In many processes that require sealing and gluing, such as the plasma treatment of ignition coil skeleton, it can not only remove the non-volatile oil on the surface, but also greatly improve the surface activity of skeleton, that is, it can improve the bonding strength of skeleton and epoxy resin, avoid bubbles, and improve the welding strength of enameled wire and skeleton contacts after winding. In this way, the ignition coil in the production process of all aspects of the performance has been significantly improved, improve the reliability and service life.