Cleaning-free lead-free solder soldering fluid

Abstract

The invention relates to a clean-free lead-free solder scaling powder. The constitution of the scaling powder has the mixture ratio of: 1 to 4 percent of organic acid active agent, 0.5 to 3 percent of anion surface active agent, 5 to 10 percent of heat resistant resin, 2 to 5 percent of high-boiling solvent, and rest of refined modified rosin. The scaling powder and Sn-Cu as well as Sn-Ag-Cu series lead-free solder have good matching effect; the welding performance of the lead-free tin wire can be improved; in the welding process, welding between the scaling powder and a solder ball has little splash, no odor, no corrosion, and little postweld solder residue; the residue of the postweld scaling powder has no generation of crack; electrical insulating property is high, the ion pollution is low, the reliability after packaging the electronic product is ensured, and the scaling powder can avoid to be cleaned after welding.

Description

technical field [0001] The invention relates to soldering flux, in particular to a no-cleaning lead-free soldering flux. Background technique [0002] Flux is widely used in the technical field of soldering materials for electronic information products. In response to the global environmental protection law and the development requirements of the electronic information industry, it is an inevitable trend for electronic information products and electrical products to be lead-free. The most obvious performance difference between lead-free solder and lead-containing solder is that the lead-free solder itself has poor wetting ability and the soldering temperature used is high. Therefore, the flux corresponding to the lead-free solder needs to have strong wettability, high temperature resistance and corrosion resistance. At present, the packaging of electronic products generally uses active rosin core tin-lead solder wire and active rosin core lead-free solder wire. Since the ac...

AI Technical Summary

Problems solved by technology

At present, active rosin-core tin-lead solder wire and active rosin-core lead-free solder wire are generally used for the packaging of electronic products. Since the active agent in the existing active rosin-core tin-lead solder wire is an amine salt containing halogen, the flux residue after soldering There are more substances, and there are more residual halogen ions, which brings hidden dangers to the reliability and stability of electronic products

In order to ensure the electrical insulation and reliability of electronic products, the flux residues on the printed board must be cleaned. For this reason, it is necessary to use chlorofluorocarbons or organic solvents as cleaning agents. These chemical agents are harmful to the destruction of the atmospheric ozone layer. Depleted substances and substances that are gradually banned by green production and environmental protection requirements; at the same time, the use of organic solvents not only increases production costs and causes waste of resources, but also causes environmental pollution and endangers human health once these organic solvents volatilize into the atmosphere; organic solvents are easy to burning, so there is a safety hazard

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