Indoor atmospheric corrosion of electronic materials in tropical-mountain environments
Introduction
Atmospheric corrosion deals with the aggressiveness of environmental factors on metallic structures. Corrosion rates can vary dramatically between locations, being the pollutant deposition rate an important variable in the corrosion process [1]. There is a vast data and knowledge on outdoor atmospheric corrosion; leading to development of standards and classification systems [2]. Mendoza and Corvo [3] explored the variations of outdoor and indoor atmospheric corrosion for non-ferrous metals in a Cuban tropical environment. They found an interaction between chloride deposition rate and both rainfall (outdoors) and time of wetness (indoors). They concluded that these are the most significant variables influencing the corrosion process. In a similar way, Rocha et al. [4] performed experiments in a tropical environment located in Bolivia for ferrous and non-ferrous metals. In the case of steel, the results showed differences in the ISO classification. They found a C2 classification for outdoor category in contrast with an IC4 classification for indoor category; this is probably due to “Heat Trap” effect [4].
Indoor exposure studies have increased over the last decades, and great interest has grown regarding its influence in electronic material corrosion [5], [6], [7], [8], [9]. Indoor environments have a known effect on the performance of this type of materials, particularly regarding surface-related properties [10]. Metallic degradation can lead to equipment failures and even breakdowns in environments with a relatively low pollutant concentration. Takano and Mano [11] concluded that failures in electrical contacts and connectors were due to copper corrosion with the consequent formation of copper (I) oxide (Cu2O). Abbot [12] evaluated the effect of H2S, SO2, NO2 and Cl2 on contact electric materials, and it was found a synergic effect between SO2 and NO2 and atmospheric corrosion. Sulphidric acid have also been reported as a corrosion accelerator when is combined with NO2, particularly in the case of silver samples [13]. Likewise, other studies have shown that reliability of electronic equipment decreases due to contact corrosion [14], [15]. Frankenthal [16] evaluated the passivation and breakdown of electronic metals by factors such as moisture, contamination and applied voltage. Tidblad [17] performed statistical and superficial studies on the effect of acid deposition over metals used as electric contacts.
In Latin America, TROPICORR project (Tropical environment effect on degradation of electronic equipment) was involved in atmospheric corrosion studies seeking to explain the electronic materials behavior in tropical environments during long exposures. It also aimed to contribute establishing standard criteria applied to these specific conditions. In this paper, we reported the main results obtained during one year exposure in three atmospheric environments in Colombia. Rural environment representing unpolluted conditions was located in San Pedro town (outside Medellín, Antioquia); meanwhile urban and industrial atmospheres were located in the University of Antioquia campus (Northwest of Medellín) and Eafit University campus (Southwest of Medellín), respectively. The selection of the atmospheres location was based on previous studies [18].
Section snippets
Experimental
Metallic samples and pollutant collectors were located inside metallic boxes in three tropical atmospheres categorized as rural, urban and industrial environments. The classification was made according with the international standard ETS 300 019-1-0 [19]. Low carbon steel (SAE AISI C1019), silver, copper, tin, and nickel plates of 99.5% of purity were exposed by periods of 1, 3, 6, and 12 months. Corrosion rate was measured by both gain and mass loss techniques according to the ISO/TC156/WG4-N
Visual appearance
Fig. 1 exhibits the visual appearance of the samples after exposure. For each material, a photograph of the unexposed sample is presented. As a general point of view, samples exposed in the rural station presented just slight corrosion product formation on the surface. Carbon steel and nickel show corrosion products covering the surface during exposures in urban environment. Likewise, copper and tin samples exhibits surface darkening in this station. Also, nickel exhibits whitish corrosion
Conclusions
- 1.
Deposition rates of pollutants are lower inside the metallic boxes than outdoor, leading to a low corrosion rate for copper, carbon steel, tin and nickel. According to the ISO 9223 classification of time of wetness, urban and urban-industrial stations were classified as τ3, meanwhile the rural station corresponds to τ4. These results indicate that for indoor conditions, aggressiveness predictions by using TOW according to existing ISO standards are inaccurate.
- 2.
In the urban environment,
Acknowledgment
The authors thank to Programa de Sostenibilidad of the University of Antioquia for its financial support to this study.
References (46)
- et al.
Atmospheric corrosivity modeling — a review
Material and Design
(2002) - et al.
Outdoor and indoor atmospheric corrosion of non-ferrous metals
Corrosion Science
(2000) Passivity and corrosion of electronic materials and devices
Corrosion Science
(1990)- et al.
Time of wetness in tropical climate: considerations on the estimation of TOW according to ISO 9223 standard
Corrosion Science
(2008) - et al.
Indoor atmospheric corrosion in Cuba. A report about indoor localized corrosion
Corrosion Science
(2007) - et al.
Corrosion Science
(1999) - et al.
Atmospheric corrosion of historical organ pipes: the influence of environment and materials
Corrosion Science
(2008) - et al.
Atmospheric corrosion of nickel in various outdoor environments
Corrosion Science
(2004) - et al.
A laboratory study of the effect of NO2 on the atmospheric corrosion of zinc
Atmospheric Environment
(2007) - et al.
Influence of the corrosion products of copper on its atmospheric corrosion kinetics in tropical climate
Corrosion Science
(2004)
Corrosion-related problems affecting electronic circuitry
Material Performance
Environmental Damage to Electronic Products, Reliability and Failure of Electronic Materials and Devices
Corrosion of Electronic Materials and Devices by Submicron Atmospheric Particles, Interface
Corrosion of microelectronic and magnetic storage devices
Atmospheric Corrosion
The failure mode and lifetime of static contacts
IEEE Transactions and Parts, Materials and Packaging
Effects of industrial air pollutants on electrical contact materials
IEEE Transactions and Parts, Hybrids and Packaging
Multiple contaminants gas effects on electronic equipment corrosion
Corrosion
Investigation of corrosion related failures in electronic systems
Material Performance
The effect of dust contamination on electric contacts
IEEE Transactions and Parts, Hybrids and Packaging
Cited by (17)
Atmospheric corrosion of silver, copper and nickel exposed to hydrogen sulphide: a multi-analytical investigation approach
2022, Corrosion ScienceCitation Excerpt :In this case, the authors observed green corrosion products associated with nickel sulphate without any further characterisation. For indoor tests in tropical environments, some authors showed the influence of SO2 on the corrosion of nickel [32,33] leading to the formation of sulphate-based corrosion products. Such sulphate species were also observed during several outdoor exposure tests [34,35].
Assessment of acid mist on mortar biodeterioration simulating the wall of Jardim da Princesa, the National Museum of Rio de Janeiro, Brazil
2021, International Biodeterioration and BiodegradationCitation Excerpt :These observations corroborate the hypothesis that acid mist causes more damage to the material than humidity caused by the water mist, because it keeps the surface moister beyond the acids act on surface deterioration. These observations are in accordance with a study that demonstrated the impact of atmospheric conditions on the degree of material deterioration (Gil et al., 2010). Additionally, microbial influence was greater than that of the atmosphere in the process of surface deterioration, due to production of acids and other metabolites (Pitzurra et al., 2003).
Assessment of failure of consumer electronics due to indoor corrosion in subtropical climates
2019, Handbook of Materials Failure Analysis: With Case Studies from the Electronic and Textile IndustriesElectrochemical migration, whisker formation, and corrosion behavior of printed circuit board under wet H2S environment
2013, Electrochimica ActaCitation Excerpt :At the same time, the residue of a small amount of Cl− and Br− on the material during the manufacturing process may also be a direct factor of corrosion failure of PCB [7]. The atmospheric corrosion mechanism of electronic materials and other cases of atmospheric corrosion are similar, as they are all affected by relative humidity [7–10], temperature [8,11], pollutants (Cl−, H2S, SO2 and NOx, etc.) [7,12–16] and other factors synergies [17,18]. Uniform corrosion frequently occurs to copper, gold, nickel, silver, aluminum and other materials in electronic devices.
Effects of gaseous and particulate contaminants on information technology equipment reliability-a review
2022, Journal of Electronic Packaging, Transactions of the ASMEInfluence of Co-deposition of Pollutant Particulates Ammonium Sulfate and Sodium Chloride on Atmospheric Corrosion of Copper of Printed Circuit Board
2022, Journal of the Chinese Society of Corrosion and Protection