1. Plastic Molding Type (Referred To As PP Plastic Molding):

The coil will be saturated with varnish for a period of time after the preliminary assembly, then dried and hardened after being taken out. The inside of coil is insulated by varnish filled. The process is not completed until coil is coated by the plastic injecting into a mould. In the early days, plastic molding type ignition coil was mostly used for motorcycles.

2. Asphalt Filled Type:

The coil is placed in a metal can case and filled with asphalt around the coil to completely cover it. Asphalt filled type ignition coil is the earliest insulation method for making automotive ignition coils.

3. Oil Filled Type:

As same as the asphalt filled type, except that asphalt is changed to insulating oil as the insulating layer. The insulation resistance and permeability is excellent. However, the disadvantage of oil filled type ignition coil is that polychlorinated biphenyl is poisonous, so oil filled type ignition coil was banned in Taiwan since 1980.

4. Epoxy resin filled type:

The coil is housed in a resinous case and filled with epoxy resin as an insulating material. Epoxy resin filled type ignition coil is currently the mainstream of ignition coils for both automobiles and motorcycles.

At present, our company adopts epoxy resin potting insulation method to manufacture ignition coils.