How does water-based flux maintain the insulation performance of solder joints in high-humidity environments?
Publish Time: 2025-10-08
In modern electronics manufacturing, soldering quality not only affects the reliability of electrical connections but also directly impacts the long-term stability of products in complex environments. Especially in applications with high humidity, high temperature, or high salt fog, if flux residue absorbs moisture, it can cause electrochemical migration, increased leakage current, or even short-circuit failure, seriously threatening equipment safety. Traditional fluxes containing rosin or halogens, while highly active, leave residues that absorb moisture and are corrosive, making them difficult to meet high-reliability requirements. Water-based flux uses pure water as a solvent, is rosin- and halogen-free, and produces zero volatile organic compound (VOC) emissions during the soldering process. There's no corrosion risk before or after soldering, minimal residue, and no cleaning required. It has also passed rigorous copper mirror corrosion tests, copper plate corrosion tests, and high-humidity insulation resistance tests, demonstrating excellent insulation stability in high-humidity environments.1. Halogen- and rosin-free formula eliminates hygroscopic residue.The core advantage of water-based flux lies in its highly pure composition. Traditional flux relies on rosin for film formation and halogen activators for enhanced deoxidation. However, the residues of both are hydrophilic and easily absorb moisture in high-humidity environments, forming conductive pathways. This water-based flux, however, eliminates both rosin and halogens in favor of a low-residue active system composed of organic acids and amine compounds. The reaction products largely evaporate or decompose at the high temperatures of soldering, leaving only trace amounts of non-ionic, non-hygroscopic organic salts. These residues lack electrolyte properties and, even under long-term exposure to relative humidity exceeding 90%, will not absorb moisture and reduce surface resistance, fundamentally safeguarding the insulation performance of the solder joint.2. Pure Water Solvent Enables a Green and Pollution-Free ProcessUsing pure water as the sole solvent not only avoids VOC emissions associated with organic solvents such as alcohols, glycol ether, and ether, but also eliminates the potential impact of solvent residue on insulation performance. Water evaporates completely during the soldering heating process, leaving no trace, resulting in a pristine post-solder surface. This "zero solvent residue" property, combined with an extremely low solids content, makes the flux virtually invisible after completing its soldering mission, eliminating the need for subsequent cleaning. This reduces manufacturing costs while avoiding the risk of secondary contamination from incomplete cleaning. It is particularly suitable for high-density, fine-pitch surface-mount soldering (SMT) and through-hole reflow soldering.3. Reliability Verified by Rigorous Corrosion and Insulation TestingWater-based flux has passed multiple international standard tests, fully verifying its long-term stability in high-humidity environments. In copper mirror corrosion testing, post-solder samples showed no discoloration or corrosion spots under high-temperature and high-humidity conditions, demonstrating its non-corrosiveness to metals. Copper plate corrosion testing further confirmed its lack of electrochemical corrosion.4. Suitable for High-Reliability Electronics Manufacturing ScenariosDue to its high insulation stability and environmentally friendly properties, this type of water-based flux is widely used in automotive electronics, medical equipment, communication base stations, outdoor power supplies, and new energy control modules, where reliability is critical. These products often operate in humid environments with drastic temperature fluctuations for extended periods. Degradation of solder joint insulation performance can directly lead to functional failure or even safety incidents. Using this flux not only extends product lifespan but also complies with environmental regulations such as RoHS and REACH, helping companies achieve green smart manufacturing.In summary, water-based flux, with its pure, halogen-free and rosin-free formula, pure water-based cleaning process, and extremely low residue, effectively blocks moisture adsorption and electrochemical failure pathways in high-humidity environments, ensuring long-term stability and undiminished insulation performance at solder joints. It represents not only a technological innovation in soldering materials but also a crucial support for electronics manufacturing's progress toward high reliability and environmental standards.
