Fine Silver Particle Dispersion Resistivity Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fine silver particle dispersions face challenges in maintaining resistivity stability over time, which affects the performance and reliability of conductive thick films in electrical devices.
Innovation Solution
A method involving a fine silver particle dispersion comprising 60-95 wt.% fine silver particles with a particle diameter of 50-300 nm, 4.5-39 wt.% solvent, and 0.1-3 wt.% resin with a glass transition temperature of 70-300°C, applied to a substrate and heated, along with the option of incorporating a glass frit or additional silver powder, to enhance stability and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fine silver particle dispersion is used for forming conductive thick films, then electrical conductivity is achieved, but resistivity stability over time deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters of the dispersion medium by specifying precise ranges of solvents (water, alcohols, glycols) and resin content (0.1-10 wt%), along with controlled pH levels (2-10) and redox potential (-0.5 to +0.5V), to maintain silver particle stability and resistivity over extended preservation periods
Solution Approach 2:
The invention creates a composite dispersion system combining fine silver particles (50-300nm) with multiple solvent components and resin additives, forming a stable colloidal suspension that maintains both electrical conductivity and resistivity stability over time through synergistic interactions between components
2Reliability
If fine silver particles with diameter 50-300 nm are used, then conductivity is improved, but particle aggregation occurs leading to resistivity instability
Solution Approach 1:
The patent introduces resin substances and controlled pH conditions as intermediary elements that adsorb onto silver particle surfaces, creating electrostatic or steric barriers that prevent aggregation while maintaining dispersion stability and electrical conductivity
Solution Approach 2:
The invention optimizes particle size parameters to 50-300 nm and controls chemical parameters including pH (2-10) and redox potential (-0.5 to +0.5V) to maintain particles in a stable dispersed state that resists aggregation while preserving conductive properties
3Reliability
If resin content is increased to 0.1-3 wt.% for stability, then preservation stability improves, but manufacturing precision requirements increase
Solution Approach 1:
The patent defines a broad but controlled resin content range of 0.1-3 wt.% with specified pH (2-10) and redox potential (-0.5 to +0.5V) parameters, creating a tolerance window that maintains stability while accommodating reasonable manufacturing variations without requiring extreme precision
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 approach provides preservation stability of resistivity, ensuring consistent performance of conductive thick films and electrically conductive pastes, suitable for forming circuits, electrodes, and bonding layers in various electrical devices.
Implementation Method 1
0.1 to 3 wt. % of a resin, wherein the glass transition temperature (Tg) of the resin is 70 to 300° C.
Implementation Method 2
a fine silver particle dispersion comprises, (i) 60 to 95 wt. % of fine silver particles
Implementation Method 3
heating the applied fine silver particle dispersion at 80 to 1000° C.
Implementation Method 4
heating the applied fine silver particle dispersion at 80 to 1000° C.
Implementation Method 5
A conductive paste comprising a fine silver particle dispersion and a glass frit
Data Source
AI summary
This disclosure relates to a method of manufacturing an electrically conductive thick film comprising steps of: (a) applying a fine silver particle dispersion on a substrate, wherein the fine silver particle dispersion comprises, (i) 60 to 95 wt. % of fine silver particles, wherein particle diameter (D50) of the fine silver particles is 50 to 300 nm, (ii) 4.5 to 39 wt. % of a solvent; and (iii) 0.1 to 3 wt. % of a resin, wherein the glass transition temperature (Tg) of the resin is 70 to 300° C., wherein the weight percentages are based on the weight of the fine silver particle dispersion; and (b) heating the applied fine silver particle dispersion at 80 to 1000° C.