A continuous supply of high purity nitrogen is essential for many modern soldering applications. So much so that Trizo invested in our own in-house nitrogen generator in 2024. Before going into the benefits of onsite generation, it’s worth reiterating why soldering under a nitrogen atmosphere is so important in modern PCB manufacture.
Most metals oxidise rapidly given the opportunity – even more so at elevated temperatures. Metallic oxides are not solderable – so surface oxidation will reduce electrical conductivity and make the joint more prone to failure.
Flux removes oxidation from surfaces to be soldered and improves wetting. But there’s typically a time gap between flux removal and solder application. At elevated soldering temperatures, oxidation can happen quickly – to an extent that can affect joint integrity.
Miniaturisation Increases Risk
As assemblies, components and solder joints have become more compact, the threat posed by atmospheric oxygen has increased. Tiny amounts of oxidation became more significant, making it more important to eliminate oxygen from the production environment.
Soldering in an inert nitrogen atmosphere prevents oxidation, which is why the purity of the nitrogen supply is important – particularly for high-reliability markets.
Is Nitrogen Always Needed?
Using a nitrogen atmosphere in wave soldering processes has been an established practice for many years. It’s been less common in reflow soldering where, it’s argued, the solder-flux paste used to locate surface mount components should leave little opportunity for residual oxidation.
In fact, there’s a body of evidence to support the view that nitrogen improves solder joint integrity and reliability in wave and selective soldering processes.
Miniaturisation means the pitch between leads becomes finer. So solder particles in the paste must also become smaller to improve paste print definition. This increases the ratio of surface area to volume and the risk of surface oxidation.
A nitrogen atmosphere also means we can use less aggressive, low-residue fluxes to simplify the cleaning process and produce more reliable products. Consumer electronics are less concerned with residues and often have a no-clean approach if products are expected to have a short lifespan. That’s not the market we operate in – we’re all about cleanliness and precision.
Trizo serves customers in high-reliability markets. We use nitrogen environments extensively across all types of soldering processes. A reliable source of high-purity nitrogen is an integral part of many of our production processes. Like everything else that’s critical for high-reliability manufacturing, it makes sense to manage it in-house.
By generating nitrogen on site we can be certain of a continuous supply of high purity gas, which means uninterrupted production and reliable performance from the products we manufacture.
If you’re interested in learning more about modern electronics manufacturing for high-reliability markets access our free resource centre to find out more.
