Reliability testing of electronic packages in harsh environments

The aim of this work is to consider the issues and challenges in designing and setting up a suitable testing regime which can be utilized for the electronics under the combination of harsh conditions. The ultimate objective is to evaluate the reliability and service life of electronic components that are subject to a combination of multiple loadings which can take the forms of mechanical, thermal, chemical or electrical inputs. This study is focused on the testing of electronic substrates under the combination of thermal loading up to 180°C and mechanical loading in terms of high frequency vibration between 300Hz and 2000Hz, which is closely associated with automotive and aerospace industry. In this work, the test packages include alumina ceramic substrates which are commonly used for high temperature applications onto which the individual components, including silicon chips, are attached through gold wire ball bonding as means of the interconnections. The tests are carried out by changing the temperature and vibration frequencies, and then the attached components are examined by visual inspection and optical as well as scanning electron microscope. The results have revealed a significant difference between the thermal testing without vibration and the testing combined thermal-with vibration derived using the packages. It is apparent to observe such difference in terms of severe damage and degradation as the results of applying multiple loadings, thereby, the acceleration of failure may be predicted in particularly on the wire bonds and their interconnect integrity between the silicon chips and the alumina ceramic substrates.