Semiconductor device with electromagnetic shield

A semiconductor device having a leadless package so formed as to house therein at least one electronic semiconductor part which is at most only minimally passivated and to be surface-mounted on a circuit board,

• said leadless package having an enclosure member formed of a sheet-type laminate, having an insulation layer, and first and second conductive layers on respective opposite sides of the insulation layer, which has been deformed into a one-piece tray shape having a circumferentially bounded concavity with a substantially flat bottom and which is defined by said first conductive layer, wherein said concavity has a substantially flat edge along an opening of said tray shape and houses therein said at least one electronic semiconductor part;
• and wherein said second conductive layer forms an electromagnetic shielding surface which is held at ground potential;
• wherein said first conductive layer has a plurality of wiring conductors formed thereon, first ends of which are connected to respective terminal electrodes of said semiconductor part while second ends thereof extend to a circumferential edge of said concavity so as to be connected to terminal electrodes corresponding to electronic parts on said circuit board;
• wherein said semiconductor part is resin-molded in said concavity;
• and
• wherein there is formed between said bottom and circumferential edge of said concavity a substantially flat step correspondingly to the position of terminal electrodes of said semiconductor part, said first ends of said wiring conductors being disposed on said step.