Understanding Wave and Selective Soldering Processes

Over the last few weeks we’ve been discussing the relative benefits of Through-hole and Surface Mount technology, as well as the combined benefits of both. If you choose Through-hole or mixed technology, your PCB will require soldering to keep the components in place. This can be done through either wave or selective soldering. To understand which option is best for your PCB design, we'll look at the processes involved in both techniques, and next week we will examine the pros and cons offered by each.

Chris RubberDragon, Flickr Creative Commons

Over the last few weeks we’ve been discussing the relative benefits of Through-hole and Surface Mount technology, as well as the combined benefits of both. If you choose Through-hole or mixed technology, your PCB will require soldering to keep the components in place. This can be done through either wave or selective soldering. To understand which option is best for your PCB design, we'll look at the processes involved in both techniques, and next week we will examine the pros and cons offered by each.

Wave Solder Machine

A wave solder machine goes through 3 separate processes:

1. First the machine applies a layer of flux to the underside of the entire board, helping to clean the components and PCB in the places that require solder. Impurities, such as forming oxide layers, can affect the soldering process and lead to poor quality of solder joints.
2. After the flux has been applied, the PCB is slowly heated, to both activate the flux before soldering and to help prevent the board from suffering thermal shock.
3. Lastly, the PCB is passed over a molten “wave” of solder via a conveyor system. As the PCB moves over the wave, a connection is made between the electronic component leads, the PCB pads/holes and the solder itself, which forms an electrical connection.
   
   

Selective Solder Fountain

A selective solder machine also involves 3 separate processes, however, in selective solder:

1. Flux is applied only to the components that need to be soldered as opposed to the entire board. The flux is applied with a nozzle which can vary in size to accommodate the area to be soldered. This is especially useful when soldering densely populated PCB's.
2. Once the flux has been applied, the PCB is gradually heated to activate the flux and prevent thermal shock to the board, just as in the wave soldering process.
3. In the last step, rather than a “wave” of solder, small, accurate nozzles are used to deposit the solder and form the connection.
   
   

PCB Assembly in Northern New Jersey from Telan Corporation

Now that you have insight into the processes behind wave and selective soldering, you can better understand what you need from a Northern New Jersey PCB assembly service. Telan Corporation offers both wave and selective soldering to accommodate all your PCB assembly needs. With over 35 years in the industry, Telan Corporation has the resources and experience necessary to meet all your PCB assembly requirements in Northern New Jersey. Contact us today and put our experience to work for you.