Laser micromachining technology can be used for cutting, drilling, engraving, marking, thermal infiltration, welding, and other micro-fabrication processes in equipment manufacturing, automotive and aerospace precision manufacturing, and various micro-fabrication industries using lasers, such as the machining of inkjet printer nozzles as small as 20 microns. Various micro-optical elements can be processed using laser surface treatment technologies such as micro-pressure shaping, polishing, and plasma-assisted micro-forming during the softening phase by adjusting external mechanical forces. Laser-induced filling of porous glass and amorphization of glass ceramics can be used to change the tissue structure.
Laser micromachining technology has the advantages of non-contact, selective processing, small heat-affected zone, high precision and high repetition rate, and high flexibility in processing parts of various sizes and shapes. In fact, the biggest feature of laser micromachining technology is "direct writing" processing, which simplifies the process and enables fast prototyping of micro-mechanics. In addition, this method does not have the environmental pollution problems caused by methods such as corrosion, which can be described as "green manufacturing".
The short wavelength, small focus spot diameter, and high power density of the excimer laser make it very suitable for microfabrication and semiconductor material processing. In the excimer laser micromachining system, mask projection processing is mostly used, and the workpiece can also be etched directly using the focused spot, which combines excimer laser technology with CNC technology. The laser beam is scanned on the substrate material by combining the relative motion of the laser beam and the X-Y worktable, and micro-patterns can be directly written or three-dimensional microstructures can be processed.
It uses excimer laser deep etching instead of synchrotron radiation lithography, which avoids technical difficulties such as high-precision synchrotron radiation mask manufacturing and overlay alignment. At the same time, the economy and wide use of laser sources are much better than that of synchrotron radiation sources, greatly reducing the manufacturing cost of LIGA technology, making it widely used. Although laser-LIGA technology is inferior to synchrotron radiation in processing microstructures with high aspect ratios, it is completely acceptable for general microcomponent processing. Moreover, laser-LIGA technology does not require chemical etching development like synchrotron radiation lithography, but directly writes and etches without lateral infiltration corrosion, so the edge of laser micromachining is steep, and the lithographic performance is superior to synchrotron radiation lithography.
It is a processing technology derived from the advanced rapid prototyping technology of stereolithography (SLA) applied to micro-manufacturing due to its high precision and miniaturization, so it is called micro-stereolithography. Compared with otherlaser micromachining technologies, the biggest feature of micro-stereolithography technology is that it is not restricted by the shape of microdevices or system structures, and can process any three-dimensional structures including free-form surfaces, and can mold different micro-components at one time, eliminating the micro-assembly process. In addition, this technology has the advantages of short processing time, low cost, and automatic processing, creating favorable conditions for mass production of micro-mechanics.
Pulsed laser etching and shaping is a new research field of laser technology. It uses short-wavelength harmonic or picosecond, femtosecond lasers combined with high-precision CNC machine tools to etch and process various materials. Using short pulses to etch the surface of these materials and removing the materials, the quality of the microstructures formed on the surface is much higher than that when processed with long pulses. The laser beam focal spot diameter is 5mm and the x, y-direction feed is 5mm. Each layer is removed by 1.3mm, and the average surface roughness is 0.16mm. Laser micro-cutting and shaping is essentially the same as laser etching. It uses harmonic or femtosecond lasers as the light source, finely focuses the beam, precisely controls the energy input, and has small heat effects to remove and cut micro-materials.