The Basic Research On The Composite Processing Technology Of Nanosecond Laser And Water Jet In Silicon Micro Channel

With the development of science and technology,the application of silicon as a semiconductor material in the microelectronics industry has become increasingly widespread.In particular,the demand for silicon microstructures has been increasing year after year.At the same time,the requirements on the processing quality and efficiency of silicon microstructures have become higher and higher.In order to realize high quality aspect ratio silicon microchannel processing,this paper proposed a hybrid processing method of nanosecond laser and water jet,making full use of nanosecond laser’s efficient processing characteristics and the features of water jet cooling and scouring to make high-quality,high-efficiency processing of silicon microchannels.First of all,this paper studied the optical path of laser and water jet combined processing and builds a photo-liquid coupling device based on this.The geometrical characteristics of the laser propagation in the device were studied.The limit of focal range and the necessary conditions for the laser focus on the Z-axis direction and the self-coupling of the upper surface of the nozzle were obtained.On the basis of fully analyzing the characteristics of stable water jets,a multi-inlet optical-liquid coupling device flow channel was designed.The FLUENT module of ANSYS was used to simulate and analyze the flow channel of the coupling device.The photo-liquid coupling device was processed and verified by experiments.The characteristics of water jets in different states were studied,and two intuitive stable water jet judgment criteria were proposed.The coupling debugging process was improved for this device.Secondly,the material removal process of silicon nanosecond laser and water jet composite machining was studied,and the removal mechanism of silicon was verified by the actual processing morphology.Based on the related knowledge of heat transfer and thermoelasticity,a finite element simulation model of nanosecond laser and water jet composite processing of silicon was developed and the machining process was simulated.The machining process was studied from the temperature field,stress field,and material removal rule.The effect of unique pulse characteristics on the processing morphology was verified by experiments.According to the non-linear phenomenon in the process,the test verifies the correlation of this phenomenon with the laser repetition frequency.Finally,the single-channel and multi-channel processing technology of nano-second laser and water jet machining of silicon microchannels was studied.In the single-channel processing,the processing features under different process parameters were compared to summarize the processing rules.The processing morphology under different processing layers and processing strategies was compared in multi-channel processing,and the processing rule of line width was explored.According to the optimized process parameters,IC wafers,MEMS wafers,and stainless steel tube cutting tests were performed.The paper developed a new type of optical-liquid coupling device,and study nanosecond laser and water jet composite processing silicon by theoretical simulation and experimental analysis.The paper explored the micro-channel processing technology,and had important guiding significance for the future processing of silicon microstructures.