The benefits of selective soldering with nitrogen

Selective soldering with nitrogen is an essential process in the production of printed circuit boards (PCBs). It is used for bonding components to PCBs that could otherwise be damaged if exposed to a lot of heat. Another area of application are mixed-technology circuit boards with layout constraints. 

How does selective soldering work?

soldering iron tips of automated manufacturing soldering and assembly pcb board

Selective soldering is an automated process. It gives you the precision of hand soldering with none of its delays and inconsistencies.

  • Preparation: The first step is to program the solder pot with the positions on the PCB that have to be soldered.
  • Fluxing: In the fluxing stage, flux is applied to the components that must be soldered. This is a major difference to wave soldering, where flux covers the entire PCB.
  • Preheating: Then the temperature of the assembly is raised until there is sufficient heat for activating the flux. This ensures the effective filling of spaces with solder.
  • Soldering: Finally, there is the soldering process itself. A soldering pen distributes solder material on the board in a pattern programmed to only cover the points that need to be soldered. Then the soldering of the leads to the PCB can commence. The solder pot lowers and moves to the next spot. 

The benefits of selective soldering

Different soldering methods are available for PCB production. The most common are wave, selective soldering and reflow soldering. In the choice between these options, selective soldering offers distinct benefits:

  • Selective soldering results in better wetting, which refers to the ability of the molten solder to create a bond between component and PCB.
  • It also reduces the amount of flux required, which lowers operating costs and reduces the leftover residue.
  • Selective soldering eliminates the need for PCB cleaning or brushing because it results in clean, shiny joints.
  • The process reduces defect formation and other problems.

The role of nitrogen in selective soldering

Because of its inert properties, nitrogen is applied in soldering to ensure the process is free from oxygen. That is because oxygen would react with the solder. This would create an oxide layer that can lead to quality problems or short circuits in the selective soldering units. 

How to make on-site nitrogen generation pay off for you

Many companies rely on nitrogen deliveries. However, this option comes with a high cost of gas. You not only have to pay a lot for the nitrogen itself but also for rental fees for the nitrogen cylinders. In addition, purchasing nitrogen from a vendor requires you to free storage space, which can lead to supply bottlenecks and logistics headaches.

A much better alternative is on-site nitrogen generation with a compressor and a nitrogen generator.

This eliminates these challenges while also offering a series of additional benefits. First and foremost is the reduction in costs. A cubic meter of nitrogen generated on-site is significantly cheaper than a cubic meter of purchased nitrogen.

Equally important is supply control. Nitrogen is critical to your soldering activities. Can you really afford to be dependent on third party suppliers?

In addition, a nitrogen generator allows you to select the required gas purity. This is critical in ensuring appropriate solder spreading behavior at low temperatures. Setting the right purity also allows you to reduce your energy and thus operating costs.

Finally, you can eliminate the transport emissions associated with gas deliveries and lower your carbon footprint. 

Increasing the effectiveness of selective soldering with nitrogen

Different factors determine the effectiveness of the selective soldering process. These include the configuration of the machine, the attributes of the flux, and the nozzle choice. And, of course, the nitrogen you use is important. You have to make sure it is of the right purity to prevent dross formation. High-purity nitrogen can also extend the lifetime of the nozzles, which saves costs.

A nitrogen generator from Pneumatech is the optimal solution for providing you with a steady supply of high-quality nitrogen. This not only lowers your operating costs but also can help you to take your selective soldering operation to the next level. To learn more, contact one of our experts now. 

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