Preparation of ultrafine silver powder using ascorbic acid as reducing agent and its application in MLCI

The preparation of ultrafine silver powder with chemical reduction method was investigated. Ascorbic acid was employed as reducing agent. Reaction of AgNO3 with ascorbic acid gives polyhedron monodispersed ultrafine silver powder. Effect of reaction temperature on particles was studied. The average congeris sizes (D50) reduces linearly from 3.1 μm to 1.0 μm as the reaction temperature increases from 20 °C to 60 °C. The silver powder having excellent dispersibility and different size was prepared through different pH value or different dosage surfactant. The TG/DTA of silver was discussed with thermal analyzer. As-prepared silver powder was applied in ferrite multi-layer chip inductor (MLCI). The silver end termination has high adhesion strength, excellent solderability and solder leaching resistance behavior.