Preparation method for filling ultralow-resistivity conductive paste with high-purity nano material

Abstract

The invention relates to a preparation method for filling ultralow-resistivity conductive paste with a high-purity nano-material. The preparation method comprises the following steps: preparing a nano-copper-based nano-material by using a chemical method, adding silver nitrate in the preparation process, and reducing silver oxalate generated by the silver nitrate into elemental Ag in a high-temperature state. On one hand, the elemental Ag has good conductivity as nano-copper, on the other hand, the elemental Ag has very strong oxidability, and the elemental Ag serving as an oxidant can significantly enhance the gas explosion effect of CO and CO2 in a roasting furnace, so that elemental copper generated along with the elemental Ag is cut into the nano-copper with finer and more uniform particles; and oxide generation is effectively avoided, the purity of the nano material is improved, and the resistivity is reduced. The resistivity of the prepared nano material is reduced to 26.9 microhm.cm from 12.6 milliohm.cm of an existing common material and is close to the theoretical resistivity 1.75 microhm.cm of copper, and the effect is remarkable.

Description

technical field [0001] The invention relates to a preparation method of ultra-low resistivity conductive slurry filled with high-purity nanometer materials. Background technique [0002] The printing of conductive coatings, conductive inks, and conductive screen printing in the electronics industry requires a large amount of low-resistivity nano-silver powder and nano-copper powder. Among them, nano-silver powder is a precious metal and is expensive, which severely limits the use and upgrading of electronic materials; Nano-copper powder is a base metal with good electrical conductivity. However, nano-copper powder is easily oxidized, and the resistivity of copper will increase tens of thousands of times after oxidation, which will affect its electrical conductivity. [0003] Nanoscale materials (10-100nm) have different characteristics from conventional materials due to their small size, large specific surface area, quantum size effect and macroscopic quantum tunneling effec...

AI Technical Summary

Problems solved by technology

[0007] Mechanized grinding method: high grinding cost, low efficiency, expensive equipment, and great safety hazards (heat generation during grinding, spontaneous combustion, explosion);

[0008] Arc method: under high temperature conditions, it is difficult to control the oxidation of copper

[0009] It can be seen that nano-copper powder is easily oxidized during the production process, which is the biggest problem encountered in the preparation of nano-copper powder at present.

Due to the substantial increase in the resistivity of oxidized copper, its electrical conductivity is seriously affected, resulting in the high preparation cost and high sales price of nano-copper powder, making it difficult to realize industrial production and application.

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