A Guide to Soldering: Types, Tools, And Process

Soldering refers to the process of joining different types of metals together by melting solder. It involves melting and flowing a filler metal into the joint, which cools down to form a bond between two items. The solder alloy is generally made of tin and lead. Soldering is an essential procedure in the fabrication and assembly of printed circuit boards (PCB). It helps to create permanent and strong connections in the PCB. However, you can also reverse the connections by implementing the desoldering methods. Soldering differs from welding; as in soldering, the workpieces are not melted.

While solders typically contain lead, due to environmental concerns and the RoHS (“Restriction of Certain Hazardous Substances”) directive, it is increasingly dictating the use of lead-free solders for electronics. These lead-free solders may contain antimony, bismuth, brass, copper, indium, tin, or silver. The OEMs and PCB engineers should also comply with IPC 620B standards to regulate the soldering process and quality of the finished product in cable and wire harness assemblies. The stakeholders must use solder stencils to control solder flow during the soldering process and create high-quality products. Solder stencils cost depends on its design principles such as its apertures, thickness, frame, and material used for constructing it. You can customize the solder stencil to meet your project requirements and eliminate the tedious, error-prone process of hand soldering the prototype PCBs.

The Soldering Process

A hot iron connected to a temperature controller helps to melt the solder. With the adjustable heat control, you need to set the right temperature to trigger the melting. Touch the iron tip to the copper pad, and the resistor leads simultaneously. Remember, you should not touch the solder directly to the iron tip. While holding the soldering iron on the copper pad and the lead, you should touch the solder to the joint. Ensure that the joint is hot enough for melting the solder. Incorrect temperature can lead to bad solder. Once it melts, allow the solder to cool down naturally.

Soldering Tools

  • Soldering Station: It functions as a control station for soldering iron. It offers better flexibility and control during the soldering process and helps to adjust the iron temperature and other settings. It creates an advanced and more secure work area.
  • Soldering Iron and Iron Tips: Soldering iron is an electrical tool heated to melt solder around electrical connections. You can customize the soldering iron tips to accommodate components and techniques.
  • Soldering Wire or Paste: The soldering wire and pastes should be lead-free for RoHS Based on particle size, the soldering paste is available in varying grades.
  • Flux: The commonly used flux are Rosin fluxes, Resin fluxes, and organic (water-soluble) fluxes. Flux is used for cleaning the surfaces on which soldering will take place to develop more effective bonds.
  • Solder: Solder is a metal alloy material that you must melt to create a permanent bond between electrical components. It can be both lead and lead-free, and the commonly used diameters of 0.032 and 0.062.

Types Of Soldering

  • Soft soldering(90 °C – 450 °C): It has the lowest filler metal melting point compared to other soldering techniques.
  • Hard (silver) soldering (>450 °C): It uses brass or silver as the bonding metal. It requires a blowtorch for achieving the right soldering temperature.
  • Brazing(>450 °C): It uses metal with a much higher melting point.

To Conclude:

These are a few essential details you should know about soldering. It will help you perform the soldering process more efficiently and make strong bonds in the circuit board.

Comments are closed