An electronic component has a casing having a resin injecting section having at least one wall. At least one circuit board is housed in the casing, next to the resin injecting section via the wall. At least one lead terminal is provided in the casing. The lead terminal has a first end and a second end, and a middle section connected between the first and second ends. The first end of the lead terminal is connected to the circuit board in a way that the middle section of the lead terminal is provided as straddling the wall of the resin injecting section. Also provided is at least one lead wire having a third end and a fourth end. The third end of the lead wire is connected to the second end of the lead terminal in the resin injecting section. The fourth end of the lead wire is pulled out from the casing. The third end of the lead wire and the second end of the lead terminal connected to each other are embedded in resin injected in the resin injecting section whereas the middle section of the lead terminal straddling the wall of the resin injecting section is not embedded in the resin. Instead of straddling the wall of the resin injecting section, the middle section of the lead terminal may be inserted into an opening provided on the wall and connected to the circuit board.
An electronic control unit includes an electronic circuit substrate and a casing that accommodates the electronic circuit substrate. A plurality of electronic components are mounted on the electronic circuit substrate. A plurality of connector terminals extend through a side wall of the casing for electrically connecting the electronic circuit substrate to external wires. A retainer portion capable of retaining liquid seal agent is arranged at an inner side of the wall through which the connector terminals extend.
