NOx sensor chip

Abstract

The invention relates to an NOx sensor chip which is mainly characterized by comprising a first substrate, a second substrate, a third substrate, a fourth substrate, a fifth substrate, a six substrate which are sequentially overlapped from top to bottom, wherein a pump oxygen outer electrode is arranged on the upper surface of the first substrate, the second substrate includes a first cavity, a second cavity, a third cavity and a fourth cavity, a diffusion barrier layer with a certain porosity is arranged between the third cavity and the fourth cavity, a main pump oxygen electrode is arranged in the third cavity, an auxiliary pump oxygen electrode and a test electrode are arranged in the fourth cavity, a porous protection layer is covered on the test electrode, the fourth substrate is provided with a reference gas channel, a reference electrode is arranged at the top of the channel, and a heating electrode is arranged between the fifth substrate and the sixth substrate. By adopting the structure, the NOx sensor chip has the advantages that the pollution caused by volatilization of gold in the electrode can be prevented, the substrates are sintered and tightly combined, the structure is simple, the process is simple, and the concentration of oxynitride in automobile exhaust can be accurately measured.

Description

technical field [0001] The invention relates to the field of automobile exhaust detection systems, in particular to an automobile exhaust detection sensor chip, in particular to a NOx sensor chip. Background technique [0002] The NOx sensor is a very important sensor in automobiles, which is used to detect the concentration of NOx in automobile exhaust emissions. The standards and regulations introduced by countries around the world are becoming more and more stringent to address the environmental pollution caused by vehicle exhaust emissions. This sensor, based on a ceramic sensing element, measures the NOx concentration in vehicle exhaust and sends an input signal to the engine electronic control unit (ECU) for the most efficient control of the engine's combustion process and exhaust aftertreatment. In diesel locomotives, this is achieved by injecting ammonia into the Selective Catalytic Reduction (SCR) system; in gasoline engines, it is achieved by controlling the regen...

AI Technical Summary

Problems solved by technology

[0007] 2. It is difficult to solve the problem of thermal shock resistance and durability after the main part and the lead-in components are bonded

[0008] 3. It is difficult to connect the electrode leads due to unevenness between the main body and the lead-out components

[0010] Some researchers also replaced the zirconia on the upper and lower layers of the heating electrode with a dense alumina substrate, which reduced the production process of the dense alumina insulating layer on the upper and lower parts of the heating electrode. However, due to the difference in the properties of the alumina and zirconia materials, the two materials There are still some technical difficulties in the close bonding of substrates stacked and sintered

Images