A reworking method on degraded products after the printing of crystal silicon solar battery

Abstract

The invention discloses a rework method of defective products of crystalline silicon solar cells after printing. The method includes the following three steps: an aluminum paste at the back surface of a cell is removed by using an HCl cleaning liquid; silver pastes at the positive and negative surfaces of the cell is removed by using isopropanol; the cell, the pastes of which is basically removed is treated with deep cleaning by using the deep cleaning liquid so as to thoroughly clean tiny impurities. The conversion efficiency of the cell can achieve the level of a normal cell by using the method for processing, and the appearance is not different from the normal cell, thus the invention achieves the purpose of rework cleaning. The failure rate of the silk screen printing of the cells is reduced to about 0.2 percent from original about 2 percent, thereby increasing the qualified rate and the yield of the silicon solar cells.

Description

technical field [0001] The invention relates to the processing of solar cells, in particular, the invention relates to a method for reworking defective products after printing of crystalline silicon solar cells. Background technique [0002] At present, the back electric field and the back electrode of the crystalline silicon solar cell are located on the back of the solar cell, forming the back electric field and the bottom electrode of the silicon cell. Cooperating with the upper electrode on the surface of the silicon cell, it plays the role of transmitting the electric energy generated by the silicon solar cell to the outside world. The positive electrode and the back electrode are made of silver paste, and the back electric field is made of aluminum paste through printing, drying and sintering. [0003] In the normal production process of cell screen printing, there are often some defective screen printing products caused by printing abnormalities. These defective prod...

AI Technical Summary

Problems solved by technology

Since the front of the cell is a blue SiN anti-reflection film, and there are many tiny pyramids on the suede, the slurry on the suede pits is very difficult to clean, and it will be damaged if the force is too large. Suede, destroying the PN junction, so the existing rework technology often leaves traces of wiping on the blue surface of the cell (also produces a defective cell), and the cell after the PN junction is wiped due to electrical If the performance is poor, it will become a defective product or even a waste product in terms of electrical performance.

However, there is no literature report on how to rework the defective products printed on the back and the defective products with aluminum paste on the front.