Back-Contact Solar Cell Busbar Layout for Low-Silver Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing back-contact solar cell technologies face issues with high silver consumption, deformation after welding, low tensile force, and low production yield due to large silver paste grids and pads, leading to increased material costs and reduced module efficiency.
Innovation Solution
A non solder pad ultrafine main busbar back-contact solar cell design with narrow, segmented main busbar lines and the use of curing adhesive for connecting welding strips, eliminating the need for pads and high-temperature processing, which reduces silver consumption and enhances tensile force and production yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If pads are provided on main busbar lines with conventional width, then welding connection is achieved, but silver consumption increases and cell deformation occurs after welding
Solution Approach 1:
The patent divides the continuous main busbar line into multiple segments separated by insulation layers. Each segment is independently formed and connected to fingers, eliminating the need for large pads while maintaining reliable electrical connection through the segmented structure
Solution Approach 2:
The patent removes the pad component entirely from the electrode structure. Instead of using pads to connect main busbar lines to fingers, the design directly connects narrow main busbar lines to fingers through insulation layers, eliminating the source of silver consumption and welding-induced deformation
2Strength
If high-temperature welding is used to connect welding strips to main busbar lines, then strong bonding is achieved, but cell deformation occurs and production yield decreases
Solution Approach 1:
The patent replaces the thermal welding process with a mechanical bonding system using adhesive layers. The adhesive layers provide strong bonding between welding strips and main busbar lines without requiring high-temperature processing, thereby preventing cell deformation and improving production yield
3Reliability
If wide main busbar lines are used, then current collection is improved, but silver paste consumption increases
Solution Approach 1:
The patent changes the width parameter of main busbar lines from conventional wide dimensions to narrow dimensions (10-100 μm). This parameter change reduces silver paste consumption while maintaining effective current collection through the increased number of segmented lines and optimized insulation layer configuration
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution achieves low silver consumption, high bifaciality, and improved production yields with reduced deformation and increased CTM values, while maintaining excellent bonding force without high-temperature processing.
Implementation Method 1
a curing adhesive located above a Z-axis direction of the welding strip area corresponding to the corresponding main busbar line
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present disclosure provides a non solder pad ultrafine main busbar back-contact solar cell, a back-contact solar cell module, and a preparation method, wherein the back-contact cell includes a first finger and a second finger, a first main busbar line, a second finger, a first insulation layer, and a second insulation layer, wherein the widths of the first main busbar line and the second main busbar line in the X-axis direction are each independently 10-100 µm; the first main busbar lines or the second main busbar lines are respectively provided in an extending manner or at intervals along the same axis perpendicular to the corresponding fingers connected thereto, and when spaced apart, the distance L between two adjacent corresponding main busbar lines in the Y-axis direction is 5-100 mm.