Solar Cell Module Solder Layout for Stronger Wire Bonding

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The durability of solar cell modules is compromised due to poor bond strength of wires in existing manufacturing processes, which affects the module's reliability and efficiency.

Innovation Solution

A solar cell module design that uses a wire film with two types of solder, where the high melting point solder on the bridge wiring member and terminal wiring member attracts more of the low melting point solder, improving the bond strength by varying the solder width and interval between components, thereby enhancing the connection between solar cells and wiring members.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a film with wires is used to simplify manufacturing, then ease of manufacture is improved, but bond strength of wires deteriorates

Engineering Contradiction:
Improveease of manufactureVSAvoidbond strength of wires
Core Design Contradiction:
Ease of manufactureVSStrength

Solution Approach 1:

The patent applies local quality by providing a solder layer with higher melting point on the bridge wiring member and terminal wiring member surfaces, while using lower melting point solder for wire connections to solar cells. This localized differentiation of solder properties optimizes both manufacturing ease and bond strength in different regions of the module.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the melting point parameter of solder by using two different types of solder with distinct melting points. The higher melting point solder (first type) is used on bridge and terminal wiring members, while lower melting point solder (second type) is used for wire connections, creating optimal bonding conditions for each component type.

Inventive Principle:
Principle #35Parameter changes

2Strength

If solder with higher melting point is used on bridge wiring member, then bond strength is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvebond strengthVSAvoiddevice complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by pre-coating the bridge wiring member and terminal wiring member surfaces with a solder layer having higher melting point before assembly. This preliminary preparation ensures strong bonds are formed during the heating process without requiring complex post-assembly operations.

Inventive Principle:
Principle #10Preliminary action

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 design improves the bond strength of wires in the bridge and terminal wiring members, increasing the durability and manufacturing ease of solar cell modules while maintaining efficiency.

Implementation Method 1

a melting point of a first type solder provided on a surface of the bridge wiring member and a terminal wiring member is higher than a melting point of a second type solder provided on a surface of the wire, and the second type solder is connected to the first type solder on the surface of the bridge wiring member and the terminal wiring member

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

By heating the stack formed by the layering to a temperature higher than the melting point of the solder, the wires are connected to the solar cell

Methodology Applied
Scientific EffectMelting: Melting

Data Source

PatentEP3675180B1Solar cell module including solar cells
Publication Date: 2024.02.07 PANASONIC HOLDINGS CORP
  • EP3675180B1 patent drawingFigure 1
  • EP3675180B1 patent drawingFigure 2
  • EP3675180B1 patent drawingFigure 3

AI summary

The finger electrode is formed by hard-soldered silver paste. The melting point of the first type solder layer provided on the surface of the terminal wiring member is higher than the melting point of the second type solder layer provided on the surface of the wire. The first width, in the first direction, of the second type solder layer in the first portion where the wire is connected to the terminal wiring member is larger than the second width, in the first direction, of the second type solder layer in the second portion where the wire is connected to the finger electrode.