Safeguarding the reliability of electronics exposed to the severe conditions occurring in tropical climates, such as India, has not been adequately understood or dealt with in international specifications. Consequently, components and equipment supplied to such specifications have failed in such climates. The vulnerability of supposedly hermetic components has been suspected as a result of a full analysis of moisture ingress, and this has been borne out by comprehensive analyses of the actual failures of components supplied to international specifications, and the climatic conditions actually occurring in India. Understanding of reliability assessment and achievement has been significantly advanced by such analysis and has shown the necessity and applicability of the highly accelerated stress testing technique invented at British Telecom Laboratories more than two decades ago. Comparison has shown the significant cost benefit from the use of plastic encapsulated devices of proven reliability.

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