A secondary overprinting process for front electrodes

Abstract

The invention discloses a secondary overprinting process of the front electrode, which comprises the following steps: using No. 1 screen printing machine to print the back electrode; using No. 2 screen printing machine to print the back electric field; after the back electrode and the back electric field are printed, the battery The pattern printing of the grid lines on the front side of the chip is completed through the secondary overprinting of the main grid lines and the auxiliary grid lines, that is, the main grid lines and the auxiliary grid lines are printed separately. The present invention adopts the secondary overprinting technology for the grid lines on the front of the cell, without affecting the aspect ratio of the auxiliary grid lines, reduces the height of the main grid lines, improves the printing quality, and reduces the consumption of silver paste, so as to reduce the production cost of the battery sheet. cost and improve conversion efficiency.

Description

technical field [0001] The invention relates to a screen printing technology for a crystalline silicon solar cell, in particular to a secondary overprinting process for a front electrode. Background technique [0002] As we all know, the current cost of battery production and manufacturing mainly comes from the consumption cost of front silver. With the continuous soaring of silver dots in the market, how to reduce the consumption of silver paste to reduce the cost is particularly important. The traditional printing mode busbar and fine grid The same printed pattern is printed and formed at one time, and the silver paste consumption of the busbar accounts for more than 30% of the overall silver paste consumption. When high-efficiency batteries pursue a large aspect ratio, the height of the busbar will also increase, and then It will bring a large loss of silver paste and increase the manufacturing cost of the cell; the current double-printing (double-printing) machine has to...

AI Technical Summary

Problems solved by technology

[0002] As we all know, the current cost of battery production and manufacturing mainly comes from the consumption cost of front silver. With the continuous soaring of silver dots in the market, how to reduce the consumption of silver paste to reduce the cost is particularly important. The traditional printing mode busbar and fine grid The same printed pattern is printed and formed at one time, and the silver paste consumption of the busbar accounts for more than 30% of the overall silver paste consumption. When high-efficiency batteries pursue a large aspect ratio, the height of the busbar will also increase, and then It will bring a large loss of silver paste and increase the manufacturing cost of the cell; the current double-printing (double-printing) machine has too strict requirements on the overprinting accuracy of the double-printed pattern, and the width of the fine grid line of the cell is not easy to control, resulting in Unstable conversion efficiency and increased printing defect rate, the main defect is uneven thickness

[0003] In the traditional cell screen printing process, the front grid line pattern of the battery cell is printed at one time. The main grid line and the auxiliary grid line use the same process screen. For the process flow, see figure 1 , which means that while making the auxiliary grid lines higher, the height of the main grid lines is also increased. The silver paste consumption of the main grid lines accounts for more than 30% of the overall silver paste consumption, but the height of the main grid lines The increase will not improve the conversion efficiency of the cell

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