Low solid content cleaning-free welding aid used for leadless welding

Abstract

The invention relates to a low-solid-content no-clean flux used for lead-free soldering, and belongs to the technical field of semiconductor materials. The weight percentage of each component is: resin: 0.2%~1.0%, compound active agent: 1.0%~2.0%, high boiling point solvent: 4%~10%, organic acid: 0.2%~1.6%, general solvent is The remaining amount, the preparation method is: add the resin and organic acid into the general solvent according to the formula ratio, heat to 60°C, stir until dissolved, then add the high boiling point solvent and compound active agent, stir for 5 minutes, and let it stand Filter and serve. In the flux of the present invention, the solid content is less than 3%. When used for soldering, there is less solid residue on the printed assembly board, the board surface is clean, the ion pollution is low, and no cleaning is required after soldering. Moreover, the insulation resistance of the printed assembly board after welding is high, which can meet the no-cleaning requirements of the printed assembly board.

Description

technical field [0001] The invention relates to a low-solid-content no-clean flux used for lead-free soldering, and belongs to the technical field of electronic materials. Background technique [0002] The traditional solder used for soldering electronic information products is lead-tin solder, which has been used for many years. It is characterized by low melting point (183°C), good solderability, and strong soldering operability. Since the European Union promulgated the directive on restricting the use of six toxic and hazardous substances (lead, cadmium, mercury, hexavalent chromium, polybrominated biphenyls and polybrominated diphenyl ethers) in 2003, my country also promulgated the "Management Measures for Pollution Control of Electronic Information Products" in 2006. , so that the use of lead-tin solder is limited. At present, in order to protect the human ecological environment, more and more electronic information products have switched to lead-free solder. However,...

AI Technical Summary

Problems solved by technology

[0004] (2) Solder is easy to oxidize, forming tin slag, causing waste

[0005] (3) Weldability is poor, and it is easy to form virtual welding and missing welding, which affects the reliability of the whole machine

[0006] Due to the shortcomings of lead-free solder itself, the flux originally used for lead-tin solder can no longer meet the soldering requirements of lead-free solder

As we all know, if the solid content of the flux is too high, on the one hand, it will cause a lot of residues on the printed component board and the surface of the board is not clean; The impact of the whole instrument