Solar Cell Inspection Criteria
Defect Parameter | A Grade | B Grade Exceptions | C Grade Exceptions |
(Label Color) | (White) | (Green) | (Pink) |
1. Bow | Bow < 2.0 mm | Bow > 2.0 mm | |
2. Cell color | Cell color must be within the limit sample range | Color may be outside limit sample range No yellow/gold No red/brown | Any color is accepted |
3. Variation in blue AR coating color | Shades of blue on one single cell must be within the color limit sample range | Any variation is accepted No yellow/gold No red/brown | Any variation is accepted |
4. Highcontrast stains, spots, fingerprints and water marks | Total area < 4 mm2 | Total area < 2 cm2 | All stains are allowed |
5. Lowcontrast stains, spots, fingerprints and water marks | Total area < 4cm2 | Total area <8 cm2 | All stains are allowed |
6. Metal screen printing paste smears or dots | < 2 smears for a total area < 2 mm² allowed. | Total area < 10 mm² allowed. | Total area < 200 mm² allowed. |
7. Variations in the front grid width | Length < 3.0 mm Width < 0.5 mm | Length >3.0 mm Width < 1.0 mm | Length > 3.0 mm Width > 1.0 mm |
8. Grid line interruptions | Length < 3.0 mm < 2 line breaks per gridline | Length < 5.0 mm < 10 breaks per cell | Length < 20.0 mm < 10 breaks per cell |
9. Position tolerance of the front print pattern | No print area can be within 1.0 mm of edge of cell | No print area can be within 0.5 mm of edge of cell | |
10. Front surface defects on edge of cell (not through the entire cell thickness) | A total edge defect area less than 50 mm long and less than 1 mm wide is allowed. | ||
11. Silver front bus bar | 1 spot missing < 2 mm silver allowed | < 3 spots missing < 2 mm silver allowed | |
12. Silver back pads | No exposed silicon > 5.0 mm along the edges of the pad No high spots > 0.2 mm | No exposed silicon >10.0 mm along the edges of the pad | |
13. Minimum distance of back print to edges | 0.5 mm | 0.0 mm | |
14. Missing areas in the Al back print | A missing area < 100 mm² in total is allowed. A missing total area < 1000 mm² allowe | A missing total area < 2500 mm² allowed | |
15. Bumps, beads, droplets on the back Aluminum print | Small bumps allowed. Surface beads < 0.2 mm height allowed. Total area < 20 mm² allowed. | Surface beads < 0.5 mm height allowed. | |
16. Attached broken pieces on the cell surfaces, cracks, breaks, holes | Not allowed | ||
17. V Shape chip | Not allowed | Up to two chips < 10 mm outside gridline | Up to two chips < 500 mm2 each are |
18. Edge chips (through the cell thickness) | Two chips < 1.0 mm long and not deeper than 0.5 mm is allowed | Up to two chips < 10 mm outside gridline allowed. | Up to two chips < 500 mm2 each are allowed. |
poly cell 156*156