Experimental demonstration of an anode voltage sensor for high voltage IGBT over-voltage protection

Abstract

This paper deals with the design and fabrication of a monolithically integrated over-voltage sensor together with high voltage IGBTs. This solution will be of interest in harsh environment applications such as power modules for traction. First, the anode voltage sensor concept is introduced and an initial experimental validation on 600 V insulated gate bipolar transistor (IGBT) devices is provided. Then, guidelines for the design of a 3.3 kV IGBT including the proposed anode voltage sensor are pointed out together with its process fabrication. Finally, experimental results on fabricated 3.3 kV IGBTs are presented and compared with simulated expected behaviour.

Volatge-sensor monolithically integrated in 3.3 kV IGBTs

“…The evolution of the sensor voltage with the anode voltage presented in previous works [2,4] shows the behavior in a stationary regime. The device is anode-cathode biased from 0 V to the breakdown voltage value and the voltage in the sensor electrode is measured in every step.…”

“…The design of the voltage sensor layout has been analyzed in previous work [1], where the stripped and cellular designs had been contemplated. The experimental feasibility of this voltage sensor has also been demonstrated and its stationary electrical performance analysed in [2]. In this work we focus our studies in a stripped design (Fig.…”

3.3 kV PT‐IGBT with voltage‐sensor monolithically integrated

“…4.Afloating guard ring edge termination is used to reach the desired voltage capability and a current sensor is also included in the left-right part of the active area. The steady-state electrical performance of the first prototypes is demonstrated in [4]. Suitable packaging is being developed for single chip reliability test in unclamped inductive test bench.…”

“…Therefore the new anode voltage sensor structure is a way to implement an anode voltage mirror at the top of the IGBT chip. The design of the anode voltage sensor layout has already been analysed in a previous work [4], comparing stripe and cellular sensor designs. The technological feasibility of the anode voltage sensor has also been demonstrated and its stationary electrical performance is analysed in [6].…”

“…The safe operation of each of the paralleled IGBT included in a power module has to guaranteed in extreme conditions, such as short‐circuit or hard switching events. In this sense, the combined direct measurement of anode current and anode voltage at any time during the switching cycle has to be obtained [4] and the control circuitry has to be accordingly modified to increase the IGBT intelligence. The current sensor is already in use in commercial large area IGBTs and it consist on an additional cathode electrode including a small number of individual core cells.…”