Preparation method of lead-free silver electrode paste for low-temperature PTC heat-sensitive electronic components

Abstract

The invention relates to a preparation method of lead-free silver electrode slurry for a low-temperature PTC temperature-sensitive electronic component. The preparation method comprises the steps of the preparation of low-temperature micron glass powder, the preparation of an organic carrier and the preparation of silver conductor slurry. According to the preparation of the low-temperature micron glass powder, components in mass percentage of 25 to 85% of Bi2O3, 5 to 35% of B2O3, 2 to 10% of ZnO, 2 to 5% of SnO, 1 to 5% of Al2O3, 3 to 10% of TeO2, 1 to 5% of BaO and 1 to 5% of TiO2 are selected; the raw materials are weighed according to proportions, the raw materials are subjected to ball milling of a planetary ball mill for 60 to 90 minutes with ethyl alcohol adopted as a medium, and obtained products are uniformly mixed, an obtained mixture is dried, so that a uniformly-mixed oxide can be obtained; the mixture is melt in a high-temperature sintering furnace; the melt mixture is poured into deionized water, so that a large-particle glass crude product is obtained, the product is dried under 80 to 95 DEG C, the dried large-particle glass crude product is arranged in a ball-milling tank so as to be subjected to ball milling of the planetary ball mill, and the ratio of the glass crude product to pure water to zirconia spheres of which the diameter phi is 1mm is 1:2:2; and after the large-particle glass crude product is subjected to ball milling for 8 to 12 hours, an obtained product passes through a 300-mesh screen, so that the low-temperature lead-free glass powder of which the particle size ranges from 0.7 to 1 . 5 microns can be obtained. The lead-free glass powder obtained by the using the preparation method of the invention has the advantages of low softening temperature, high bonding strength, narrow distribution, small particle size and high consistency.

Description

technical field [0001] The invention relates to the technical field of electronic paste, in particular to a preparation method of lead-free silver electrode paste for low-temperature PTC heat-sensitive electronic components. Background technique [0002] PTC thermistors can be used as switch PTC ceramic components in computers and their peripheral equipment, mobile phones, battery packs, air conditioners, telecommunication and network equipment, transformers, industrial control equipment, automobiles and other electronic products. [0003] Among them, the main components of the applied silver paste include functional phase silver powder, inorganic binder (such as glass powder, oxide powder, etc.), organic binder, other solvents and additives. At present, the sintering temperature of this slurry is 550-600°C in China, and there are two disadvantages. One is that the slurry made of glass powder is finer and rougher, resulting in a thicker film layer and poor compactness during...

AI Technical Summary

Problems solved by technology

At present, the sintering temperature of this slurry is 550-600°C in China, and there are two disadvantages. One is that the slurry made of glass powder is finer and rougher, resulting in a thicker film layer and poor compactness during the printing process. Holes are generated, printing performance is not good, and then the conductivity is affected. Second, the sintering temperature of the glass powder is high, and the adhesion is insufficient. At the same time, on low-temperature PTC components, a good inorganic coating on the surface of the protection component is required.