Photovoltaic modules are an indispensable part of the electronics industry, have you ever wanted to make them? Today, photovoltaic power station manufacturers will share with you the production process of volt modules.
Module production process After cell sorting - single welding - string welding - splicing (that is, the string welded cells are positioned and spliced together) - intermediate test (intermediate test is divided into: infrared test and appearance inspection) - lamination - trimming - appearance after layer - infrared after layer - framing (generally aluminum frame) - assembly junction box - cleaning - testing (this link is also divided into infrared test and appearance inspection to determine the grade of the module) - packaging.
(1) Battery test
Due to the randomness of the cell manufacturing conditions, the performance of the produced batteries is not the same, so in order to effectively combine the same or similar performance of the cells, they should be classified according to their performance parameters, and the battery test is to classify the output parameters (current and voltage) of the battery by testing it. In order to improve the utilization rate of the battery, make qualified battery components.
(2) Front welding
The busbar is welded to the busbar on the front (negative) of the battery, the busbar is tinned copper strip, and the welding machine we use can spot weld the ribbon on the busbar in the form of multiple points. The heat source for welding is an infrared lamp (using the thermal effect of infrared rays). The length of the ribbon is about 2 times the length of the side of the battery. The extra ribbon is connected to the back electrode of the cell behind it when it is soldered on the back.
(3) The back is connected in series
The back welding is to connect the cells together to form a component string, the process we currently use is manual, the positioning of the battery mainly depends on a membrane board, there is a groove for placing the cell sheet, the size of the groove corresponds to the size of the battery, the position of the groove has been designed, the components of different specifications use different templates, and the operator uses an electric soldering iron and solder wire to weld the front electrode (negative electrode) of the "front battery" to the "back battery" on the back electrode (positive electrode), so that they are connected together in turn and the leads are soldered out at the positive and negative electrodes of the component string.
(4) Laminated laying
After the back side is connected in series and passed the inspection, the component string, glass, cut EVA, glass fiber, and back plate are laid according to a certain level and ready to be laminated. The glass is pre-coated with a reagent (primer) to increase the bond strength of the glass and EVA. When laying, ensure the relative position of the battery string and glass and other materials, adjust the distance between the cells, and lay a good foundation for lamination. (Laying level: bottom to top: tempered glass, EVA, cell, EVA, fiberglass, backsheet).
(5) Module lamination
The laid battery is placed in a laminator, the air inside the module is pumped out by vacuuming, and then the EVA is melted by heating to bond the battery, glass and backplate together, and finally the component is cooled and removed. The lamination process is a critical step in the production of modules, and the lamination temperature and lamination time are determined according to the nature of the EVA. When we use fast-curing EVA, the lamination cycle time is about 25 minutes. The curing temperature is 150°C.
When laminating, EVA melts and extends outward due to pressure to solidify to form burrs, so it should be removed after lamination.
It is similar to installing a mirror frame for glass and installing an aluminum frame for glass components to increase the strength of the module, further seal the battery assembly, and prolong the service life of the battery. The gaps between the bezel and the glass components are filled with silicone. The frames are connected by corner keys.
(8) Soldering junction box
A box is soldered at the back of the component to facilitate the connection between the battery and other devices or cells.
(9) High voltage test
High-voltage test refers to the application of a certain voltage between the frame of the module and the electrode lead to test the voltage resistance and dielectric strength of the module to ensure that the module is not damaged under harsh natural conditions (lightning strikes, etc.).
(10) Component testing
The purpose of the test is to calibrate the output power of the battery, test its output characteristics, and determine the quality level of the module. At present, the main test is to simulate the sunlight test standard test condition (STC), and the test time required for a panel is generally about 7-8 seconds.