Breakdown mechanisms of the coreless transformer in data couplers at high voltages

The galvanic isolation of electronic components, circuits, devices and systems is a highly relevant topic in electrical engineering. To transmit information through the galvanic isolation, so-called data couplers are used that can send and receive optical, capacitive or inductive signals. An important function of these couplers is the protection of users and equipment from over-voltages resulting from electrical network The insulation of these data couplers has to withstand infrequent high electric field transients and over-voltages over the application lifetime. The development of such a device is a challenging task, because each of the insulation materials can play an important role in its breakdown behavior. Within this work, an inductive data coupler from Infineon Technologies AG was optimized to meet the requirements of reinforced isolation concerning high field robustness in a wide range of environments. Within the course of this optimization, a large variety of breakdown mechanisms were investigated and analyzed under high electric fields.