Introduction to Photovoltaic Modules and 21 Common Quality Issues -1

　　Component Definition

　　1. Having encapsulation and internal connections;

　　2. Capable of providing independent DC power output;

　　3. The smallest indivisible photovoltaic cell combination device.

　　Why manufacture components? Can't battery cells be used directly?

　　1. Electrodes exposed to air are highly prone to oxidation.

　　2. The power of a single crystalline silicon solar cell is relatively low, with a voltage of only about 0.5V.

　　3. The thickness is too thin, easy to break, and difficult to transport.

　　4. Poor weather resistance and rapid degradation of battery cells.

　　Component classification

　　1. Classified by solar cell type. Crystalline silicon (single, polycrystalline silicon) solar photovoltaic modules, amorphous silicon thin film solar photovoltaic modules, gallium arsenide, photovoltaic modules, etc.

　　2. Classified by packaging materials and processes: epoxy resin, encapsulated solar panels, laminated encapsulated battery components.

　　3. Classified by different purposes: ordinary solar photovoltaic modules, building materials solar photovoltaic modules. Among them, building materials solar photovoltaic modules are divided into single-sided glass transparent photovoltaic modules, double-sided laminated glass photovoltaic modules, and double-sided hollow glass photovoltaic modules.

　　Component manufacturing process

　　Common problems with components

　　1. The surface of the component is dirty;

　　2. The battery cells have color differences;

　　3. Components have bubbles and EVA has delamination phenomenon;

　　4. Component fragmentation;

　　5. Other quality issues;

　　Common causes, impacts, and measures of component problems.

　　Reasons for Mesh like Hidden Cracks

　　1. The battery cells are subjected to external forces during welding or handling;

　　2. Without preheating at low temperatures, the battery cells suddenly expand and cause hidden cracks when subjected to high temperatures in a short period of time.

　　Component impact:

　　1. Network cracks can affect component power attenuation;

　　2. The long-term appearance of fragments and hot spots in the network hidden cracks directly affects the performance of the components.

　　Preventive measures:

　　1. Avoid excessive external impact on battery cells during the production process;

　　2. During the welding process, the battery cells should be insulated in advance (hand soldered) and the temperature of the soldering iron should meet the requirements;

　　3. EL testing requires strict inspection.

　　Reasons for EVA delamination

　　1. The cross-linking degree is not qualified Caused by factors such as low temperature of the laminating machine and short laminating time;

　　2. Foreign objects on the surfaces of raw materials such as EVA, glass, and backboards;

　　Uneven composition of EVA raw materials (such as ethylene and vinyl acetate) results in failure to dissolve at normal temperatures, leading to delamination.

　　4. Flux: Excessive usage can cause delamination of the main gate line when exposed to high temperatures for a long time.

　　Component impact:

　　When the delamination area is small, it affects the high-power failure of the component. When the delamination area is large, it directly leads to component failure and scrapping.

　　Preventive measures:

　　1. Strictly control important parameters such as temperature and time of the laminating machine, and regularly conduct crosslinking degree experiments according to requirements, and control the crosslinking degree within 85% ± 5%;

　　2. Strengthen the improvement of raw material suppliers and raw material inspection;

　　3. Strengthen the appearance inspection of finished products during the manufacturing process;

　　4. Strictly control the amount of flux used, and try not to exceed 0.3mm on both sides of the main gate line.

　　Reasons for delamination caused by poor silicone and hidden cracks in battery cells

　　1. The cross-linking degree is not qualified Caused by factors such as low temperature of the laminating machine and short laminating time;

　　2. Foreign objects on the surfaces of raw materials such as EVA, glass, and backboards;

　　3. There are gaps in the glue applied to the frame, and after rainwater enters the gaps, the component heats up during long-term operation, causing delamination at the edges of the component;

　　4. The battery cell or component may crack due to external force.

　　Component impact:

　　1. Layering can cause water ingress inside the component, resulting in internal short circuits and component reporting;

　　2. Cross hidden cracks can cause wrinkles and fragments to cause battery failure, and the power attenuation of components directly affects their performance.

　　Preventive measures:

　　1. Strictly control important parameters such as temperature and time of the laminating machine and conduct cross-linking degree experiments regularly according to requirements;

　　2. Strengthen the improvement of raw material suppliers and raw material inspection;

　　3. Strengthen the appearance inspection of finished products during the manufacturing process;

　　4. The final assembly requires strict operating procedures for gluing, and the silicone needs to be completely sealed;

　　5. Avoid external collision when lifting and placing components.

　　Reasons for Component Burnout

　　1. The contact area between the busbar and the solder strip is small or there is virtual soldering, resulting in increased resistance and heating, causing component burnout.

　　Component impact:

　　1. It has no impact on the components in a short period of time. Components that work on external power generation systems for a long time will be burned out and eventually scrapped.

　　Preventive measures:

　　1. During the welding of busbars and component repair processes, it is necessary to strictly follow the requirements of the operation manual to avoid welding areas that are too small during the welding process;

　　2. After welding is completed, it is necessary to visually check whether the welding is OK;

　　3. Strictly control the soldering iron problem within the control range (375 ± 15) and the soldering time within 2-3 seconds.

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