semiconductor casing mounting structure

A mounting structure for a semiconductor package of the surface mounting type is described, wherein at least one semiconductor chip (21) is mounted on a chip pad (23); a conductive pattern (32) is formed on a printed circuit board (38) which is positioned below a bared side of a chip pad of the housing, a non-conductive thin film (31) or a layer conductive layer is formed between said conductive pattern and said die pad; and said conductive pattern is electrically connected to said chip pad so that a voltage difference is generated between to thereby reduce the electric noise of the casing and facilitate high-speed operation of the housing without reducing a mounting density.