A lighting device for a lamp device is provided. The lighting device includes a circuit board and film capacitors packaged on the circuit board by using leadless flow solders. Each film capacitor comprises polypropylene films and lead wires, and a material of the lead wires has a thermal conductivity lower than a thermal conductivity of copper, and terminals and internal materials of the film capacitors are leadless. A diameter of the lead wires is 0.6- (mm) or less, a cross-sectional area is 35 mm.sup.2 or less, and a temperature at a terminal end of the lead wires in the film capacitors during a soldering process is 130.degree. C. or less.