Solar Cell Edge Isolation
One important process step in the manufacturing of solar cells is the removal of doping around the edge of the solar cell, since this layer acts as a short for the p-n junction of the cell. PVA Tepla has developed an etching process for this application in coin stack configuration, which is based on fluorinated chemistry.
The coin stack loading will expose the edges to the process while the top and bottom surfaces are protected. Rotating the cell stack during process will provide the etching uniformity around the four sides of the stack. Throughput can be expected around 800 cells per hour.
The cells will be coin-stacked using the load bench and cell clamp, which are provided as option to the system. The system as well as the load bench and cell clamp allows processing of 4”, 5” or 6” cells as well as different stack height configurations.
The process requires a rather high amount of fluorinated gas in combination with an oxidant gas to create the required etching environment.