Solar Cell Soldering Pattern Exposure Without Dielectric Burn-Through
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Solution Overview
Problem
Existing solar cell manufacturing methods face limitations in forming metal grid electrodes, particularly due to the inability of silver paste to burn through certain dielectric layers without special glass materials and the risk of damaging the solar cell during passivation layer removal.
Innovation Solution
A method involving forming an electrode pattern with a soldering pattern on a substrate, covering it with a dielectric layer, and using laser ablation to expose the soldering pattern, allowing for direct soldering to bus ribbons while protecting the substrate and enabling the use of various electrode materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If metal paste is screen printed and sintered at high temperature to burn through dielectric layer, then metal grid electrodes are formed, but the choice of electrode materials is restricted and special glass materials are required
Solution Approach 1:
The patent segments the electrode structure into two functional parts: a soldering pattern (exposed metal) for electrical connection and a dielectric layer (with openings) for insulation and protection. This segmentation allows the metal to be deposited without needing to burn through the dielectric, enabling use of pure silver or other materials that cannot withstand high-temperature sintering through dielectric layers.
Solution Approach 2:
The dielectric layer is formed first, then openings are created in predetermined locations before metal deposition. This preliminary structuring of the dielectric layer with openings eliminates the need for high-temperature burn-through processes, allowing gentle deposition methods that preserve material purity and expand material choices.
2Ease of manufacture
If laser ablation is used to remove passivation layer before forming metal grid electrodes, then electrode formation is enabled, but the solar cell may be damaged and performance degraded
Solution Approach 1:
The dielectric layer with openings is formed in advance through low-damage methods (spin coating, spray coating, or gentle laser ablation followed by filling). This preliminary structuring eliminates the need for aggressive laser ablation of the passivation layer, protecting the solar cell from damage while enabling subsequent low-temperature metal deposition.
Solution Approach 2:
The dielectric layer serves as an intermediary structure that provides the necessary openings for metal contact without requiring direct laser damage to the passivation layer. This intermediary approach allows controlled metal deposition through pre-formed openings, avoiding the harmful effects of aggressive laser ablation on the solar cell structure.
3Reliability
If dielectric layer is formed to protect electrode pattern, then insulation is provided, but soldering pattern must be exposed for bus ribbon connection
Solution Approach 1:
The dielectric layer is applied with local variations: it covers most areas for insulation but has predetermined openings at soldering locations. This local quality differentiation allows the same dielectric material to provide both insulation where needed and metal exposure where connections are required, simplifying the overall structure compared to using different materials or layers.
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 stable connections with bus ribbons, avoids substrate damage, and allows for the use of diverse electrode materials, resulting in improved soldering strength and photovoltaic conversion efficiency.
Implementation Method 1
removing the dielectric layer from the soldering pattern area to expose it for soldering, using laser ablation to precisely remove the dielectric layer without damaging the substrate
Data Source
AI summary
A method for preparing a solar cell includes providing a substrate with a first conducting layer, the substrate including a first surface and a second surface opposite to each other in a thickness direction of the substrate, the first conducting layer being formed on the first surface; forming a first electrode pattern on a side of the first conducting layer away from the substrate, the first electrode pattern being electrically connected to the first conducting layer, the first electrode pattern including a first soldering pattern, the first soldering pattern being configured for soldering to one or more first bus ribbons; forming a first dielectric layer on a side of the first electrode pattern away from the substrate, and covering the first electrode pattern with the first dielectric layer; and removing a portion of the first dielectric layer corresponding to the first soldering pattern, and exposing the first soldering pattern.