Application Status of Laser Precision Machining at Home and Abroad

Laser precision drilling With the advancement of technology, the traditional drilling method can not meet the demand in many occasions. For example, processing a small hole having a diameter of several tens of micrometers on a hard tungsten carbide alloy; processing a deep hole of several hundred micrometers in a hard and brittle red or sapphire can not be realized by a conventional mechanical processing method. The instantaneous power density of the laser beam is as high as 108 W/cm2, and the material can be heated to a melting point or a boiling point in a short time to achieve perforation on the above materials. Compared with electron beam, electrolysis, electric spark, and mechanical punching, laser drilling quality is good, repeatability is high, versatility is high, efficiency is high, cost is low, and comprehensive technical and economic benefits are remarkable. Foreign laser precision drilling has reached a very high level. A Swiss company uses solid-state lasers to drill turbine blades, which can process micropores from 20um to 80um in diameter and have a diameter to depth ratio of 1:80. The laser beam can also process various tiny shaped holes such as blind holes, square holes, etc. on brittle materials such as ceramics, which cannot be achieved by ordinary machining.

Laser precision cutting has many advantages over traditional cutting methods. For example, it can produce narrow cuts, almost no cutting residue, small heat affected zone, low cutting noise, and can save materials by 15% to 30%. Since the laser hardly produces mechanical force and pressure on the material to be cut, it is suitable for cutting hard and brittle materials such as glass, ceramics and semiconductors, and the laser spot is small and the slit is narrow, so it is especially suitable for small parts. Precision cutting. A Swiss company uses solid-state lasers for precision cutting, and its dimensional accuracy has reached a very high level.

A typical application for laser precision cutting is to cut the surface mount template (SMTstencil) in Printed Circuit Board PCB (PrintdCircuitsBoards). The traditional SMT template processing method is a chemical etching method, and its fatal disadvantage is that the processing limit size is not less than the thickness of the board, and the chemical etching process is complicated, the processing cycle is long, and the corrosive medium pollutes the environment. Laser processing can not only overcome these shortcomings, but also reprocess the finished template, especially the processing precision and gap density are significantly better than the former (see Figure 6). The production cost is also much higher than the chemical etching to the present. Slightly lower than the former. However, due to the high technical content of the complete equipment used in laser processing, the price is also very high. At present, only a few companies in the United States, Japan, Germany and other countries can produce the whole machine.

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