Multilayer circuit board, drive control device, and motor unit for electric power steering

A multilayer circuit board formed by alternately stacking conductor layers and insulating layers, wherein a power section, in which a current is applied to an inverter circuit to which a switching element is mounted, and a control calculation section, to which a control device that controls the switching element is mounted, are disposed in different regions on the multilayer circuit board, the power section includes a drive current wiring for applying a current, the drive current wiring includes a same shape portion formed in a same shape in each of the conductor layers and a traversing portion in which a notch portion formed by notching a portion of the drive current wiring is formed at least on any one of the conductor layers, a signal wiring for transmitting a control signal of the inverter circuit mounted in the power section traverses the notch portion, and a dimension of a width of the traversing portion in a direction perpendicular to a longitudinal direction of the drive current wiring is larger than a dimension of a width of the same shape portion;

• wherein the drive current wiring includes a first drive current wiring and a second drive current wiring, the first drive current wiring being connected to a battery and having a battery voltage potential, and the second drive current wiring having a GND potential, and the first drive current wiring and the second drive current wiring are formed in parallel.