The design of the capacitor primarily depends on the application of capacitor in circuit.A few major criteria are listed below to help decide the type of capacitor required

  1. Polyester film is preferred for compactness, better heat bearing, but polypropylene is preferred where signal is high frequency pulasting field.
  2. Aluminium metallisation is better for low dissipation factor, while Zinc is more suited for high frequency circuits.
  3. Also, the style of metallisation, like heavy edge, segmentation or various other form can improve the characteristics to various degree. Capacitors come in dip, box or radial form. Here, economy, requirement of shape and size play an important and this has no significant bearing on electrical parameters of capacitors.