Bifacial Solar Cell Metallization Layout for ECA Ribbon Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing metallization layouts for solar cells are inefficient in minimizing electrical resistance, maximizing light exposure area, and reducing silver paste consumption, particularly in bifacial solar cells, as they often require additional non-conductive materials and auxiliary bus bars that increase costs and reduce efficiency.
Innovation Solution
A metallization layout for bifacial solar cells using electrically conductive adhesive (ECA) to attach a ribbon to the bus bar without an extra non-conductive layer or auxiliary bus bar, featuring a grid structure with protrusions and optimized placement of horizontal and vertical elements to ensure reliable connections and reduced ECA consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional metallization layouts are used with auxiliary bus bars and non-conductive layers, then ribbon attachment is achieved, but device complexity and manufacturing cost increase
Solution Approach 1:
The invention extracts and removes the auxiliary bus bar and non-conductive layer from the traditional metallization structure. The bus bar is designed with integrated attachment areas that directly bond to ribbons through screen printing of conductive paste, eliminating the need for separate auxiliary structures and simplifying the overall device architecture while maintaining reliable electrical connections
Solution Approach 2:
The invention merges the functions of the bus bar and ribbon attachment structure into a single integrated component. The conductive paste is printed directly onto the bus bar to create the attachment area, combining the electrical conduction function and mechanical attachment function into one unified structure, thereby reducing device complexity and manufacturing steps
2Reliability
If additional non-conductive layers and auxiliary bus bars are added, then ribbon attachment is enabled, but silver paste consumption increases
Solution Approach 1:
The invention removes the non-conductive layer that traditionally required additional silver paste for creating attachment areas. By directly printing conductive paste onto the bus bar metal surface, the structure eliminates unnecessary material layers and reduces overall silver paste consumption while maintaining effective electrical and mechanical connections
Solution Approach 2:
The invention applies conductive paste only in specific localized areas on the bus bar where ribbon attachment is needed, rather than covering entire bus bar surfaces. This selective application of conductive material optimizes silver paste usage by concentrating it only where functional requirements demand, thereby reducing total consumption
3Reliability
If traditional metallization layouts are used, then connections are established, but light exposure area is reduced
Solution Approach 1:
The invention uses partial action by applying conductive paste only in the specific areas where ribbon attachment is required, rather than covering entire bus bar surfaces. This selective placement minimizes the footprint of metallization structures, maximizing the active light-exposing area of the solar cell while maintaining sufficient electrical connection reliability at the attachment points
Solution Approach 2:
The conductive paste is applied with localized precision only where needed for ribbon bonding, creating minimal obstruction to light exposure. The metallization design concentrates conductive material in functional attachment zones rather than distributing it broadly, thereby preserving maximum active area for photon absorption while ensuring reliable electrical connections
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 layout achieves reduced silver paste consumption, maintains high electrical performance, and maximizes light exposure area while minimizing mechanical stresses, resulting in reliable cell connections and cost savings through efficient ECA use.
Implementation Method 1
a cell connector, said cell connector comprising a first portion connected to said front area of said first solar cell by means of an electrically conductive adhesive
Implementation Method 2
HJT bifacial solar cells are typically realized by employing a very thin layer of hydrogenated amorphous Silicon (a-Si:H)
Data Source
AI summary
The present invention concerns a bifacial solar cell (1) comprising a front side (10) and a back side (20), said front and back sides (10, 20) having a respective outer layer (34) made of transparent conductive oxide, on which is placed a respective metallization grid (11, 21), each metallization grid (11, 21) comprising first collectors (111, 211) running parallel to each other in a horizontal direction (x) of said solar cell (1) and second collectors (112, 212) crossing said first collectors (111, 211), each second collector (112, 212) comprising two vertical elements (112a, 112b, 212a, 212b) and at least one horizontal element (112c, 212c) every one or two first collectors (111) or 3 or 6 first collectors (211) connecting said two vertical elements (112a, 112b, 212a, 212b), said solar cell module being characterized in that said metallization grids (11, 21) furtherly comprise at least one respective front or back area (113, 213), said front or back area (113, 213) comprising said at least one horizontal element (112c, 212c) and a portion of the underlying outer layer (34) made of transparent conductive oxide, so that a cell connector can be attached to said solar cell (1) by means of an electrically conductive adhesive deposited on said front or back area (113, 213) without needing a physical barrier for said electrically conductive adhesive. The present invention also concerns a solar cell module and a method of manufacturing thereof.