Traditional cleaning methods: mainly mechanical cleaning and chemical cleaning, etc. Mechanical cleaning is a contact cleaning, which will generate stress and damage the substrate; chemical cleaning will corrode the surface of the workpiece, and the pollution is harmful to the human body.
Principle of laser cleaning: Using a high power density laser to act on the surface of the workpiece to be cleaned (non-contact), the pollutants on the surface of the workpiece absorb the focused laser energy, rapidly expand, vaporize, and peel off, thereby separating from the surface of the workpiece to achieve the purpose of cleaning.
Therefore, laser cleaning has the advantages of high efficiency, non-contact, no damage, green environmental protection, low cost, and flexible control. Compared with traditional cleaning methods, laser cleaning technology occupies an absolute advantage.
Laser cleaning spot energy distribution: the energy density is higher than the damage threshold of the substrate, the substrate is easily damaged, and the energy density is lower than the pollutant ablation threshold, the cleaning effect cannot be achieved. Therefore, laser cleaning generally needs to select an appropriate energy density to ensure pollution. The material is removed and the substrate is not damaged. Single-mode lasers are generally Gaussian beams. The beam quality is good, it can focus a small spot and has an ultra-high energy density. It is suitable for the removal of high-adhesion pollutants such as heavy rust, and can also have a certain texturing effect. In some cases, the cleaning of precision objects such as molds requires that the substrate cannot be damaged, so a flat-top beam with uniform energy distribution is required for cleaning.