Silver powder is an essential component in conductive silver paste, and its particle size, shape, and surface modification parameters have a significant impact on the surface microstructure of conductive silver paste.

This article will explore the influence of silver powder on the surface microstructure of conductive silver paste, in order to provide theoretical support and practical guidance for the preparation and application of conductive silver paste.

The particle size and distribution of silver powder are important factors determining the surface microstructure of conductive silver paste.

Silver powders of different particle sizes have different specific surface areas and porosity, which directly affect the adhesion, permeability, and conductivity of conductive silver paste. Research has shown that as the particle size of silver powder decreases, the specific surface area and porosity increase, which is beneficial for improving conductivity. However, excessively small silver powder particle size may lead to difficulties in drying conductive silver paste and increased preparation costs.

The shape of silver powder is also one of the factors affecting the surface microstructure of conductive silver paste. Silver powders of different shapes have different specific surface areas and porosity, which directly affect the adhesion, permeability, and conductivity of conductive silver paste. Research has shown that flake silver powder has a large specific surface area and porosity, which is beneficial for improving conductivity; However, the specific surface area and porosity of spherical silver powder are relatively small, and its conductivity is relatively poor.
The surface modification of silver powder is also one of the factors affecting the surface microstructure of conductive silver paste.

By modifying the surface of silver powder, its polarity and hydrophilicity can be altered, thereby affecting the adhesion, permeability, and conductivity of conductive silver paste. Research has shown that surface modification can improve the wettability and stability of silver powder surfaces, thereby enhancing their conductivity.

The role of silver powder in conductive silver paste mainly includes the following aspects:
1. Enhance conductivity: Silver powder, as a good conductor, forms a continuous conductive film on the surface of the substrate, which can significantly improve the conductivity of the material. In addition, the interconnection between silver powders also plays an important role in improving the overall conductivity performance.

2. High temperature oxidation resistance: Silver powder is prone to oxidation at high temperatures, but can remain stable at lower temperatures. Therefore, in high-temperature environments, silver powder can effectively protect the substrate from the effects of high-temperature oxidation.

3. Enhance adhesion: By surface modification and other methods, silver powder can better adhere to the substrate surface, improving the adhesion of conductive silver paste. At the same time, the interconnection between silver powders also makes the entire conductive layer more firmly bonded to the substrate.

4. Reduce contact resistance: Due to the low contact resistance between silver powders, it can effectively reduce the contact resistance of the entire conductive layer and improve the conductivity of the material.

5. Improve electromagnetic shielding performance: In some application scenarios, conductive materials need to have certain electromagnetic shielding performance. Due to its excellent electromagnetic shielding performance, silver powder can effectively improve the electromagnetic shielding effect of materials.

In summary, this article discusses the influence of silver powder on the surface microstructure of conductive silver paste. By adjusting parameters such as particle size, shape, and surface modification of silver powder, the adhesion, permeability, and conductivity of conductive silver paste can be significantly improved. This has important theoretical and practical significance for the preparation and application of conductive silver paste.