Due to the development of electrical industry, a rapid size reduction of semiconductor devices has taken place, which includes the increase of power on the unit surface with itself also. This can be the main reason why thermal investigation of the electronic devices has already been focused on during the design, as well. There is another fact which also raises attention to the importance of this situation. One of the main reasons of device-errors is high temperature.
One of the most important requirements of present-day electrical devices is reliability for which we have to design consciously. It is also important that the system should be built up with having similar device properties for both view of manufacturing and view of cost-effectiveness.
During my thesis, I carried out a process which can estimate the lifetime of the investigated device with considering real use case and use of laboratory testing data. This process is shown through real application, which is the lifetime estimation of the IGBT found in the inverter of an electric car.
If a simulation of the 3D model of device is running, the time domain temperature profile can be determined from a given power profile which power profile is calculated from given driving profile. From this determined temperature profile the frequency of the temperature changes can be calculated which occur in the temperature profile.
Finally, if the previous data is combined with lifetime curve of the investigated device, the estimated lifetime can be determined. Throughout my thesis, I introduce each part of process in details and I present a case study about the above presented process.