Development of Novel Solar Cell Micro Crack Detection Technique

This paper presents the development of a solar cell inspection manufacturing execution system (MES). The main objective of the MES is to detect micro cracks in the manufacturing process of solar cells. Hence, to accept or reject a solar cell during the assembling unit. The proposed MES consists of three stages, at first stage, the inspection system will be placed on the manufacturing process of the solar cell. After the solar cell has been manufactured, it will pass under an in-line electroluminescent (EL) system. At this stage, an OR operation between a healthy/no-crack and the inspected solar cell image will be obtained. This OR operation will generate a better calibration for the cracks in the photovoltaic solar cell image. The final calibrated image presents a high quality, and low noise structure, thus easier to identify the micro cracks size, location, and orientation. The last stage evaluates the calibrated image using the plot profile which is well known as the distance in pixels versus the gray level of the image. The plot profile will indicate whether to accept or reject the solar cell, 10% confidence interval for the gray level was used to identify the upper and lower detection limits.