INTERNAL COMBUSTION ENGINE IGNITION COIL, AND METHOD OF PRODUCING THE SAME

An ignition coil (1) having a case (2), a core (22) installed in the case, a primary spool (25) disposed substantially coaxially around an outer circumference of the core within the case, a primary coil (26) comprising a wire wound around the primary spool, a secondary spool (23) disposed substantially coaxially around the outer circumference of the core within the case, a secondary coil (24) comprising a wire wound around the secondary spool and a resin insulating material (5) filled within the case, the ignition coil being characterized in that the spool of the primary and the secondary spools which is disposed between the secondary coil and the core and/or which is disposed between the secondary coil and the primary coil comprises a base resin having an adhesive strength to the resin insulating material which is less than that provided by polybutylene terephthalate and an insulation breakdown voltage which exceeds that provided by polyphenylene sulfide.