What are the main additive components of solder wire that personnel in the soldering industry know?

Recently, a user mentionedSolder wireWhat are the main added ingredients? Today, let's elaborate on a question: Soldering industry personnel know that tin wire is not pure tin but is composed of tin alloy components. Tin alloys mainly include tin-lead alloy, tin-silver-copper alloy, tin-copper alloy, etc. During the production process, tin wire is made into hollow wire, with rosin, flux, water-soluble resin, activator, etc. inside. Then it is drawn into a wire and evenly wound on a reel. Now, the solder paste manufacturer will explain it:

Due to different production processes, tin wires are classified into two types: solder-free cores and solder-rosin cores. The solder-rosin type can be further divided into:RTypeRATypeRＡM The alloy composition of tin wire varies, and so does its melting point.

Tin-lead alloys are also classified into the following types based on the different proportions of tin and lead:

AlloySn63/Pb37 Melting point183℃

AlloySn60-Pb40 Melting point185℃ -190℃

AlloySn55-Pb45 Melting point187℃ -202℃

AlloySn50-Pb50 Melting point190℃ -216℃

AlloySn45-Pb55 Melting point192℃ -227℃

AlloySn40-Pb60 Melting point194℃ -238℃

Lead-free and environmentally friendly tin wire alloys are mainly divided into the following types: 

AlloySn99.3 Cu0.7 Melting point217-227℃(The most common and frequently used)

Alloy Sn96.5Ag3.0Cu0.5Melting point210℃～217℃

Alloy Sn99Ag0.3Cu0.7 Melting point217℃～220℃

AlloySn97Ag3 Melting point221℃(Due to its high cost, it is rarely used)

At present, the solder wires in use are mostly rosin core (hollow core) solder wires and solid solder wires. The intuitive understanding is that solder wire contains rosin and does not contain rosin. Those with rosin are easier to weld. Rosin also has antioxidant effects. No additional flux needs to be added during use, and solid solder wire should be used together with flux. It's very difficult to weld without flux.

The above is an explanation of the differences in melting points between lead-free and alloy products. You can take a look and choose a better product for soldering based on the corresponding products in your factory. Only in this way can the quality of the product be guaranteed to a certain extent. If you still have any questions, please feel free to consult!