Solder wire is a fusible metal alloy used to create permanent, electrically conductive bonds between electronic components and printed circuit boards (PCBs). It serves as the foundational joining material in electronics assembly and repair, melting at relatively low temperatures to form secure mechanical and electrical connections that can be reworked if needed .

Modern solder wire consists of two primary components: the metal alloy (typically tin-based) that forms the actual joint, and a flux core (hollow channels inside the wire filled with chemical cleaning agents). The flux activates during soldering to remove oxidation from metal surfaces, improve wetting, and prevent re-oxidation during the process .

1.Alloy Composition

Available in leaded (Sn63/Pb37 - 183°C) and lead-free (SAC305 - 217°C) formulations. Leaded solder offers easier wetting and shiny joints; lead-free is RoHS compliant for environmental standards.

2. Rosin Flux Core

Contains a built-in rosin or no-clean flux core that cleans oxidation from surfaces during soldering, improves solder flow, and leaves minimal non-corrosive residue.

3. Diameter Options

Multiple diameters from 0.3mm to 1.5mm – thinner wires (0.3-0.6mm) for fine-pitch SMD and micro-soldering; thicker wires (0.8-1.2mm) for general PCB assembly and through-hole components.

4. Low Melting Point

Melting temperature range of 183°C to 227°C depending on alloy, allowing precise, controlled soldering without damaging heat-sensitive components.

5. Bright, Reliable Joints

Produces shiny, strong solder joints with excellent wettability, good conductivity, and smooth fillet formation – essential for reliable electrical connections and mechanical strength.