Hindawi Publishing CorporationISRN CorrosionVolume 2013 Article ID 846405 7 pageshttpdxdoiorg1011552013846405

Research ArticleCopper Corrosion by Atmospheric Pollutants inthe Electronics Industry

Benjamin Valdez Salas1 Michael Schorr Wiener1

Roumen Zlatev Koytchev1 Gustavo Loacutepez Badilla2 Rogelio Ramos Irigoyen1

Monica Carrillo Beltraacuten1 Nicola Radnev Nedev1 Mario Curiel Alvarez1

Navor Rosas Gonzalez2 and Jose Mariacutea Bastidas Rull3

1 Engineering Institute Autonomous University of Baja California Boulevard Benito Juarez y Calle a la Normal SNColonia Insurgentes Este 21280 Mexicali BCN Mexico

2 Polytechnic University of Baja California Calle de la Claridad SN Colonia Plutarco Elias Calles 21376 Mexicali BCN Mexico3 National Center of Metallurgical Research Avenue Gregorio del Amo 8 28040 Madrid Spain

Correspondence should be addressed to Benjamin Valdez Salas benvaluabcedumx

Received 10 July 2013 Accepted 23 August 2013

Academic Editors L Bazzi G Bereket and A Hermann

Copyright copy 2013 Benjamin Valdez Salas et al This is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work is properlycited

Hydrogen sulphide (H2S) is considered one of the most corrosive atmospheric pollutants It is a weak diprotic reducing acid

readily soluble in water and dispersed into the air by winds when emitted from natural industrial and anthropogenic sources It isa pollutant with a high level of toxicity impairing human health and the environment quality It attacks copper forming thin filmsof metallic sulphides or dendrite whiskers which are cathodic to the metal substrate enhancing corrosion H

2S is actively involved

in microbially influenced corrosion (MIC) which develops in water involving sulphur based bacteria in oxidizing and reducingchemical reactions H

2S is found in concentrated geothermal brines in the atmosphere of geothermal fields and in municipal

sewage systems Other active atmospheric pollutants include SOX NOX and COThis investigation reports on the effects of H2S on

copper in microelectronic components of equipment and devices with the formation of nonconductive films that lead to electricalfailures

1 Introduction

The electronics industry is spread out worldwide it is animportant sector in the Mexican economy representing 80of industrial companies in the northwest of the countryTheirassembly plants are located in three cities Mexicali an aridzone Tijuana an urban-industrial area and Ensenada amarine region on the Pacific Ocean coast all belonging tothe State of Baja California near the Mexico-USA borderThe electronics industry appeared in Mexico during thesixties with the manufacture of electronic products suchas radios audio record and play devices and televisionsThis industry designs and manufactures microelectroniccomponents called microcontrol devices (MCD) integrated

with microelectromechanical systems (MEMS) A study wasconducted in the indoor areas of three electronics plantsin these cities Copper and its alloys are widely applied inthe electric energy electronics and semiconductor industriesbecause of their high electrical and thermal conductivityductility and malleability

Copper is considered a noble metal it resists attack byoxygen although some air pollutants such as H

2S change

its surface properties even at ambient temperature forminga thin layer having completely different properties comparedwith the puremetal surfaceThis layer lowers catastrophicallythe adhesion of the soldering alloy or conductive resinsand paste provoking failures of the printed circuit board(PCB) of the microelectronic devices Compounds such as

2 ISRN Corrosion

geerite (Cu8S5) are formed on Cu in the presence of H

2S and

patinas as Cu2O posnjakite (Cu

4SO(OH)

6H2O) brochan-

tite (Cu4SO4(OH)6H2O) and antlerite (Cu

3SO4(OH)4) are

formed in the presence of humidity [1] The formationof tarnish films on a copper surface exposed to environ-ments containing atmospheric pollutants and high humidityinvolves themovement ofmetallic ions over the surface awayfrom the metal generating a creep process that increases thecontact resistance leading to electric failures of the electronicdevices Copper sulphidation is a fast process occurring onthe metal-gas phase interface impairing the Cu corrosionresistance [2 3] This paper presents the corrosion processof Cu exposed to H

2S polluted environments under varied

conditions of temperature and humidity in the indoor areasof electronics manufacturing plants located in Mexicali BajaCalifornia Mexico [4]

2 H2S a Corrosive Toxic Pollutant

It is appropriate to report in the context of the present paperabout the corrosivity and toxicity of H

2S since this also

affects the quality of the environment human health andthe durability of the engineering materials which are centralissues of modern society H

2S acts as a pollutant in the indoor

areas of manufacturing plants of the electronics industry itpromotes the formation of thin copper sulphide films on PCBsurfaces Recent investigations [5 6] proved that the mainH2S source is a geothermal field generating underground

sources of steam and H2S located about 40 km south from

Mexicali city To avoid this air pollution and consequentcorrosion is impossible without the application of high costair cleaners [7 8]

H2S gas emitted into the atmosphere from additional

heavy sources such as municipal sewage causes respiratorydiseases and inflammation of the eyes it has an offensiveodor of rotten eggs therefore it is easy to detect even atlow concentration of 10 to 30 ppb (parts per billion) in theatmosphere around the geothermal fields

The corrosion activity of H2S is evident in

Fe +H2S 997888rarr FeS +H

2 (1)

Cu +H2S 997888rarr CuS +H

2 (2)

3 Experimental

31 Air Pollutants Measurements Data on air pollutants weregathered every fiveminutes and organized in files formonthlyperiodsThe specialized instruments controlled by theUnitedStates Environmental Protection Agency (US-EPA) monitor-ing air pollution were a chemiluminescence NO

119883analyzer

model 42 of Thermo Environmental Instruments Inc agas filter CO analyzer model 3000E of Advanced PollutionInstruments Inc (API) a SO

2photometric analyzer from

ThermoElectronCorporation and anO3analyzermodel 400

of API This electronic instrument has filters to separate dustparticles from gases

The practices recommended in ISO standards for atmo-spheric corrosion were taken into account The Cerro Prieto

geothermal wells in the vicinity of Mexicali emit H2S into

the atmosphere surrounding the fields and the power plantsOther H

2S emissions came from the plant chimney stacks

vapour ducts noise silencers and cooling towers totaling22740 t per year [9 10] Since the production capacity ofCerro Prieto has not changed over the last 5 years or so itmay be estimated that the same H

2S concentration in the

atmosphere around the geothermal wells ranges from 10to 30 ppb Typical ranges of natural and anthropogenic H

2S

under outdoor and indoor conditions are 0724 ppb and 01to 07 ppb respectively [11 12]

32 Corrosion RateMeasurement Rectangularmetallic spec-imens of Cu with an exposition surface of 645 cm2 wereprepared The specimens were polished to 400 SiC paperwashed degreased with acetone dried with hot air andweighed before being installed in ametallic chamber of expo-sure under indoor conditions for 1- 3- 6- 12- and 24-monthperiods The corrosion rates were determined by applyingthe gravimetric method according to ASTM G 31 standardmethod In order to simulate controlled indoor conditionsthe chamber was fabricated with precoated aluminum witha total volume of 01m3 and conditioned with two air inletblinds coupled to metallic filters in order to permit thepenetration of gases with the flow of air to prevent thepenetration of dust and to avoid mistakes in the weight losscalculations [13 14]The chamber was provided with metallicinternal supports to hold the specimens it was installed onthe roof of an electronics manufacturing plant at 10m aboveground level [15 16]

After each period of exposure the metallic samples wereremoved and weighed to obtain the mass gainThe corrosionproductsmorphologywas observedwith a stereoscope beforebeing removed cleaned and reweighed to obtain the massloss on an analytical balance to the nearest 00001 g of accu-racy Corrosion of Cu surfaces under constant concentrationof H2S and controlled relative humidity (RH) conditions

occurred using a closed system consisting of an acrylic sealedchamber with an inlet valve in order to provide a 01 ppmH2S concentration and a ventilator coupled to a humidity

generator to provide 80 RH [17 18]

33 Surface Examination The copper specimens exposed toa controlled H

2S environment during short times were ana-

lyzed to determine their surface characteristics by a ScanningElectron Microscopy (SEM) applying a JEOL (JEOL LtdPeabody MA) JSM-6360 coupled with an Energy DispersiveX-ray (EDX) analyzer (AMETEK Inc Mahwah NJ) usedfor chemical composition analysis

4 Results

41 Corrosion of Copper The corrosion rate (CR) of Cuspecimens exposed in the test chamber during 24 months(Figure 1) demonstrates that the extent of corrosion augmentswith the exposure time reaching values of 270mgsdotmminus2 afterthe two years of exposure at RH values ranged from 15to 75 and temperatures from 4∘C to 45∘C depending on

2 ISRN Corrosion

geerite (Cu8S5) are formed on Cu in the presence of H

2S and

patinas as Cu2O posnjakite (Cu

4SO(OH)

6H2O) brochan-

tite (Cu4SO4(OH)6H2O) and antlerite (Cu

3SO4(OH)4) are

formed in the presence of humidity [1] The formationof tarnish films on a copper surface exposed to environ-ments containing atmospheric pollutants and high humidityinvolves themovement ofmetallic ions over the surface awayfrom the metal generating a creep process that increases thecontact resistance leading to electric failures of the electronicdevices Copper sulphidation is a fast process occurring onthe metal-gas phase interface impairing the Cu corrosionresistance [2 3] This paper presents the corrosion processof Cu exposed to H

2S polluted environments under varied

conditions of temperature and humidity in the indoor areasof electronics manufacturing plants located in Mexicali BajaCalifornia Mexico [4]

2 H2S a Corrosive Toxic Pollutant

It is appropriate to report in the context of the present paperabout the corrosivity and toxicity of H

2S since this also

affects the quality of the environment human health andthe durability of the engineering materials which are centralissues of modern society H

2S acts as a pollutant in the indoor

areas of manufacturing plants of the electronics industry itpromotes the formation of thin copper sulphide films on PCBsurfaces Recent investigations [5 6] proved that the mainH2S source is a geothermal field generating underground

sources of steam and H2S located about 40 km south from

Mexicali city To avoid this air pollution and consequentcorrosion is impossible without the application of high costair cleaners [7 8]

H2S gas emitted into the atmosphere from additional

heavy sources such as municipal sewage causes respiratorydiseases and inflammation of the eyes it has an offensiveodor of rotten eggs therefore it is easy to detect even atlow concentration of 10 to 30 ppb (parts per billion) in theatmosphere around the geothermal fields

The corrosion activity of H2S is evident in

Fe +H2S 997888rarr FeS +H

2 (1)

Cu +H2S 997888rarr CuS +H

2 (2)

3 Experimental

31 Air Pollutants Measurements Data on air pollutants weregathered every fiveminutes and organized in files formonthlyperiodsThe specialized instruments controlled by theUnitedStates Environmental Protection Agency (US-EPA) monitor-ing air pollution were a chemiluminescence NO

119883analyzer

model 42 of Thermo Environmental Instruments Inc agas filter CO analyzer model 3000E of Advanced PollutionInstruments Inc (API) a SO

2photometric analyzer from

ThermoElectronCorporation and anO3analyzermodel 400

of API This electronic instrument has filters to separate dustparticles from gases

The practices recommended in ISO standards for atmo-spheric corrosion were taken into account The Cerro Prieto

geothermal wells in the vicinity of Mexicali emit H2S into

the atmosphere surrounding the fields and the power plantsOther H

2S emissions came from the plant chimney stacks

vapour ducts noise silencers and cooling towers totaling22740 t per year [9 10] Since the production capacity ofCerro Prieto has not changed over the last 5 years or so itmay be estimated that the same H

2S concentration in the

atmosphere around the geothermal wells ranges from 10to 30 ppb Typical ranges of natural and anthropogenic H

2S

under outdoor and indoor conditions are 0724 ppb and 01to 07 ppb respectively [11 12]

32 Corrosion RateMeasurement Rectangularmetallic spec-imens of Cu with an exposition surface of 645 cm2 wereprepared The specimens were polished to 400 SiC paperwashed degreased with acetone dried with hot air andweighed before being installed in ametallic chamber of expo-sure under indoor conditions for 1- 3- 6- 12- and 24-monthperiods The corrosion rates were determined by applyingthe gravimetric method according to ASTM G 31 standardmethod In order to simulate controlled indoor conditionsthe chamber was fabricated with precoated aluminum witha total volume of 01m3 and conditioned with two air inletblinds coupled to metallic filters in order to permit thepenetration of gases with the flow of air to prevent thepenetration of dust and to avoid mistakes in the weight losscalculations [13 14]The chamber was provided with metallicinternal supports to hold the specimens it was installed onthe roof of an electronics manufacturing plant at 10m aboveground level [15 16]

After each period of exposure the metallic samples wereremoved and weighed to obtain the mass gainThe corrosionproductsmorphologywas observedwith a stereoscope beforebeing removed cleaned and reweighed to obtain the massloss on an analytical balance to the nearest 00001 g of accu-racy Corrosion of Cu surfaces under constant concentrationof H2S and controlled relative humidity (RH) conditions

occurred using a closed system consisting of an acrylic sealedchamber with an inlet valve in order to provide a 01 ppmH2S concentration and a ventilator coupled to a humidity

generator to provide 80 RH [17 18]

33 Surface Examination The copper specimens exposed toa controlled H

2S environment during short times were ana-

lyzed to determine their surface characteristics by a ScanningElectron Microscopy (SEM) applying a JEOL (JEOL LtdPeabody MA) JSM-6360 coupled with an Energy DispersiveX-ray (EDX) analyzer (AMETEK Inc Mahwah NJ) usedfor chemical composition analysis

4 Results

41 Corrosion of Copper The corrosion rate (CR) of Cuspecimens exposed in the test chamber during 24 months(Figure 1) demonstrates that the extent of corrosion augmentswith the exposure time reaching values of 270mgsdotmminus2 afterthe two years of exposure at RH values ranged from 15to 75 and temperatures from 4∘C to 45∘C depending on

ISRN Corrosion 3

0

50

100

150

200

250

300

1 3 6 12Exposure time (months)

24

Cor

rosio

n ra

te (m

gm

2)

Figure 1 Corrosion rate of copper exposed in the corrosionchamber during 24 months

Table 1 Copper sulphides in films formed by reaction with H2S atindoor areas of electronics plants in Mexicali City

Mineral Chemical compositionChalcocite Cu2SDjurlcite Cu195SDigenite Cu182SGeerite Cu162S

the year season SO2and NO

119883were the species with major

concentration levelsCorrosion of Cu in the presence of air H

2S and humidity

produces oxides andor sulphides as wet films leading toelectrical failures in electronic equipment [10] On the otherhand corrosion of Cu occurs when the RH overpasses the80 and the SO

2concentration is larger than 01 ppm The

corrosion behavior also depends on the state of the metalsurface smooth corrugated polished and nonuniformSometimes a Cu

2O film that slows the rate of corrosion

gradually dissolves in the presence of an acidic electrolyteconstituted by SO

2 and then the corrosion products formed

are different due to the surface conditions At levels of SO2

greater than the air quality standards in combination withNO2and O

3at different concentrations in indoor plants

cuprite (Cu2O) and copper sulphides form as depicted in

Figures 2 and 3Some spectacular structures of hexagonal crystals of Cu

sulphide are shown in Figure 3 The SEM results of theexposed samples showed the formation of spots of CuSduring the first two days which grew continuously until allspots united together as large films covering the entire samplesurface The concentration of H

2S in the electronics plant

atmosphere was 09 ppm at the Cerro Prieto geothermal fieldatmosphere it reaches 15 ppm and higher concentrationsdue to the continuous emission of gases accompanying theproduced steam [11]

The EDX analysis performed in different points of thecorroded copper surfaces reveals the formation of several sul-phides of stoichiometric composition with a general formulaCu119883S where the values of119883 vary from 16 to 2The estimated

00

03

06

08

11

14

100 200 300 400 500 600 700 800 900

Cu

CO

(kC

ount

)

Figure 2 SEMpicture for Cu surface after 2 days in 03 ppmH2Sair

magnification 400x

000 200 400 600 800 1000 1200 1400 1600 1800

Cu

S

Cu00

02

05

07

09

12

(kC

ount

)

Figure 3 SEMpicture for Cu surface after 2 days in 03 ppmH2Sair

magnification 1200x

composition of the copper sulphide corrosion products andthe corresponding mineral are displayed in Table 1

42 Film Formation Mechanisms Under conditions ofhumidity and in contact with air contaminated with H

2S Cu

generates two types of corrosion products oxides and sul-phides according to the following electrochemical reactionsOxidation

2Cu 997888rarr 2Cu2+ + 4eminus

Oxidation anodic reaction(3)

O2+ 2H2O + 4eminus 997888rarr 4OHminus

Reduction cathodic reaction(4)

2Cu +O2+ 2H2O 997888rarr 2Cu(OH)

2

Total corrosion reaction(5)

2Cu (OH) 997888rarr Cu2O +H

2O

Hydroxide converts to oxide(6)

4 ISRN Corrosion

0 16 32 48 64 80

08

1624

32400

6

12

18

minus02

0

02

04

06

08

CL-H

2S

(ppm

)

RH ()T ( ∘C)

Correlation of Cl of H2S with climatic factors in summer

Figure 4 Correlation of copper corrosion with H2S relative

humidity and temperature in the electronics industry (summer2010)

Sulphidation

Cu 997888rarr Cu2+ + 2eminus

Oxidation anodic reaction(7)

H2S 997888rarr H+ + SHminus

Reduction cathodic reaction(8)

2SHminus 997888rarr 2Sminus +H2

Reduction cathodic reduction(9)

Cu +H2S 997888rarr CuS +H

2

Total sulphidation reaction(10)

43 Influence of Atmospheric Pollutants Mexicali city hashighly contaminated air because of the presence of fine dustcoming from the desert around but the gaseous pollutantssuch as SO

119883 NO119883 CO andO

3are generated from the diverse

industrial activities Air pollutants penetrate to indoor loca-tions of electronics plants and corrode Cu-made devicesTherelative humidity (RH) and temperature reach up to 50and 30∘C during the major part of the year Table 2 presentsthe relation between the concentrations of these pollutantsand the Mexicali climatic factors The two most aggressivepollutants are sulphur-containing H

2S and SO

2 both acidic

but one reducing (H2S) and the other oxidant (SO

2) agents

Their behaviour and corrosivity during the seasons of the yearare presented in Table 3

The corrosion data collected arranged in Tables 2 and 3correlate values of RH temperature and CR provoked by thedifferent atmospheric pollutants These data were evaluatedand displayed using the MATLAB software a mathematicalcomputing software (MathWorks Inc USA) to determinethe relationship between the environmental factors and thecorrosion rate of metals used in the electronics industryFigure 4 is a particular 3D graph depicting the correlation of

0102030405060700

I

II

III

CL

O3

0 75 15 225 30 375 45

RH ()

SO2

Correlation of corrosivity levels with atmospheric pollution

T ( ∘C)

NOX

COX

Figure 5 Correlation of climatic factors and pollutants with corro-sivity indexes

0 10 20 30 40 50 60 70 80

05101520253035400

60

120

180

240

CR (m

gm

2middoty

ear)

RH ()

Correlation of CR with climatic factors in summer

H2S O3

CO

T ( ∘C)

NOX

SOX

Figure 6 Correlation of CR of copper with climatic factors insummer in Mexicali (2010)

the CR of Cu with the RH and the temperature indicating incircles the maximum and the minimum CR

The maximum CR appears at 88 RH and 16∘C and theminimum CR is recorded at 18 RH and 20∘C expressingthe critical influence of humidity and temperature levelsThese levels are controlled inside the electronics plant butsometimes corrosion occurs

An additional MATLAB graph depicts the influence offrequent industrial pollutants NO

119883 SO119883 O3 and CO

119883

on the corrosivity indexes of Cu published by ISO theInternationalOrganization for Standardization [7] (Figure 5)

Other MATLAB graphs correlate the CR of Cu with theclimatic factors and pollutants in summer 2010 in Mexicali(Figure 6) and those in winter 2010 too (Figure 7)

ISRN Corrosion 5

Table 2 Relation of concentration of air pollutants and climate factors in Mexicali

SeasonsClimatic factors

Sulfur dioxide (SO2) Carbon monoxide (CO) Nitrogen oxides (NO119883) Ozone (O3)

RHa119879b

119862c RHa

119879b

119862c RHa

119879b

119862c RHa

119879b119862

c

SpringMax 493 348 016 391 293 69 343 286 048 483 273 021Min 233 204 008 286 221 4 298 199 001 285 152 006

SummerMax 838 459 011 739 459 57 708 399 054 732 445 037Min 461 236 003 475 292 16 447 224 018 443 265 001

WinterMax 778 274 050 728 247 84 691 246 075 879 277 051Min 166 178 017 393 239 6 632 138 017 472 288 005

aRH relative humidity b119879 temperature ∘C and c119862 air pollution concentration (C) ppm

Table 3 Correlation of corrosion rate the year season and air pollutants in indoor conditions of industrial plants

SeasonsClimatic factors

Hydrogen sulfide (H2S) Sulfur dioxide (SO2)RHa

119879b

119862c CRd RHa

119879b

119862c CRd

SpringMax 888 334 015 255 856 232 034 176Min 345 176 009 130 467 151 023 112

SummerMax 899 421 014 265 882 399 045 245Min 385 243 011 181 423 282 018 114

WinterMax 875 256 042 382 888 223 067 338Min 432 178 026 245 389 123 025 136

aRH relative humidity b119879 temperature ∘C c119862 air pollution concentration (C) ppm and dCR corrosion rate mgm2sdotyear

5 Discussion

The climatic variables and the atmospheric pollutants arethe principal factors that enhance the corrosion in indoorconditions of the metals utilized in the electronics industryof the State of Baja California Mexico The evaluation ofthese parameters and their effect on the metalsrsquo surfacesdemonstrates the relationship of atmospheric corrosion withthe damage caused to the electrical connections resistorsdiodes connectors and wires of the electrical-electronicequipment This corrosion damage generates low yielding byelectrical failures in the industrial devices and equipmentThe maximum and minimum RH temperature and CR andthe relationship with the air pollutants were analyzed duringdifferent seasons of the year These data were expressedgraphically applying the MATLAB software A study on thecorrelation of climate factors with the function of electronictest equipment installed inside a clean room of an electronicsplant in the city of Tijuana was conducted it was done atvarious levels of RH and temperature relating them to theelectric current circulating in the test equipment to indicatethe correct or incorrect state of the microcomponents They

include electronic components such as transistors capacitorscoils resistors and diodes that are assembled in the semi-conductor wafer based on a silicon microelectronic boardThe bad air quality in Tijuana should be attributed to the lastcold winters that have caused more burning of fossil fuelsto supply electricity for urban-heating systems increasingthe emissions of corrosive pollutants worsening the smogwhich comprises fire smoke car exhaust gases and dust alltrapped in the air mist The health impact is vast too raisingthe number of people suffering from respiratory illness thattriggers heart and asthma attacks The city of Ensenada islocated on the coast of the Pacific Ocean in the northwestof Mexico in a marine region It has a tropical marineclimate with cold winter mornings around 5∘C and 35∘Cin the summer RH is around 20 to 80 varying duringthe seasons of the year The climate factors analyzed werehumidity temperature winds and rains to determine thetime of wetness (TOW) a critical factor in the determinationof CR and its extent

Santa Ana winds (SAW) constitute a climatic phe-nomenon that alters the atmospheric conditions they orig-inate in the Santa Ana canyon in the Mojave desert which

6 ISRN Corrosion

0 10 20 30 40 50 60 70 80

036912151821240

90

180

270

360

CR (m

gm

2middoty

ear)

RH ()

H2S O3

CO

Correlation of CR with climatic factors in winter

T ( ∘C)

NOX

SOX

Figure 7 Correlation of CR of copperwith climatic factors inwinterin Mexicali (2010)

cause fast changes in the climate conditions in southwestCalifornia and northwest Baja California SAW form whenthe desert becomes cooler usually during the autumn andspring seasons rising temperatures humidity and meteoro-logical conditions influence the indoor environment of theelectronics industryThe principal air corrodent encounteredin Ensenada is the NaCl aerosols from the sea in addition toCO NO

119883and SO

2from traffic vehicles power stations and

industrial and landfill emissions which increase atmosphericcorrosivity [13 14]

6 Conclusions and Recommendations

A study was conducted during a span of two years on thecorrosion of metallic materials used in the manufacture ofelectronic devices and equipmentThe gaseous air pollutantsfor example H

2S SO

119883 NO119883 and CO generated by the

geothermal fields the electricity industry and the motorvehicles burning fossil fuels lead to the appearance of corro-sion on the metalsrsquo surfaces Copper suffers in particular dueto the attack by sulphur-containing pollutants H

2S and SO

119883

forming copper sulphides and oxides that impair their elec-trical conductivity properties The installation and effectivemaintenance systems to clean and control the contaminatedair that infiltrates into the electronics production rooms suchas filters would prevent andor minimize this atmosphericcorrosion Encapsulation and hermetic sealing of microcom-ponents prevent a reaction with the pollutants Removalof moisture by efficient air conditioning and continuousmaintenance of an optimum environmental condition of theindoor areas of electronics plants avoids andor mitigatescorrosion

Conflict of Interests

The authors of this paper declare not to have any director indirect financial relation with the commercial identity

mentioned in the paper thatmight lead to a conflict of interestfor any of them

References

[1] B Valdez M Schorr M Quintero et al ldquoCorrosion and scalingat Cerro Prieto geothermal fieldrdquo Anti-Corrosion Methods andMaterials vol 56 no 1 pp 28ndash34 2009

[2] L Veleva B Valdez G Lopez L Vargas and J Flores ldquoAtmos-pheric corrosion of electro-electronics metals in urban desertsimulated indoor environmentrdquo Corrosion Engineering Scienceand Technology vol 43 no 2 pp 149ndash155 2008

[3] J F Flores and S B Valdez ldquoCabina de simulacion de corrosionpara la industria electronica en interiorrdquo Ingenieros vol 6 no21 2003 (Spanish)

[4] ASTM ldquoStandard practice for conducting atmospheric cor-rosion test on metalsrdquo ASTM G50-76 ASTM West Con-shohocken Pa USA 2003

[5] G Lopez B Valdez and M Schorr ldquoSpectroscopy analysisof corrosion in the electronics industry influenced by SantaAna Winds in marine environments of Mexicordquo in Indoor andOutdoor Air Pollution INTECH 2011

[6] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation attack inindoor atmospheresrdquo ISO 11844-1 ISO Geneva Switzerland2005

[7] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation of indoorcorrosivityrdquo ISO 11844-2 ISO Geneva Switzerland 2006

[8] A Moncmanova Environmental Deterioration of MaterialsWIT Press 2007

[9] L B Gustavo Caracterizacion de la corrosion en materialesmetalicos de la industria electronica en Mexicali BC [Tesis dedoctorado] UABC Instituto de Ingenierıa Mexicali Mexico2008

[10] G Lopez H Tiznado G Soto W de la Cruz B Valdez and RM Schorr Zlatev ldquoCorrosion de dispositivos electronicos porcontaminacion atmosferica en interiores de plantas de ambien-tes aridos y marinosrdquo Revista Nova Scientia vol 3 no 1 2010

[11] G Lopez H Tiznado G S Herrera et al ldquoUse of AES in corro-sion of copper connectors of electronic devices and equipmentsin arid and marine environmentsrdquo Anti-Corrosion Methods andMaterials vol 58 no 6 pp 331ndash336 2011

[12] M Reid J Punch C Ryan et al ldquoMicrostructural developmentof copper sulfide on copper exposed to humid H

2Srdquo Journal of

the Electrochemical Society vol 154 no 4 pp C209ndashC214 2007[13] B Valdez M Schorr R Zlatev et al ldquoCorrosion control in

industryrdquo in Environment and Industrial Corrosion Practicaland Theoretical Aspects INTECH 2012

[14] S B ValdezWM Schorr B G Lopez et al ldquoH2S pollution and

its effect on corrosion of electronic componentsrdquo inAir Quality-New Perspective INTECH 2012

[15] B G Lopez S B Valdez W M Schorr and G C NavarroldquoMicroscopy and spectroscopy of MEMS used in the electronicindustry of Baja California region Mexicordquo in Air Quality-NewPerspective INTECH 2012

[16] B G Lopez S B Valdez K R Zlatev P J Flores B M CarrilloandW M Schorr ldquoCorrosion of metals at indoor conditions inthe electronics manufacturing industryrdquo Anti-Corrosion Meth-ods and Materials vol 54 no 6 pp 354ndash359 2007

ISRN Corrosion 7

[17] J Smith Z Qin F King L Werme and D W ShoesmithldquoSulfide film formation on copper under electrochemical andnatural corrosion conditionsrdquo Corrosion vol 63 no 2 pp 135ndash144 2007

[18] K Demirkan G E Derkits Jr D A Fleming et al ldquoCorrosionof Cu under highly corrosive environmentsrdquo Journal of the Elec-trochemical Society vol 157 no 1 pp C30ndashC35 2010

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4 ISRN Corrosion

0 16 32 48 64 80

08

1624

32400

6

12

18

minus02

0

02

04

06

08

CL-H

2S

(ppm

)

RH ()T ( ∘C)

Correlation of Cl of H2S with climatic factors in summer

Figure 4 Correlation of copper corrosion with H2S relative

humidity and temperature in the electronics industry (summer2010)

Sulphidation

Cu 997888rarr Cu2+ + 2eminus

Oxidation anodic reaction(7)

H2S 997888rarr H+ + SHminus

Reduction cathodic reaction(8)

2SHminus 997888rarr 2Sminus +H2

Reduction cathodic reduction(9)

Cu +H2S 997888rarr CuS +H

2

Total sulphidation reaction(10)

43 Influence of Atmospheric Pollutants Mexicali city hashighly contaminated air because of the presence of fine dustcoming from the desert around but the gaseous pollutantssuch as SO

119883 NO119883 CO andO

3are generated from the diverse

industrial activities Air pollutants penetrate to indoor loca-tions of electronics plants and corrode Cu-made devicesTherelative humidity (RH) and temperature reach up to 50and 30∘C during the major part of the year Table 2 presentsthe relation between the concentrations of these pollutantsand the Mexicali climatic factors The two most aggressivepollutants are sulphur-containing H

2S and SO

2 both acidic

but one reducing (H2S) and the other oxidant (SO

2) agents

Their behaviour and corrosivity during the seasons of the yearare presented in Table 3

The corrosion data collected arranged in Tables 2 and 3correlate values of RH temperature and CR provoked by thedifferent atmospheric pollutants These data were evaluatedand displayed using the MATLAB software a mathematicalcomputing software (MathWorks Inc USA) to determinethe relationship between the environmental factors and thecorrosion rate of metals used in the electronics industryFigure 4 is a particular 3D graph depicting the correlation of

0102030405060700

I

II

III

CL

O3

0 75 15 225 30 375 45

RH ()

SO2

Correlation of corrosivity levels with atmospheric pollution

T ( ∘C)

NOX

COX

Figure 5 Correlation of climatic factors and pollutants with corro-sivity indexes

0 10 20 30 40 50 60 70 80

05101520253035400

60

120

180

240

CR (m

gm

2middoty

ear)

RH ()

Correlation of CR with climatic factors in summer

H2S O3

CO

T ( ∘C)

NOX

SOX

Figure 6 Correlation of CR of copper with climatic factors insummer in Mexicali (2010)

the CR of Cu with the RH and the temperature indicating incircles the maximum and the minimum CR

The maximum CR appears at 88 RH and 16∘C and theminimum CR is recorded at 18 RH and 20∘C expressingthe critical influence of humidity and temperature levelsThese levels are controlled inside the electronics plant butsometimes corrosion occurs

An additional MATLAB graph depicts the influence offrequent industrial pollutants NO

119883 SO119883 O3 and CO

119883

on the corrosivity indexes of Cu published by ISO theInternationalOrganization for Standardization [7] (Figure 5)

Other MATLAB graphs correlate the CR of Cu with theclimatic factors and pollutants in summer 2010 in Mexicali(Figure 6) and those in winter 2010 too (Figure 7)

ISRN Corrosion 5

Table 2 Relation of concentration of air pollutants and climate factors in Mexicali

SeasonsClimatic factors

Sulfur dioxide (SO2) Carbon monoxide (CO) Nitrogen oxides (NO119883) Ozone (O3)

RHa119879b

119862c RHa

119879b

119862c RHa

119879b

119862c RHa

119879b119862

c

SpringMax 493 348 016 391 293 69 343 286 048 483 273 021Min 233 204 008 286 221 4 298 199 001 285 152 006

SummerMax 838 459 011 739 459 57 708 399 054 732 445 037Min 461 236 003 475 292 16 447 224 018 443 265 001

WinterMax 778 274 050 728 247 84 691 246 075 879 277 051Min 166 178 017 393 239 6 632 138 017 472 288 005

aRH relative humidity b119879 temperature ∘C and c119862 air pollution concentration (C) ppm

Table 3 Correlation of corrosion rate the year season and air pollutants in indoor conditions of industrial plants

SeasonsClimatic factors

Hydrogen sulfide (H2S) Sulfur dioxide (SO2)RHa

119879b

119862c CRd RHa

119879b

119862c CRd

SpringMax 888 334 015 255 856 232 034 176Min 345 176 009 130 467 151 023 112

SummerMax 899 421 014 265 882 399 045 245Min 385 243 011 181 423 282 018 114

WinterMax 875 256 042 382 888 223 067 338Min 432 178 026 245 389 123 025 136

aRH relative humidity b119879 temperature ∘C c119862 air pollution concentration (C) ppm and dCR corrosion rate mgm2sdotyear

5 Discussion

The climatic variables and the atmospheric pollutants arethe principal factors that enhance the corrosion in indoorconditions of the metals utilized in the electronics industryof the State of Baja California Mexico The evaluation ofthese parameters and their effect on the metalsrsquo surfacesdemonstrates the relationship of atmospheric corrosion withthe damage caused to the electrical connections resistorsdiodes connectors and wires of the electrical-electronicequipment This corrosion damage generates low yielding byelectrical failures in the industrial devices and equipmentThe maximum and minimum RH temperature and CR andthe relationship with the air pollutants were analyzed duringdifferent seasons of the year These data were expressedgraphically applying the MATLAB software A study on thecorrelation of climate factors with the function of electronictest equipment installed inside a clean room of an electronicsplant in the city of Tijuana was conducted it was done atvarious levels of RH and temperature relating them to theelectric current circulating in the test equipment to indicatethe correct or incorrect state of the microcomponents They

include electronic components such as transistors capacitorscoils resistors and diodes that are assembled in the semi-conductor wafer based on a silicon microelectronic boardThe bad air quality in Tijuana should be attributed to the lastcold winters that have caused more burning of fossil fuelsto supply electricity for urban-heating systems increasingthe emissions of corrosive pollutants worsening the smogwhich comprises fire smoke car exhaust gases and dust alltrapped in the air mist The health impact is vast too raisingthe number of people suffering from respiratory illness thattriggers heart and asthma attacks The city of Ensenada islocated on the coast of the Pacific Ocean in the northwestof Mexico in a marine region It has a tropical marineclimate with cold winter mornings around 5∘C and 35∘Cin the summer RH is around 20 to 80 varying duringthe seasons of the year The climate factors analyzed werehumidity temperature winds and rains to determine thetime of wetness (TOW) a critical factor in the determinationof CR and its extent

Santa Ana winds (SAW) constitute a climatic phe-nomenon that alters the atmospheric conditions they orig-inate in the Santa Ana canyon in the Mojave desert which

6 ISRN Corrosion

0 10 20 30 40 50 60 70 80

036912151821240

90

180

270

360

CR (m

gm

2middoty

ear)

RH ()

H2S O3

CO

Correlation of CR with climatic factors in winter

T ( ∘C)

NOX

SOX

Figure 7 Correlation of CR of copperwith climatic factors inwinterin Mexicali (2010)

cause fast changes in the climate conditions in southwestCalifornia and northwest Baja California SAW form whenthe desert becomes cooler usually during the autumn andspring seasons rising temperatures humidity and meteoro-logical conditions influence the indoor environment of theelectronics industryThe principal air corrodent encounteredin Ensenada is the NaCl aerosols from the sea in addition toCO NO

119883and SO

2from traffic vehicles power stations and

industrial and landfill emissions which increase atmosphericcorrosivity [13 14]

6 Conclusions and Recommendations

A study was conducted during a span of two years on thecorrosion of metallic materials used in the manufacture ofelectronic devices and equipmentThe gaseous air pollutantsfor example H

2S SO

119883 NO119883 and CO generated by the

geothermal fields the electricity industry and the motorvehicles burning fossil fuels lead to the appearance of corro-sion on the metalsrsquo surfaces Copper suffers in particular dueto the attack by sulphur-containing pollutants H

2S and SO

119883

forming copper sulphides and oxides that impair their elec-trical conductivity properties The installation and effectivemaintenance systems to clean and control the contaminatedair that infiltrates into the electronics production rooms suchas filters would prevent andor minimize this atmosphericcorrosion Encapsulation and hermetic sealing of microcom-ponents prevent a reaction with the pollutants Removalof moisture by efficient air conditioning and continuousmaintenance of an optimum environmental condition of theindoor areas of electronics plants avoids andor mitigatescorrosion

Conflict of Interests

The authors of this paper declare not to have any director indirect financial relation with the commercial identity

mentioned in the paper thatmight lead to a conflict of interestfor any of them

References

[1] B Valdez M Schorr M Quintero et al ldquoCorrosion and scalingat Cerro Prieto geothermal fieldrdquo Anti-Corrosion Methods andMaterials vol 56 no 1 pp 28ndash34 2009

[2] L Veleva B Valdez G Lopez L Vargas and J Flores ldquoAtmos-pheric corrosion of electro-electronics metals in urban desertsimulated indoor environmentrdquo Corrosion Engineering Scienceand Technology vol 43 no 2 pp 149ndash155 2008

[3] J F Flores and S B Valdez ldquoCabina de simulacion de corrosionpara la industria electronica en interiorrdquo Ingenieros vol 6 no21 2003 (Spanish)

[4] ASTM ldquoStandard practice for conducting atmospheric cor-rosion test on metalsrdquo ASTM G50-76 ASTM West Con-shohocken Pa USA 2003

[5] G Lopez B Valdez and M Schorr ldquoSpectroscopy analysisof corrosion in the electronics industry influenced by SantaAna Winds in marine environments of Mexicordquo in Indoor andOutdoor Air Pollution INTECH 2011

[6] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation attack inindoor atmospheresrdquo ISO 11844-1 ISO Geneva Switzerland2005

[7] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation of indoorcorrosivityrdquo ISO 11844-2 ISO Geneva Switzerland 2006

[8] A Moncmanova Environmental Deterioration of MaterialsWIT Press 2007

[9] L B Gustavo Caracterizacion de la corrosion en materialesmetalicos de la industria electronica en Mexicali BC [Tesis dedoctorado] UABC Instituto de Ingenierıa Mexicali Mexico2008

[10] G Lopez H Tiznado G Soto W de la Cruz B Valdez and RM Schorr Zlatev ldquoCorrosion de dispositivos electronicos porcontaminacion atmosferica en interiores de plantas de ambien-tes aridos y marinosrdquo Revista Nova Scientia vol 3 no 1 2010

[11] G Lopez H Tiznado G S Herrera et al ldquoUse of AES in corro-sion of copper connectors of electronic devices and equipmentsin arid and marine environmentsrdquo Anti-Corrosion Methods andMaterials vol 58 no 6 pp 331ndash336 2011

[12] M Reid J Punch C Ryan et al ldquoMicrostructural developmentof copper sulfide on copper exposed to humid H

2Srdquo Journal of

the Electrochemical Society vol 154 no 4 pp C209ndashC214 2007[13] B Valdez M Schorr R Zlatev et al ldquoCorrosion control in

industryrdquo in Environment and Industrial Corrosion Practicaland Theoretical Aspects INTECH 2012

[14] S B ValdezWM Schorr B G Lopez et al ldquoH2S pollution and

its effect on corrosion of electronic componentsrdquo inAir Quality-New Perspective INTECH 2012

[15] B G Lopez S B Valdez W M Schorr and G C NavarroldquoMicroscopy and spectroscopy of MEMS used in the electronicindustry of Baja California region Mexicordquo in Air Quality-NewPerspective INTECH 2012

[16] B G Lopez S B Valdez K R Zlatev P J Flores B M CarrilloandW M Schorr ldquoCorrosion of metals at indoor conditions inthe electronics manufacturing industryrdquo Anti-Corrosion Meth-ods and Materials vol 54 no 6 pp 354ndash359 2007

ISRN Corrosion 7

[17] J Smith Z Qin F King L Werme and D W ShoesmithldquoSulfide film formation on copper under electrochemical andnatural corrosion conditionsrdquo Corrosion vol 63 no 2 pp 135ndash144 2007

[18] K Demirkan G E Derkits Jr D A Fleming et al ldquoCorrosionof Cu under highly corrosive environmentsrdquo Journal of the Elec-trochemical Society vol 157 no 1 pp C30ndashC35 2010

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Polymer ScienceInternational Journal of

ISRN Corrosion

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CompositesJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

International Journal of

BiomaterialsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Ceramics

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013

MaterialsJournal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

ISRN Materials Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

ISRN Nanotechnology

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

MetallurgyJournal of

BioMed Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Polymer Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Na

nom

ate

ria

ls

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal ofNanomaterials

ISRN Corrosion 5

Table 2 Relation of concentration of air pollutants and climate factors in Mexicali

SeasonsClimatic factors

Sulfur dioxide (SO2) Carbon monoxide (CO) Nitrogen oxides (NO119883) Ozone (O3)

RHa119879b

119862c RHa

119879b

119862c RHa

119879b

119862c RHa

119879b119862

c

SpringMax 493 348 016 391 293 69 343 286 048 483 273 021Min 233 204 008 286 221 4 298 199 001 285 152 006

SummerMax 838 459 011 739 459 57 708 399 054 732 445 037Min 461 236 003 475 292 16 447 224 018 443 265 001

WinterMax 778 274 050 728 247 84 691 246 075 879 277 051Min 166 178 017 393 239 6 632 138 017 472 288 005

aRH relative humidity b119879 temperature ∘C and c119862 air pollution concentration (C) ppm

Table 3 Correlation of corrosion rate the year season and air pollutants in indoor conditions of industrial plants

SeasonsClimatic factors

Hydrogen sulfide (H2S) Sulfur dioxide (SO2)RHa

119879b

119862c CRd RHa

119879b

119862c CRd

SpringMax 888 334 015 255 856 232 034 176Min 345 176 009 130 467 151 023 112

SummerMax 899 421 014 265 882 399 045 245Min 385 243 011 181 423 282 018 114

WinterMax 875 256 042 382 888 223 067 338Min 432 178 026 245 389 123 025 136

aRH relative humidity b119879 temperature ∘C c119862 air pollution concentration (C) ppm and dCR corrosion rate mgm2sdotyear

5 Discussion

The climatic variables and the atmospheric pollutants arethe principal factors that enhance the corrosion in indoorconditions of the metals utilized in the electronics industryof the State of Baja California Mexico The evaluation ofthese parameters and their effect on the metalsrsquo surfacesdemonstrates the relationship of atmospheric corrosion withthe damage caused to the electrical connections resistorsdiodes connectors and wires of the electrical-electronicequipment This corrosion damage generates low yielding byelectrical failures in the industrial devices and equipmentThe maximum and minimum RH temperature and CR andthe relationship with the air pollutants were analyzed duringdifferent seasons of the year These data were expressedgraphically applying the MATLAB software A study on thecorrelation of climate factors with the function of electronictest equipment installed inside a clean room of an electronicsplant in the city of Tijuana was conducted it was done atvarious levels of RH and temperature relating them to theelectric current circulating in the test equipment to indicatethe correct or incorrect state of the microcomponents They

include electronic components such as transistors capacitorscoils resistors and diodes that are assembled in the semi-conductor wafer based on a silicon microelectronic boardThe bad air quality in Tijuana should be attributed to the lastcold winters that have caused more burning of fossil fuelsto supply electricity for urban-heating systems increasingthe emissions of corrosive pollutants worsening the smogwhich comprises fire smoke car exhaust gases and dust alltrapped in the air mist The health impact is vast too raisingthe number of people suffering from respiratory illness thattriggers heart and asthma attacks The city of Ensenada islocated on the coast of the Pacific Ocean in the northwestof Mexico in a marine region It has a tropical marineclimate with cold winter mornings around 5∘C and 35∘Cin the summer RH is around 20 to 80 varying duringthe seasons of the year The climate factors analyzed werehumidity temperature winds and rains to determine thetime of wetness (TOW) a critical factor in the determinationof CR and its extent

Santa Ana winds (SAW) constitute a climatic phe-nomenon that alters the atmospheric conditions they orig-inate in the Santa Ana canyon in the Mojave desert which

6 ISRN Corrosion

0 10 20 30 40 50 60 70 80

036912151821240

90

180

270

360

CR (m

gm

2middoty

ear)

RH ()

H2S O3

CO

Correlation of CR with climatic factors in winter

T ( ∘C)

NOX

SOX

Figure 7 Correlation of CR of copperwith climatic factors inwinterin Mexicali (2010)

cause fast changes in the climate conditions in southwestCalifornia and northwest Baja California SAW form whenthe desert becomes cooler usually during the autumn andspring seasons rising temperatures humidity and meteoro-logical conditions influence the indoor environment of theelectronics industryThe principal air corrodent encounteredin Ensenada is the NaCl aerosols from the sea in addition toCO NO

119883and SO

2from traffic vehicles power stations and

industrial and landfill emissions which increase atmosphericcorrosivity [13 14]

6 Conclusions and Recommendations

A study was conducted during a span of two years on thecorrosion of metallic materials used in the manufacture ofelectronic devices and equipmentThe gaseous air pollutantsfor example H

2S SO

119883 NO119883 and CO generated by the

geothermal fields the electricity industry and the motorvehicles burning fossil fuels lead to the appearance of corro-sion on the metalsrsquo surfaces Copper suffers in particular dueto the attack by sulphur-containing pollutants H

2S and SO

119883

forming copper sulphides and oxides that impair their elec-trical conductivity properties The installation and effectivemaintenance systems to clean and control the contaminatedair that infiltrates into the electronics production rooms suchas filters would prevent andor minimize this atmosphericcorrosion Encapsulation and hermetic sealing of microcom-ponents prevent a reaction with the pollutants Removalof moisture by efficient air conditioning and continuousmaintenance of an optimum environmental condition of theindoor areas of electronics plants avoids andor mitigatescorrosion

Conflict of Interests

The authors of this paper declare not to have any director indirect financial relation with the commercial identity

mentioned in the paper thatmight lead to a conflict of interestfor any of them

References

[1] B Valdez M Schorr M Quintero et al ldquoCorrosion and scalingat Cerro Prieto geothermal fieldrdquo Anti-Corrosion Methods andMaterials vol 56 no 1 pp 28ndash34 2009

[2] L Veleva B Valdez G Lopez L Vargas and J Flores ldquoAtmos-pheric corrosion of electro-electronics metals in urban desertsimulated indoor environmentrdquo Corrosion Engineering Scienceand Technology vol 43 no 2 pp 149ndash155 2008

[3] J F Flores and S B Valdez ldquoCabina de simulacion de corrosionpara la industria electronica en interiorrdquo Ingenieros vol 6 no21 2003 (Spanish)

[4] ASTM ldquoStandard practice for conducting atmospheric cor-rosion test on metalsrdquo ASTM G50-76 ASTM West Con-shohocken Pa USA 2003

[5] G Lopez B Valdez and M Schorr ldquoSpectroscopy analysisof corrosion in the electronics industry influenced by SantaAna Winds in marine environments of Mexicordquo in Indoor andOutdoor Air Pollution INTECH 2011

[6] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation attack inindoor atmospheresrdquo ISO 11844-1 ISO Geneva Switzerland2005

[7] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation of indoorcorrosivityrdquo ISO 11844-2 ISO Geneva Switzerland 2006

[8] A Moncmanova Environmental Deterioration of MaterialsWIT Press 2007

[9] L B Gustavo Caracterizacion de la corrosion en materialesmetalicos de la industria electronica en Mexicali BC [Tesis dedoctorado] UABC Instituto de Ingenierıa Mexicali Mexico2008

[10] G Lopez H Tiznado G Soto W de la Cruz B Valdez and RM Schorr Zlatev ldquoCorrosion de dispositivos electronicos porcontaminacion atmosferica en interiores de plantas de ambien-tes aridos y marinosrdquo Revista Nova Scientia vol 3 no 1 2010

[11] G Lopez H Tiznado G S Herrera et al ldquoUse of AES in corro-sion of copper connectors of electronic devices and equipmentsin arid and marine environmentsrdquo Anti-Corrosion Methods andMaterials vol 58 no 6 pp 331ndash336 2011

[12] M Reid J Punch C Ryan et al ldquoMicrostructural developmentof copper sulfide on copper exposed to humid H

2Srdquo Journal of

the Electrochemical Society vol 154 no 4 pp C209ndashC214 2007[13] B Valdez M Schorr R Zlatev et al ldquoCorrosion control in

industryrdquo in Environment and Industrial Corrosion Practicaland Theoretical Aspects INTECH 2012

[14] S B ValdezWM Schorr B G Lopez et al ldquoH2S pollution and

its effect on corrosion of electronic componentsrdquo inAir Quality-New Perspective INTECH 2012

[15] B G Lopez S B Valdez W M Schorr and G C NavarroldquoMicroscopy and spectroscopy of MEMS used in the electronicindustry of Baja California region Mexicordquo in Air Quality-NewPerspective INTECH 2012

[16] B G Lopez S B Valdez K R Zlatev P J Flores B M CarrilloandW M Schorr ldquoCorrosion of metals at indoor conditions inthe electronics manufacturing industryrdquo Anti-Corrosion Meth-ods and Materials vol 54 no 6 pp 354ndash359 2007

ISRN Corrosion 7

[17] J Smith Z Qin F King L Werme and D W ShoesmithldquoSulfide film formation on copper under electrochemical andnatural corrosion conditionsrdquo Corrosion vol 63 no 2 pp 135ndash144 2007

[18] K Demirkan G E Derkits Jr D A Fleming et al ldquoCorrosionof Cu under highly corrosive environmentsrdquo Journal of the Elec-trochemical Society vol 157 no 1 pp C30ndashC35 2010

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Polymer ScienceInternational Journal of

ISRN Corrosion

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CompositesJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

International Journal of

BiomaterialsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Ceramics

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013

MaterialsJournal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

ISRN Materials Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

ISRN Nanotechnology

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

MetallurgyJournal of

BioMed Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Polymer Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Na

nom

ate

ria

ls

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal ofNanomaterials

6 ISRN Corrosion

0 10 20 30 40 50 60 70 80

036912151821240

90

180

270

360

CR (m

gm

2middoty

ear)

RH ()

H2S O3

CO

Correlation of CR with climatic factors in winter

T ( ∘C)

NOX

SOX

Figure 7 Correlation of CR of copperwith climatic factors inwinterin Mexicali (2010)

cause fast changes in the climate conditions in southwestCalifornia and northwest Baja California SAW form whenthe desert becomes cooler usually during the autumn andspring seasons rising temperatures humidity and meteoro-logical conditions influence the indoor environment of theelectronics industryThe principal air corrodent encounteredin Ensenada is the NaCl aerosols from the sea in addition toCO NO

119883and SO

2from traffic vehicles power stations and

industrial and landfill emissions which increase atmosphericcorrosivity [13 14]

6 Conclusions and Recommendations

A study was conducted during a span of two years on thecorrosion of metallic materials used in the manufacture ofelectronic devices and equipmentThe gaseous air pollutantsfor example H

2S SO

119883 NO119883 and CO generated by the

geothermal fields the electricity industry and the motorvehicles burning fossil fuels lead to the appearance of corro-sion on the metalsrsquo surfaces Copper suffers in particular dueto the attack by sulphur-containing pollutants H

2S and SO

119883

forming copper sulphides and oxides that impair their elec-trical conductivity properties The installation and effectivemaintenance systems to clean and control the contaminatedair that infiltrates into the electronics production rooms suchas filters would prevent andor minimize this atmosphericcorrosion Encapsulation and hermetic sealing of microcom-ponents prevent a reaction with the pollutants Removalof moisture by efficient air conditioning and continuousmaintenance of an optimum environmental condition of theindoor areas of electronics plants avoids andor mitigatescorrosion

Conflict of Interests

The authors of this paper declare not to have any director indirect financial relation with the commercial identity

mentioned in the paper thatmight lead to a conflict of interestfor any of them

References

[1] B Valdez M Schorr M Quintero et al ldquoCorrosion and scalingat Cerro Prieto geothermal fieldrdquo Anti-Corrosion Methods andMaterials vol 56 no 1 pp 28ndash34 2009

[2] L Veleva B Valdez G Lopez L Vargas and J Flores ldquoAtmos-pheric corrosion of electro-electronics metals in urban desertsimulated indoor environmentrdquo Corrosion Engineering Scienceand Technology vol 43 no 2 pp 149ndash155 2008

[3] J F Flores and S B Valdez ldquoCabina de simulacion de corrosionpara la industria electronica en interiorrdquo Ingenieros vol 6 no21 2003 (Spanish)

[4] ASTM ldquoStandard practice for conducting atmospheric cor-rosion test on metalsrdquo ASTM G50-76 ASTM West Con-shohocken Pa USA 2003

[5] G Lopez B Valdez and M Schorr ldquoSpectroscopy analysisof corrosion in the electronics industry influenced by SantaAna Winds in marine environments of Mexicordquo in Indoor andOutdoor Air Pollution INTECH 2011

[6] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation attack inindoor atmospheresrdquo ISO 11844-1 ISO Geneva Switzerland2005

[7] ldquoCorrosion ofmetals and alloys Classification of low corrosivityof indoor atmospheres determination and estimation of indoorcorrosivityrdquo ISO 11844-2 ISO Geneva Switzerland 2006

[8] A Moncmanova Environmental Deterioration of MaterialsWIT Press 2007

[9] L B Gustavo Caracterizacion de la corrosion en materialesmetalicos de la industria electronica en Mexicali BC [Tesis dedoctorado] UABC Instituto de Ingenierıa Mexicali Mexico2008

[10] G Lopez H Tiznado G Soto W de la Cruz B Valdez and RM Schorr Zlatev ldquoCorrosion de dispositivos electronicos porcontaminacion atmosferica en interiores de plantas de ambien-tes aridos y marinosrdquo Revista Nova Scientia vol 3 no 1 2010

[11] G Lopez H Tiznado G S Herrera et al ldquoUse of AES in corro-sion of copper connectors of electronic devices and equipmentsin arid and marine environmentsrdquo Anti-Corrosion Methods andMaterials vol 58 no 6 pp 331ndash336 2011

[12] M Reid J Punch C Ryan et al ldquoMicrostructural developmentof copper sulfide on copper exposed to humid H

2Srdquo Journal of

the Electrochemical Society vol 154 no 4 pp C209ndashC214 2007[13] B Valdez M Schorr R Zlatev et al ldquoCorrosion control in

industryrdquo in Environment and Industrial Corrosion Practicaland Theoretical Aspects INTECH 2012

[14] S B ValdezWM Schorr B G Lopez et al ldquoH2S pollution and

its effect on corrosion of electronic componentsrdquo inAir Quality-New Perspective INTECH 2012

[15] B G Lopez S B Valdez W M Schorr and G C NavarroldquoMicroscopy and spectroscopy of MEMS used in the electronicindustry of Baja California region Mexicordquo in Air Quality-NewPerspective INTECH 2012

[16] B G Lopez S B Valdez K R Zlatev P J Flores B M CarrilloandW M Schorr ldquoCorrosion of metals at indoor conditions inthe electronics manufacturing industryrdquo Anti-Corrosion Meth-ods and Materials vol 54 no 6 pp 354ndash359 2007

ISRN Corrosion 7

[17] J Smith Z Qin F King L Werme and D W ShoesmithldquoSulfide film formation on copper under electrochemical andnatural corrosion conditionsrdquo Corrosion vol 63 no 2 pp 135ndash144 2007

[18] K Demirkan G E Derkits Jr D A Fleming et al ldquoCorrosionof Cu under highly corrosive environmentsrdquo Journal of the Elec-trochemical Society vol 157 no 1 pp C30ndashC35 2010

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Polymer ScienceInternational Journal of

ISRN Corrosion

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CompositesJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

International Journal of

BiomaterialsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Ceramics

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013

MaterialsJournal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

ISRN Materials Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

ISRN Nanotechnology

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

MetallurgyJournal of

BioMed Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Polymer Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Na

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal ofNanomaterials

ISRN Corrosion 7

[17] J Smith Z Qin F King L Werme and D W ShoesmithldquoSulfide film formation on copper under electrochemical andnatural corrosion conditionsrdquo Corrosion vol 63 no 2 pp 135ndash144 2007

[18] K Demirkan G E Derkits Jr D A Fleming et al ldquoCorrosionof Cu under highly corrosive environmentsrdquo Journal of the Elec-trochemical Society vol 157 no 1 pp C30ndashC35 2010

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Polymer ScienceInternational Journal of

ISRN Corrosion

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CompositesJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

International Journal of

BiomaterialsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Ceramics

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013

MaterialsJournal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

ISRN Materials Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

ISRN Nanotechnology

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

MetallurgyJournal of

BioMed Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Polymer Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Na

nom

ate

ria

ls

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal ofNanomaterials

Submit your manuscripts athttpwwwhindawicom

ScientificaHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CorrosionInternational Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Polymer ScienceInternational Journal of

ISRN Corrosion

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

CompositesJournal of

Advances in

Materials Science and EngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

International Journal of

BiomaterialsHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Ceramics

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom

Volume 2013

MaterialsJournal of

NanotechnologyHindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal of

ISRN Materials Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawi Publishing Corporation httpwwwhindawicom Volume 2013

The Scientific World Journal

ISRN Nanotechnology

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

NanoparticlesJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Smart Materials Research

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

MetallurgyJournal of

BioMed Research International

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

ISRN Polymer Science

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Na

nom

ate

ria

ls

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2013

Journal ofNanomaterials