As the frequency and circuit density of an electronic device become higher and its size becomes smaller, a problem related to interference due to radiation of an undesired electromagnetic wave arises. It is therefore required to suppress leakage of an undesired electromagnetic wave to the outside. There is known a method of covering, with a conductive resin film, the surface of a nonconductive resin layer for sealing a semiconductor chip in order to impart a shielding function to a semiconductor package. There is also proposed a technique of realizing a module which includes a transmission/reception antenna and has a shielding function by forming apertures in a portion, of a conductive resin film and a nonconductive resin layer for sealing a semiconductor chip, which covers the upper surface of the semiconductor chip.
In the conventional techniques, the surface of the semiconductor package with the antenna is covered with a conductive resin film, and apertures for enabling radiation and reception of a desired electromagnetic wave to be used for communication are formed in the conductive resin film. In this case, a diffraction wave occurring in an edge portion of the conductive resin film degrades an antenna gain in a desired radiation direction depending on the package size and the frequency of the desired electromagnetic wave.