Multi-layer ceramic chip varistor device surface insulation method

A method for insulating external surfaces of a multi-layer ceramic chip varistor device, comprising:

• coating a high insulating material on external surfaces of a ceramic body after the ceramic body is sintered but before the device's external electrodes are formed;
• forming an insulating layer on external surfaces of the ceramic body after the ceramic body is put through a heat treatment process;
• coating and sintering external electrodes onto the ceramic body in a sintering process;
• and
• extending internal electrodes inside the ceramic body by a heat treatment process to ensure a good electric contract between the internal and external electrodes.

A method for insulating external surfaces of a multi-layer ceramic chip varistor device, comprising:

• immersing the device's ceramic body in an acid or alkaline solution in a dip etching process after the ceramic body is formed but before the device's external electrodes are formed, during which the device's internal electrodes are exposed out of the ceramic body as the ceramic body is etched and shrunk;
• coating a high insulating material on external surfaces of the ceramic body;
• forming an insulating layer on external surfaces of the ceramic body after the ceramic body is put through a heat treatment process;
• and
• coating and sintering external electrodes onto the ceramic body in a sintering process during which a good electric contact is established and ensured between the internal and external electrodes.