Disclosed is a field coil assembly of an electromagnetic clutch including a bobbin from which lead wires, which are both ends of a coil made of an aluminum-based material, protrude outward, a core that surrounds the bobbin such that the lead wires are exposed, a bobbin terminal installed at the bobbin while being adjacent to the lead wire of the coil, and a connector coupled to the core and including a lead wire terminal. The lead wires of the coil are connected to the bobbin terminal through heating and pressing.