The laser industry is developing rapidly, and the laser cutting technology has become more mature. At present, the integration of computer technology, numerical control technology, testing technology and material processing technology, etc., has become a composite high-tech, laser cutting was previously confined to metal materials, and now also gradually expanded to the field of non-metallic materials such as wood, plastic, paper and glass.
The rapid development of electronic display equipment, plasma displays, liquid crystal displays and other electronic display equipment is widely used in televisions, computers, monitors, cell phones and other electronic products, in the production process of these electronic products, the need for glass cutting and slicing as well as display substrate cutting and processing, which poses a challenge to the traditional glass cutting technology.
Laser glass cutting because of its high precision, high speed, high quality, high efficiency and other unique advantages of glass cutting favorite and hot spot, laser cutting in the glass industry has a very broad application prospects.
Introduction to the process of laser cutting glass
Unlike traditional mechanical cutting tools, the energy of the laser beam cuts the glass in a non-contact way. Laser cutting glass can be categorized into two methods in principle: the melt cutting method and the crack control method. However, when the thickness of the glass exceeds 1mm, these two process methods are difficult to achieve one-step cutting, and the glass is prone to bursting during processing.
Therefore, glass cutting based on 532nm wavelength nanosecond laser is focused on: how to optimize the application of the process method, reduce the rate of glass chipping, improve the glass yield, and achieve efficient cutting.
Bottom-up cutting sequence
Since there will be fine dust and debris after the glass is micro-cracked, if the cutting is done from the top down, the dust and debris will accumulate in the gap, affecting the energy emission, and the glass will be shattered and burst.
Thanks to the excellent light transmission of the glass itself, it is possible to pass through the glass. Focus the light spot on the lower surface of the glass and cut the layers from the bottom up, with an extractor fan placed underneath the cutting position. Under the effect of gravity and suction, glass debris and dust can fall off normally without affecting the glass cutting. As shown in Figure 2-2 below.
Multi-line cutting
To ensure that the dust and debris are extracted smoothly, it is not enough to cut from the bottom up. The laser used in this experiment has a single line cutting width of less than 100μm, and it is necessary to increase the width of the slit by multi-line cutting to form a sufficient channel for extracting the dust, and the spacing of the coils in each layer is adjusted accordingly by the power of the laser and the thickness of the glass. At the same time, part of the literature shows that the optimization of the spacing from inside to outside or outside to inside, as well as the multi-line spacing will effectively reduce the chipping size at the outer edges, and that the multi-line also contains parallel and or helical lines.
The parameters that mainly affect the cutting effect are: marking speed, on-light delay, off-light delay, inflection delay, laser frequency, laser pulse width, laser energy duty cycle, radius of the helix, helix spacing and deep engraving layer height. Marking speed, for example, the parameters themselves directly affect the cutting efficiency, if the speed is too fast, it will also lead to a single point of depth is not enough, did not cut effectively from the bottom to the top, the internal heat buildup, the glass will burst; Conversely, if the speed is too slow, the energy buildup will lead to the dust did not fall when it was re-melted, the same will lead to glass cracking and so on.
