Patent ID: 8395404

Claim:
An electronic device comprising: an electronic part including a rewiring substrate, a semiconductor chip, and a plurality of solder bumps, the rewiring substrate having a rectangular planar shape and having a first surface and a second surface being opposite each other, the semiconductor chip mounted on the first surface, the plurality of solder bumps arranged on the second surface in a matrix form in a row direction and a column direction, the plurality of solder bumps including a plurality of functional bumps and a plurality of nonfunctional bumps; and a wiring substrate having an electronic-pail mounted surface and including a wire and a plurality of lands, the plurality of lands arranged on the electronic-part mounted surface in a matrix form corresponding to the plurality of solder bumps, the plurality of lands including a plurality of functional lands and a plurality of nonfunctional lands, each of the plurality of functional lands coupled with a corresponding one of the plurality of functional bumps so as to form a plurality of functional connection portions that provides an electric connection between the semiconductor chip and the wire of the wiring substrate, each of the plurality of nonfunctional lands coupled with a corresponding one of the plurality of nonfunctional bumps so as to form a plurality of nonfunctional connection portions that does not provide an electric connection between the semiconductor chip and the wire of the wiring substrate, wherein: each of the plurality of nonfunctional connection portions is arranged next to another one of the plurality of nonfunctional connection portions in at least one of the row direction and the column direction so as to form a nonfunctional connection portion group; the plurality of nonfunctional lands includes a power source land fixed to a power source potential and a ground land fixed to a ground potential; the power source land and the ground land are arranged next to each other in the row direction or the column direction; a short circuit between the nonfunctional connection portion including the power source land and the nonfunctional connection portion including the ground land is detectable by detecting an electric current that flows between the power source and the ground; the plurality of nonfunctional bumps is arranged in four corner regions of the second surface of the rewiring substrate; the plurality of functional lands includes a plurality of signal lands; and each of the plurality of signal lands is arranged next to one of the plurality of nonfunctional lands in the row direction or the column direction.