Investigation of computer hardware failure due to corrosion

Abstract

Failure analysis was conducted on two failed electronic cardsfrom the Computer Center of the Kuwait Institute for Scientific Research. The results of the elemental analysis indicated that the corrosion product film found on contact pins and soldered through holes was composed of copper and sulphur compounds. Chemical analysis of the air in the computer room indicated a high level of nitrogen oxide (up to 300 ppb), whereas other gases such as H2S and SO2 were below the detectahle limits (100 and 200 ppb respectively) of the analytical technique used. It was concluded that the initial high relative humidity ( ∼ 75%) had synergised with the strongly oxidising nitrogen oxide and H2S and/or SO2 to bring about the corrosion of copper substrate in ‘bare spots’ or gaps in the soldered contacts, causing card failure. Other factors, such as galvanic coupling of the copper substrate with nickel, silver, and gold plates, and the relatively high local temperature, may have accelerated the corrosion process. A decrease in the relative humidity to the optimum value of 45% did not obviate card failure. It was concluded that efficient air filters should be utilised in the computer environment, as electronic equipment can be damaged by levels of pollutant gases 10 times lower than those cited for human safety requirements.