Laser drilling is a laser processing technology that uses a high-power-density. Short-time stay (less than laser cutting) pulse heat source to perform drilling. The aperture can formed by single or multiple pulses.
In the punching process, a small hole of sufficient size is first prepare using the punching mode, so that the subsequent cutting process starts from here. The drilling or penetrating process requires a repeatable pulse laser beam with high peak power, which is also achieve with a high air pressure. After the workpiece penetrates, the laser beam cuts through the peak power and even changes to a pulse-free mode.
The solid-state laser has a short wavelength and can achieve high-intensity pulse output, so it is more suitable for laser drilling, such as Nd: YAG laser, Nd: glass laser, and Nd: ruby laser.
CO2 lasers are commonly use to make holes in non-metallic materials, such as ceramics, composites, plastics or rubber. Laser drilling of metal materials requires pulsed lasers, and the beam focusing power density should be above 10 ^ 5 W / mm ^ 2 (6.5 W / in. ^ 2 × 10 ^ 7 W / in. ^ 2).
Focusing of the laser beam.
Laser drilling process
In the laser drilling mode, a short focal length lens is need to focus the high peak power beam of the pulsed laser on a spot of the order of 0.6 mm in diameter to achieve the power density level required for drilling.
Low divergence of the laser beam can achieve with specific laser resonators. The beam diameter can controlle by changing the aperture of the focusing device. Therefore, the aperture can be used to increase the energy density of the focused beam and increase the intensity distribution of the beam.
Advantages of laser drilling technology
Laser drilling has most of the advantages of laser cutting. It only needs to make a certain angle between the light beam and the surface of the material to achieve the laser beam intake and drilling, which effectively avoids the occurrence of impact and breakage events caused by structural interference during mechanical processing.
Other laser drilling advantages
1. Short opening time
2. Strong automation adaptability
3.Can be used for penetrating processing of difficult-to-open materials
4. Compared with mechanical drilling, there is no mechanical wear between the workpiece and the workpiece during the drilling process.
Laser drilling is the earliest practical laser processing technology and one of the important application areas of laser processing. Laser drilling is mainly used for metal materials such as steel, platinum, molybdenum. Tantalum, magnesium, germanium, silicon, light metal materials such as copper, zinc, aluminum. Stainless steel, heat-resistant alloys, nickel-based alloys, titanium, platinum. And common hard alloys Materials and ceramic substrates, artificial stones, diamond films, ceramics. Rubber, plastics, glass, etc. in non-metallic materials.