Cleaning-free flame-retardant soldering flux and preparation method thereof

The invention discloses a cleaning-free flame-retardant soldering flux and a preparation method thereof. The cleaning-free flame-retardant soldering flux is prepared from the following raw materials of, in percentage by weight, 0.3%-1% of succinic acid, 0.3%-1% of adipic acid, 0.1%-1% of malic acid, 0.05%-0.7% of alkylphenol polyoxyethylene, 0.8%-2% of rosin, 0.2%-1% of terpineol, 5%-12% of methanol, 1%-5% of dimethyl methylphosphonate and the balance solvent. The cleaning-free flame-retardant soldering flux is colorless and transparent and does not have pungent smell, the surface of a soldered circuit board looks clean, cleaning is not needed, the wettability is good, non-flammable and non-explosive effects can be realized, the expansion rate is larger than 85%, the insulation resistance generated after soldering is larger than 4*10 ohm, the ion pollution degree is smaller than 0.1 micro gramme NaCl/cm , and the corrosivity and the drying degree are qualified. 本发明公开了一种免清洗阻燃助焊剂及其制备方法。该免清洗阻燃助焊剂由下述按照重量百分比计的原料制成