Abstract: A Voltage Source Converter having at least one phase leg connected to opposite poles of a direct voltage side of the converter and comprising a series connection of switching elements including at least one energy storing capacitor and configured to obtain two switching states, namely a first switching state and a second switching state, in which the voltage across said at least one energy storing capacitor and a zero voltage, respectively, is applied across the terminals of the switching element, has semiconductor chips of said switching elements arranged in stacks comprising each at least two semiconductor chips. The converter comprises an arrangement configured to apply a pressure to opposite ends of each stack.