Sticks

Bars and sticks are the reference format for feeding wave soldering baths and for dip tinning processes. They are made from high purity metals (≥ 99.9%) and undergo treatments that reduce oxidation tendency, improving bath stability and containing dross formation. Large format ingots, typically in the order of tens of kilograms, are used for initial filling of tanks; sticks, with lower unit weight, allow progressive topping up during production, reducing thermal shocks and maintaining more stable alloy composition. On request, customized formats can be made to adapt to automatic loading or specific machine constraints. From a metallurgical point of view, bath management is fundamental: contamination from copper, iron or aluminum must be kept within defined limits to avoid wetting defects and opaque soldering. The most used lead-free alloys are 99.3Sn0.7Cu (eutectic at 227°C), SAC305 (for continuity with SMT joints) and 99SnCuNiGe (Sn100C), particularly appreciated for lower dross formation and high wettability even in air. Low silver variants (e.g. SAC0307) allow cost containment while maintaining adequate performance. Typical applications include wave soldering of through-hole PCBs, dip-soldering of connectors and tinning of conductors or mechanical parts. Control of bath temperature, atmosphere (air/nitrogen) and PCB preheating directly affects joint quality. To maintain the alloy within specification, we propose periodic bath analyses and support in dross and residue management. Each bar/rod is marked with alloy code and batch number, guaranteeing traceability. Compositions comply with ISO 9453 / J-STD-006; targeted additions (Ni, Ge, Sb, Bi) are available to optimize fluidity, strength or melting temperature according to process.