Views: 0 Author: hu Publish Time: 2021-09-08 Origin: dapeng
As a clean, pollution-free, and renewable energy source, solar energy has greatly promoted the development of the photovoltaic industry. There are many types of solar cells. According to the materials, they can be divided into silicon solar cells, multiple compound thin film solar cells, polymer multilayer modified electrode solar cells, nanocrystalline solar cells, and organic solar cells. Among them, solar silicon cells are currently the most mature. , Occupies a dominant position in the application.
The traditional silicon wafer cutting method is mechanical cutting, which is slow, has poor section flatness, has many fragments, and is not environmentally friendly. Silicon is a brittle material. Mechanical cutting can easily break the edges, causing damage to the elastic strain area, dislocation network area, and fragmented crystal area on the surface of the silicon. It may even cause invisible cracks, affecting electrical parameters and other hazards. Laser cutting technology has the advantages of no contact, no mechanical stress, small slit width, flat and smooth section, high precision, fast speed, stable performance, etc.; it will not damage the silicon wafer structure, and its electrical parameters are better than traditional mechanical cutting methods. It can be used for scribing and cutting of large-area cells, so as to accurately control the cutting precision and thickness, further reduce cutting debris and improve battery utilization.
Fibo PreciCut series laser adopts QCW working mode, which has the characteristics of high peak power, large pulse energy, excellent beam quality and ultra-high power stability. It is widely used in precision welding (3C industry, power battery industry, medical industry), precision Cutting (brittle material and fine metal flake cutting, ceramic scribing), precision punching, additive manufacturing and other fields; the output mode can be switched between continuous and quasi-continuous according to customer needs, so it has more Processing advantages.
Feibo Laser PreciCut M2 and CW mode lasers are separately tested for 2mm solar photovoltaic cell silicon wafers. The results show:
PreciCut M2 has a smooth cutting section, no burrs, and no cracks on the silicon chip during cutting;
CW laser: The silicon chip is cracked and has burrs.
It can be seen from the waveform diagram: QCW works in a pulsed mode, emitting light every certain time; CW laser works in a continuous mode, the output laser will not be interrupted, and the laser power is constant; the former mode is phased in. Compared with the latter, the heat input to the workpiece during processing is smaller, and it is not easy to be thermally broken when cutting brittle materials; the QCW mode can control the pulse width of a single pulse by changing the duty cycle, which means that the action time of the laser and the processing material can be controlled. In this way, the heat input to the workpiece is controlled, and the debugging range for processing different materials is wider, and it is more advantageous than the CW laser in precision processing.