A complete set of equipment on the production line for the production of solar cell modules: laser scribing machine (solar cell cutting silicon wafer cutting), solar module laminator, solar module tester, solar cell sorting machine and other equipment can be produced by domestic manufacturers.

(1) Laser scribing machine

The laser scribing machine (Figure 1) is mainly used for the scribing and cutting of semiconductor substrate materials such as solar cells, silicon, germanium, and gallium arsenide. The laser scribing machine adopts a computer-controlled semiconductor pump and lamp-pumped laser workbench, which can make various movements according to the graphic trajectory. Pump is the meaning of excitation or excitation. Laser is also called laser. The Chinese translation of English laser has high brightness, high collimation, and high coherence. It can be used in industrial processing, medical, military and other fields.

Solar cell module production equipment
Figure 1 – Laser scribing machine

Diode pumped and lamp pumped lasers both use Nd: YAG (neodymium-doped yttrium aluminum garnet) crystal as the working material for laser production. The absorption peak of this material for pump light is around 808nm. Lamp pumping uses the light emitted by the krypton lamp to pump Nd: YAG crystal produces 1064nm working laser, but the spectrum of the light emitted by the krypton lamp is wider, but there is a slightly larger peak at 808nm, and the light of other wavelengths is finally converted into useless heat and dissipated.

There is also a semiconductor pump, which uses a semiconductor laser diode to emit a 808nm laser to pump the Nd: YAG crystal to generate laser light. Since the emission wavelength of the semiconductor laser diode coincides with the absorption peak of the laser working material, and the pump light mode can be well matched with the laser oscillation mode, the light conversion efficiency is very high. The light conversion efficiency of diode-pumped lasers can reach more than 35% (lamp-pumped light efficiency is only 3%~6%), and the efficiency of the whole machine is an order of magnitude higher than that of lamp-pumped lasers, so only a lightweight water cooling system is required. Therefore, the semiconductor pump laser is small in size, light in weight, and compact in structure.

(2) Solar module laminator

The solar module laminator (Figure 2) is used for the packaging of monocrystalline (polycrystalline) solar modules, and can automatically complete the processes of heating, vacuuming, and laminating according to the set procedure; the automatic method is to pre-set the control parameters of the lamination through the console, and automatically run after the cover is closed manually, and the cover is automatically opened after the lamination is completed, waiting for the next batch of components to be packaged; the manual mode is to operate manually through the control buttons on the console. The flat laminated platform enables the solar panels to be placed horizontally, uniformly heated, with a high degree of automation and stable performance. One person can easily complete the operation of placing and removing the solar panels.

Solar cell module production equipment
Figure 2 – Solar Module Laminator

(3) Solar module tester

The solar module tester (Figure 3) is specially used for the testing of solar monocrystalline silicon and polycrystalline silicon battery modules. By simulating the solar spectrum light source, the relevant electrical parameters of the battery components are measured. Generally, there is a unique calibration device, input compensation parameters, automatic/manual temperature compensation and light intensity compensation, with automatic temperature measurement and temperature correction functions.

Solar cell module production equipment
Figure 3 – Solar Module Tester

Measuring the electrical performance of a solar cell comes down to measuring its volt-ampere characteristics. Since the volt-ampere characteristics are related to the test conditions, the measurement must be carried out under uniformly specified standard test conditions, or the measurement results must be converted to standard test conditions in order to identify the electrical performance of the solar cell. Standard test conditions include standard sunlight (standard spectrum and standard irradiance) and standard test temperature. The temperature can be controlled manually, and the standard sunlight can be simulated artificially or searched under natural conditions. Using simulated sunlight, the spectrum depends on the type of electric light source and the filter reflection system: the irradiance can be calibrated with the calibration value of the standard solar battery short-circuit current. In order to reduce the spectral mismatch error, the spectrum of the simulated sunlight should be as close as possible to the standard sunlight spectrum, or a standard solar cell with basically the same spectral response as the measured battery should be selected.

Regarding the detection of solar cell efficiency, one case is that the spectrum of the solar simulator is completely consistent with the standard solar spectrum, and the other is that the spectral response of the tested solar cell is completely consistent with the spectral response of the standard solar cell. Both of these special cases are difficult to implement strictly, but in contrast, the latter case is more difficult to achieve. Because there are many kinds of solar cells to be tested, it is impossible for every cell to be tested to be equipped with a standard solar cell whose spectral response is exactly the same. 

The reason why the spectral response is difficult to control is due to technological reasons, and under the influence of many complex factors, even solar cells produced in the same process, structure, material, or even the same batch cannot guarantee the same spectral response; on the other hand, it comes from the difficulty of testing. The measurement of the spectral response is much more troublesome than the volt-ampere characteristics, and it is not easy to measure correctly. It is impossible to measure the spectral response of each solar cell before measuring the volt-ampere characteristics. Therefore, in order to improve the spectral matching, the best way is to design a precision solar simulator with a spectral distribution that is very close to the standard solar spectrum. The standard stipulates that the ground standard sunlight spectrum adopts the AM15 standard sunlight spectrum of total radiation, and the total irradiance of the ground sunlight is specified as 1000W/m. The standard test temperature is specified as 25°C. If limited by objective conditions, testing can only be performed under non-standard conditions, the measurement results must be converted to standard test conditions.

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