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Summary analysis of common major quality issues of solar PV modules
- Apr 12, 2018 -

Photovoltaic Components Common Quality Problems Phenomenon and Analysis

 

Mesh cracking reason

 

1. The battery is subjected to external forces during welding or handling.

 

2. The battery is suddenly warmed up in a short time without preheating at low temperature

 

Swelling caused by temperature expansion

 

Component impact:

 

1. Mesh cracking will affect the power attenuation of the component.

 

2. Fragmentation of the mesh cracks occurs for a long time, hot spots and other components directly affect the performance

 

Precaution:

 

1. Avoid the battery is too impacted by external force during the production process.

 

2. During the welding process, the battery should be insulated in advance (hand soldering).

 

Meet the requirements.

 

3. EL testing requires strict inspection..
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  Meshed crack

 

Causes of EVA delamination

 

1. The degree of cross-linking is unqualified (such as low laminator temperature, short lamination time, etc.)

 

2. There are foreign materials on the surface of raw materials such as EVA, glass and backboard.

 

3. EVA raw material components (such as ethylene and vinyl acetate) are not uniform and cause delamination due to inability to dissolve at normal temperatures.

 

4. Excessive amount of flux, long-term exposure to high temperatures outside the extension of the bus line delamination

 

Component impact:

 

1. When the delamination area is small, the power failure of the module is affected. When the delamination area is large, it will directly lead to the invalidation of the component failure

 

Precaution:

 

1. Strictly control the laminating machine temperature, time and other important parameters and do cross-linking degree experiments as required, and control the degree of cross-linking within 85%±5%.

 

2. To strengthen the improvement of raw material suppliers and inspection of raw materials.

 

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

 

4 strictly control the amount of flux, try not to exceed 0.3mm on both sides of the busbar

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  Silica gel causes stratification & causes cross-hidden cracks

 

1. The degree of cross-linking is unqualified (such as low laminator temperature, short lamination time, etc.)

 

2. There are foreign materials on the surface of raw materials such as EVA, glass and backboard.

 

3. There is a crack in the frame glue, and after the rain enters into the gap, the component is heated during a long time and the component edge is delaminated.

 

4. Cells or components are cracked by external forces

 

Component impact:

 

1. Stratification can cause water in the module to cause short-circuit inside the module and cause the module to be scrapped.

 

2. Cross-hidden cracks will cause damage to the cells due to streaks of debris. Component power attenuation directly affects component performance.

 

Precaution:

 

1. Strictly control the laminating machine temperature, time and other important parameters and do cross-linking experiments as required.

 

2. To strengthen the improvement of raw material suppliers and inspection of raw materials.

 

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

 

4. Strict requirements for the operation of the final assembly and the silicone must be completely sealed

 

5. Avoid impact by external forces when lifting components

 

Silicone is not battery

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  Good stratification Fork hidden crack

 

Component burnout causes

 

1. The contact area between the bus bar and the ribbon is small or the resistance is increased due to the resistance welding.

 

Component impact:

 

1. No impact on the components in a short time, the components will be burned out after working for a long time on the external power generation system and eventually lead to scrap

 

Precaution:

 

1. In the process of welding the bus bar and the component repair process, welding must be strictly performed in accordance with the requirements of the work instructions, so as to avoid that the welding area is too small in the welding process.

 

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

 

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

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  Internal burnout of components

 

Component junction box causes fire

 

1. The lead wire is not clamped in the card slot and it will ignite and catch fire.

 

2. If the welding area of the lead and the junction box is too small, the resistance is too large to cause a fire.

 

3. Excessive length of wire lead to contact with the plastic parts of the junction box will cause fire

 

Component impact:

 

1. A fire causes the components to be scrapped, and it is likely to cause a fire.

 

Precaution:

 

1. Strictly follow the sop operation to fully insert the lead into the slot

 

2. The welding area of lead wire and junction box solder joint is at least 20mm2.

 

3. Strictly control the lead length to meet the drawing requirements, according to the sop operation.

 

Avoid contact with terminal box plastic parts.

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  Battery splitting reason

 

1. Cracks caused by improper operation during welding

 

2. The component splinters are caused by incorrect maneuvering

 

3. Laminator failures appear component sheet

 

Component impact:

 

1. Fragment partial failure affects component power attenuation,

 

2. Monolithic cell power attenuation or complete failure affects component power attenuation

 

Precaution:

 

1. Busbar welding and rework areas operate strictly in accordance with the sop method

 

2. When the person lifts and puts the component, the component shall be lifted and placed in strict accordance with the process requirements.

 

3. Ensure the regular maintenance of the laminator. Every replacement of the equipment must be done strictly after the first confirmation ok in production.

 

4. EL testing is strictly controlled and inspections are prohibited.

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  Excessive amount of battery flux

 

1. The welding machine adjusts the spray flux to cause excessive spraying

 

2. Excessive fluxing caused by personnel rework

 

Component impact:

 

1. Affect the EGA delamination of the component's busbar position.

 

2. Lightning bolts appear dark spots on the power generation system for a long time after the components are used. This affects the power attenuation of the module and reduces the service life of the module or leads to scrapping.

 

Precaution:

 

1. Adjust the welding flux of welding machine. Check regularly.

 

2. Rework area Please use designated soldering pen when replacing the battery. Do not apply flux with big brush

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  Weld, overweld causes

 

1. Excessive soldering temperature or fluxing

 

2. Excessive welding temperature or excessive welding time will lead to over-welding.

 

Component impact:

 

1. Welds delaminate ribbons and cells in a short time, affecting power attenuation or failure of components.

 

2. Over-welding causes damage to the internal electrodes of the solar cell, directly affecting the attenuation of the power of the component, reducing the service life of the component or causing scrap

 

Precaution:

 

1. Ensure that the welding machine temperature, flux injection quantity and welding time parameter settings. And regularly check,

 

2.Rework area must ensure the temperature of the soldering iron, welding time and use the correct flux pen smear flux.

 

3. Strengthen EL inspections to avoid the loss of the next process.

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Deflection due to ribbon or warpage after welding

 

1. Abnormal welding machine positioning will cause the ribbon offset phenomenon

 

2. The deviation of the busbars from the busbars after welding will cause the offset of the strips after the welding.

 

3. The temperature is too high, the bending hardness of the ribbon leads to bending of the battery after welding.