STIRRI® V4-UHF-TF™ Universal No-Clean Tacky Flux

The next-generation industrial standard for critical aerospace, EV, and high-reliability electronics assembly.

STIRRI® V4-TF™ is an industrial-grade, AIRfree™ universal tacky flux engineered for high-performance soldering in demanding environments. Directly upgrading the popular V3-TF formula, V4-TF introduces an improved high-boiling-point solvent system for superior cleanability and enhanced stability during intense hot-air rework.

By blending high-purity rosin with advanced synthetic resin, V4-TF delivers instant tack and excellent wetting alongside exceptional electrical insulation. Backed by our proprietary HX-Booster™ package, it powerfully strips heavy oxides to guarantee robust, void-free solder joints.

🚀 Key Performance Advantages

• AIRfree™ Homogeneity: Eliminates microscopic air bubbles to prevent solder splattering and ensure consistent, clog-free automated dispensing.

• Dual-Tracer QC System: Features a Visual QC-Aid™ (glows under UV light for instant residue inspection) and an Olfactory QC-Aid™ (pleasant scent marker) to streamline quality control.

• Extreme Thermal Stability: Withstands peak lead-free reflow temperatures up to 250°C and maintains structural integrity during hot-air rework up to 450°C.

• Powertrain Ready (EV Optimized): Specially engineered to resist migration caused by the intense magnetic fields present in electric vehicle powertrains.

• High Mechanical Strength: Creates exceptionally resilient solder joints that resist fatigue from high vibrations, G-forces, and thermal shock.

• Fully Non-Corrosive: Once fully activated, residues are entirely benign, non-conductive, and fully compliant with J-STD-004C no-clean standards.

📋 Technical Specifications & Compatibility

🛡️ Core Target Applications

• Aerospace & Defense: Designed to meet rigorous reliability standards for long-endurance, high-altitude operations (HALE, UAS, avionics).

• Electric Vehicles (EV/eVTOL): Perfect for high-current battery management systems (BMS), power inverters, and sensitive sensor arrays.

• Medical Electronics: Safe for high-density, mission-critical assemblies where contamination is not an option.

💡 Tech Note on HX-Booster™ Activation:

Because the oxide-stripping HX-Booster™ augments halogens, unactivated (raw) flux residue may display temporary conductivity. This is entirely resolved by optimizing your thermal profile (ensuring adequate time/heat for full activation) or by running a standard post-solder cleaning cycle.

Looking for a 100% halogen-free, resin-based alternative? Check out our HX-ZERO™ formulation: V4-UHF-TF.

🛠️ Process & Cleaning Recommendations

While V4-TF is a true no-clean formulation leaving minimal, benign residue, cleaning is highly recommended prior to applying conformal coatings to ensure pristine surface adhesion.

Ready for Implementation: This advanced formulation is in its final field-validation phase and is available now for implementation. Contact us directly to request samples, review validation data, or discuss pairing this flux with your conformal coating workflow.