Printed circuit board

A printed circuit board, wherein

• a power source conductor layer;
• a ground conductor layer;
• and
• a signal wiring layer having a circuit element thereon;
• are multilayered with dielectric layers interposed therebetween, the printed circuit board, comprising;
• a first power source plane provided in the power source conductor layer to supply a power source potential to the circuit element, the first power source plane being connected to a power source terminal of the circuit element through a via;
• a second power source plane provided in the power source conductor layer separated from the first power source plane by a gap;
• a connecting line provided in the power source conductor layer, connecting the first power source plane to the second power source plane;
• and
• a ground plane provided in the ground conductor layer, the ground plane being connected to a ground terminal of the circuit element through a via,
• wherein a dielectric layer among the dielectric layers interposed between the power source conductor layer and the ground conductor layer has a thickness equal to or less than 100 micrometer, and
• wherein the ground plane has an opening at a portion covering a projected image when the connecting line is projected onto the ground conductor layer.