After the partial breakdown of the film dielectric, the metalized film has a self-healing function that causes it to naturally revert to the electrical performance phenomenon before the breakdown. The metalized film is covered on one or both sides of the edge or in the center to create a blank insulating strip without evaporating metal, known as the margin, and its width is referred to as the margin in the actual fabrication of capacitors. The same city also uses sheet resistance to denote the thickness of the metal layer and is used to describe the resistance of the metal layer on the metalized film in the unit square area. According to customer requirements, safety films can be made in a variety of parameters.
