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The benefits of reflow soldering with nitrogen

Reflow soldering is the most commonly used method for attaching surface-mount components to printed circuit boards (PCBs), playing a crucial role in modern electronics manufacturing. But beyond just melting solder paste, the process has evolved—especially when paired with nitrogen—to deliver greater consistency, reliability, and cost-efficiency.

How does reflow soldering work?

In reflow soldering, solder paste is first applied to the PCB using a stencil, coating only the contact pads. Surface-mount components are then placed using a pick-and-place machine. The assembled board is passed through a reflow oven, where it goes through four key stages:

  • Pre-heat: The temperature gradually rises to safely evaporate solvents in the solder paste and avoid thermal shock to components.
  • Soak: The board is held at a steady temperature to activate the flux and ensure even heat distribution across the PCB.
  • Reflow: Heat peaks to melt the solder, allowing it to bond the components to the board through a process known as wetting.
  • Cooling: The board is cooled in a controlled manner to solidify the solder joints without introducing stress or cracks.
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The benefits of reflow soldering

Reflow soldering isn’t just widely adopted—it’s preferred for a reason. Its versatility and efficiency make it the go-to method for modern electronics manufacturing. Here are some of the key benefits it brings to the table:

 

  • Precision and repeatability: Reflow soldering supports mass production by delivering consistent results across high volumes of complex PCBs.
  • Strong electrical connections: The process forms reliable joints that ensure stable electrical performance.
  • Compatibility with fine-pitch components: Reflow soldering enables the use of compact, high-density component layouts, including BGAs and microchips.
  • Automation-ready: It integrates seamlessly with automated assembly lines, improving throughput and reducing manual errors.

The role of nitrogen in reflow soldering

Introducing nitrogen into the reflow oven creates an inert atmosphere that significantly improves soldering results. In an oxygen-rich environment, solder can oxidise during heating, weakening the joints. Nitrogen displaces oxygen and helps:

 

  • Minimise oxidation on solder and component leads
  • Improve wetting, resulting in cleaner, shinier solder joints
  • Reduce soldering defects like voids, bridging, or tombstoning
  • Enable lower peak temperatures, protecting heat-sensitive components

 

This not only enhances solder joint quality but also extends the lifespan of components and the PCB itself.

Why on-site nitrogen generation makes sense

Relying on external nitrogen delivery for reflow soldering can be costly and logistically demanding. On-site nitrogen generation offers a smarter, more cost-effective alternative—especially for manufacturers running continuous or high-volume production.

 

With an on-site nitrogen generator:

 

  • You gain full control over your nitrogen supply
  • Costs are significantly reduced over time, with no rental or delivery fees
  • Purity and flow rates can be adjusted based on your process needs
  • There’s no disruption from delayed deliveries or supplier issues

 

In short, it's an investment that quickly pays for itself—particularly when soldering quality and operational uptime are key to your business.

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Get in touch

Curious about how nitrogen can improve your reflow soldering process? Or interested in calculating the ROI of on-site nitrogen generation for your facility? Get in touch with our team today—we’re happy to answer your questions and help you explore the right solution for your production line.

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