Patent ID: 7504908

Claim:
An electric circuit device, comprising: a substrate including a first conductive plate; and an electric element formed on the substrate, wherein the electric element, including: an n-number (n is a positive integer) of second conductive plate respectively passing a first current from a power source side to an electrical load circuit side; and an m-number (m is a positive integer) of third conductive plate being alternately stacked to the n-number of the second conductive plate and each passing a second current, which is a return current of the first current, from the electrical load circuit side to the power source side, wherein the first conductive plate passes the second current, which is received from the electrical load circuit side, to one each end of the m-number of third conductive plate, while passing the second current, which is received from the other each end of the m-number of third conductive plate, to the power source side, the n-number of second conductive plate has lower inductance than a self-inductance when the first and second currents respectively flows in the n-number of second conductive plate and the m-number of third conductive plate, and when the length of the second and third conductive plates along direction perpendicular to direction in which the first and second currents flow is W, and the length of the second and third conductive plates along the direction in which the first and second currents flow is L, in a overlap part between the second and third conductive plates, W and L have a relationship of W≧L, wherein the second current, including: a component of the first current passing in the m-number of third conductive plate; and a component of the second current passing in the first conductive plate, wherein the first conductive plate, including: a first flat plate member being connected to the one each end of the m-number of third conductive plate; a second flat plate member being connected to the other each end of the m-number of third conductive plate; and a current control unit being disposed between the first flat plate member and the second flat plate member and more reducing the component of second current than that of first current.