In-situ monitoring of field conditions and interconnect integrity for an electronic on-board module

An electronic test module is designed in order to monitor field failures of board assembly interconnections while simultaneously measuring the environmental loading conditions. The test module is built-in on the ceiling of a daily driving bus. During operation, when the engine is on, daisy chain interconnections as well as temperature and accelerometer sensors are measured continuously. The purpose is to extract critical loading conditions which could be a first step towards the introduction of prognostic health monitoring units. After 1.5 years of testing, no failures were identified for two types of assembly materials: solder and conductive adhesive. Temperature fluctuations turned out to be very small with a limited maximum temperature around 35°C due to ambient regulation of the bus interior. Furthermore, relatively mild acceleration values are monitored at low frequency. New experiments in more harsh environments are solicited.