The ability of an object to conduct current is called conductivity. The conductivity of various metals is different. Generally, silver has the best conductivity, followed by copper and gold.
Silver conductive slurry can be divided into two categories: polymer Silver conductive slurry (drying or curing film, using organic polymer as bonding phase); sintered silver conductive slurry (sintering film, sintering temperature > 500 C, glass powder or oxide as bonding phase).
According to the classification of the particle size, the average particle size of silver powder is nano-silver powder < 0.1 micron (100nm); 0.1 micron < Dav (average particle size) < 10.0 micron is silver powder; Dav (average particle size) > 10.0 micron is coarse silver powder. There are many preparation methods of powder. For silver, physical method (plasma, atomization method), chemical method (silver nitrate thermal decomposition method, liquid phase reduction method) can be used once. As silver is a precious metal, it is easy to be reduced to the elemental state, so the liquid phase reduction method is the most important method to prepare silver powder. By dissolving silver salts (silver nitrate, etc.) in water, adding chemical reductants (such as hydrazine hydrate) and depositing silver powder, silver reduction powder can be obtained by washing and drying. The average particle size of silver reduction powder is between 0.1-10.0 micron. The choice of reductant, the control of reaction conditions and the use of interfacial activator can prepare silver micro-powder with different physical and chemical characteristics (particle shape, dispersion degree, average). The polished silver powder and silver flake can be obtained by mechanical processing (ball milling, etc.) of the reduction powder, including particle size distribution, specific surface area, bulk density, compacting density, grain size and crystallinity.