Patent ID: 8773833

Claim:
An electronic control device comprising: a substrate; a plurality of component-mounted wires disposed on the substrate; a plurality of electronic components mounted on the respective component-mounted wires; a common wire disposed on the substrate and coupled with each of the electronic components; an interrupt wire coupled between one of the component-mounted wires and the common wire, the interrupt wire configured to melt in accordance with heat generated by an overcurrent so as to interrupt a coupling between the one of the component-mounted wires and the common wire via the interrupt wire; a connection wire via which the interrupt wire is coupled with a connection object that is one of the common wire and the one of the component-mounted wires; and a solder disposed between each of the electronic components and a corresponding one of the component-mounted wires, the solder having a lower melting point than the interrupt wire, wherein the connection wire has a first end portion adjacent to the interrupt wire and a second end portion adjacent to the connection object, wherein a cross-sectional area of the first end portion is smaller than a cross-sectional area of the second end portion, wherein the second end portion includes at least two narrow-down portions adjacent to the connection object and a middle portion between the first end portion and the narrow-down portions, and wherein a total cross-sectional area of the narrow-down portions is smaller than a cross-sectional area of the middle portion.