Back-Contact Solar Cell Busbar Layout for Simultaneous Electroplating

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Solution Overview

Problem

The electroplating process in back-contact solar cells is complicated due to the discontinuous design of fingers, requiring sequential connection to busbars, leading to low electroplating efficiency.

Innovation Solution

The use of conductive connectors at the ends of busbars to facilitate simultaneous electroplating of finger pre-plating layers, eliminating the need for sequential connection to busbars, thereby simplifying the process and improving efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fingers are designed to be discontinuous and divided into finger segments to avoid short circuits, then short circuit prevention is improved, but electroplating process complexity increases due to requiring sequential connection to busbars

Engineering Contradiction:
Improveshort circuit preventionVSAvoidelectroplating process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces conductive connectors as intermediary components between the discontinuous finger segments and the busbars. These connectors bridge the gaps in the finger structure, allowing electrical connection without requiring direct sequential connection to busbars during electroplating. The conductive connectors serve as mediators that simplify the electroplating process while maintaining the discontinuous finger design for short circuit prevention.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If sequential connection to busbars is used for electroplating finger segments, then short circuit avoidance is improved, but electroplating efficiency decreases

Engineering Contradiction:
Improveshort circuit avoidanceVSAvoidelectroplating efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

Conductive connectors are introduced as intermediary components that enable simultaneous electroplating of multiple finger segments. Instead of sequentially connecting each finger segment to busbars, the conductive connectors provide common electrical connection points that allow parallel processing, thereby improving electroplating efficiency while maintaining short circuit avoidance through the discontinuous finger design.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If discontinuous finger design is implemented to prevent short circuits, then cell reliability is improved, but manufacturing process simplicity deteriorates

Engineering Contradiction:
Improvecell reliabilityVSAvoidmanufacturing process simplicity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The conductive connectors serve as intermediary elements that simplify the manufacturing process of discontinuous fingers. By providing standardized connection points, these connectors make the assembly and electroplating processes more manageable despite the complexity introduced by the discontinuous finger design. The connectors act as intermediaries that bridge the gap between the fragmented finger segments and the overall cell structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 electroplating process is streamlined, enhancing efficiency and reliability of forming electroplating layers on finger segments without the complexity of sequential connections.

Implementation Method 1

first fingers include first finger pre-plating layers forming ohmic contact with the substrate

Methodology Applied
Scientific EffectOhmic contact: Conduction (electrical)

Implementation Method 2

an electroplating layer can be formed on the finger metal layer by an electroplating device through electroplating (for example, copper electroplating)

Methodology Applied
Scientific EffectElectroplating: Electroplating

Data Source

PatentEP4708365A1Back-contact solar cell, cell assembly, and photovoltaic system
Publication Date: 2026.03.11 GUANGDONG AIKO SOLAR ENERGY TECH CO LTD
  • EP4708365A1 patent drawingFigure 1
  • EP4708365A1 patent drawingFigure 2
  • EP4708365A1 patent drawingFigure 3~4

AI summary

A back-contact solar cell (100), a cell assembly (200) and a photovoltaic system (1000). In a back electrode structure (20) of the back-contact solar cell (100), first fingers (21) include first finger pre-plating layers (211) forming ohmic contact with a substrate (10) and first finger electroplating layers (212) plating the first finger pre-plating layers (211), and second fingers (22) include second finger pre-plating layers (221) forming ohmic contact with the substrate (10) and second finger electroplating layers (222) plating the second finger pre-plating layers (221). The first busbars (23) make contact with the first finger pre-plating layers (211), the first fingers (21) are disconnected at second busbars (24), the second busbars (24) make contact with the second finger pre-plating layers (221), and the second fingers (22) are disconnected at the first busbars (23). A first conductive connector (30) and a second conductive connector (40) are arranged at two ends of the first busbars (23) and the second busbars (24) respectively, the first conductive connector (30) is connected to ends of all the first busbars (23) facing away from the second conductive connector (40), and the second conductive connector (40) is connected to ends of all the second busbars (24) facing away from the first conductive connector (30).