Thermal stress and reliability analysis of microstrip isolator under temperature shock

The stress of microstrip isolator under 50 temperature shocks was simulated using ANSYS. Simulation results showed that the maximum stress of microstrip isolator was in ferrite substrate after 50 temperature shocks, and the maximum stress of ferrite substrate increased from 38.3MPa to 60MPa with a growth of 56.7% and especially increased by 43.3% after first 5 temperature shocks, and the bottom surface of ferrite substrate was its maximal stress region. The importance of first 5 shocks in 50 temperature shocks was analyzed, and the influence of each part in microstrip isolator on device reliability was discussed according to stress distribution under 50 temperature shocks, material properties, and process features, and some measures were provided for improving microstrip isolator reliability under temperature shock.