Low Void High Reliability Solder Paste for QFN & LGA

Low Void High Reliability Solder Paste for QFN & LGA – TENSAN TS-506

In advanced surface-mount assembly, QFN (Quad Flat No‑lead) and LGA (Land Grid Array) packages present unique challenges: large thermal pads, hidden solder joints, and high mechanical stress under temperature cycling. Void formation in these joints is a critical failure risk, compromising thermal conductivity and long‑term reliability. That is exactly why engineers demand a High reliability solder paste for QFN LGA that combines ultra‑low voiding with consistent print performance.

Low Void High Reliability Solder Paste for QFN & LGA – TENSAN TS‑506 is a lead‑free, no‑clean solder paste formulated specifically to address these challenges. With its Sn98.5Ag1.0Cu0.5 alloy and advanced flux chemistry, TS‑506 delivers exceptional void reduction, strong wetting, and stable printing—making it the trusted choice for high‑reliability SMT assemblies.

What Is TENSAN TS‑506?

TENSAN TS‑506 is a no‑clean solder paste for SMT assembly that excels in applications where joint integrity is paramount:

• Ultra‑low voiding – Specially engineered flux system minimises gas entrapment, especially on large thermal pads
• High reliability – Meets stringent SIR and corrosion requirements, ensuring stable electrical performance
• Excellent wetting – Provides strong fillet formation on ENIG, OSP, HASL, and immersion finishes
• Stable printing – Consistent viscosity and shape retention for fine‑pitch and mixed‑size pad designs
• No‑clean residue – Transparent, non‑conductive residue that supports ICT probing without cleaning

Key Specifications

Alloy & Physical Properties

Electrical & Reliability Properties

Why Choose TENSAN TS‑506 as Your Low Void High Reliability Solder Paste for QFN & LGA?

1. Ultra‑Low Voiding for Thermal and Mechanical Reliability

Voids in QFN thermal pads and LGA joints act as thermal insulators, causing hotspots and reducing current‑carrying capacity. They also accelerate crack propagation under thermal cycling. TS‑506’s flux system is optimised to release volatiles gradually during reflow, allowing trapped gases to escape before solder solidifies. In internal tests, voiding rates consistently fall below 15% on large pad designs—significantly lower than conventional pastes. This makes TS‑506 a true High reliability solder paste for QFN LGA applications.

2. Robust Electrical Reliability Under Harsh Conditions

With SIR values exceeding 1.0×10⁸ Ω at 40°C/90% RH and 5.0×10⁸ Ω at 80°C/85% RH, TS‑506 ensures minimal leakage current even in humid environments. The L0 halogen level and copper mirror test (no penetration) confirm that the flux residue is non‑corrosive, preserving signal integrity over the product’s lifetime. These attributes are critical for automotive and industrial modules where High reliability solder paste for QFN LGA is a non‑negotiable requirement.

3. Excellent Wetting and Solder Joint Formation

Despite its reduced silver content, TS‑506 delivers rapid wetting on all common PCB finishes. The advanced activator package promotes strong intermetallic bonding, producing bright, full fillets with minimal dewetting. This ensures that every QFN pad and LGA land receives sufficient solder coverage, reducing the risk of open joints or head‑in‑pillow defects.

4. Stable Printing and Long Stencil Life for High‑Mix Production

Consistent deposit volume is essential for QFN/LGA assemblies where pad sizes vary widely. TS‑506’s rheology is tailored to maintain transfer efficiency over extended print runs. Typical print speeds of 25–150 mm/s and stencil thicknesses of 100–150 μm are well supported, with fine‑pitch capability down to 0.25 mm. This stability reduces rework and scrap, making it an ideal Low Void High Reliability Solder Paste for QFN & LGA for both prototype and volume manufacturing.

5. Minimal, Test‑Friendly No‑Clean Residue

After reflow, the residue is transparent and readily penetrated by ICT probes, eliminating the need for post‑reflow cleaning. This not only saves process costs but also avoids the environmental and handling concerns associated with cleaning solvents.

Storage and Handling Guidelines

Recommended Temperature Curve

Typical Applications for QFN and LGA Devices

TENSAN TS‑506 is field‑proven in industries where High reliability solder paste for QFN LGA is essential:

• Automotive electronics – ECUs, BMS, sensor modules, lighting controllers
• Telecommunications – 5G small cells, RF front‑end modules, baseband processors
• Industrial controls – PLCs, motor drives, I/O modules
• Power management – DC‑DC converters, power MOSFET packages
• Consumer devices – High‑end smartphones, tablets, wearables with dense QFN/LGA footprints

Quality Assurance

Every batch of TENSAN TS‑506 is accompanied by a Certificate of Analysis confirming:

• Model and batch number
• Alloy composition (Sn98.5Ag1.0Cu0.5)
• Flux content (wt%)
• Viscosity measurement at 25°C

Our rigorous quality control ensures consistent performance, lot after lot.

Frequently Asked Questions

Q: How does TS‑506 achieve low voiding on large thermal pads?

A: The flux system is formulated to provide a controlled outgassing window during the preheat and soak zones, allowing volatiles to escape before solder melts, while the alloy’s wetting speed ensures rapid coalescence that pushes remaining gas outward.

Q: Is TS‑506 suitable for both air and nitrogen reflow?

A: Yes. TS‑506 performs excellently in both environments. Nitrogen can further reduce oxidation and improve wetting, but is not mandatory.

Q: What is the shelf life of TS‑506?

A: Six months from production date when stored at 2–10°C.

Q: Does the residue require cleaning for high‑reliability applications?

A: No. The residue is non‑conductive, non‑corrosive, and fully compatible with ICT and functional testing. It meets IPC‑J‑STD‑004 requirements for no‑clean fluxes.

Q: Can TS‑506 be used for fine‑pitch QFNs (0.4 mm pitch)?

A: Yes, the Type 4 powder and controlled viscosity support 0.4 mm and even 0.3 mm pitch printing with proper stencil design.

Conclusion

When your design relies on QFN or LGA packages, you cannot afford to compromise on joint reliability. TENSAN TS‑506 offers the perfect balance of ultra‑low voiding, stable printing, and robust electrical properties—all at a cost‑effective low‑silver alloy composition. It is the definitive Low Void High Reliability Solder Paste for QFN & LGA that engineers trust for mission‑critical assemblies.

By adopting this High reliability solder paste for QFN LGA, you reduce rework, improve thermal dissipation, and extend product life. Whether you are producing automotive ECUs or 5G infrastructure, TS‑506 delivers the performance you need.

Choose TENSAN TS‑506 – your reliable partner for QFN and LGA soldering excellence.