Electronic control device including interrupt wire

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;
• 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;
• and
• a protective layer covering a surface of the substrate including the interrupt wire, the protective layer defining an opening portion, and only a portion of the interrupt wire in a length direction of the interrupt wire being exposed through the opening portion,
• 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 interrupt wire is disposed adjacent to the electronic component other than the electronic component that is coupled with the interrupt wire, and the interrupt wire is disposed adjacent to a wire other than the component-mounted wire and the common wire that are coupled with the interrupt wire, and
• wherein the protective layer is provided by a solder resist layer which is directly attached on a surface of the interrupt wire.