Silicon Microwave Transistor-based Rapid Aging, Accelerated Life Testing

Be aimed at the time-consuming and costly problem with the conventional burn-in process of silicon microwave transistors, a fast burn-in method is designed based on the theory of accelerated life test. The activation energy of silicon microwave transistor is calculated in the accelerated life tests (including step-stress diagnostic test and constant stress accelerated life test), and the required value of accelerated burn-in stress can be calculated according to the calculated value of activation energy .This method can reduce the test time and not influence the result, with the same conditions, which have both low cost and high efficiency test. In this paper, silicon microwave transistors can be used for rapid mass production of the old method of refining power burn-in replacement test.Based on the analysis of existing theories and experimental research findings, the step stress and constant stress accelerated life test are designed in this study. Thermal stress for the step of pre-diagnostic test 20℃is used in the step-stress diagnostic testing to find the limits of working stress to the device which is at the temperature of 260℃;three groups of constant stress accelerated life tests use the same thermal stress of 120 ,and 190℃, 220℃, 250℃are set as the sample temperatures.The activation energy of the sample batch is calculated by best linear unbiased estimation and least squares and other statistical methods which is Ea=0.8eV.It is means that the silicon microwave transistor burn-in at the condition of original work which is at the temperature of 187.5℃for 168 hours and a rapid burn-in which is at the temperature of 230℃working for 24 hours is basically equivalent.In the end two sets of comparative test are designed to verify the effect of rapid burn-in, by which it is testified that there have been no laking stress or over stress conditions during the accelerated burn-in process.