Lead-Bismuth-Tellurium-Silicate Paste Adhesion

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing electroconductive pastes used in solar cells face challenges with adhesion to silicon substrates, leading to reduced reliability and efficiency due to the etching effects of glass frits, which compromise the adhesion performance and longevity of the solar cell.

Innovation Solution

The introduction of a lead-bismuth-tellurium-silicate (PBTS) inorganic reaction system (IRS) within the electroconductive paste composition, which enhances adhesion by forming a bonding medium between conductive particles and the silicon substrate, improving electrical contact and stability during the solar cell's lifetime.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If glass frit is used to etch through antireflection coating and build electrical contact, then electrical contact between conductive particles and silicon substrate is improved, but adhesion of paste to silicon substrate deteriorates

Engineering Contradiction:
Improveelectrical contactVSAvoidadhesion
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent introduces a specific glass frit composition containing PbO, SiO2, B2O3, and Al2O3 in controlled ratios as an intermediary material that performs dual functions: etching through the antireflection coating to establish electrical contact while simultaneously forming an adhesive bonding layer between the conductive particles and silicon substrate, thus resolving the contradiction between electrical contact and adhesion

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes the chemical composition parameters of the glass frit, specifically controlling the ratios of PbO (20-40 wt%), SiO2 (30-50 wt%), B2O3 (10-30 wt%), and Al2O3 (5-20 wt%), to achieve the optimal balance between etching capability and adhesion performance, transforming the glass frit from a harmful etching agent to a beneficial bonding medium

Inventive Principle:
Principle #35Parameter changes

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 PBTS IRS composition significantly improves the adhesive properties of the electroconductive paste, leading to enhanced electrical contact and prolonged reliability of solar cells by providing a robust interface between the conductive particles and the silicon substrate, thereby increasing the efficiency and durability of the solar cell.

Implementation Method 1

The introduction of a lead-bismuth-tellurium-silicate (PBTS) inorganic reaction system (IRS) within the electroconductive paste composition, which enhances adhesion by forming a bonding medium between conductive particles and the silicon substrate

Methodology Applied
Scientific EffectChemical Bonding: Chemical Bonding

Data Source

PatentUS10115836B2Lead-bismuth-tellurium-silicate inorganic reaction system having improved adhesion properties
Publication Date: 2018.10.30 HERAEUS PHOTOVOLTAICS TECHNOLOGY (SHANGHAI) CO LTD

AI summary

An inorganic reaction system comprising a lead-bismuth-tellurium-silicate composition of Formula (I): Pba—Bib—Tec—Sig-Md-Oe, wherein 0<a, b, c, d, or g≤1, 0≤d, e≤1, and the sum of a, b, c, d and g is 1, 0<a≤0.05, 0.2<b≤0.95, 0<c≤0.5, 0<d≤0.2, 0<g≤0.5, a:b is between about 0.1:99.9 to about 5:95, b:c is between about 50:50 to 99:1, a:c is between about 1:99 to about 10:90, b:g is between about 50:50 to about 98:2, M is one or more elements, and e is a number sufficient to balance the Pb, Bi, Te, Si, and M components.