Scaling powder for aluminium soldering tin wire core and preparation method thereof

Abstract

The invention relates to a soldering flux for a soldering tin wire core through aluminium soldering and a preparation method thereof. The soldering flux is used for an inner core of a soldering tin wire through aluminium soldering or aluminium alloy soldering. The soldering flux comprises the following compositions in a formula in weight percentage: 14 to 28 percent of modified resin, 12 to 24 percent of ammonium borofluoride, 38 to 56 percent of organic amine, 4 to 10 percent of zinc source, 0.5 to 8 percent of tin salt and 0.1 to 2 percent of a fluorin surfactant. The zinc source is zinc salt, zinc powder or activated zinc oxide; the tin salt is inorganic tin salt or organic acid tin; and the fluorin surfactant is one or two of FC4430, FC4432, F5010, FSN-100, F501, F502 and FS-300. The soldering flux is in a solid state at normal temperature, has the characteristics of having good stiffness, high activity and simple preparation process, remarkably improving solderability of a soldering material and the cleanness of a weld spot and the like and is suitable for producing the soldering tin wire containing the soldering flux in the core and soldering aluminum and aluminum alloy.

Description

technical field [0001] The invention relates to an aluminum and aluminum alloy soldering flux and a preparation method thereof. The flux is used for the inner core of solder wire for soldering of aluminum and aluminum alloys, and belongs to the technical field of soldering of electronic and electrical products. The flux for aluminum brazing solder wire cores of the invention is also suitable for soldering nickel-based alloys and stainless steel materials. Background technique [0002] The thermal conductivity and electrical conductivity of aluminum and aluminum alloys are similar to those of copper, but their production costs and prices are lower than those of copper. Aluminum has long been desired to replace the use of copper in the electronics industry. However, the brazing weldability of aluminum and its alloys is much more difficult than that of other metals (alloys). The main reason is that there is a very dense oxide film on the surface of aluminum and its alloys (Al...

AI Technical Summary

Problems solved by technology

This flux is a reactive flux with strong corrosiveness

At the same time, the flux must be effective at a temperature above 450°C, and the flux cannot become a uniform fluid at a temperature of 130°C, so it is not suitable for solder wire cores

The flux composition (percentage by weight) described in "Aluminum and Aluminum Alloy Soldering Flux and Its Use" (Patent No. 88100868) applied by Fujian Normal University is: 1-50% of amino-containing organic fluoroborate, heavy metal fluorine Borate 0.5-50% and amino alcohol 10-98%; the soldering temperature of this flux is high (300°C) and the flux is viscous liquid at room temperature, so it is difficult to be used in the production of flux-cored solder wire

The aluminum welding flux used in the "welding aluminum tin wire" reported by Chinese Patent No. 01128512.5 consists of fluorosilicate heavy metal salt (5~20%), fluoroboric acid heavy metal salt (5~20%), polyethylene polyamine (60%) ~80%) and vaseline (5~10%); the flux uses vaseline as a carrier, and the viscous liquid state of the flux at room temperature is also not conducive to the production of solder wire, and the flux activity is limited

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