Wave Soldering or Selective Soldering – Which One to Choose and Why?

Wave Soldering or Selective Soldering – Which One to Choose and Why?

Jan 11,2021
Soldering is one of the important processes in electronics. The process involves the joining and mounting of different electronic components onto the printed circuit board (PCB). This helps in forming an electrical connection. There are different types of soldering methods in use today depending upon the requirements and applications. These include robotic, hand, selective, and wave soldering techniques. Wave and selective soldering techniques are the most widely used in the electronics industry. But, which one should you choose for your PCB assembly? This post discusses both wave and selective soldering techniques in detail.

An Introduction to Wave Soldering Process

Wave soldering is popularly known as flow soldering. It is an in-line process wherein the base of the PCB is treated with flux, and is preheated, and immersed in molten solder. It is one of the most preferred methods for soldering a large number of PCBs at the same time. The process begins by:
  • Applying a layer of flux to the electrical components that need to be soldered. The flux cleans the metal before soldering, which is one crucial step as any impurities can affect the soldering process.
  • Preheating of the circuit board activates the flux and ensures the board will not suffer from thermal shock.
  • The solder wave will move over the board and begin soldering the components during the stage. Afterwards, a cooling method brings down the temperature and bonds the solder in place.

Advantages of Wave Soldering

The following are some important advantages of this method:
  • Affordable and time-saving
  • Initiates less warpage
  • Suitable for THT Assembly
  • Provides strong solder joint quality
  • Produces bulk PCBs

Detailed Discussion on Selective Soldering

Selective soldering is one variant of wave soldering used for soldering PCBs that are assembled using through-hole components. As double-sided PCBs are used in many products, the use of selective soldering has also increased. This soldering technique is used when there is the space complexity of components; components are tall due to which they block the wave technique from soldering the board and many more. Like wave soldering, selective soldering comprises three stages:
  • Flux application to the electronic components
  • The circuit board preheating
  • Soldering the components

Advantages of Selective Soldering

Owing to its inherent process flexibility, this method can be used to solder a wide range of printed circuit board assemblies. It has distinct advantages including:
  • Guaranteed process reproducibility
  • Reduced usage of expensive aperture wave solder masks or pallets
  • Reliable solder joints without overheating components
  • Best for low as well as high volume production
  • Low running cost
Hope the above information would help you gain valuable knowledge about both wave and selective soldering techniques. All this explains why these soldering methods are important in the electronics industry. Regardless of the type of soldering technique one chooses, it requires a lot of expertise, else it can lead to spoiling the PCB design. Thus, it is always a good idea to employ industry experts to provide quality soldering services. Sierra Assembly Technology Inc. has a vast experience in manufacturing best PCB solutions of different capabilities and specifications.