Reliability issues and implications of electronic circuit design in an industrial or a research environment

Reliability of electronic components is defined in terms of mean time between failures (MTBF). Temperature variations and operating conditions have a substantial effect on the MTBF of individual components as well as overall performance of the system. To fundamentally improve reliability, the design should be focused on improving the robustness of the basic functions of circuit or process and apply parameter design methods to optimize the basic functions approach under real conditions. These robust design activities should be conducted by taking into consideration the physics of individual components, operating conditions, circuit board layout, and power requirements. Because of the evolution of the reliability of electronic circuits toward very low failure rate, the statistical analyses through accelerated ageing experiments become too expensive. Today, a deterministic approach of the physics of failure is necessary to estimate the life duration of the circuits. As the ageing mechanisms are highly dependent on the circuit operating conditions, electrical simulation is a very useful tool to help the assessment of the degradation effect. Cooling methods such as sidewall cooling of chassis is described in MIL-STANDARDS. However, temperatures of mounted electronic components can be reduced significantly if heat pipes instead of solid metal plates of sidewall cooling are used to transport the heat generated by electronic components. This paper addresses the above issues and gives recommendations regarding the circuit design that MTBF of a system can be increased. Specific cases of studies are performed to investigate the validity of the proposed methods.