Novel environmental-protection flux

Abstract

The invention discloses novel environmental-protection flux which comprises solvent, surfactants and an addition agent. Main ingredients of the flux comprise deionized water, polypropylene glycol 1200, hydroxybenzotriazole, secondary alcohol ethoxylate, tripropylene glycol n-butyl ether, tetraethylene glycol dimethyl ether, succinic acid and an aliphatic dicarboxylic acid mixture. The solvent of the flux is formed by mixing the deionized water of different types, alcohols and ethers. The mixed solvent has a suitable boiling point, more polar groups and moderate viscosity, and endows the flux with high activity. Few residues are generated. The effect of protecting the welding surface is achieved. Different types of the surfactants with different components are used in cooperation, and the surfactants have a good synergistic effect and can improve wettability of welding flux and prevent oxidation. The surface of the flux is clean, and the flux is free from halogen, low in carbon, environmentally friendly and capable of meeting the use requirement of welding.

Description

technical field [0001] The invention relates to a welding flux and a preparation method thereof, in particular to a welding flux used in the welding process of electronic products. Background technique [0002] The rapid development of the electronics industry has brought great prospects for the application of fluxes. Fluxes should not only provide excellent fluxing performance to meet the basic needs of use, but also meet a series of mechanical and electrical performance requirements to reduce the Oxidation and rust occur on the surface of the soldered object. Therefore, the characteristics of the flux have a decisive effect on the process and product quality of the entire surface mount technology, and are one of the core elements related to the production process of the electronics industry. [0003] At present, the components of fluxes at home and abroad generally include activators, solvents, surfactants and special components, and the special components are generally co...

AI Technical Summary

Problems solved by technology

[0004] In the field of electronics industry, various electronic components on the circuit board need to be coated with flux, and then connected to the PCB board as a whole through wave soldering, reflow soldering or manual soldering. Most of the fluxes currently used are rosin-type fluxes. Soldering flux or water-soluble flux has a high solid content. Traditional rosin-type fluxes are mainly composed of rosin and solvents, and also contain halogen components. There are many residues after welding and are highly corrosive. If the residues are not effectively removed, it will It affects the insulation performance of the product, resulting in poor quality stability of the product. It must be cleaned to ensure the working life and electrical performance of the electronic product. However, there are many cleaning techniques and process steps for the circuit board assembly, which makes the operation inconvenient. And many cleaning The agent contains ingredients that are harmful to the environment, which is not conducive to environmental protection and energy saving

[0005] In view of the above shortcomings, the Chinese patent with the publication number CN101890596A discloses a low-carbon environment-friendly water-based flux, which is composed of a solvent and an active additive, and the solvent accounts for 80% to 97% by weight of the total weight of the flux. The main component is deionized water, and also includes one or more of polyethylene glycol 800, polyethylene glycol 1000, polyethylene glycol 1200, and polyethylene glycol 1400, and the solvent also contains Ether compounds between 14 and active additives include one or more water-soluble organic weak acids and water-soluble surfactants. The flux uses water as the main solvent, is non-flammable, and is safe to use. However, the flux in the The surfactant component is relatively single, and the effect of this flux on improving wettability and preventing oxidation is very limited

[0006] The flux prepared by deionized water and surfactant is gradually replacing the traditional flux obtained by using rosin as the solute and alcohol as the solvent. The US patent with application number US5145531 and the US patent with application number US5507882 respectively use this method to obtain a new type of flux, however, the solvent type and active agent composition involved in the above flux still need to be further explored

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