Preparation method of high-tap-density small-granularity sphere-like silver powder for LTCC (low temperature co-fired ceramic) inner electrode

Abstract

The invention relates to a preparation method of high-tap-density small-granularity sphere-like silver powder for an LTCC (Low Temperature Co-Fired Ceramic) inner electrode, which comprises the following steps of: (1) dissolving silver nitrate in pure water to obtain a silver nitrate solution with the concentration of 250-300g/L; (2) dissolving a reducing agent in pure water to obtain a reducing agent solution with the concentration of 100-180g/L; (3) dissolving a dispersing agent and a granularity control agent in pure water to obtain a base solution; (4) the silver nitrate solution and the reducing agent solution are added into the base solution in a parallel flow mode and stirred, a surface modifier solution is added after a reaction is conducted for 15-20 min, and silver powder is obtained; (5) washing the silver powder until the conductivity of the washing liquid is less than or equal to 20 microseconds, and carrying out solid-liquid separation to obtain an Ag powder filter cake; and (6) drying, powdering and screening the Ag powder filter cake to obtain the high-tap-density small-particle-size sphere-like superfine silver powder with the average particle size of 1.0-4.0 microns and the tap density of 6.0-6.5 g/cm < 3 >. According to the method, the reducing agent, the dispersing agent, the particle size control agent and the like in the reduction process are scientifically and reasonably controlled through the liquid phase reduction method, and therefore the superfine silver powder with the small particle size and the high tap density is obtained.

Description

technical field [0001] The invention relates to the technical field of preparation of precious metal materials, in particular to a preparation method of high-vibration small-sized spherical silver powder used for LTCC inner electrodes. Background technique [0002] With the rapid development of electronic industry, new energy and other technical fields, as a functional material with high surface activity and excellent electrical conductivity, ultrafine silver powder is widely used in conductive paste, energy industry, composite materials, catalysts, antibacterial materials and other fields. Among them, conductive paste, as a functional material, is widely used in the production of various electronic components, such as LTCC, chip components, etc. Silver powder is the most important raw material of conductive paste, which has an important influence on parameters such as film formation, film thickness, electrical properties, solderability and adhesion during the preparation p...

AI Technical Summary

Problems solved by technology

However, when the liquid phase chemical reduction method is used to prepare silver powder, there are problems that the particle size distribution of silver powder is too wide, the content of organic impurities is high, it is easy to form agglomerated large particles, it is not easy to settle, the process of solid-liquid separation is difficult, and the yield is low.

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