FAQ

• 1. What are solder products used for?

  Solder products are used to join metal surfaces by melting a solder alloy, creating strong electrical and mechanical connections in electronic and industrial applications.

• 2. What is the difference between leaded and lead-free solder?

  Leaded solder contains tin and lead, offering a lower melting point and easier workability. Lead-free solder uses alternative metals (such as Ag, Cu, Bi) and meets environmental regulations like RoHS.

• 3. What is flux and why is it needed?

  Flux removes oxides from metal surfaces, improves wetting, and helps solder flow smoothly to form reliable joints.

• 4. What types of solder wire are available?

  Solder wire comes in solid wire (no flux) and flux-cored wire containing one or more flux cores for easier soldering.

• 5. What is the advantage of flux-cored solder wire?

  Flux-cored wire simplifies the soldering process, improves wetting, reduces oxidation, and minimizes the need for additional flux.

• 6. What are common lead-free solder alloys?

  Popular lead-free alloys include SAC305 (Sn96.5Ag3.0Cu0.5), SAC105, Sn99.3Cu0.7, and Sn42Bi58.

• 7. What is the melting temperature of solder?

  It varies by alloy. For example, Sn63Pb37 melts at 183°C, while SAC305 melts around 217–219°C.

• 8. Do solder pastes require refrigeration?

  Most solder pastes should be stored at 0–10°C, though some special formulations can be stored at room temperature.

• 9. What are solder preforms?

  Preforms are pre-shaped solder pieces designed to deliver precise solder volume and consistent joint quality.

• 10. What is no-clean solder?

  No-clean solder contains flux that leaves minimal, non-corrosive residues that usually do not require cleaning.

• 11. How do I choose the correct solder diameter?

  Fine diameters (0.3–0.8 mm) are ideal for small components, while larger wires (1.0–1.6 mm) are better for heavier joints.

• 12. What is the shelf life of solder products?

  Solid solder wire typically lasts many years. Solder paste generally has a shelf life of 6–12 months depending on storage conditions.

• 13. Can solder products be used on different PCB finishes?

  Yes. Most solder alloys and fluxes are compatible with finishes such as HASL, ENIG, OSP, and Immersion Tin/Silver.

• 14. Are halogen-free solder products available?

  Yes. Many fluxes and solder pastes are available in zero-halogen formulations for improved environmental and reliability performance.

• 15. What certifications should solder products comply with?

  QLG have passed ISO 9001, ISO 14001, ISO 45001, and IATF 16949 standards, as well as RoHS and REACH for lead-free products.