The basic principle of laser marking
August 21, 2022
Laser marking is the use of a laser beam to mark permanent surfaces on a variety of different materials. The effect of marking is to expose deep substances by evaporation of surface substances, or to "engraving" traces by chemical and physical changes of surface materials caused by light energy, or to burn off some substances by light energy to show the desired etching. Pattern, text.
At present, there are two recognized principles of laser processing:
(1) "Heat processing" A laser beam with a higher energy density (which is a concentrated energy flow), which is irradiated on the surface of the material to be processed, absorbs laser energy on the surface of the material, and generates a thermal excitation process in the irradiation region, thereby making the material The surface (or coating) temperature rises, causing metamorphosis, melting, ablation, evaporation, and the like.
(2) "Cold processing" (ultraviolet) photons with high load energy, which can break the chemical bonds in the material (especially organic materials) or the surrounding medium, so that the material undergoes non-thermal process damage. This cold working has special significance in laser marking processing because it is not thermal ablation, but cold peeling that breaks the chemical bond without causing "thermal damage" side effects, and thus does not affect the inner layer and the surrounding area of the surface to be processed. Produces heat or thermal deformation. For example, in the electronics industry, excimer lasers are used to deposit a thin film of a chemical on a substrate material to create a narrow trench in the semiconductor substrate.
