STIRRI-V4-UHF-TF Tacky Flux (REL0)

Universal No-Clean Tacky Flux for High-Reliability Electronics Assembly

Professional-grade soldering performance for aerospace, EV, medical, and demanding electronics applications.

✔ AIRfree™ Universal Tacky Flux
✔ J-STD-004C Compliant No-Clean Formulation
✔ Up to 250°C Lead-Free Reflow
✔ Up to 450°C Hot-Air Rework
✔ Lead-Free & Leaded Alloy Compatible
✔ Low-VOC Formulation

Built for PCB assembly, electronics manufacturing, precision soldering, and high-reliability rework where consistent wetting, oxide removal, thermal stability, and controlled residue performance matter.

Built for Demanding Soldering Applications

Reliable solder joints start with the right soldering flux.

Standard fluxes can struggle when assemblies require strong wetting, consistent dispensing, high-temperature rework, and reliable performance across demanding electronics applications.

STIRRI® V4-UHF-TF™ is an industrial-grade, AIRfree™ universal tacky flux developed as an advanced upgrade to the V3-TF formula. Its improved high-boiling-point solvent system provides enhanced cleanability and stability during intense hot-air rework.

The combination of high-purity rosin and advanced synthetic resin provides instant tack, excellent wetting, and electrical insulation, while the proprietary HX-Booster™ package enhances heavy-oxide removal to support robust, reliable solder joints.

Whether you're working with aerospace electronics, EV power electronics, BMS systems, medical electronics, or high-reliability PCB assemblies, V4-TF is designed to give your soldering process greater consistency and control.

Why Choose the STIRRI V4-UHF-TF™ Tacky Flux?

Choosing a professional electronics soldering flux is about more than simply improving solder flow. Consistent dispensing, thermal stability, residue inspection, alloy compatibility, and process control all contribute to a dependable assembly process.

STIRRI V4-UHF-TF™ combines:

AIRfree™ technology for consistent, bubble-free dispensing

HX-Booster™ oxide removal for improved solder wetting

High-temperature stability for reflow and hot-air rework

Dual QC tracing for easier residue inspection

EV-focused formulation for demanding powertrain environments

Broad alloy compatibility for lead-free and leaded soldering processes

Designed for professional electronics manufacturing, assembly, repair, and rework environments.

Why STIRRI Compared to Standard Tacky Flux

The Difference You Notice in Production

 Consistent Flux Application

AIRfree™ homogeneity helps eliminate microscopic air bubbles, supporting smooth automated dispensing while reducing splattering and clogging.

 Stronger Oxide Removal

The HX-Booster™ package is designed to aggressively remove heavy oxides, helping improve wetting and support reliable solder joint formation.

 Stable During High-Temperature Rework

With resistance to temperatures up to 250°C during lead-free reflow and structural stability up to 450°C during hot-air rework, V4-TF is built for demanding thermal processes.

 Easier Quality Control

The Visual QC-Aid™ fluoresces under UV light, providing a practical way to identify residue during inspection. The Olfactory QC-Aid™ adds an additional process-identification marker.

 Ready for EV Electronics

The formulation is engineered to resist migration associated with the intense magnetic fields found in electric vehicle powertrain environments.

Premium Features

How to Use the STIRRI V4-UHF-TF™

Using V4-TF is straightforward:

1. Apply the flux using time/pressure dispensing, positive displacement, stencil printing, or jetting.

2. Position and solder the components according to your established assembly process.

3. Follow the appropriate thermal profile to allow the flux to fully activate and perform effectively.

4. Complete reflow or hot-air rework within the appropriate temperature range for your application.

5. Inspect the assembly using the Visual QC-Aid™ under UV light where applicable.

6. Clean before conformal coating where required. Cleaning is highly recommended before applying conformal coatings to support clean surface adhesion.

Important Process Note

Because HX-Booster™ enhances halogen activity, raw, unactivated flux residue may temporarily display conductivity. Proper thermal activation with sufficient time and heat resolves this, or a standard post-solder cleaning process can be used where appropriate.

Who Is It For?

STIRRI V4-UHF-TF™ is ideal for:

Aerospace & Defense Manufacturers

For avionics, HALE, UAS, and other high-reliability electronics requiring dependable soldering performance.

EV & eVTOL Electronics Engineers

Suitable for battery management systems, power inverters, high-current electronics, and sensitive sensor arrays.

Medical Electronics Manufacturers

Designed for high-density, mission-critical electronic assemblies where controlled processing and contamination management are important.

PCB Assembly Professionals

Ideal for electronics manufacturers using automated dispensing, stencil printing, jetting, and other professional soldering processes.

Rework & Repair Technicians

A practical choice for demanding hot-air rework applications requiring strong wetting and high-temperature stability.

Technical Specifications

Frequently Asked Questions

Is STIRRI V4-UHF-TF™ a no-clean flux?

Yes. V4-TF is a J-STD-004C compliant no-clean tacky flux designed to leave minimal, benign residue once fully activated.

What temperature can the flux handle?

V4-TF supports peak lead-free reflow temperatures up to 250°C and hot-air rework up to 450°C.

What solder alloys is it compatible with?

It is compatible with both lead-free and leaded solder alloys, including SnAgCu, SnBi, Indium/Antimony blends, and SnPb.

Can it be used for PCB assembly?

Yes. V4-TF supports professional application methods including time/pressure dispensing, positive displacement, stencil printing, and jetting.

Is it suitable for EV electronics?

Yes. The formulation is specifically engineered for demanding EV powertrain environments, including applications such as battery management systems, power inverters, and sensor arrays.

Does the flux need to be cleaned?

V4-TF is designed as a no-clean formulation. However, cleaning is highly recommended before applying conformal coatings to support optimal surface adhesion.

Is there a halogen-free alternative?

Yes. For applications requiring a 100% halogen-free, resin-based formulation, the HX-ZERO™ V4-UHF-TF formulation is the alternative referenced by the manufacturer.

Ready for Your Electronics Assembly Process?

When your application demands reliable solder wetting, consistent dispensing, strong oxide removal, thermal stability, and controlled residue performance, STIRRI V4-UHF-TF™ is engineered to meet the challenge.

From aerospace and defense electronics to EV power systems, medical assemblies, PCB manufacturing, and professional rework, this industrial-grade no-clean tacky flux provides the performance and process control needed for demanding electronics applications.

Ready to evaluate STIRRI V4-UHF-TF™? Contact Dialedin to request samples, review validation data, or discuss compatibility with your soldering and conformal coating workflow.