Recently developed insulated-gate bipolar transistor (IGBT) press-pack (PP) devices with a blocking voltage of 4.5 kV are being used in medium-voltage converters as an alternative to integrated gate-commutated thyristors (IGCTs). This paper presents an overview of PP packaging and both semiconductor technologies. A quantitative comparison of these devices is achieved through measurements for a 4.5-kV 1.2-kA IGBT and a 4.5-kV 4-kA IGCT. The laboratory test bench for the switching transient characterization at a dc-link voltage of 2.5 kV and currents up to 3 kA is described. Conduction, blocking, and switching behavior for junction temperatures up to 125 $^{\circ}\hbox{C}$ are investigated. The IGCT and the IGBT are tested using a $di/dt$ -limiting clamp circuit. In addition, the IGBT is tested in hard switching mode.