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March 5, 2024 - Updated February 8, 2023 - Originally Posted Storage To Prevent CorrosionWhich storage method will better protect against corrosion, nitrogen or super-dry? L.M. |
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Long-term storage of electronic components really is concerned with mitigating two distinct risks:
Specifically for protection from oxidation, a cabinet with a dry-air atmosphere does very little. You need to eliminate oxygen from the atmosphere in the cabinet to eliminate it reacting with solderable metal surfaces. By far the easiest way to do this is to use a dry nitrogen purge. That gets you protection from both moisture uptake and oxidation.
Process Engineer Astronautics Fritz's career in electronics manufacturing has included diverse engineering roles including PWB fabrication, thick film print & fire, SMT and wave/selective solder process engineering, and electronics materials development and marketing. Fritz's educational background is in mechanical engineering with an emphasis on materials science. Design of Experiments (DoE) techniques have been an area of independent study. Fritz has published over a dozen papers at various industry conferences.
Actually a combination of low RH atmosphere and nitrogen (low oxygen) will be the best at preventing corrosion. If your goal is only reducing corrosion, then nitrogen is good because it displaces oxygen. If you goal is also prevention of moisture absorption (MSL) low RH is best. Nitrogen is good for reducing oxygen and low RH is good for reducing moisture. Neither system can reduce oxygen or moisture (water) to 0% so as said, a combination of low RH atmosphere and nitrogen would be the best.
Senior Project Engineer Electronic Controls Design Inc Paul been with Electronic Controls Design Inc. (ECD) in Milwaukie, Oregon for over 39 years as a Senior Project Engineer. He has seen and worked with the electronic manufacturing industry from many points of view, including: technician, engineer, manufacture, and customer. His focus has been the design and application of measurement tools used to improve manufacturing thermal processes and well as moisture sensitive component storage solutions.
Both are equally good at protecting against corrosion and oxidation, but you must have clean parts (low in ionic and organic contamination) post plating, rinsing and lead tinning. If you see corrosion on either condition the parts are very contaminated and typically the fabrication rinsing is the main source.
President/Senior Technical Consultant Foresite Mr. Munson, President and Founder of Foresite, has extensive electronics industry experience applying Ion Chromatography analytical techniques to a wide spectrum of manufacturing applications.
My recommendation would be a vacuum seal utilizing a nitrogen purge with a large desiccant pack.
President JSK Associates Based in. Northern California since 1971. Founded JSK Associates in 1979. Actively involved in soldering, cleaning, chemistries. 30 years experience in EOS/ESD control.
Concerning the prevention of corrosion, there is several reasons to consider depending on the factors causing corrosion: Material surface – which kind of material is considered, is it sensitive to corrosion? Residues that create acidic or alkaline environment – fluxes, cleaning chemistry, etching materials Ionic residues – salts like sodium chloride Humidity level – water presence often multiplies corrosion effects Temperature storage environment for materials Intermetallic effects – electrochemical migration Corrosive gases environment When reasons and influence factors are clearly detected, a strategy for corrosion prevention can be defined
Product Manager Soldering Inventec Dehon Product manager for soldering products, including solder pastes, liquid and tacky fluxes.
Both nitrogen storage and super-dry storage can be effective in preventing the corrosion of electronic components and printed circuit boards (PCBs). In nitrogen storage, electronic components and PCBs are stored in an environment filled with nitrogen gas. This displaces oxygen and moisture, which are causes of corrosion, and maintains a low relative humidity within the storage container, reducing the risk of corrosion and ensuring the reliable performance of the components and PCBs. Super-dry storage, on the other hand, stores components and PCBs in an environment with extremely low moisture levels, achieved through desiccant materials such as silica gel. The low moisture reduces the risk of corrosion and ensures the reliable performance of the components and PCBs. While both storage methods have their benefits, nitrogen storage has the advantage of being more easily controlled and maintained as the nitrogen atmosphere can be managed more effectively than desiccants which can lose effectiveness over time. Hence, the humidity level stability over time is better in nitrogen and therefore the effect on corrosion is typically superior.
CTO Cybord Electronic and Mechanical Engineer with 25 years experience in technology development. CTO of Cybord, developing electronic component authentication technology using deep-tech visual inspection and big-data. Author of a book and 24 papers.
Corrosion is caused by oxidation. You need an atmosphere of oxygen & water for corrosion to begin. Nitrogen is an inert gas that will not react with metals. When Nitrogen purges Oxygen from the atmosphere there is no chance for corrosion. On the other hand, a super dry atmosphere will also help to avoid corrosion since air humidity is kept to a minimum. Both processes will protect from corrosion but first you need to know how susceptible the material is to oxidation.
Senior Manufacturing Engineer Northrop Grumman Edithel is a chemical engineer with 20 year experience in manufacturing & process development for electronic contract manufacturers in US as well as some major OEM's. Involved in SMT, Reflow, Wave and other assembly operations entailing conformal coating and robotics.
Specifically for corrosion prevention, nitrogen use is the way to go.
Engineering and Operations Management Independent Consultant Georgian Simion is an independent consultant with 20+ years in electronics manufacturing engineering and operations.
Contact me at georgiansimion@yahoo.com. |
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