Automated characterization of PhotoMOS switches as relay replacement in production test for automotive IC

The aim of this thesis is to identify the characteristics of PhotoMOS switches for being used on the test boards of automotive IC production in ascertaining the mechanical relays replacement possibility, and this study was conducted in Infineon Technology AG. PhotoMOS switches have been successfully used at ambient temperature for several applications in electronic companies, but to date, no further information about the performances of PhotoMOS especially at hot and cold temperatures are known. For this reason, the author decided to test further key parameters, with the aim of describing the technology’s suitability for further development. This thesis first explains the principle of operation and how a PhotoMOS solid state relay works. In the second stage, several testing procedures are undertaken experimentally to determine the existence of, for instance, the leakage current of the output pins of a PhotoMOS on the testing load boards at 120°, and presents the results. Finally, after applying the required test conditions to the designed main board and collecting all the data, within an eleven-week testing phase, the results of the experiment show that PhotoMOS switches are well suited to ascertaining the replacement of mechanical relays by PhotoMOS, but more effort is required for this purpose. Before considering any application, the author recommends further research about the PhotoMOS use cases.