Patent attributes
A substrate for a semiconductor package includes a dielectric substrate, a circuit pattern formed on a first surface of the dielectric substrate, and an electromagnetic band gap (EGB) pattern. The EGB pattern includes multiple unit structures formed on a second surface of the dielectric substrate, where each unit structure includes a flat conductor electrically connected to the circuit pattern through a ground connection, and multiple spiral-patterned conductors electrically connected to the flat conductor. The second surface is formed on an opposite side of the dielectric substrate from the first surface. Each flat conductor is electrically connected to a flat conductor of another one of the unit structures. At least one of the spiral-patterned conductors in each one of the unit structures is electrically connected to another one of the spiral-patterned conductors.