What Is Laser Drilling?

The laser drilling process is a thermophysical process of the interaction between laser and matter. It is determined by the characteristics of the laser beam (including the wavelength, pulse width, beam divergence angle, focus state, etc.) of the laser and many thermophysical properties of the substance.

Chinese name: Laser drilling

Foreign name: laser hole drilling

Brief introduction of laser drilling

The high-density laser beam is used to irradiate the material to be processed, so that the material is quickly heated to the vaporization temperature and evaporated to form holes. Laser drilling is the earliest practical laser processing technology, and it is also one of the main application areas of laser processing. It is classified as laser removal in laser processing, also called evaporation processing.

With the rapid development of modern industry and science and technology, more and more materials with high hardness and high melting point are used, and traditional processing methods can no longer meet certain process requirements. Compared with conventional punching methods, it has the following significant advantages:

Laser drilling speed is fast, high efficiency and good economic benefits.

Laser drilling can obtain a large depth-to-diameter ratio.

Laser drilling can be performed on various materials such as hard, brittle and soft.

Laser drilling without tool loss.

Laser drilling is suitable for large number and high density group hole processing.

Small holes can be machined on the inclined surface of difficult-to-machine materials by laser.

Laser drilling technology

Laser drilling is the earliest practical laser processing technology and one of the main application areas of laser processing. The traditional processing methods of materials with high hardness and high melting point can no longer meet certain process requirements. This type of processing task is difficult, sometimes even impossible, with conventional machining methods, and laser drilling is not difficult to achieve. The laser beam is highly concentrated in space and time. Using lens focusing, the spot diameter can be reduced to the micron level to obtain a laser power density of 105-1015W / cm2. Such a high power density can perform laser drilling in almost any material, and has the following significant advantages compared with other methods such as mechanical drilling, electrical discharge machining and other conventional drilling methods: 1) fast laser drilling speed and efficiency High, good economic benefits. Because laser drilling uses a high-energy laser beam with a power density of l07-109W / cm2 to effect the material instantaneously, the action time is only 10-3-10-5s, so the laser drilling speed is very fast. By combining high-performance lasers with high-precision machine tools and control systems, and program control through microprocessors, high-efficiency drilling can be achieved. Compared with electric spark drilling and mechanical drilling, laser drilling on different workpieces has an efficiency improvement of 10-1000 times.

Application of laser drilling technology parameters:

Due to the high energy and high focus of lasers, laser drilling technology is widely used in many industrial processing processes, making more and more difficult materials with high hardness and high melting point. For example, processing micron-sized pores on high-melting-point metal molybdenum plates; processing small holes of tens of microns on hard tungsten carbide; processing deep holes of hundreds of microns on red and sapphire; Silk first class. Using the characteristics of the high concentration of the laser in space and time, the spot diameter can be easily reduced to the micron level, thereby achieving a laser power density of 100 ~ 1000W / cm2. Such a high power density enables laser drilling in almost any material. Laser punching machines usually consist of five parts: solid-state laser, electrical system, optical system, projection system, and three-dimensional mobile workbench. The five components work together to complete the punching task.

The solid-state laser is mainly responsible for generating a laser light source, and the electrical system is mainly responsible for supplying power to the laser and controlling the laser output mode (pulse or continuous), while the function of the optical system is to precisely focus the laser beam on the processing part of the workpiece on. To this end, it contains at least two parts: a laser focusing device and an observation and targeting device. The projection system is used to display the back of the workpiece. The worktable is controlled manually or by a numerical control device, and moves in the three-coordinate direction to adjust the position of the workpiece conveniently and accurately. The table in the processing area on the table is generally made of glass, because the opaque metal table will cause inconvenience to the inspection, and the table will be damaged after the workpiece is punctured. Suction and blowing devices are provided under the focusing objective above the worktable to keep the working surface and focusing objective clean.

Laser punching laser punching machine results

Xinghua Laser: Following the 2009 mastery and application: the core technology of laser drilling equipment (laser flying cavity) is the world's leading technology, and has become the domestic leader in laser micro-hole processing. The smallest processing aperture can be 0.01MM micro-holes.

Laser drilling advantages

Compared with the traditional punching process, the laser punching machine has the following advantages:

(1) Laser drilling speed is fast, high efficiency and good economic benefits.

(2) Laser drilling can obtain a large aspect ratio.

(3) Laser drilling can be performed on various materials such as hard, brittle and soft.

(4) There is no tool loss for laser drilling.

(5) Laser drilling is suitable for large number and high density group hole processing.

(6) Small holes can be machined on the inclined surface of difficult-to-machine materials with a laser.

(7) Laser drilling has simple requirements for workpiece clamping, and it is easy to realize online and automation on the production line.

(8) Laser drilling is easy to punch complicated shapes, and it can also be punched in vacuum.

Development status of laser drilling

In 2001, the world's first double-disc tip paper laser puncher was launched at Huagong Laser.

Laser drilling equipment

1.Laser drilling laser

The laser is an important part of the laser drilling equipment, and its main function is to convert the electric power provided by the power supply system into laser energy with a certain conversion efficiency. According to the material properties of the laser, it can be divided into gas lasers and solid-state lasers. The gas lasers used for drilling are mainly carbon dioxide lasers, while the solid lasers used for drilling are mainly ruby lasers, neodymium glass lasers and YAG lasers.

Carbon dioxide laser has many unique advantages. Its conversion efficiency is higher than other lasers, and it can be absorbed by many non-metal materials (such as plexiglass, plastic, wood, multilayer composite sheet, quartz glass, etc.). More importantly, compared with other lasers, CO2 lasers can perform high power output. When combined with other technologies, high-speed drilling can be achieved, with a maximum speed of 100 holes / second, which is difficult for other lasers.

However, because of the inconvenience of focusing and dimming the carbon dioxide laser, the one-time investment of the equipment is relatively large, and it is not as common in laser drilling equipment as the other three laser applications. Solid-state lasers are widely used in laser drilling because of their unique advantages. Its main advantages are: (1) The output wavelength is short. (2) The output light can be transmitted with ordinary optical materials. (3) The whole machine is small in size, easy to use and maintain, and less expensive than a carbon dioxide laser.

2.Lathe punching machine

A simple and versatile form of laser drilling machine is a three-dimensional machine. The two-dimensional motion is represented by X and Y in the horizontal plane, the two coordinate axes are perpendicular to each other, and the third Z axis is perpendicular to the ZY plane. Each dimension can be driven by a stepper motor to run on a linear ball guide. Its accuracy is determined by the accuracy of the screw and the accuracy of the ball guide. If equipped with a microprocessor system, the three-dimensional machine tool can complete laser processing of various holes in the plane and group holes in a certain range. When it is necessary to process a series of holes in a pipe or barrel material, the machine tool should have a five-dimensional function. In addition to the three-dimensional mentioned above, the added two-dimensional is a 360-degree rotation of the XY plane. We define it as the A axis, XY The plane is inclined at 0-90 degrees in the Z direction, and we define it as the B axis. With such various types of laser drilling processing, the five-dimensional worktable can be competent. In the case of saving equipment investment, the numerical control of the B axis can be changed to manual. This will not only save money, but also basically complete all punching tasks.

3.Laser drilling equipment

Over the years, the overall level of laser punching machines at home and abroad has been in a rapid development stage. The output power of the laser has gradually increased, the pulse width has become narrower, the frequency range has become wider, and other parameters have become more and more beneficial. Development of the direction of punching. The flexibility of the light guide system and the control part of the laser punching machine is constantly improved, which makes the range of punching constantly expand. At present, there are dozens of laser punching machines in China. In addition to colleges and universities and scientific research institutes, the number of companies specialized in manufacturing laser equipment has gradually increased. This shows that China's laser processing is developing towards industrialization.

Laser drilling applications

Laser drilling technology is widely used in industrial production due to its advantages of high speed, high efficiency, good economic benefits, and wide application fields. Lasers can be used to perform punching and cutting operations on textile fabrics, leather products, paper products, metal products, and plastic products. Application areas include garment making, shoe making, handicraft gift making, machinery and equipment, parts making, etc. ^[1]