An apparatus for transporting a leadframe sheet during semiconductor die assembly includes a rail having sub-rails defining a machine track and an inner space along which the leadframe sheet is moved. A position detector senses a position of the leadframe sheet as the leadframe sheet moves along the machine track. A controller including a processor is coupled to the position detector for receiving the position of the leadframe sheet. A pressurized gas stopper is positioned within the inner space including a gas distributor having at least one gas inlet for receiving a pressured gas supply and at least one gas outlet for directing a flow of gas toward the leadframe sheet sufficient to stop movement of the leadframe sheet. The controller provides control signals for controlling the flow of gas to provide non-contact stopping of the leadframe sheet at one or more locations along the machine track.