A small-size limiting current type zirconium oxide oxygen sensor core and its preparation method
By using the structure of porous Pt electrode and YSZ solid electrolyte layer in the zirconia oxygen sensor core, combined with magnetron sputtering technology, the problems of core size and heating inhomogeneity in the prior art are solved, and low power consumption is achieved , high-precision and fast-responsive oxygen sensor.
Patent Information
- Application Number
- CN202111489395.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-08
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2041-12-08
AI Technical Summary
The existing zirconia solid electrolyte oxygen sensor core preparation method is difficult to achieve small size and high precision, and the heating unevenness and high power consumption are high, which cannot meet the needs of low-power, small size, fast response and high-precision oxygen sensors.
The structure of the porous Pt electrode anode layer, the YSZ solid electrolyte layer, the porous Pt electrode cathode layer, the insulating layer and the heating electrode layer was adopted. The film was deposited by magnetron sputtering technology, and the total thickness was controlled between 1.1μm-24μm, and the S-shaped insulating layer was used. and heat the electrode layer to ensure uniform heating and oxygen transport.
The core is small in size, reducing power consumption and heating inhomogeneity, improving the accuracy and response speed of the oxygen sensor, and meeting the needs of low-power, small-size, fast response and high-precision oxygen sensors.
Smart Images
Figure CN114062464B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oxygen sensors, and in particular to a small-size limiting current type zirconium oxide oxygen sensor core and a preparation method thereof. Background Art
[0002] The limiting current type zirconia oxygen sensor has a wide range of applications in the medical, industrial, automotive, warehousing and other fields due to its advantages such as fast response speed, no reference gas required and low sealing requirements. The oxygen sensor with zirconia as solid electrolyte requires an operating temperature of 650℃ or above, so a heating voltage is required to make it work properly.
[0003] At present, the method for preparing zirconia solid electrolyte oxygen sensor core is mostly ceramic tape casting process. The thickness of a single-layer tape-cast green body is generally controlled at 0.03-2.5mm. The entire core generally requires 2 to 3 layers of solid electrolyte. After the functional layers are stacked, the core thickness reaches the millimeter level, which consumes a lot of energy during the heating process and cannot guarantee the heating consistency. With the increase and expansion of application scenarios and application needs, the demand for low-power, small-size, fast-response, and high-precision oxygen sensors is more urgent. The traditional ceramic tape casting process makes it difficult to reduce the size of each functional layer of the core to the micron or even nanometer level, and its accuracy cannot be guaranteed, which causes deviations in the final performance of the oxygen sensor.
[0004] Therefore, there is an urgent need for a small-sized limiting current oxygen sensor core and its preparation process. Summary of the invention
[0005] The purpose of the present invention is to overcome the defects and shortcomings in the prior art. To this end, the present invention provides a small-sized limiting current type zirconia oxygen sensor core and a preparation method thereof, which can produce a micron-sized core, reduce power consumption, improve heating uniformity, and enhance the accuracy of the oxygen sensor.
[0006] In order to achieve the above-mentioned object, the present invention provides a small-sized limiting current type zirconia oxygen sensor core, which comprises, from top to bottom, a porous Pt electrode anode layer, a YSZ solid electrolyte layer, a porous Pt electrode cathode layer, an insulating layer and a heating electrode layer, wherein the porous Pt electrode anode layer, the porous Pt electrode cathode layer and the heating electrode layer are all connected with conductive wires; the total thickness of the small-sized limiting current type zirconia oxygen sensor core is 1.1μm-24μm.
[0007] Furthermore, the thickness of the porous Pt electrode anode layer is 0.2 μm-3 μm.
[0008] Furthermore, the thickness of the YSZ solid electrolyte layer is 0.3 μm-12 μm.
[0009] Furthermore, the thickness of the porous Pt electrode cathode layer is 0.2 μm-3 μm.
[0010] Furthermore, the thickness of the insulating layer is 0.2 μm-3 μm.
[0011] Furthermore, the thickness of the heating electrode layer is 0.2 μm-3 μm.
[0012] Furthermore, the shape of the insulating layer is consistent with the shape of the heating electrode layer, and the shape of the insulating layer is S-shaped.
[0013] The present invention also provides a method for manufacturing the above-mentioned small-size limiting current type zirconia oxygen sensor core, the steps of which are:
[0014] Step 1, prepare a silicon substrate, first use acetone to ultrasonically clean the silicon substrate for 10min-20min, then use anhydrous ethanol to ultrasonically clean it for 10min-30min, then clean it in deionized water for 10min-20min, and blow dry the silicon substrate;
[0015] Step 2: Fix the dried silicon substrate in step 1 on the substrate plate in the sputtering chamber of the multi-target magnetron sputtering equipment, and evacuate the sputtering chamber to 4×10 -5 Pa-6×10 -3 Pa, a mixed gas of oxygen and argon is introduced into the sputtering chamber, the flow rate of the mixed gas is 16sccm-75sccm; the volume ratio of the oxygen and argon is 1:1-1:20;
[0016] Step 3, adjusting the pressure in the sputtering chamber, and performing thin film deposition of the functional layer on the silicon substrate, wherein the functional layer is deposited on the silicon substrate in the order of a porous Pt electrode anode layer, a YSZ solid electrolyte layer, a porous Pt electrode cathode layer, an insulating layer, and a heating electrode layer; the total thickness of the functional layer is 1.1 μm-24 μm;
[0017] Step 4, placing the functional layer in an annealing furnace for thermal annealing treatment, the annealing temperature is 500° C.-1000° C., and the annealing time is 0.5 h-1.5 h, so as to eliminate the residual stress of the functional layer during the magnetron sputtering process;
[0018] Step 5: Cool the functional layer to room temperature, and weld the porous Pt electrode anode layer, the porous Pt electrode cathode layer and the heating electrode layer with corresponding conductive wires to obtain a small-sized limiting current type zirconia oxygen sensor core.
[0019] Furthermore, the step 3 comprises the following steps:
[0020] Step 3-1, when sputtering the porous Pt electrode anode layer, DC sputtering is used for sputtering deposition; the pressure of the sputtering chamber is 20Pa-80Pa, and the film deposition rate is 6nm / min-15nm / min, so as to obtain a porous Pt electrode anode layer with a thickness of 0.2μm-3μm;
[0021] Step 3-2, when sputtering the YSZ solid electrolyte layer, radio frequency sputtering is used for sputtering deposition. The material of the YSZ solid electrolyte layer is yttrium trioxide and zirconium oxide, and the mass percentage of yttrium trioxide is 3 mol%-8 mol%; the target substrate distance is 90 mm, the pressure of the sputtering chamber is 0.1 Pa-0.75 Pa, and the film deposition rate is 2 nm / min-5 nm / min, so as to obtain a YSZ solid electrolyte layer with a thickness of 0.3 μm-12 μm;
[0022] Step 3-3, when sputtering the porous Pt electrode cathode layer, DC sputtering is used for sputtering deposition; the deposition power is maintained at 400 W, the pressure of the sputtering chamber is 20 Pa-80 Pa, and the film deposition rate is 6 nm / min-15 nm / min, so as to obtain a porous Pt electrode cathode layer with a thickness of 0.2 μm-3 μm;
[0023] Step 3-4, when sputtering the insulating layer, radio frequency sputtering is used for sputtering deposition; the material of the insulating layer is aluminum oxide with a purity of more than 99%, the deposition power is maintained at 400W, the pressure of the sputtering chamber is 0.1Pa-0.75Pa, and the film deposition rate is 2nm / min-5nm / min, so as to obtain an insulating layer with a thickness of 0.2μm-3μm;
[0024] Step 3-5, when sputtering the heating electrode layer, DC sputtering is used for sputtering deposition; the pressure of the sputtering chamber is 0.1Pa-0.75Pa, and the film deposition rate is 2nm / min-5nm / min to obtain a heating electrode layer with a thickness of 0.2μm-3μm.
[0025] Compared with the prior art, the beneficial effects of the present invention are: meeting the requirements for low power consumption, small size, fast response and high precision oxygen sensors, the present invention uses a thin film deposition process to prepare a small-sized core with a thickness of micrometer level, and the core only needs one layer of YSZ solid electrolyte. The details are as follows:
[0026] (1) The core size is miniaturized, that is, the total thickness of each functional layer of the prepared core is 1.1 μm-24 μm, which greatly reduces the thickness of the core, thereby reducing power consumption and improving heating unevenness during subsequent heating treatment;
[0027] (2) Uniform heating and high accuracy in measuring oxygen concentration. The heating electrodes in the core are distributed in an S-shape, which allows all positions of the YSZ solid electrolyte layer, especially the corners, to be heated evenly at the same time. This further ensures that the transport characteristics of oxygen remain consistent when passing through the YSZ solid electrolyte layer, thereby improving the accuracy of the oxygen sensor;
[0028] (3) The core only needs one layer of YSZ solid electrolyte, and no additional YSZ layer with a certain shape is required; at the same time, the shape of the insulating layer is consistent with the heating electrode layer, which will not hinder the diffusion of oxygen. Therefore, there is no need to add an additional YSZ layer with a certain shape to form an oxygen diffusion channel;
[0029] (4) Fast response. The YSZ solid electrolyte has only one layer, which can reduce the diffusion path of oxygen during oxygen measurement, thereby reducing the response time and making it respond quickly. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 It is a schematic structural diagram of a small-size limiting current type zirconium oxide oxygen sensor core of the present invention.
[0031] Figure 2 for Figure 1 Top view of the .
[0032] Figure 3 for Figure 1 Bottom view of .
[0033] Among them: 1. porous Pt electrode anode layer; 2. YSZ solid electrolyte layer; 3. porous Pt electrode cathode layer; 4. insulating layer; 5. heating electrode layer; 6. conductive wire. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.
[0036] Example
[0037] See also Figures 1 to 3 The present invention provides a small-size limiting current type zirconia oxygen sensor core and a preparation method thereof, which comprises, from top to bottom, a porous Pt electrode anode layer 1, a YSZ solid electrolyte layer 2, a porous Pt electrode cathode layer 3, an insulating layer 4 and a heating electrode layer 5, wherein the porous Pt electrode anode layer 1, the porous Pt electrode cathode layer 3 and the heating electrode layer 5 are all connected with a conductive wire 6; the total thickness of the small-size limiting current type zirconia oxygen sensor core is 1.1μm-24μm.
[0038] Preferably, the thickness of the porous Pt electrode anode layer 1 is 0.2 μm-3 μm.
[0039] Preferably, the thickness of the YSZ solid electrolyte layer 2 is 0.3 μm-12 μm.
[0040] Preferably, the thickness of the porous Pt electrode cathode layer 3 is 0.2 μm-3 μm.
[0041] Preferably, the thickness of the insulating layer 4 is 0.2 μm-3 μm. Here, the insulating layer 4 may be made of aluminum oxide with a purity of more than 99%.
[0042] Preferably, the thickness of the heating electrode layer 5 is 0.2 μm-3 μm.
[0043] Preferably, the shape of the insulating layer 4 is consistent with that of the heating electrode layer 5 , and the shape of the insulating layer 4 is S-shaped.
[0044] According to the structure of the present invention described above, the present invention also provides a method for manufacturing a small-size limiting current type zirconia oxygen sensor core, the steps of which are:
[0045] Step 1, prepare a silicon substrate, first use acetone to ultrasonically clean the silicon substrate for 10min-20min, then use anhydrous ethanol to ultrasonically clean it for 10min-30min, then clean it in deionized water for 10min-20min, and blow dry the silicon substrate;
[0046] Step 2: Fix the dried silicon substrate in step 1 on the substrate plate in the sputtering chamber of the multi-target magnetron sputtering equipment, and evacuate the sputtering chamber to 4×10 -5 Pa-6×10 -3 Pa, a mixed gas of oxygen and argon is introduced into the sputtering chamber, the flow rate of the mixed gas is 16sccm-75sccm; the volume ratio of oxygen to argon is 1:1-1:20;
[0047] Step 3, adjusting the pressure in the sputtering chamber, and performing thin film deposition of the functional layer on the silicon substrate, wherein the functional layer is deposited on the silicon substrate in the order of a porous Pt electrode anode layer 1, a YSZ solid electrolyte layer 2, a porous Pt electrode cathode layer 3, an insulating layer 4, and a heating electrode layer 5; the total thickness of the functional layer is 1.1 μm-24 μm;
[0048] Step 4, placing the functional layer in an annealing furnace for thermal annealing treatment, the annealing temperature is 500° C.-1000° C., and the annealing time is 0.5 h-1.5 h, so as to eliminate the residual stress of the functional layer during the magnetron sputtering process;
[0049] Step 5: Cool the functional layer to room temperature, and weld the porous Pt electrode anode layer 1, the porous Pt electrode cathode layer 3 and the heating electrode layer 5 to the corresponding conductive wire 6 to obtain a small-sized limiting current type zirconia oxygen sensor core.
[0050] Preferably, step 3 comprises the following steps:
[0051] Step 3-1, when sputtering the porous Pt electrode anode layer 1, DC sputtering is used for sputtering deposition; the pressure of the sputtering chamber is 20Pa-80Pa, and the film deposition rate is 6nm / min-15nm / min to obtain a porous Pt electrode anode layer 1 with a thickness of 0.2μm-3μm; this porous Pt electrode anode layer 1 can diffuse gas.
[0052] Step 3-2, when sputtering the YSZ solid electrolyte layer 2, radio frequency sputtering is used for sputtering deposition. The material of the YSZ solid electrolyte layer 2 is yttrium trioxide and zirconium oxide, and the mass percentage of yttrium trioxide is 3 mol%-8 mol%. That is, the material of the YSZ solid electrolyte layer 2 is a yttrium-stabilized zirconium oxide solid electrolyte; the target substrate distance is 90 mm, the pressure of the sputtering chamber is 0.1 Pa-0.75 Pa, and the film deposition rate is 2 nm / min-5 nm / min, so as to obtain a YSZ solid electrolyte layer 2 with a thickness of 0.3 μm-12 μm;
[0053] Step 3-3, when sputtering the porous Pt electrode cathode layer 3, DC sputtering is used for sputtering deposition; the deposition power is maintained at 400W, the pressure of the sputtering chamber is 20Pa-80Pa, and the film deposition rate is 6nm / min-15nm / min to obtain a porous Pt electrode cathode layer 3 with a thickness of 0.2μm-3μm; this porous Pt electrode cathode layer 3 can diffuse gas.
[0054] Step 3-4, when sputtering the insulating layer 4, radio frequency sputtering is used for sputtering deposition; the material of the insulating layer (4) is aluminum oxide with a purity of more than 99%, the deposition power is maintained at 400W, the pressure of the sputtering chamber is 0.1Pa-0.75Pa, and the film deposition rate is 2nm / min-5nm / min, so as to obtain an insulating layer 4 with a thickness of 0.2μm-3μm;
[0055] In step 3-5, when sputtering the heating electrode layer 5, DC sputtering is used for sputtering deposition; the pressure of the sputtering chamber is 0.1Pa-0.75Pa, and the film deposition rate is 2nm / min-5nm / min, so as to obtain a heating electrode layer 5 with a thickness of 0.2μm-3μm.
[0056] The insulating layer 4 described above can prevent the current from flowing to the porous Pt electrode cathode layer 3 when the heating electrode layer 5 is working, and will not hinder the diffusion of oxygen.
[0057] The above-mentioned multi-target magnetron sputtering equipment is an existing equipment, which is equipped with a DC power supply and an RF power supply. The DC power supply can be used for the preparation of metal films, and the RF power supply can be used for the preparation of non-metallic films. Multiple targets can meet the needs of multi-layer or multiple coatings. Specifically, the magnetron sputtering coater produced by Zhengzhou Chengyue Scientific Instrument Co., Ltd. can be used. The product name is a three-inch three-target magnetron sputtering coater; the product model is CY-MSP300S-2DC1RF; the coater is equipped with two high-precision mass flow meters to meet the needs of complex gas environment construction; the instrument is equipped with an advanced turbomolecular pump group as standard, and the ultimate vacuum can reach 1.0E-5Pa. The control of the vacuum pump group and the control of the sputtering power supply can be realized on the computer program. The target-substrate distance, the pressure of the sputtering chamber, and the substrate disk are all related to the multi-target magnetron sputtering equipment, and the details will not be repeated.
[0058] The present invention may be summarized in other specific forms that do not violate the spirit or main features of the present invention. Therefore, no matter from which point of view, the above embodiments of the present invention can only be regarded as an explanation of the present invention and cannot limit the present invention. The claims indicate the scope of the present invention, while the above description does not indicate the scope of the present invention. Therefore, any changes within the meaning and scope equivalent to the claims of the present invention should be considered to be included in the scope of the claims of the present invention.
Claims
1. A method for manufacturing a small-size limiting current type zirconia oxygen sensor core, characterized in that: The steps are: Step 1, prepare a silicon substrate, first use acetone to ultrasonically clean the silicon substrate for 10min-20min, then use anhydrous ethanol to ultrasonically clean it for 10min-30min, then clean it in deionized water for 10min-20min, and blow dry the silicon substrate; Step 2: Fix the dried silicon substrate in step 1 on the substrate plate in the sputtering chamber of the multi-target magnetron sputtering equipment, and evacuate the sputtering chamber to 4× Pa-6× Pa, a mixed gas of oxygen and argon is introduced into the sputtering chamber, the flow rate of the mixed gas is 16sccm-75sccm; the volume ratio of the oxygen and argon is 1:1-1:20; Step 3, adjusting the pressure in the sputtering chamber, and performing thin film deposition of the functional layer on the silicon substrate, wherein the functional layer is deposited on the silicon substrate in the order of a porous Pt electrode anode layer (1), a YSZ solid electrolyte layer (2), a porous Pt electrode cathode layer (3), an insulating layer (4), and a heating electrode layer (5); the total thickness of the functional layer is 1.1 μm-24 μm; Step 4, placing the functional layer in an annealing furnace for thermal annealing treatment, the annealing temperature is 500° C.-1000° C., and the annealing time is 0.5 h-1.5 h, so as to eliminate the residual stress of the functional layer during the magnetron sputtering process; Step 5, cooling the functional layer to room temperature, welding the porous Pt electrode anode layer (1), the porous Pt electrode cathode layer (3) and the heating electrode layer (5) with the corresponding conductive wire (6), and obtaining a small-sized limiting current type zirconium oxide oxygen sensor core; The step 3 comprises the following steps: Step 3-1, when sputtering the porous Pt electrode anode layer (1), DC sputtering is used for sputtering deposition; the pressure of the sputtering chamber is 20Pa-80Pa, and the film deposition rate is 6nm / min-15nm / min, so as to obtain a porous Pt electrode anode layer (1) with a thickness of 0.2μm-3μm; Step 3-2, when sputtering the YSZ solid electrolyte layer (2), radio frequency sputtering is used for sputtering deposition. The material of the YSZ solid electrolyte layer (2) is yttrium trioxide and zirconium oxide, and the mass percentage of yttrium trioxide is 3 mol%-8 mol%; the target substrate distance is 90 mm, the pressure of the sputtering chamber is 0.1 Pa-0.75 Pa, and the film deposition rate is 2 nm / min-5 nm / min, so as to obtain a YSZ solid electrolyte layer (2) with a thickness of 0.3 μm-12 μm; Step 3-3, when sputtering the porous Pt electrode cathode layer (3), DC sputtering is used for sputtering deposition; the deposition power is maintained at 400 W, the pressure of the sputtering chamber is 20 Pa-80 Pa, and the film deposition rate is 6 nm / min-15 nm / min, so as to obtain a porous Pt electrode cathode layer (3) with a thickness of 0.2 μm-3 μm; Step 3-4, when sputtering the insulating layer (4), radio frequency sputtering is used for sputtering deposition; the material of the insulating layer (4) is aluminum oxide with a purity of more than 99%, the deposition power is maintained at 400W, the pressure of the sputtering chamber is 0.1Pa-0.75Pa, and the film deposition rate is 2nm / min-5nm / min, so as to obtain an insulating layer (4) with a thickness of 0.2μm-3μm; In step 3-5, when sputtering the heating electrode layer (5), direct current sputtering is used for sputtering deposition; the pressure of the sputtering chamber is 0.1Pa-0.75Pa, and the film deposition rate is 2nm / min-5nm / min, so as to obtain a heating electrode layer (5) with a thickness of 0.2μm-3μm.