1. What is "hidden" Hidden cracking is a relatively common defect of crystalline silicon photovoltaic modules. In general, it is a micro-crack that is invisible to the naked eye. The crystalline silicon module is very prone to cracking due to its own crystal structure. In the production process of crystalline silicon modules, many links may cause cell cracks. The root cause of cracking can be summarized as mechanical stress or thermal stress on the silicon wafer. Now in order to reduce the cost, the crystalline silicon cell is developing in a thinner and thinner direction, which reduces the ability of the cell to prevent mechanical damage and is more prone to cracking. 2. The effect of "hidden cracking" on component performance The structure of the crystalline silicon solar cell is shown in the figure below. The current generated by the solar cell is collected and derived mainly from the busbar lines and fine grid lines whose surfaces are perpendicular to each other. Therefore, when cracking (mostly parallel to the busbar) results in cracking of the fine gate line, the current cannot be effectively transferred to the busbar line, resulting in failure of the cell and even the entire chip, and may also cause debris. Hot spots, etc., also cause the power attenuation of the components. The cracking perpendicular to the busbars hardly affects the fine gridlines, so the area that causes the cell to fail is almost zero. The thin-film solar cell that is in rapid development has no problem of cracking because of its material and structural characteristics. At the same time, its surface collects and transmits current through a layer of transparent conductive film. Even if the cell sheet has a small flaw, the conductive film will be broken, which will not cause a large area failure of the battery. Studies have shown that if the failure area of ​​a battery in a component is within 8%, the impact on the power of the component is not significant, and 2/3 of the oblique stripe cracking in the component has no effect on the power of the component. Therefore, although cracking is a common problem in crystalline silicon cells, there is no need to worry too much. 3. Identify the "hidden" method EL (Electroluminescence) is an internal defect detection device for solar cells or modules and is a simple and effective method for detecting cracks. Using the principle of electroluminescence of crystalline silicon, the near-infrared image of the component is captured by a high-resolution infrared camera to obtain and determine the defects of the component. It has the advantages of high sensitivity, fast detection speed, and intuitive image. 4. Reasons for forming "hidden cracking" External force: The battery will be subjected to external force in welding, laminating, framed or handling, installation, construction and other processes. When the parameters are not set properly, equipment failure or improper operation will cause cracking. High temperature: When the battery is not preheated at low temperature, and then suddenly exposed to high temperature in a short time, expansion will cause cracking phenomenon, such as the welding temperature is too high, the lamination temperature and other parameters are set unreasonably. Raw materials: Defects in raw materials are also one of the main factors leading to cracking. 5. Points to prevent cracking of PV modules During the production process and subsequent storage, transportation, and installation, the battery is protected from improper external forces, and the temperature range of the storage environment is also taken into consideration. In the welding process, the battery should be insulated in advance (hand soldering). The temperature of the soldering iron should meet the requirements. Other Headlamp,Camping Headlamp,Flexible Headlamp,Cob Rechargeable Headlamp NINGBO ZHENGUO INTELLINGENT LIGHTING CO.,LTD , https://www.nbzguolight.com