Low-solid no-clean soldering flux and preparation method thereof

Abstract

The invention discloses a low-solid no-clean soldering flux and a preparation method thereof. The low-solid no-clean soldering flux is prepared from the following raw materials in parts by weight: 25to 35 parts of resin, 5 to 10 parts of resin emulsifying agents, 3 to 8 parts of o-hydroxybenzoic acid, 2 to 4 parts of fluoboric acid, 3 to 6 parts of salicylic acid, 3 to 6 parts of tripolyvinylimide, 2 to 5 parts of N,N-dimethylethanolamine, 0.3 to 0.6 part of film forming agents, 0.8 to 1.4 parts of surfactant, 1.2 to 1.6 parts of corrosion inhibitors and 20 to 35 parts of cosolvent. The low-solid no-clean soldering flux has the advantages of less residual after soldering, less corrosion and high stability, and the environmental requirements are satisfied.

Description

technical field [0001] The invention relates to the technical field of soldering flux for brazing, in particular to a low-solid no-cleaning flux and a preparation method thereof. Background technique [0002] The solder paste used in microelectronic assembly (SMT) plays an important role in the whole soldering process. The performance of solder paste directly affects the soldering quality. As an auxiliary material in solder paste (mass fraction is 10% to 20%), flux can not only provide excellent soldering performance, but also directly affect the printing performance and storage life of solder paste. Therefore, the quality of flux directly affects the entire process and product quality of SMT. Although traditional rosin-based fluxes can provide good fluxing performance, most of these fluxes have high solid content (generally, the mass fraction is 20%-40%), resulting in many residues after soldering and poor appearance. Even some rosin-based fluxes also contain halogens, m...

AI Technical Summary

Problems solved by technology

However, the flux stability is not ideal

[0004] In the Chinese invention patent application 200810219442.X, a flux for aluminum brazing solder wire core and its preparation method are disclosed. %-24%, organic amine 38%-56%, zinc source 4%-10%, stannous salt 0.5%-8%, fluorine surfactant 0.1%-2%, the flux uses modified rosin as curing additive It has a negative effect on the activity of the flux. At the same time, the ammonium fluoroborate used in a large amount has a strong pungent smell, and the residue after welding is corrosive, which is not conducive to the use of a large amount of flux. The strong moisture absorption makes the flux difficult to preserve for a long time

[0005] Based on this, it is necessary to provide a low-solid-content no-cleaning flux to solve the problems of excessive post-soldering residue, high corrosiveness, high stability, and substandard environmental protection in the prior art.

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