAC chip to generate an analog voltage,which was isolated and outputted by a linear optocoupler.The entire system was fully fiber-optically isolated,electromagnetic interference was effectively suppressed,achieved highly stable and reliable control,and provided a stable and reliable laser light source for the micromachining system.2.Based on imaging,combined with an adjustable diaphragm,focusing lens and scanning galvanometer,a deep ultraviolet laser optical transmission system was designed and built,achieved high precision control of the micro-machined area.3.Based on the development of the host computer software of Lab VIEW,a set of host computer control software was written on the PC side,which can not only realized the complex control of the laser,but also realized the precise control of the micromachining process.4.Tested and verified the micro-machining performance of the system.Firstly,the system achieved a uniform spot with an adjustable diameter of 50 ?m to 160 ?m at the point of action.Secondly,by controlling the scanning galvanometer,the laser spot action area in the range of 5 mm*5 mm was realized,and the minimum spot step was 5 ?m,which effectively controlled laser spot effect position and effect quantity.Finally,the system tested the optical resin lens.Through optical micromorphology analysis and scanning electron microscopy micromorphology analysis,the laser energy density of the excimer laser,the laser repetition frequency,and the number of pulsed lasers were explored for the effect of micro-machined optical resin lenses.In this paper,a high precision micro-machining system based on compact excimer laser was designed.It can realize different micro-machining morphologies with adjustable spot size and adjustable spot overlap.This not only provides a powerful tool for exploring the field of excimer laser material processing and studying the interaction between deep ultraviolet laser and materials,but also has certain reference value for engineering applications and theoretical research.