Principles of Laser Marking Machines

Laser marking machines operate on two recognized principles: one termed “thermal processing” and the other “cold processing.” Below is an explanation of these two principles.

The “thermal processing” method of laser marking machines utilizes a laser beam with high energy density (a concentrated energy stream). When this beam strikes the surface of the material being processed, the material absorbs the laser energy, triggering a thermal excitation process within the irradiated area. This causes the surface temperature (or coating temperature) to rise, leading to phenomena such as phase transformation, melting, ablation, and vaporization.

The “cold processing” of laser marking machines utilizes (ultraviolet) photons with high load energy. These photons can break chemical bonds within the material (especially organic materials) or surrounding media, causing non-thermal process damage to the material. This cold processing holds particular significance in laser marking applications because it represents a chemical bond-breaking cold stripping process—free from thermal ablation—that avoids “thermal damage” side effects. Consequently, it does not induce heating or thermal deformation in the underlying layers or adjacent areas of the processed surface. For instance, in the electronics industry, excimer lasers are used to deposit chemical films onto substrate materials and create narrow trenches on semiconductor wafers.

For more information on laser cutting machines, laser marking machines, and laser welding machines, please visit the official website of Wuxi Top Optics Laser Technology Co., Ltd.