Design & Research Of Nanosecond Pulse Laser Micromachining System

Pulse Laser machining has been proved to be a successful technique in precise machining and micro-fabrication. The advantage of laser machining is non-contact processing, less pollution, high precision, and applicable to a variety of processing targets, especially some hardness and brittle materials. So it is widely used in MEMS, aerospace, medical device and so on.In this paper a new nanosecond pulse laser micromachining system has been designed, which consists of computer software, nanosecond pulse LASER, mechanical and optical structures, control system, 2D work platform, assistant system. The wavelength of the laser is 355nm, and the pulse duration is less than 40ns. The pulse repetition frequency can be set from single shot to 100kHz. The 2D work platform is driven by step motors, and single step moves 625nm. The design of the control circuit is based on DSP and FPGA. When the platform moves according to designed trace, micromachining is being done by the nanosecond pulse laser. The result of the experiments shows that the stable moving speed of platform is helpful for increasing linearity, and the suitable energy and repetition frequency decide the depth and width of the line. The microstructures fabricated by the nanosecond laser micromachining system is about 20~50um wide.The main work of the system design is as follows:1. Analyzing the principle of nanosecond pulse laser machining, and designing the system.2. Designing the mechanical and optical structures of the micromachining system.3. Designing and debugging the hardware control circuit based on DSP and FPGA.4. Designing and debugging the software procedures, including parallel port communication, DSP data processing, FPGA machining control, etc.5. Experimenting on the nanosecond pulse laser micromachining system. Different parameters of the system are researched and analyzed. Then some measures are taken to improve the effect of micro-fabrication.