1.0 Introduction
In the process of manufacturing solar modules, there will be some quality problems, including cell shift, bubbles, backplane folds, foreign bodies, busbar bending, etc. This article will mainly focus on the bubble issue summary. Before introducing the cause of the bubble, first understand what kind of effect the bubble phenomenon will have on the component and what are the consequences: 1. In IEC 61216, the severe appearance defect in Chapter 7 d) Between the edge of the component and any part of the circuit Continuing bubbles or delamination channels indicate the presence of the above-described phenomenon, and the assembly experiment will not pass.
2. The air bubbles generated on the surface of active devices, when the component with the problem is installed in the system engineering, are affected by the outdoor environment. The surface temperature of the battery during power generation of the components is between room temperature and 65°C. Under the active device, the air bubbles on the surface of the active device will be dissociated and expanded to form a large area of ​​delamination. When the cell sheet is detached from the glass, the light-receiving rate will be seriously affected, resulting in a sharp drop in power.
3, there is no safe distance outside the active device but with the edge device, after the installation and system engineering of the kind of bubble, the bad problem refers to the above problem 2;
2.0 Bubble Causes and Solutions
As for the problem of bubble generation, the position of the bubble (the phenomenon of expression) can be divided into several types from the position where the bubble appears and the phenomenon shown.
1) The number of bubbles that appear in the position immediately within the module is small, and most of the bubbles are entrained with foreign objects;
A, foreign body caused by bubbles and bubble channels, as shown in Figure 1
Figure 1 Foreign matter caused by bubbles
Remedy: Improve the operating environment in the workshop and intensify the inspection before lamination.
B. Renovate the cell sheet during layout, and the bubble generated by the solder slag or residue (EVA). Remedy: Minimize the presence of residue on the layout table, and pay attention to clean the operation table.
C: EVA failure (damp or expired), as shown in Figure 2;
Figure 2 EVA failure caused by bubbles
2) There are large areas of air bubbles in the module, and the number is large:
A, equipment failure, no vacuum when laminating or laminating rubber board has broken or cracked, as shown in Figure 3;
Figure 3 large area bubbles
Remedy: 1. Adjust the lamination parameters and re-laminate.
2. Check on duty every day;
3. Make regular maintenance of the equipment.
B, improper lamination parameters
Remedy: Adjust the appropriate process parameters for the laminating parameters provided by the EVA supplier.
3) Bubbles or bubbles appearing next to the interconnects on the battery:
A. The flux remains on both sides of the interconnecting strips of the cell sheet. When laminating, it is difficult to discharge the gas after volatilization, and bubbles or bubbles are generated on both sides of the interconnecting strip. As shown in Figure 4.
The bubbles or bubbles appearing next to the interconnect strip on the battery
solution:
1. In the work instructions, indicate the amount of flux, control the amount of flux, ensure that the interconnect is kept in an infiltrated state during welding, and the interconnect strip must be welded before it reaches the infiltrated state.
2. For flux residues on the surface of the battery, use alcohol for cleaning.
B. Repairing the cell sheet during typesetting causes the EVA between the cell sheet and the glass to burn. When laminated, the air is difficult to withdraw, resulting in individual small bubbles.
solution:
1. Minimize rework on the layout table and clean the work surface after rework.
2. The EVA after scalding needs to be removed and the new batch of new EVA is re-laminated.
C. When welding cold welding, the gas at the void of the dummy weld is hard to be discharged and bubbles are easily generated. (As shown in Figure 5)
Remedy: Reduce the occurrence of Welds during welding and repair the resulting Weld.
Figure 5 Bubbles at the Weld Joint
4) Bubbles appearing next to the bus bar (especially at the isolation site):
A. The isolation at the lead-out line is relatively thick, and it is difficult to form a high-low air gap, as shown in Figure 6.
Figure 6 Bubbles appear at the bus
solution:
1. Adjust the isolation thickness.
2. Adjust the lamination parameters.
B. The thickness of the bus bar is too thick, resulting in a low level of difficulty leading to air guide difficulties, as shown in Figure 7.
Figure 7 Over-thickness of the bus belt
Remedy: The design is hard enough to take into account the parts involved in the standard, in addition, under the premise of ensuring compliance, adjust the process parameters.
5) Operation causes air bubbles, such as bare hand operation, glass cleaning residual moisture, etc., should strengthen workshop management and improve the quality of employees.
3.0 Conclusion
Bubbles are one of the most common problems in the production process of components. Companies should formulate specific response processes. The problem of air bubbles is solved according to the solution. In addition, the management of the workshop should be strengthened, and the quality of technicians should be improved, from prevention to remediation. It is foolproof. (The author WeChat public account: Photovoltaic experience network)
Refrigerant Recovery Cylinders
Refrigerant Recovery Cylinders,Refrigerant Recovery Tank,Refrigerant Recovery Bottle,Small Refrigerant Recovery Tank
LONG TERM ELEC. CO., LTD , https://www.longterm-hvac.com