SMT solder paste

Fuji Chemical SMT Solder Paste is a lead-free SAC305 alloy solder paste that combines uniformly spherical solder powder with a new-generation no-clean flux system. It delivers consistent print quality over many hours on the stencil, good wetting on common surface finishes and safe flux residues that do not require post-solder cleaning.

Typical Applications

• Reflow soldering of 0201 and 0402 chip components and fine-pitch ICs
• Soldering BGA, QFN and LGA packages on multilayer boards
• Manufacturing consumer electronics, phones and wearables
• Automotive control boards and industrial equipment
• LED modules, power supplies and telecom equipment

Advantages

1. Stable printing for up to 8 hours on the stencil with minimal viscosity change
2. Good wetting on OSP, ENIG and immersion tin; minimal solder balling and bridging
3. Reduces voiding under QFN thermal pads
4. Clear, halogen-free flux residue with high surface insulation resistance

Key Specifications

Application Notes

Remove the paste from the refrigerator and allow it to reach room temperature in the sealed jar before opening to prevent condensation. Stir gently for 1–2 minutes before placing it on the stencil. Do not mix used paste from the stencil with fresh paste in the jar. Set a reflow profile with 40–90 seconds time above liquidus and a ramp rate of 1–3 °C/second.

Checking printed paste thickness with an SPI machine after every stencil change helps catch the causes of insufficient solder and bridging early, before components are placed.

Contact the technical team at AMS Vietnam for advice on particle size and reflow profiles, and for trial runs on your SMT line.