Reliability Metrology

In this chapter, first, reliability is defined. Then, different ways of modeling reliability are discussed. Empirical models are based on field data and are easy to use. Physical models address a certain failure mechanism and are used to predict wearout. Physical models may be either analytical or they may be run by computer simulations. Other useful information on reliability may be obtained by testing either test vehicles or entire products. Comparing the test results with the test results obtained, when testing similar items with field data, gives a quite good idea on which kind of field reliability performance should be anticipated. Interconnection reliability must also be taken into account when checking the reliability of a component. Many times, the actual component may not represent a large risk, whereas solder interconnection may create risks that need to be mitigated. In the end of this chapter, some statistical distributions are discussed. Especially, practical advice on how to use Weibull distribution is revealed.