Laser marking is the use of laser beams on the surface of a variety of different substances to mark permanently. The marking effect is to reveal the deep material through the evaporation of the surface material, or to "carve" the trace through the chemical and physical changes of the surface material caused by light energy, or to burn part of the material through the light energy, showing the pattern and text needed to be etched.

There are two accepted principles:

"Thermal processing" has a laser beam with a higher energy density (it is a concentrated energy flow), irradiated on the surface of the material to be processed, the surface of the material absorbs the laser energy, and produces a thermal excitation process in the irradiated area, so that the surface of the material (or coating) temperature rises, resulting in metamorphosis, melting, ablation, evaporation and other phenomena.

"Cold working" has a high load of energy (ultraviolet) photons, which can break the chemical bonds in the material (especially organic materials) or the surrounding medium, to the point that the material is destroyed by non-thermal processes. This cold processing has a special significance in laser marking processing, because it is not thermal ablation, but does not produce "thermal damage" side effects, break the chemical bond of the cold peel, and therefore does not produce heating or thermal deformation of the inner layer of the surface to be processed and the nearby area. For example, excimer lasers are used in the electronics industry to deposit thin films of chemicals on substrate materials, opening narrow grooves on semiconductor substrates.

Comparison of different labeling methods

Compared with the inkjet marking method, the advantage of laser marking engraving is that it has a wide range of applications, and a variety of substances (metal, glass, ceramics, plastics, leather, etc.) can be marked with permanent high-quality marks. There is no force on the surface of the workpiece, no mechanical deformation, no corrosion on the surface of the material.