The choice of the right welding is not always easy. Due to my ignorance, when I first started working in the electronics industry, I used any welding that I could find. You may not be aware that welding is not only used to weld electronic devices. Plumbing also uses welding. Note that the acidic components in welding for plumbing are not suitable for electronic devices.

There Are Two Main Types of Welding

It is important to have the necessary knowledge to be able to select the right welding material and to avoid using the wrong one. The welding materials come in a variety of forms. They include granules and rods as well as pastes and wires. Most hobbyists will use welding wire. You must be able to use the welding paste if you are planning to weld SMDs.

There Are Two Categories of Welding Materials

Welding materials containing lead

Lead-free Welding Materials

The melting point is the main difference between both types of welding material. In principle, either type of welding materials can be used according to your personal preference.

Lead-Based Welding

Lead-based welding has been widely used for industrial production in the past. The welding alloy is composed of lead and tin, usually 60% lead and 40% tin, with a melting point between 180-190 degrees Celsius. Due to the possible harm that lead can cause to human health the industry is slowly phasing-out leaded weldings in favor of lead-free weldings.

Lead-Free Welding

Lead-free weld is, as its name suggests, a material that doesn't contain lead. Due to the adverse health effects of lead in electronic products, the European Union stipulates that they must be lead-free (RoHS Directive). Lead-free welding may have a higher melting temperature and be a little inconvenient but this is not a big problem.

Flux Core Solder Wire

The main purpose of the embedded flux core in welding wire is to improve electrical contact and mechanical strength.

Shenzhen STM has pointed out that flux-cores can be divided into two main categories: acid and rosin. Acid cores, which are used for plumbing, are not suitable for electronics, and so rosin is chosen. A new water-soluble flux is gaining in popularity as an alternative to rosin cores due to its environmentally friendly nature.