it is presented an inverter type motor drive device for feeding three phase ac electric power to an electric motor , the inverter type motor drive device comprising : an insulated metal substrate board on which , for each of the three phases , a plurality of power switches are mounted in straight lines in switch assemblies along a first direction , wherein two switch assemblies are assigned for each phase ; a printed circuit board on which a plurality of capacitors are mounted , wherein the printed circuit board is essentially parallel to the insulated metal substrate board ; and two dc power input terminals mounted on the printed circuit board . the motor drive device is characterised in that the inverter type motor drive device further comprises three ac power output terminals mounted on the insulated metal substrate board , wherein each of the three ac power output terminals extend through the printed circuit board while avoiding galvanic contact with the printed circuit board , and each of the three ac power output terminals comprise an elongated ac busbar mounted to the insulated metal substrate board , wherein a longitudinal direction of the ac busbar extends along the first direction ; and each of the two dc power input terminals comprise an input dc busbar , wherein the input dc busbar extends along the first direction .