Sn42Bi57Ag1 T4 solder powder

The Sn42Bi57Ag1 T4 solder powder is a lead-free low-temperature solder with 42 % Tin, 57 % Bismuth and 1 % Silver. The T4 grit (20-38 µm) enables a finer paste deposit compared to T3 and therefore cleaner print images with dense PCB layouts. With a melting point of approx. 138-140 °C, it is ideal for Temperature-sensitive components in the Semiconductor Technology & Electronics.

Properties and advantages

• Low melting point (~138-140 °C): Reduces thermal loads and protects sensitive components.
• Silver additive (1 % Ag): Improves wetting, adhesion and mechanical stability of solder joints compared to pure Sn-Bi alloys.
• Fine T4 grit: Higher print resolution, less bridging and reproducible paste rheology with small stencil openings.
• Constant flow behaviour: Homogeneous, even solder joints in automated SMT and reflow processes.
• Lead-free & RoHS compliant: Sustainable solution for modern electronics production.

Areas of application

Fine pitch, LEDs & displays

The fine T4 grit predestines Sn42Bi57Ag1 for Fine pitch layouts as well as LED and display applications where precise paste application and low process temperatures are crucial.

SMT and reflow soldering

In the Semiconductor Technology & Electronics the powder in the Stencil printing and at the Reflow soldering with stable print images and defined melting profiles.

Hard & soft soldering

For defined, lead-free processes in the Hard & soft soldering Sn42Bi57Ag1 T4 offers reliable wetting and reproducible results.

Automotive industry & electrical engineering

In the Automotive industry and the Electrical engineering the alloy is used when assemblies need to be thermally protected and durable solder joints are required at the same time.

Technical properties

• Composition: Sn 42 %, Bi 57 %, Ag 1 %
• Melting point: approx. 138-140 °C
• Grain size: T4 (20-38 µm)
• Particle morphology: Predominantly spherical for precise paste rheology
• Purity: Controlled quality with low oxidation tendency

Sustainability & regulation

As Lead-free solder Sn42Bi57Ag1 T4 fulfils the RoHS specifications. The low melting point enables energy-efficient reflow processes and supports sustainable production processes.

Conclusion

Sn42Bi57Ag1 T4 solder powder combines low process temperatures with fine grain and silver reinforcement - the right choice for Fine pitch layouts, LEDs and other sensitive applications. You can find related fields of application in the area Semiconductor Technology & Electronics and in the Hard & soft soldering.