Finger interruption check on solar cell metallisation
The printed cell stops below the camera on a vacuum carrier. Finger lines are followed under coaxial illumination; a cell with an interrupted or narrowed line is moved to the sorting tray.
Interruption location and line width are written to the cell record. A cell outside the recipe is moved to the sorting tray by the robot at the unload position; the inspection image is shown on the operator display.
- 01 Position
- 02 Illuminate
- 03 Acquire
- 04 Line analysis
- 05 Sort
The carrier stops the cell below the camera.
- Interruption length
- —
- Local line width
- —
Scenes are illustrative simulations; they are not customer references or performance guarantees.
Need
Thin conductive lines give angle-dependent, variable reflections on the shiny, textured cell surface. Print-edge roughness and angular offset of the cell on the carrier can hide a short interruption or a local narrowing.
Solution approach
A vacuum carrier holds the cell flat. Coaxial illumination sends light along the camera axis; in the perpendicular view the metal lines and the cell surface separate with stable contrast. In an image aligned to the cell edge each finger is followed along its length; gap length and local line width are compared with the recipe limits.
Process steps
- 01
Position
The carrier stops the cell below the camera.
- 02
Illuminate
Coaxial light illuminates the printed surface along the camera axis.
- 03
Acquire
A magnified image of the finger lines is captured.
- 04
Line analysis
Continuity and local width are measured along each finger.
- 05
Sort
The carrier moves to the unload position; a cell with interrupted print is moved to the sorting tray.
Related applications
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