What Is Selective Wave Soldering?

Selective wave soldering is a hybrid soldering method, combining elements of wave soldering and fountain soldering. It allows manufacturers to assemble circuit boards with through-hole components without need of hand soldering.

It has the through-hole capabilities of wave soldering, but doesn’t have the same drawbacks, making it an effective, efficient soldering method for manufacturers who need the capability.

While legacy wave soldering systems may be acquired more cheaply, other soldering methods have too many benefits to ignore unless a manufacturer has no choice but to use a wave soldering system.

Selective Wave Soldering Uses A Smaller Wave Via Nozzles

The principle difference between selective wave soldering and classic wave soldering is the size of the wave.

In a wave soldering system, a tray of liquid solder is agitated, creating a wave of a particular height. The board is masked or set into an aperture, and preheated. After preheating, the board goes through the soldering chamber and passes over the wave.

The wave of solder forms the connections, and the board goes through cool-down and comes out of the soldering chamber.

Selective wave soldering, on the other hand, uses either a nozzle or a series of nozzles to create miniature waves of solder.

The board is typically positioned with an articulating cradle, allowing the operator to dip just the through-hole components onto the wave and make the connections.

Instead of a large wave, it’s one small wave of solder out of a single nozzle.

But what are the advantages?

Benefits Of Selective Soldering Over Wave Soldering

The drawback to wave soldering is that classic wave soldering (the older automated method for through-hole components) is wasteful and imprecise.

While it has been used for decades, an experienced operator will be well-versed in its disadvantages.

All the temperature control in the world can’t make up for imprecise masking or use of an aperture; the more liquid solder is in contact with the board, the greater the chances the board or other components will be damaged.

Given the lesser degree of precision and higher chance of an error in manufacturing, there is an attendant rise in the rate of rework or boards that have to be scrapped outright.

Wave soldering systems also waste larger volumes of solder, flux, and consume larger amounts of nitrogen compared to selective soldering systems. Selective soldering systems also require drastically less downtime for maintenance and cleaning.

Selective soldering systems, of course, do require some investment to install in your shop, as well as investment in training personnel in their use and in their maintenance.

All tools have their place, and wave soldering is fine for some applications. However, when repeatable precision with minimal waste is not negotiable…a selective soldering system is the superior choice.