Solar Cell Back Contact Manufacturing via Concurrent Curing

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Solution Overview

Problem

The existing methods for producing solar cells with back contact structures face challenges in productivity and insulation performance due to excessive heat treatment, leading to reduced toughness and efficiency in photoelectric conversion.

Innovation Solution

A method involving the concurrent curing of conductive paste and insulator film precursors, with specific resin materials, to form electrodes and insulator films, ensuring appropriate heat application and maintaining film toughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the insulator film is completely cured before applying the conductive paste, then the insulation performance is improved, but the productivity is reduced due to long heat treatment time

Engineering Contradiction:
Improveinsulation performanceVSAvoidproductivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The insulator film precursor is applied and temporarily cured before the conductive paste is applied. This preliminary action provides sufficient insulation performance for the subsequent electrode formation while avoiding the need for complete curing beforehand, thereby reducing total heat treatment time and improving productivity.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heat treatment process is designed to continue through multiple stages: temporary curing of the insulator film precursor, curing of the conductive paste, and complete curing of the insulator film. This continuous heat treatment eliminates idle time between processes and improves overall productivity while maintaining insulation performance.

Inventive Principle:
Principle #20Continuity of useful action

2Reliability

If excessive heat treatment is applied to completely cure the insulator film, then the insulation performance is improved, but the toughness of the insulator film is reduced

Engineering Contradiction:
Improveinsulation performanceVSAvoidtoughness
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The insulator film precursor is temporarily cured with moderate heat treatment before electrode formation, providing sufficient insulation performance without applying excessive heat that would damage the film toughness. The complete curing is performed after electrode formation, avoiding thermal stress on the insulator film.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The heat treatment process is divided into two segments: temporary curing of the insulator film precursor at moderate temperature, and complete curing after electrode formation. This segmentation allows the insulator film to be cured without excessive heat exposure that would reduce its toughness.

Inventive Principle:
Principle #1Segmentation

3Reliability

If excessive heat treatment is applied to completely cure the insulator film, then the insulation performance is improved, but the contraction of the insulator film occurs leading to insufficient insulation

Engineering Contradiction:
Improveinsulation performanceVSAvoidfilm stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The insulator film precursor is temporarily cured with moderate heat treatment before electrode formation, providing sufficient insulation performance without causing film contraction. The complete curing is performed after electrode formation, avoiding thermal stress and contraction that would compromise insulation performance.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The conductive paste is applied after temporary curing of the insulator film precursor, ensuring the paste is electrically insulated from the first electrode. This timing prevents the paste from interfering with the insulator film formation while avoiding excessive heat treatment.

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 method enhances productivity and photoelectric conversion efficiency by reducing heat exposure and preventing film contraction, resulting in improved solar cell performance.

Implementation Method 1

curing the insulator film by heating at 140°C for 10 minutes

Methodology Applied
Scientific EffectHeat treatment: Heating

Implementation Method 2

curing the conductive paste to form a second electrode

Methodology Applied
Scientific EffectHeat treatment: Heating

Implementation Method 3

completely curing the insulator film precursor to form an insulator film

Methodology Applied
Scientific EffectHeat treatment: Heating

Implementation Method 4

improving the photoelectric conversion efficiency of a crystal silicon solar cell

Methodology Applied
Scientific EffectPhotoelectric conversion: Photoelectric Effect

Data Source

PatentEP3343643B1Method for manufacturing high-efficiency solar cell
Publication Date: 2021.08.04 SHIN ETSU CHEMICAL CO LTD
  • EP3343643B1 patent drawingFigure 1~3
  • EP3343643B1 patent drawingFigure 4~5

AI summary

The present invention is a method for producing a solar cell, the method including the steps of: forming a first electrode on a first main surface of a semiconductor substrate; applying an insulator film precursor so as to cover at least part of the first electrode; temporarily curing the insulator film precursor; applying a conductive paste to at least the insulator film precursor so as to be electrically insulated from the first electrode; curing the conductive paste to form a second electrode; and completely curing the insulator film precursor to form an insulator film, the method in which the step of applying the conductive paste so as to be electrically insulated from the first electrode is performed after the step of temporarily curing the insulator film precursor and at least part of the step of curing the conductive paste to form the second electrode and at least part of the step of completely curing the insulator film precursor to form the insulator film are concurrently performed. As a result, there can be provided a method for producing a solar cell having good photoelectric conversion characteristics with high productivity.