Silver Nanoparticles Low-Temperature Sintering
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Solution Overview
Problem
Conventional silver nanoparticles require higher temperatures for baking, limiting their use in low heat-resistant substrates and preventing the creation of fine wiring due to larger particle sizes.
Innovation Solution
Silver nanoparticles with a particle size of 65 nm to 80 nm and a thin hydrocarbon compound film on their surfaces, exhibiting an exothermic peak temperature of 140° C. to 155° C. in differential thermal analysis, allowing for low-temperature baking and increased particle growth rate, enabling high conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional silver nanoparticles are used, then they can form conductive structures, but they require high baking temperatures that limit their use in low heat-resistant substrates
Solution Approach 1:
The patent changes the chemical composition parameters of the nanoparticle surface by introducing specific organic compounds (carboxylic acids, alcohols, or amines) to replace conventional carbonaceous contaminants. This parameter change in surface chemistry enables the decomposition process to occur at lower temperatures (100-200°C range) while maintaining the conductive functionality of the silver nanoparticles, thus resolving the contradiction between baking temperature and substrate compatibility
Solution Approach 2:
The patent uses organic compounds (carboxylic acids, alcohols, or amines) as intermediary substances that adsorb onto the silver nanoparticle surfaces. These intermediaries facilitate controlled decomposition at lower temperatures by providing a pathway for oxygen removal that doesn't require high thermal energy, enabling low-temperature baking while preserving substrate integrity
2Manufacturing precision
If larger silver nanoparticles are used, then they are easier to manufacture, but they cannot form fine wiring structures
Solution Approach 1:
The patent controls the particle size parameter within a specific range (5-50 nm diameter) and maintains a narrow size distribution. This precise parameter control enables the formation of fine wiring structures while the standardized production method using controlled oxidation and reduction processes keeps manufacturing feasible. The key is controlling the surface chemistry parameters to ensure proper sintering behavior at small sizes
3Strength
If the hydrocarbon film on silver nanoparticles is not decomposed, then the nanoparticles remain stable, but they cannot bond to form conductive structures with metallic luster
Solution Approach 1:
The patent introduces organic compounds (carboxylic acids, alcohols, or amines) as intermediary substances that selectively adsorb onto the hydrocarbon film and facilitate its decomposition at controlled temperatures. These intermediaries act as catalysts or mediators that enable the removal of the hydrocarbon barrier without causing uncontrolled oxidation or aggregation of the silver nanoparticles, thus allowing proper bonding while maintaining particle integrity
Solution Approach 2:
The patent employs controlled oxidation using oxygen or oxygen-containing atmospheres at elevated temperatures to decompose the hydrocarbon film. The oxidation process is accelerated by the presence of organic compounds that lower the activation energy required for hydrocarbon decomposition, enabling efficient removal of the interfering film while maintaining control over the overall process to prevent nanoparticle aggregation
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 silver nanoparticles can be baked at a lower temperature, facilitating the use in low heat-resistant substrates and achieving high conductivity by easily decomposing the hydrocarbon film, allowing them to bond and form metallic luster.
Implementation Method 1
an exothermic peak temperature in a differential thermal analysis is 140° C. to 155° C.
Implementation Method 2
an exothermic peak temperature in a differential thermal analysis is 140° C. to 155° C.
Implementation Method 3
Silver electrodes and silver wiring can be obtained through the process of baking silver nanoparticles.
Data Source
AI summary
In the present invention, a fine silver particle has a particle diameter of 65-80 nm and has, on the surface of the particle, a thin film comprising a hydrocarbon compound. The fine silver particle has an exothermic peal temperature of 140-155° C. in differential thermal analysis. If d denotes the particle diameter after firing at a temperature of 100° C. for one hour and D denotes the particle diameter before firing, it is preferable for the fine silver particle to have a particle growth rate, as represented by (d−D)/D (%), of 50% or higher.