CN211741154U

CN211741154U - Packaging structure oxygen sensor

Info

Publication number: CN211741154U
Application number: CN202020175054.2U
Authority: CN
Inventors: 王志伟; 黄宗波; 麦希铭
Original assignee: Shenzhen Ampron Technology Corp
Current assignee: Shenzhen Ampron Technology Corp
Priority date: 2020-02-14
Filing date: 2020-02-14
Publication date: 2020-10-23
Anticipated expiration: 2030-02-14

Abstract

The utility model provides a packaging structure oxygen sensor, include: detect chip, stainless steel shell and base, it sets up inside the stainless steel shell to detect the chip, stainless steel shell and base welded fastening, be provided with the terminal that is connected to external circuit on the base, the electrode tip that detects the chip passes through welding wire and terminal welded fastening, the inside detection chip periphery that is located of stainless steel shell still fills and is provided with insulation material, the through-hole has still been seted up on stainless steel shell top, the through-hole internal fixation is provided with stainless steel metal mesh. When the utility model is used for measuring the oxygen concentration of atmosphere, the chip power is low and the energy consumption is low; the chip has a double heat insulation structure of the shell and the high-temperature cotton, so that the chip is less influenced by the environment and has higher response speed when in work; meanwhile, the chip, the base and the shell are small in size, simple in structure and convenient to install in cooperation with an external circuit.

Description

Packaging structure oxygen sensor

Technical Field

The utility model relates to a sensor technology field especially relates to an packaging structure oxygen sensor.

Background

The gas sensor is installed on an engine exhaust pipe and used for detecting certain gas concentration in automobile exhaust, and the core element of the gas sensor is generally a strip-shaped flat plate type sensing chip, and the most common gas sensor is a flat plate type oxygen sensor. The flat plate type oxygen sensor is used for measuring the concentration of oxygen components in the tail gas and feeding the measured result back to the engine controller, and the engine controller optimizes the combustion state based on the measured result, so that the emission of harmful substances is minimized.

The existing sensor is easy to loosen after being used for a long time, and the detection chip is easy to break down when the temperature changes too much.

There is a need for a more durable and stable oxygen sensor that addresses the above-mentioned problems.

SUMMERY OF THE UTILITY MODEL

The utility model provides a packaging structure oxygen sensor through carrying out the technological transformation to existing equipment, the problem of having solved.

In order to solve the technical problem, the utility model discloses specifically adopt following technical scheme:

a package structure oxygen sensor, comprising: the detection device comprises a detection chip, a stainless steel shell and a base, wherein the detection chip is arranged inside the stainless steel shell, and the stainless steel shell and the base are welded and fixed;

the detection chip comprises an outer pump electrode, an upper insulating alumina layer, a zirconia ceramic body, a lower insulating alumina layer and a heater which are sequentially arranged from top to bottom, wherein a cavity is formed in the zirconia ceramic body, an inner wall of the zirconia ceramic body on the upper surface of the cavity is provided with an inner pump electrode, a conductive hole corresponding to the position is formed in the upper insulating alumina layer and the zirconia ceramic body, conductive platinum slurry is filled in the conductive hole, and the outer pump electrode is electrically connected with the inner pump electrode through the conductive hole.

Furthermore, the welding wire is a platinum wire, and the diameter of the platinum wire is 0.1mm-0.2 mm.

Compared with the prior art, the utility model discloses following beneficial effect has:

1) the utility model discloses a platinum wire welding, with four electrode welding of chip on four terminals of kovar alloy base, can supply external circuit to insert, can not change chip resistance, prolonged the life of chip, guaranteed the heating efficiency of chip.

2) The utility model discloses there is the stainless steel metal mesh on the stainless steel shell top, has guaranteed gaseous circulation.

3) When the utility model is used for measuring the oxygen concentration of atmosphere, the chip power is low and the energy consumption is low; the chip has a double heat insulation structure of the shell and the high-temperature cotton, so that the chip is less influenced by the environment and has higher response speed when in work; meanwhile, the chip, the base and the shell are small in size, simple in structure and convenient to install in cooperation with an external circuit.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic diagram of the detection chip of the present invention;

description of reference numerals: the device comprises a detection chip 1, an outer pump electrode 11, an upper insulating alumina layer 12, a zirconia ceramic body 13, a cavity 131, a lower insulating alumina layer 14, a heater 15, an inner pump electrode 16, a conductive hole 17, a diffusion barrier 18, a stainless steel shell 2, a base 3, a binding post 4, a welding wire 5, a through hole 6 and a stainless steel metal mesh 7.

Detailed Description

The following detailed description of the present invention will be made with reference to the accompanying drawings and examples.

As shown in fig. 1-2, the embodiment provides an oxygen sensor with a package structure, which includes a detection chip 1, a stainless steel housing 2 and a base 3, where the detection chip 1 is disposed inside the stainless steel housing 2, the stainless steel housing 2 and the base 3 are welded and fixed, a terminal 4 connected to an external circuit is disposed on the base 3, an electrode end of the detection chip 1 is welded and fixed to the terminal 4 through a welding wire 5, a heat insulation material is filled inside the stainless steel housing 2 and located at the periphery of the detection chip 1, a through hole 6 is further formed in the top end of the stainless steel housing 2, and a stainless steel metal mesh 7 is fixedly disposed in the through hole 6;

the detection chip 1 includes from last outer pump electrode 11, last insulating alumina layer 12, zirconia porcelain body 13, lower insulating alumina layer 14 and the heater 15 that sets gradually extremely down, cavity 131 has been seted up to zirconia porcelain body 13 inside, cavity 131 upper surface zirconia porcelain body 13 inner wall department is provided with inner pump electrode 16, set up the corresponding electrically conductive hole 17 in position on insulating alumina layer 12 and the zirconia porcelain body 13, electrically conductive hole 17 intussuseption is filled with electrically conductive platinum thick liquid, outer pump electrode 11 is connected with inner pump electrode 16 electricity through electrically conductive hole 17.

Further, in order to obtain better conductive effect and welding effect, the welding wire 5 is a platinum wire, and the diameter of the platinum wire is 0.15 mm. The platinum wire has the advantages of higher strength, good conductivity and easy welding.

Further, in order to obtain a better heat preservation protection effect, the heat preservation material is high-temperature cotton. The high-temperature cotton has the functions of heat preservation, dust prevention and airflow buffering, and the service life and the stability of the sensor are prolonged.

Further, a diffusion barrier 18 made of a porous material is further disposed at the cavity 131 of the zirconia ceramic body 13, and the diffusion barrier 18 is used for conducting the cavity 131 to an external space. The size and the porosity of the diffusion barrier 18 control the amount of air inflow in unit time, so that the size of the chip pump current is controlled to be 80-300 muA, and the detected gas oxygen concentration range is 0% -25%.

The zirconia ceramic body 13 is a solid electrolyte and can conduct oxygen ions under a high temperature condition. When the oxygen sensor works, the heater 15 heats up to make the zirconia porcelain body 13 reach the normal working temperature; meanwhile, the inner pump electrode 16 catalyzes oxygen in the gas entering the inner cavity 131 of the chip to change the oxygen into oxygen ions, and the oxygen ions migrate from the inner pump electrode 16 to the outer pump electrode 11 through the zirconia ceramic body 13 under the action of an external pump voltage, so that pump current is generated; the magnitude of the generated pumping current is related to the oxygen concentration and the gas inlet velocity in the atmosphere with a constant material and surface area of the inner pumping electrode 16, and the magnitude of the pumping current is controlled by controlling the size and porosity of the diffusion barrier 18 to control the gas inlet rate.

Meanwhile, due to process manufacturing errors, the corresponding relation between the pump current and the oxygen concentration of each chip is different, so that each oxygen sensor needs to be calibrated independently when in use, and only one calibration is needed.

The following formula applies to the calibration of the present invention under all atmospheric conditions:

is ([ O2]) measures the sensor current in the medium

[ O2] oxygen concentration in the measurement Medium expressed in percentage

Specific constant of k sensor

To calibrate the oxygen sensor of the present invention, the oxygen sensor is first placed in a standard atmosphere (e.g., air) with a known oxygen concentration, the pump current of the oxygen sensor under normal operating conditions is measured, and then the constant k of the oxygen sensor is obtained according to a formula.

Specific constant of k sensor

Ik ([ O2]) output current with known oxygen concentration

O2, k calibrated standard gas concentration

When the embodiment is used for measuring the oxygen concentration of the atmosphere, the chip power is low and the energy consumption is low; the chip has a double heat insulation structure of the shell and the high-temperature cotton, so that the chip is less influenced by the environment and has higher response speed when in work; meanwhile, the chip, the base and the shell are small in size, simple in structure and convenient to install in cooperation with an external circuit.

Finally, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the present invention can be modified or replaced by other means without departing from the spirit and scope of the present invention, which should be construed as limited only by the appended claims.

The utility model discloses the standard part that uses all can purchase from the market, and dysmorphism piece all can be customized according to the description with the record of drawing of description, and the concrete connection mode of each part all adopts ripe bolt, rivet among the prior art. The conventional means such as welding, machines, parts and equipment are of the conventional type in the prior art, and the circuit connection adopts the conventional connection mode in the prior art, so that the details are not described.

In the description of the present invention, unless expressly stated or limited otherwise, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral part; can be mechanically or electrically connected; either directly or through an intermediary, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood in specific cases for those skilled in the art.

Claims

1. A package structure oxygen sensor, comprising: the detection device comprises a detection chip, a stainless steel shell and a base, wherein the detection chip is arranged inside the stainless steel shell, and the stainless steel shell and the base are welded and fixed;

2. The package structure oxygen sensor of claim 1, wherein the bonding wire is a platinum wire, and the diameter of the platinum wire is 0.1mm-0.2 mm.

3. The package structure oxygen sensor of claim 1, wherein the thermal insulation material is high temperature cotton.

4. The packaged structure oxygen sensor according to claim 1, wherein a diffusion barrier made of a porous material is further disposed at the cavity of the zirconia ceramic body, and the diffusion barrier is used for conducting the cavity to an external space.