Solder Paste Screen Printer

SnAgCu Solder Paste: Engineered for Precision Printing and Superior Wetting Performance

In today’s electronics assembly environment, production managers and process engineers face mounting pressure to deliver flawless soldering results on increasingly miniaturized boards. The choice of solder alloy and flux system has never been more consequential—affecting not only yield rates but also long-term field reliability. For those seeking a proven SnAgCu solder paste that reconciles fine-pitch capability with robust joint formation, TS-350 stands as a field-tested solution tailored to modern SMT challenges.

This no-clean, lead-free SnAgCu solder paste is formulated to support both high-volume production and precision rework, offering the rheological stability and metallurgical wetting action that today’s assemblies demand—from 01005 passives to 0.4 mm pitch BGAs.

Why Choose a High-Performance SnAgCu Solder Paste?

The transition from eutectic SnPb to lead-free alloys has forced manufacturers to re-evaluate every aspect of the printing and reflow process. A well-designed SnAgCu solder paste must deliver three interdependent attributes: consistent deposit geometry, rapid oxide removal, and reliable intermetallic formation. TS-350 achieves this balance through a carefully optimized flux vehicle that maintains activity over extended stencil dwell times while minimizing residue-related test failures.

Whether your line runs consumer wearables or automotive ECUs, this SnAgCu solder paste provides the operating window needed to accommodate varying board finishes, component types, and thermal profiles—all without sacrificing first-pass yield.

Product Specifications

Alloy Composition

Physical & Electrical Properties

Core Capabilities of This SnAgCu Solder Paste

1. Printing Consistency That Drives Productivity

Every SnAgCu solder paste must withstand the mechanical stresses of repetitive printing—polymer shearing, stencil separation, and ambient temperature fluctuations. TS-350 exhibits pseudoplastic behavior that ensures sharp edge definition on apertures as small as 11 mil (0.28 mm) square pads.

• Viscosity stability – Minimal drift over 8+ hours of continuous operation, reducing operator intervention.
• Slump resistance – Maintains deposit aspect ratio without bridging or bleeding, even under high humidity.
• Extended stencil life – Slow solvent evaporation minimizes clogging and extends cleaning intervals, boosting overall equipment effectiveness (OEE).

2. Wetting Dynamics for Reliable Joints

Wetting is the cornerstone of solder joint integrity. The flux system in this SnAgCu solder paste activates progressively during reflow, removing surface oxides from both component terminations and PCB pads to promote rapid intermetallic growth.

• Excellent spread and climb – Ensures consistent heel fillets on gull-wing leads and toe wetting on bottom-terminated components.
• Low voiding performance – Particularly beneficial for thermal pads under QFNs and BGAs, where void fractions remain well below industry thresholds.
• Wide reflow compatibility – Supports air and nitrogen atmospheres; recommended peak temperature 240–250°C with time above liquidus (221°C) of 20–40 seconds.

3. Clean Residue Profile for Electrical Reliability

After reflow, the residue left by this SnAgCu solder paste is translucent, hard, and non-tacky—allowing direct ICT probe access without false failures.

• Low post-reflow residue – Approximately 5% (w/w) of initial flux mass remains.
• Non-conductive and stable – Passes stringent SIR testing at both 40°C/90% RH and 80°C/85% RH, ensuring no leakage currents in high-impedance circuits.
• Probe-test friendly – Eliminates the need for a separate cleaning step in most applications, reducing process cost and cycle time.

4. Mitigation of Head-in-Pillow Defects

One of the most persistent failure modes in lead-free BGA assembly is head-in-pillow (HiP) — where the solder ball and paste deposit fail to coalesce. TS-350’s flux chemistry is specifically tailored to delay oxide re-formation during the soak phase, ensuring that molten paste and component sphere fuse completely. This SnAgCu solder paste has been validated on multiple BGA types with significant reductions in HiP-related fallout.

5. Full RoHS Compliance

This product meets the requirements of RoHS Directive 2002/95/EC, providing regulatory assurance for exports to the European Union and other markets with similar restrictions.

Storage and Handling Best Practices

To preserve the performance characteristics of this SnAgCu solder paste, adhere to the following guidelines:

Storage Conditions

Handling Sequence

Critical Note: Never open a cold container—condensation introduces moisture that can cause spattering and micro-voiding during reflow. Always warm sealed jars to ambient temperature before opening.

Recommended Reflow Profile (SnAgCu Solder Paste)

Quality Assurance and Traceability

Each batch of TS-350 is accompanied by a Certificate of Analysis (CoA) that documents:

• Model and lot number
• Alloy composition (verified by ICP or XRF)
• Flux percentage (by weight loss method)
• Viscosity at 25°C (Brookfield measurement)
• Halogen content (by ion chromatography)

This rigorous lot-to-lot control ensures that every shipment of this SnAgCu solder paste delivers identical rheological and wetting behavior, enabling process reproducibility across multiple production shifts and facilities.

Application Scope

This SnAgCu solder paste is ideally suited for:

• Mobile and consumer devices – Smartphones, tablets, earbuds, smartwatches
• Automotive systems – Engine control units, sensor clusters, LED lighting modules
• Industrial electronics – Programmable logic controllers, motor drives, power supplies
• Telecom infrastructure – 5G base stations, routers, optical transceivers
• Medical instruments – Portable monitors, diagnostic boards, imaging equipment
• High-density LED arrays – Fine-pitch COB and mini-LED assemblies

Frequently Asked Questions

Q: Is this SnAgCu solder paste suitable for both 0.5 mm and 0.25 mm pitch designs?

A: Absolutely. TS-350 is validated for standard 0.5 mm pitch down to ultra-fine 0.25 mm (10 mil) pitch, with excellent aperture release and slump resistance across the range.

Q: What stencil technology is recommended?

A: Laser-cut stainless steel stencils with electro-polished apertures—such as ALPHA® Stencils or equivalents—provide the best release and deposit consistency for this SnAgCu solder paste.

Q: Can TS-350 be used for paste-in-hole (PiH) printing?

A: Yes, its stable rheology and flux activity support PiH applications, provided adequate solder volume and stencil design are considered.

Q: How long can the paste remain on the stencil without performance degradation?

A: Under typical shop-floor conditions (23–27°C, <50% RH), TS-350 maintains print quality throughout a full shift. Unused paste should be returned to the sealed container and refrigerated promptly.

Conclusion: The Strategic Choice for Lead-Free Assembly

Selecting a SnAgCu solder paste is not merely a materials decision—it is a process-enabling choice that impacts throughput, quality, and total cost of ownership. TS-350 delivers a proven combination of print stability, wetting power, and residue cleanliness that directly translates to:

• Higher first-pass yields – Fewer touch-ups and rework loops
• Reduced inspection and test failures – Clean residues and low voiding ease downstream verification
• Extended stencil and printhead life – Lower consumable costs and less downtime
• Consistent joint microstructure – Reliable mechanical and electrical performance over product lifetime

For manufacturers who demand a robust, production-proven SnAgCu solder paste that performs across a broad spectrum of component types and process conditions, TS-350 offers the confidence that comes from years of successful deployment in high-mix, high-volume environments.

Contact InformationTENSAN VIETNAM CO., LTD

TS10 Road, Tien Son Industrial Park, Bac Ninh Province, Vietnam

Tel: +84-222-650-8818

Email: mark@sztensan.com

For inquiries about alternative alloy formulations (e.g., SAC105, SnBiAg), custom powder sizes, or specialized packaging, please reach out to your local Tensan sales representative. Technical support and process optimization services are also available upon request.