A circuit device 10 comprises a die pad 11, bonding pads 12, a circuit element 9, affixed onto die pad 11, and an insulating resin 14, which seals die pad 11, bonding pads 12, and circuit element 9, and has a configuration wherein recessed parts 15 are formed at parts of the side surfaces of insulating resin 14, and side surface of the conductive patterns that are disposed at peripheral parts are exposed from recessed parts 15. By bonding pads 12, which are to become connecting electrodes to the exterior, being exposed at the side surfaces, fillets of a brazing material 19 are formed at the sides of the device when circuit device 10 is mounted.