Solar Cell Wire Interconnection Using Thermosetting Adhesive
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Solution Overview
Problem
Existing solar cell interconnection methods result in poor contact or adhesion between welding wires and grid lines, leading to poor electric current transmission yield and increased costs.
Innovation Solution
A thermosetting adhesive is used to pre-fix a welding wire to a surface of a grid line of a cell configured to be connected to the welding wire, and the cell is heated to cure the adhesive and form an alloyed connection between the welding wire and the grid line, with the adhesive and welding wire temperatures lower than the cell heating temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing interconnection methods are used to connect welding wires to grid lines, then the manufacturing process is simple, but the contact and adhesion between welding wire and grid line are poor, resulting in poor electric current transmission yield
Solution Approach 1:
A thermosetting adhesive is introduced as an intermediary substance between the welding wire and the grid line. The adhesive is applied to the grid line surface, and the welding wire is placed on top of it. Upon heating, the adhesive cures to form a strong bond, ensuring reliable electrical contact and adhesion while maintaining a relatively simple manufacturing process.
Solution Approach 2:
The method utilizes temperature as a critical parameter to change the state of the thermosetting adhesive. By heating the cell to a temperature above the adhesive's glass transition temperature or curing temperature, the adhesive transitions from a soft, tacky state to a cured, rigid state, forming a strong bond between the welding wire and grid line. This parameter change enables reliable interconnection without excessive complexity.
2Reliability
If excessive silver paste is consumed to manufacture grid lines for subsequent interconnection, then the grid lines can be adequately formed, but the manufacturing cost increases
Solution Approach 1:
The thermosetting adhesive serves as a mediator that reduces the need for excessive silver paste in grid line formation. Instead of relying solely on thick silver paste layers to ensure adequate contact and adhesion, the adhesive provides the necessary bonding function, allowing for more optimized and potentially reduced silver paste consumption while maintaining connection reliability.
Solution Approach 2:
The method replaces the mechanical/adhesive function of excessive silver paste with a dedicated thermosetting adhesive material. The adhesive is specifically formulated to provide strong bonding and electrical contact, substituting the need for over-engineered silver paste applications and reducing material waste.
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
This method ensures effective electrical contact and improved bonding force between the welding wire and grid line, reducing the risk of separation and enhancing electric current transmission yield while minimizing silver paste consumption and costs.
Implementation Method 1
heating the cell having the welding wire pre-fixed thereon, to cure the thermosetting adhesive and form an alloyed connection between the welding wire and the grid line
Implementation Method 2
A curing temperature of the thermosetting adhesive and a melting point of a surface coating of the welding wire are both lower than a temperature at which the cell is heated
Data Source
AI summary
The present application relates to a solar cell and an interconnection method therefor. The interconnection method for the solar cell includes: using a thermosetting adhesive to pre-affix a welding wire onto a surface of a gate line of a cell used to connect with the welding wire, each gate line used to connect with the welding wire being partially covered by the thermosetting adhesive; heating the cell having the welding wire pre-affixed, such that the thermosetting adhesive is cured, and the welding wire and the gate line are alloyed and connected, the curing temperature of the thermosetting adhesive and the melting point of a surface coating of the welding wire both being lower than the temperature at which the cell is heated.