Laser marking machine General knowledg

Laser marking is the use of a laser beam to make permanent marks on the surface of a variety of different substances. The effect of marking is to expose the deep substance through the evaporation of the surface substance, or to “engrave” traces through the chemical and physical changes of the surface substance caused by light energy, or to burn off part of the substance through light energy to reveal the patterns and words that need to be etched.

There are two accepted principles:

“Thermal processing” is a laser beam with a high energy density (it is a concentrated energy stream), irradiated on the surface of the material to be processed, the surface of the material absorbs the laser energy, and a thermal excitation process is generated in the irradiated area, so that the temperature of the material surface (or coating) rises, resulting in metamorphosis, melting, ablation, evaporation and other phenomena. Laser marking machine

“Cold working” is a very energetic (ultraviolet) photon that can break chemical bonds within a material (especially an organic material) or the surrounding medium, to the point where the material is not destroyed by a thermal process. This kind of cold working has special significance in laser marking processing, because it is not thermal ablation, but a cold peel that breaks the chemical bond without the side effect of “thermal damage”, so that there is no heating or thermal deformation on the inner layer and the adjacent area of the surface to be processed. For example, in the electronics industry, excimer lasers are used to deposit thin films of chemicals on the substrate material, creating narrow grooves in the semiconductor substrate.

Comparison of different labeling methods

Compared to inkjet marking, laser marking grooves have the advantage of a wide range of applications and the ability to mark a wide range of materials (metal, glass, ceramics, plastics, leather, etc.) with permanent, high-quality marks. There is no force on the surface of the workpiece, no mechanical deformation, and no corrosion on the surface of the material (see the table below)

Comparison of other marking technologies

Marking process, speed, performance, image and text change

Laser marking is fast and easy to change

Laser mask marking is fast, better, and not easy to change

Chemical corrosion is fast, good, and not easy to change

Photographic corrosion is fast, good, and not easy to change

Inkjet printing is fast, poor, and easy to change

Mechanical indentation is fast, poor, and not easy to change

The investment mold is fast and good, and it is not easy to change

Pneumatic punching needle medium speed is good and easy to change

It can engrave a variety of non-metallic materials. It is used in clothing accessories, pharmaceutical packaging, wine packaging, architectural ceramics, beverage packaging, fabric cutting, rubber products, shell nameplates, craft gifts, electronic components, leather and other industries.

Laser marking machine

●It can engrave metal and a variety of non-metallic materials. It is more suitable for some product processing that requires fine and high precision.

●Used in electronic components, integrated circuits (IC), electrical appliances, mobile communications, hardware products, tool accessories, precision instruments, glasses and watches, jewelry, auto parts, plastic buttons, building materials, PVC pipes, medical equipment and other industries.

●Applicable materials include: common metals and alloys (iron, copper, aluminum, magnesium, zinc and other metals), rare metals and alloys (gold, silver, titanium), metal oxides (all kinds of metal oxides are acceptable), special surface treatment (phosphating, aluminum anodizing, electroplating surface), ABS materials (electrical appliances shells, daily necessities), inks (translucent buttons, printed products), epoxy resin (packaging and insulation of electronic components).

Laser marking machines can be divided into: CO2 laser marking machine, semiconductor laser marking machine, YAG laser marking machine, fiber laser marking machine according to different lasers. According to the different laser visibility, it can be divided into: ultraviolet laser marking machine, green laser marking machine, infrared laser marking machine), according to the different laser wavelengths, it can be divided into: deep ultraviolet laser marking machine (below 200 nm), ultraviolet laser marking machine (355nm), green laser marking machine (532nm), lamp pump YAG laser marking machine (1064nm), semiconductor side pump YAG laser marking machine, semiconductor end pump YAG laser marking machine (1064nm), fiber laser marking machine (1064nm) , CO2 laser marking machine (10.64um).

Fiber laser marking machine principle: Fiber laser marking machine uses laser beams to mark permanent marks on the surface of various substances. The effect of marking is to expose the deep substance through the evaporation of the surface substance, or to “engrave” traces through the chemical and physical changes of the surface substance caused by light energy, or to burn off part of the substance through light energy, showing various graphics such as patterns, texts, and barcodes that need to be etched. The so-called fiber laser marking machine means that the marking machine uses a fiber laser, which has the characteristics of small size (no water cooling device, air cooling), good beam quality (basic mode), and maintenance-free.

The fiber laser marking machine is mainly composed of: the fiber laser marking machine is mainly composed of fiber laser, high-speed scanning galvanometer, marking software, industrial control computer and electronic control cabinet and other components. Among them, fiber lasers are the main core components.

Advantages of fiber laser marking machine: fiber laser marking machine is the most advanced laser marking equipment in the world, which has the characteristics of good beam quality, small size, fast speed, long working life, flexible and convenient installation and maintenance-free. It is widely used in integrated circuit chips, computer accessories, industrial bearings, clocks and watches, electronic and communication products, aerospace devices, various auto parts, home appliances, hardware tools, molds, wires and cables, food packaging, jewelry, tobacco and military affairs and many other fields of graphic and text marking, as well as mass production line operations. [1]

CO2 laser marking machine principle: CO2 laser marking machine is carbon dioxide laser marking machine (CO2 is carbon dioxide). It is a laser galvanometer marking machine that uses CO2 gas as the working medium. CO2 laser marking machine is a CO2 laser with CO2 gas as the medium, CO2 and other auxiliary gases are charged into the discharge tube and high voltage is added to the electrode, and the glow discharge is produced in the discharge tube, so that the gas releases a wavelength of 10.64um laser, after the laser energy is amplified, after being focused by galvanometer scanning and F-Theta mirror, under the control of computer and laser marking control card, the image, text, number and line can be marked on the workpiece according to the user’s requirements.

CO2 laser marking machine: CO2 laser marking machine is mainly composed of CO2 laser, 10.64 field mirror, 10.64 beam expander, CO2 laser power supply, galvanometer scanner, control computer, laser control card, laser control software, laser machine frame, laser circulating water system, circuit control system and other components.

The main features of CO2 laser marking machine: the use of carbon dioxide laser, is a general-purpose model, post-focusing mode, small size, high degree of integration. The machine is suitable for marking most non-metallic materials, such as paper packaging, plastic products, non-metallic labels, leather fabrics, glass ceramics, resin plastics, bamboo and wood products, PCB boards, etc. CO2 laser is a gas laser with a wavelength of 10.64um in the far-infrared frequency band, using CO2 gas charging into the discharge tube as the medium for generating laser, when the high voltage is added to the electrode, the glow discharge in the discharge tube can be generated, the gas molecules can be released from the laser, and the laser energy is amplified to form an excitation beam for material processing.

The principle of semiconductor laser marking machine: the working principle of laser marking with semiconductor laser pumped all-solid-state laser (DPSSL) is to use a high-power semiconductor quantum well laser instead of a gas lamp to pump a solid-state crystal as a gain medium laser resonator, so that it can produce a new wavelength of laser, and use the crystal standby frequency mixing to produce SHG, THG and other wavelength lasers. Through the design, the entire laser marking process, operating procedures and quality standards from incoming material re-inspection, partial assembly production, process inspection, assembly and debugging to finished product general inspection have been established.

Semiconductor laser marking machine composition: mainly composed of four systems: optical path system, circuit system, water system and control system. The optical path system is mainly composed of red light, all-mirror, semi-reflective, module, Q, field mirror, beam expander, scanning, etc. The circuit system is mainly composed of control circuit (control box), laser power supply, Q power supply and scanning power supply. The control system is mainly composed of a galvanometer scanner, a computer, and control software (board). The waterway system is mainly composed of water tanks and water pipes, forming a circulating waterway.

Advantages of semiconductor laser marking machine: good laser beam mode, high electro-optical conversion efficiency, low power consumption, maintenance-free; Some photoelectric measurement manufacturers change the light source of the laser in the measuring equipment from the original He-Ne laser to the diode laser to obtain the best machine life (the He-Ne laser life is generally 10^4HR, and the diode laser life is 10^5HR, a difference of ten times), especially suitable for long-term operation on site; The function of the switch can be achieved in an instant, and it is suitable for communication purposes. And the semiconductor laser marking machine will stabilize quickly as soon as it is turned on, and it is very suitable for the circuit to modulate its output, such as the pulse wave modulation method can be used to measure the distance (and the He-Ne laser marking machine must be turned on for 30 minutes before it stabilizes, which is absolutely not comparable to the semiconductor laser marking machine); Diode lasers can be made from compounds such as gallium arsenide in the periodic table using group III./V of the periodic table, and when the current passes through the pn interface, various visible and invisible lasers will be emitted depending on the compound. As long as the semiconductor laser changes the proportion of the combined elements, it can change different energy intervals, different energy intervals, provides different output wavelengths, and is very widely used in communication and measurement with various sensors because of its infrared and red wavelengths; The operation is simple and convenient, and the marking quality and accuracy are high; In terms of mechanical properties: compact structure, sturdy and small size.

YAG laser marking machine series has the highest cost-effective high-end product – semiconductor laser marking machine. In recent years, with the reduction of manufacturing costs, it has replaced the lamp-pumped laser marking machine to become the preferred model for laser processing users, and the use of semiconductor laser marking machine can greatly save the cost of power consumption and consumables in later maintenance, obtain better laser marking effect, and can improve the reliability of the equipment and greatly reduce the amount of maintenance.

Advantages of diode laser marking machine:

1. Lamp-saving: The life of the semiconductor diode is as long as 10,000 hours, and it can be up to three years without replacing consumables based on eight hours of work a day, while the life of the krypton lamp is only a few hundred hours, so the semiconductor laser marking machine can be called a maintenance-free system.

2. Power saving: the power consumption of the semiconductor laser marking machine is only about 2KW, while the lamp-pumped laser marking machine needs about 6KW, that is, the semiconductor laser marking machine can save 4 degrees of electricity per hour, according to the industrial electricity per hour of one yuan, the same working hour, the semiconductor laser marking machine per hour of work is less than the lamp-pumped laser marking machine 4 yuan of electricity.

3. Better marking effect: the monochromaticity of the laser produced by the semiconductor pump is better, the mode of the laser is better, the light spot after the laser focus is smaller, the energy is more concentrated, and the better marking effect can be obtained, so the semiconductor laser marking machine can make the process effect that the lamp-pumped laser marking machine can not achieve.

4. Maintenance-free: The lamp-pumped laser marking machine needs to replace the krypton lamp frequently, and the optical path must be re-adjusted every time the lamp is changed. The semiconductor laser marking machine is maintenance-free, which greatly increases the stability and reliability of the equipment and reduces the workload of daily maintenance.

5. Other savings that are not accurately calculated: the lamp-pumped laser marking machine is bulky and noisy, and the huge chiller will produce more heat, especially in the southern summer, the ambient temperature is higher, and the excess heat will make the working environment of workers worse, or more air conditioning systems are needed to adjust the temperature of the working environment, which increases the production cost.

The laser power supply of the fiber laser marking machine is a device that provides power for the fiber laser, and its input voltage is AC220V alternating current. It is installed in the control box of the marking machine.

The fiber laser marking machine adopts imported pulsed fiber laser, which has a good output laser mode and long service life, and is designed to be installed in the shell of the marking machine.

The galvanometer scanning system is composed of two parts: optical scanner and servo control. The whole system is designed and manufactured using new technologies, new materials, new processes and new working principles.

The optical scanner uses a servo motor with a moving magnet deflection working mode. It has the advantages of large scanning angle, large peak torque, large load inertia, small electromechanical time constant, fast working speed, stability and reliability. The precision bearing anti-backlash mechanism provides over-bottom axial and radial run-out errors; The “electronic torque bar” replaces the traditional elastic material torque bar, which greatly improves the service life and long-term work reliability; The working principle of zero power holding at any position not only reduces the power consumption, but also reduces the heating effect of the laser marking machine device, and eliminates the need for constant temperature device; The advanced high-stability precision position detection sensing technology provides high linearity, high resolution, high repeatability, and low drift performance.

The optical scanner is divided into an X-direction scanning system and a Y-direction scanning system, and each servo motor axis is fixed with a laser reflector lens. Each servo motor is individually controlled by a digital signal from a computer to control its scanning trajectory.

The role of the focusing system is to focus parallel laser beams at one point. Mainly using f-θ lens, different f-θ lenses have different focal lengths, marking effects and ranges are not the same, fiber laser marking machine uses imported high-performance focusing system, its standard lens focal length f=160mm, effective scanning range Φ110mm. The lens model can be selected according to the user’s needs.

Optional F-theta lenses are:

f=100mm, effective focusing range Φ65mm.

f=160mm, effective focusing range Φ110mm.

The computer control system is the center of the control and command of the entire laser marking machine, and it is also the carrier of software installation. Through the coordinated control of the acousto-optic modulation system and galvanometer scanning system, the marking of the workpiece is completed.

The computer control system of fiber laser marking machine mainly includes chassis, motherboard, CPU, hard disk, memory module, D/A card, floppy drive, monitor, keyboard, mouse, etc.