Symmetric structural type oxygen sensor chip and manufacturing method thereof

A symmetric structural type oxygen sensor chip, comprising:

• a substrate layer, an insulating layer, and a heater layer;
• wherein
• the substrate layer and the insulating layer take the position of the heater layer as a symmetry axis to form a tightly combined symmetry structure, encapsulating the heater layer in a middle;
• the substrate layer comprises four layers, from top to bottom, a first substrate layer, a second substrate layer, a third substrate layer, and a fourth substrate layer;
• the insulating layer comprises an upper insulating layer and a lower insulating layer, both of which are disposed between the second substrate layer and the third substrate layer;
• the heater layer is disposed between the upper insulating layer and the lower insulating layer;
• an air passage layer is disposed above the second substrate layer, an outer electrode layer is disposed on a upper surface of the first substrate layer, an inner electrode layer is disposed between the first substrate layer and the second substrate layer, a protective layer for isolating gas and protecting the outer electrode layer is disposed on a top of the outer electrode layer, a first insulating layer is disposed between the first substrate layer and the outer electrode layer, a end lead is disposed on an outer side of the fourth substrate layer, and a second insulating layer is disposed between the end lead and the fourth substrate layer;
• the substrate layer is a zirconia film containing mullite and alumina, the zirconia film is pressed from zirconia slip, wherein the zirconia slip contains alumina with a volume content of 5% and mullite with a volume content of 10%;
• and
• the insulating layer is an alumina insulating layer.