Manganese-cobalt-nickel-based MEMS temperature sensor chip and preparation and packaging method thereof

Abstract

The invention provides a manganese-cobalt-nickel-based MEMS temperature sensor chip and a preparation and packaging method thereof, and the preparation method of the temperature sensor chip comprises the steps: providing a preposed powder material which at least comprises cobalt sesquioxide, manganese dioxide and nickel sesquioxide; mixing the front powder material with an organic solvent to obtain printing slurry of the sensor; a substrate is provided, a pattern is formed through photoetching, an electrode layer is formed on the surface of the substrate, and then the electrode layer is patterned into an interdigital electrode; patterning the printing slurry on an electrically polarized substrate through a patterning process; sintering the substrate with the printing slurry to obtain a sensitive film with an electrode layer; and forming a protective layer above the sensitive film to obtain the manganese-cobalt-nickel-based MEMS temperature sensor chip. According to the invention, the MEMS technology is introduced into the processing process of the negative temperature coefficient temperature sensor chip, the size of the sensor chip can be reduced to a micron level, the miniaturization of the manganese-cobalt-nickel-based temperature sensor can be realized, and the measurement precision of the manganese-cobalt-nickel-based temperature sensor can be improved.

Description

Technical Field

[0001] This application relates to the field of negative temperature coefficient thermistors, specifically to a manganese cobalt nickel-based MEMS temperature sensor chip and its fabrication and packaging methods. Background Technology

[0002] Negative temperature coefficient (NTC) thermistor materials can be used to fabricate temperature sensors for temperature measurement in automotive electronics, industrial production, and consumer electronics. In automotive electronics, they can be used to measure and control the temperature inside the passenger compartment. In consumer electronics, they can be used to measure and control the temperature of air conditioning vents. In industrial production, they can be used to monitor the ambient temperature in real time during the operation of equipment with high temperature range requirements.

[0003] Currently, research on the miniaturization of negative temperature coefficient (NTC) temperature sensors is limited. Commercially available high-performance temperature sensors, such as Fluke's 5641 series, are relatively large, making it difficult to perform precise temperature measurement and control for specific applications and posing a risk of embargoes. Similarly, TDK's high-end thermistor temperature sensors also face embargo risks. Ternary metal oxides with manganese-cobalt-nickel spinel structures and their element-doped multi-element metal oxide systems are common NTC thermistor materials, readily available in daily life and research. However, they still suffer from large size. Similar thin-film NTC sensors fabricated by radio frequency magnetron sputtering, as mentioned in patent CN112735709A, are also expensive. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the purpose of this application is to provide a manganese cobalt nickel-based MEMS temperature sensor chip and its fabrication and packaging methods.

[0005] A first aspect of this application provides a method for fabricating a manganese-cobalt-nickel based MEMS temperature sensor chip, comprising:

[0006] A pre-treatment powder material is provided, wherein the pre-treatment powder material comprises at least cobalt trioxide, manganese dioxide, and nickel trioxide;

[0007] The pre-powder material is mixed with an organic solvent to obtain the sensor printing paste;

[0008] A substrate is provided, a pattern is formed by photolithography, an electrode layer is formed on the surface of the substrate, and then the electrode layer is patterned into interdigitated electrodes;

[0009] The printing paste is patterned on an electrically polarized substrate using a patterning process;

[0010] A substrate containing printing paste is sintered to obtain a sensitive film with an electrode layer;

[0011] A protective layer is formed on the sensitive membrane to obtain a manganese cobalt nickel-based MEMS temperature sensor chip.

[0012] Optionally, the pre-powder material may also include ferric oxide.

[0013] Optionally, the process of mixing the pre-powder material with an organic solvent to obtain a printing paste for the sensor is described, wherein the organic solvent is a mixture of terpineol, ethyl cellulose and dibutyl phthalate, and the mass percentage of terpineol, ethyl cellulose and dibutyl phthalate in the mixture is (70-90):(10-20):(5-10).

[0014] Optionally, the process of mixing the pre-powder material with an organic solvent to obtain the sensor printing paste is described, wherein the mass percentage of the pre-powder material to the organic solvent is (50-70):(30-50).

[0015] Optionally, the printing paste is patterned on an electrically polarized substrate using a patterning process, wherein the patterning process employs a microelectronic printer dispensing process or a screen printing process.

[0016] Optionally, the substrate with printing paste is sintered to obtain a sensitive film with an electrode layer, wherein the sintering temperature is 700℃~1100℃.

[0017] A second aspect of this application provides a manganese cobalt nickel-based MEMS temperature sensor chip, which is prepared using the method described above.

[0018] A third aspect of this application provides a packaging method for a manganese-cobalt-nickel based MEMS temperature sensor chip, comprising:

[0019] The manganese cobalt nickel-based MEMS temperature sensor chip prepared by the method, or the manganese cobalt nickel-based MEMS temperature sensor chip, is placed in the center of an insulating substrate;

[0020] A cover plate is placed on the insulating substrate to enclose the temperature sensor chip in the cavity between the cover plate and the insulating substrate;

[0021] The cover plate is fixedly connected to the insulating substrate at the connection point;

[0022] The interdigitated electrodes on the sensor chip are connected to the package pins on the insulating substrate to achieve electrical signal output.

[0023] Optionally, fixing the cover plate to the insulating substrate at the connection point includes: using a vacuum reflow soldering process to heat-press the cover plate to the insulating substrate at the connection point.

[0024] Optionally, the interdigitated electrodes on the sensor chip are connected to the package pins on the insulating substrate to achieve electrical signal output, including: an electrode is led out between the interdigitated electrodes and the package pins on the insulating substrate through a gold wire.

[0025] The method for fabricating a manganese cobalt nickel-based MEMS temperature sensor chip provided in this application introduces MEMS technology into the negative temperature coefficient temperature sensor chip processing through the synergistic effect of each step, simplifying the sensor chip fabrication process and reducing the size of the sensor chip to the micrometer level. This helps to achieve the miniaturization of manganese cobalt nickel-based temperature sensors and improve their measurement accuracy.

[0026] Other technical effects resulting from the additional features will be further illustrated in the corresponding embodiments. Attached Figure Description

[0027] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0028] Figure 1 This is a flowchart illustrating a method for fabricating a manganese cobalt nickel-based MEMS temperature sensor chip according to an exemplary embodiment;

[0029] Figure 2 This is a schematic diagram showing the steps of a method for fabricating a manganese cobalt nickel-based MEMS temperature sensor chip according to an exemplary embodiment.

[0030] Figure 3 This is a schematic diagram of the structure of a manganese cobalt nickel-based MEMS temperature sensor according to an exemplary embodiment;

[0031] Figure 4 The temperature-resistance curve is shown in Application Example 1;

[0032] In the diagram: 1 is the substrate, 2 is the positive photoresist, 3 is the electrode layer, 4 is the sensitive film, and 5 is the protective layer;

[0033] 6 is the cover plate, 7 is the chip, 8 is the lead, 9 is the insulating substrate, 10 is the external lead, and 11 is the package pin. Detailed Implementation

[0034] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of the present application, and these all fall within the protection scope of the present application. Parts not described in detail in the following embodiments can be implemented using existing technology.

[0035] Currently, negative temperature coefficient temperature sensors are relatively large, making accurate temperature measurement and control difficult, and they also face the risk of embargoes. To address these issues, this application provides a method for fabricating a manganese-cobalt-nickel based MEMS temperature sensor chip, thereby resolving these problems.

[0036] Reference Figure 1 and Figure 2 As shown in one embodiment of this application, the fabrication method of a manganese cobalt nickel-based MEMS temperature sensor chip includes the following steps:

[0037] S1. Provide pre-powder materials, which include at least cobalt trioxide, manganese dioxide and nickel trioxide;

[0038] S2. Mix the pre-powder material with an organic solvent to obtain the sensor printing paste;

[0039] S3. Provide a substrate 1, form a pattern by photolithography, form an electrode layer 3 on the surface of the substrate 1, and then pattern the electrode layer 3 into interdigitated electrodes;

[0040] S4. The printing paste is patterned on the electrically polarized substrate 1 using a patterning process.

[0041] S5. Sinter the substrate with printing paste to obtain the sensitive film 4 with the electrode layer (i.e., the temperature sensitive layer);

[0042] S6. A protective layer 5 is formed on the sensitive film 4 to obtain a manganese cobalt nickel-based MEMS temperature sensor chip.

[0043] Specifically, in S3, substrate 1 uses rigid substrates such as alumina, silicon oxide, glass, and sapphire. Positive photoresist 2 is spin-coated onto substrate 1 and pre-baked. Electrode pattern areas are formed using photolithography. Electrode layer 3 uses suitable electrode materials with good conductivity, such as Pt, Au, Cu, Ag, and Al. A lift-off process is used to fabricate interdigitated electrodes, which effectively reduces the resistance of the sensitive film 4, allowing for better compatibility with electrical instruments. In S6, protective layer 5 uses insulating ceramic materials such as silicon dioxide, aluminum oxide, aluminum nitride, and silicon carbide. Protective layer 5 is located on the top layer of the device.

[0044] The embodiments described above in this application introduce MEMS technology into the fabrication process of negative temperature coefficient temperature sensor chips through the synergistic effect of each step, simplifying the sensor chip fabrication process and reducing the size of the sensor chip to the micrometer level. This helps to achieve the miniaturization of manganese cobalt nickel-based temperature sensors and improve their measurement accuracy.

[0045] In order to form a negative temperature coefficient thermistor material, in some specific embodiments of this application, in S1, the pre-powder material also includes ferric oxide.

[0046] Specifically, the main components of the pre-powder material are cobalt trioxide, manganese dioxide, and nickel trioxide, with ferric oxide as the fourth material. The components are mixed in proportion and then ground to obtain the pre-powder material for the temperature sensor.

[0047] Specifically, the preparation method of the pre-powder material is as follows:

[0048] S1.1 Calculate the mass ratio of raw materials cobalt trioxide, manganese dioxide, nickel trioxide, and ferric oxide according to the set molar ratio of each component of manganese, cobalt, nickel, and iron;

[0049] S1.2 After weighing the raw materials cobalt trioxide, manganese dioxide, nickel trioxide and ferric oxide according to the calculated mass ratio, add anhydrous ethanol to the raw materials and wet ball mill them to obtain a uniformly mixed powder raw material with a particle size of less than 100um.

[0050] S1.3. The raw materials after ball milling are dried, ground, and sieved to obtain the pre-powder material for the temperature sensor.

[0051] For example, the molar ratio of manganese, cobalt, nickel and iron in the pre-powder material is: manganese:cobalt:nickel:iron = (45~55):(20~25):(15~20):(5~10).

[0052] It should be noted that the fourth material can also be transition metal oxides such as zinc oxide, copper oxide, and chromium oxide.

[0053] In order to form the printing paste for the sensor, in some specific embodiments of this application, in S2, the organic solvent is a mixture of terpineol, ethyl cellulose and dibutyl phthalate, wherein the mass percentage of terpineol, ethyl cellulose and dibutyl phthalate in the mixture is (70-90):(10-20):(5-10).

[0054] In some specific embodiments of this application, the mass percentage of the pre-powder material to the organic solvent is (50-70):(30-50).

[0055] Specifically, the pre-powder material is ground and sieved to obtain uniform powder particles, which are then mixed with organic solvents.

[0056] In order to pattern the printing paste on the polarized substrate through a patterning process, in some specific embodiments of this application, in S4, the patterning process adopts a microelectronic printer dispensing process or a screen printing process.

[0057] Specifically, the dispensing diameter of microelectronic printers ranges from 50 to 200 μm, and the diameter range can be adjusted as needed.

[0058] Compared with existing technologies (such as CN112735709A), the method of preparing electrode layers by screen printing or microelectronic printer dispensing in the embodiments of this application is lower in cost and simpler and more convenient to implement.

[0059] In order to form a sensitive film with an electrode layer, in some specific embodiments of this application, a substrate with printing paste is sintered at high temperature, the organic solvent in the paste is dried and a conductive spinel phase appears, and a sensitive film with an electrode layer is obtained, wherein the sintering temperature is 700℃~1100℃.

[0060] The embodiments described above in this application introduce MEMS technology into the traditional negative temperature coefficient temperature sensor manufacturing process, solving the technical problems of high stability, high dimensional accuracy, and high uniformity requirements for negative temperature coefficient temperature sensor chips.

[0061] The manganese cobalt nickel-based MEMS temperature sensor chip prepared by the above method includes a substrate, an electrode, a temperature-sensitive layer and a protective layer. The electrode is disposed on the substrate, and the temperature-sensitive layer is disposed on the electrode. The temperature-sensitive layer realizes signal transmission through the electrode, and the protective layer is located on the temperature-sensitive layer.

[0062] Currently, the most common packaging method for thermistors is glass packaging. Glass packaging has advantages such as good stability and corrosion resistance. However, glass packaging has disadvantages such as difficulty in molding, mismatch between glass and sensitive material, and slow response speed. In addition, the packaging temperature is close to the sintering temperature of the thermistor, which will affect the performance of the prepared sensor.

[0063] To address the aforementioned problems, based on the same technical concept, another embodiment of this application provides a packaging method for the aforementioned manganese cobalt nickel-based MEMS temperature sensor chip, as described above. Figure 3 The encapsulation method includes the following steps:

[0064] M1. Place the above-mentioned manganese cobalt nickel-based MEMS temperature sensor chip in the center of an insulating substrate;

[0065] M2. Cover the insulating substrate with a cover plate to enclose the temperature sensor chip in the cavity between the cover plate and the insulating substrate;

[0066] M3. Secure the cover plate to the insulating base at the connection point;

[0067] M4. Connect the interdigitated electrodes on the sensor chip to the package pins on the insulating substrate to achieve electrical signal output.

[0068] Specifically, the encapsulated structure includes an insulating substrate 9, a cover plate 6, and a chip 7. The cover plate 6 is connected to the insulating substrate 9, and the chip 7 is placed between the substrate and the cover plate to achieve chip 7 encapsulation. The interdigitated electrodes on the sensor chip are connected to the encapsulation pins 11 on the insulating substrate through leads 8, and the electrodes are led out through external leads 10 to obtain a manganese cobalt nickel-based MEMS temperature sensor.

[0069] In order to achieve a fixed connection between the cover plate and the insulating substrate and improve the sealing performance of the device, in some specific embodiments of this application, the cover plate and the insulating substrate are fixedly connected at the connection point, including: using a vacuum reflow soldering process to heat-press and bond the cover plate and the insulating substrate at the connection point to ensure the vacuum state inside the sensor packaging cover plate.

[0070] In order to achieve electrical output of the signal, in some specific embodiments of this application, the interdigitated electrodes are led out through gold wires between the interdigitated electrodes and the package pins on the insulating substrate.

[0071] Compared with traditional thermistor temperature sensors, the embodiments of this application utilize the high sensitivity of manganese cobalt nickel oxide compounds to simplify the sensor manufacturing process, optimize the sensor packaging structure, improve the sensor measurement accuracy, effectively reduce the existing packaging size, and save process costs.

[0072] The preferred features in the above embodiments can be used individually in any embodiment, or in any combination thereof, provided they do not conflict with each other. Furthermore, parts not described in detail in the embodiments can be implemented using existing technologies.

[0073] The following examples and comparative examples will be used to further illustrate this application in order to better understand the above-mentioned technical solutions. It should be understood that the following are only some examples and are not intended to limit this application.

[0074] Application Example 1:

[0075] This embodiment provides a method for fabricating the printing and packaging structure of a region sensor based on MEMS technology, such as... Figure 2 and Figure 3 As shown, a method for fabricating a manganese cobalt nickel oxide MEMS temperature sensor can be divided into NTC temperature sensor chip fabrication and chip packaging, as described in detail below:

[0076] See Figure 2 As shown, the manganese-cobalt-nickel based MEMS temperature sensor chip can be fabricated using the following method, with the specific steps as follows:

[0077] S1: Cobalt trioxide, manganese dioxide, nickel trioxide, and ferric oxide were weighed according to a ratio of manganese:cobalt:nickel:iron = 45:25:20:10. The mixture was then wet-milled in a ball mill for 12 hours using zirconia ball milling media to obtain a mixed precursor slurry with uniform particle size and good dispersibility. The slurry was then dried at low temperature at 80°C for 5 hours. The resulting powder was ground and sieved to below 100 μm.

[0078] S2: A mechanical solvent is obtained by mixing terpineol, ethyl cellulose and dibutyl phthalate in a mass ratio of 70:20:10.

[0079] The obtained powder was mixed with a mixed organic solvent of terpineol, ethyl cellulose and dibutyl phthalate, and ultrasonically stirred for 30 minutes to obtain a stable microelectronic printing paste with a solid content controlled at 65 wt%.

[0080] S3: As Figure 2 As shown in (a), the substrate material is alumina ceramic with a size of 5mm×5mm×0.5mm. Positive photoresist is spin-coated and pre-baked.

[0081] Electrode pattern areas are formed using a mask lithography process, and an electrode layer (approximately 300 nm thick) is formed by sputtering Au onto the surface.

[0082] Excess areas were removed using a lift-off process to obtain a regular, interdigitated electrode structure with controllable spacing. The electrode spacing was 50 μm, and the linewidth was 50 μm.

[0083] S4: Install the prepared sensor paste into the microelectronic printer cartridge, adjust the printing pressure and printing path, and use the precision dispensing function to deposit the paste onto the area covered by the interdigital electrodes to form a uniform sensitive layer pattern. The dispensing diameter is controlled within 100μm. After printing, perform preliminary curing at 100℃ in an oven.

[0084] S5: The substrate containing the temperature-sensitive layer is placed in a tube furnace and heated to 950°C in air at a heating rate of 5°C / min. After holding at this temperature for 2 hours, it is allowed to cool naturally. After sintering, the sensitive layer and the electrode layer form good contact, exhibiting a dense microstructure and good resistance-temperature response characteristics, such as... Figure 4 As shown.

[0085] S6: After the sensitive layer is sintered, an ion beam deposition method is used to deposit a layer of silicon dioxide as a protective layer on its surface, with a deposition thickness of approximately 300 nm. This protective layer can effectively prevent moisture and impurity ions from affecting the sensitive layer, improving the stability and reliability of the device under actual operating conditions.

[0086] See Figure 3 As shown, the manganese-cobalt-nickel based MEMS temperature sensor can be packaged using the following method, with the specific steps as follows:

[0087] M1: Place the device in the center of the lower cover plate (i.e., the insulating substrate) of the package cavity.

[0088] M2: The top cover of the cover plate is covered with a silicon oxide glass cover, and the two are hot-pressed together by vacuum reflow soldering process. This ensures the integrity of the vacuum cavity structure while reducing the interference of thermal stress on the device performance.

[0089] M3: Finally, gold wire bonding technology is used to connect the interdigitated electrodes on the sensor chip to the package pins through gold wires to achieve electrical signal output.

[0090] M4: Solder the gold-plated copper wire to the package pins to obtain the external leads of the sensor.

[0091] The entire packaging structure is less than 5mm×5mm×1mm in size, which meets the miniaturization requirements of MEMS chip-level packaging.

[0092] Application Example 2:

[0093] This embodiment provides a method for fabricating the printing and packaging structure of a region sensor based on MEMS technology, such as... Figure 2 and Figure 3 As shown, a method for fabricating a manganese cobalt nickel oxide MEMS temperature sensor can be divided into NTC temperature sensor chip fabrication and chip packaging, as described in detail below:

[0094] See Figure 2 As shown, the manganese-cobalt-nickel based MEMS temperature sensor chip can be fabricated using the following method, with the specific steps as follows:

[0095] S1: Mix cobalt trioxide, manganese dioxide, nickel trioxide, and ferric oxide in a ratio of manganese:cobalt:nickel:iron = 55:

[0096] The components were weighed in a 25:15:5 ratio and wet-milled in a ball mill for 12 hours using zirconia ball milling media to obtain a mixed precursor slurry with uniform particle size and good dispersibility. The slurry was then dried at low temperature at 80°C for 5 hours, and the resulting powder was ground and sieved to below 100 μm.

[0097] S2: A mechanical solvent is obtained by mixing terpineol, ethyl cellulose and dibutyl phthalate in a mass ratio of 70:25:5.

[0098] The obtained powder was mixed with a mixed organic solvent of terpineol, ethyl cellulose and dibutyl phthalate, and ultrasonically stirred for 30 minutes to obtain a stable microelectronic printing paste with a solid content controlled at 55 wt%.

[0099] S3: As Figure 2 As shown in (a), the substrate material is alumina ceramic with a size of 5mm×5mm×0.5mm. Positive photoresist is spin-coated and pre-baked.

[0100] Electrode pattern areas are formed using a mask lithography process, and Pt (approximately 300 nm thick) is sputtered onto the surface to form an electrode layer 3.

[0101] Excess areas were removed using a lift-off process to obtain a regular, interdigitated electrode structure with controllable spacing. The electrode spacing was 50 μm, and the linewidth was 50 μm.

[0102] S4: Install the prepared sensor paste into the microelectronic printer cartridge, adjust the printing pressure and printing path, and use the precision dispensing function to deposit the paste onto the area covered by the interdigital electrodes to form a uniform sensitive layer pattern. The dispensing diameter is controlled within 100μm. After printing, perform preliminary curing at 100℃ in an oven.

[0103] S5: The substrate containing the temperature-sensitive layer is placed in a tube furnace and heated to 850°C in air at a heating rate of 5°C / min. After holding at that temperature for 2 hours, it is naturally cooled. After sintering, the sensitive layer and the electrode layer form good contact, and the whole exhibits a dense microstructure with good resistance-temperature response characteristics.

[0104] S6: After the sensitive layer is sintered, an ion beam deposition method is used to deposit a layer of silicon dioxide as a protective layer on its surface, with a deposition thickness of approximately 300 nm. This protective layer can effectively prevent moisture and impurity ions from affecting the sensitive layer, improving the stability and reliability of the device under actual operating conditions.

[0105] See Figure 3 As shown, the manganese-cobalt-nickel based MEMS temperature sensor can be packaged using the following method, with the specific steps as follows:

[0106] M1: Place the device in the center of the lower cover plate (i.e., the insulating substrate) of the package cavity.

[0107] M2: The top cover of the cover plate is covered with a silicon oxide glass cover, and the two are hot-pressed together by vacuum reflow soldering process. This ensures the integrity of the vacuum cavity structure while reducing the interference of thermal stress on the device performance.

[0108] M3: Finally, gold wire bonding technology is used to connect the interdigitated electrodes on the sensor chip to the package pins through gold wires to achieve electrical signal output.

[0109] M4: Solder the gold-plated copper wire to the package pins to obtain the external leads of the sensor.

[0110] The entire packaging structure is less than 5mm×5mm×1mm in size, which meets the miniaturization requirements of MEMS chip-level packaging.

[0111] The above embodiments of this application realize the miniaturization of traditional negative temperature coefficient material temperature sensors. The advantage lies in reducing the sensor chip size to the micrometer level through MEMS technology, and proposing an feasible fabrication method for mass production of sensors, which greatly improves production efficiency and reduces corresponding costs. Through contact-type insulating encapsulation, the response time of the sensor can be effectively shortened and the measurement accuracy can be improved.

[0112] The MEMS temperature sensor prepared in the above embodiments of this application has the characteristics of adjustable resistance, fast response speed and good long-term stability, and can be used in scenarios such as temperature detection of key vehicle components, temperature detection of air conditioning vents, and temperature detection in industrial production.

[0113] In the description of the embodiments of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0114] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0115] In the description of the embodiments in this application, "multiple" means two or more, unless otherwise explicitly specified. In this application, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "fixed," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0116] The terms "comprising" and "having," and any variations thereof, in the embodiments of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or devices.

[0117] The foregoing has described some specific embodiments of this application. It should be understood that this application is not limited to the specific embodiments described above, and those skilled in the art can make various modifications or variations within the scope of the claims, which do not affect the substantive content of this application. The above-described preferred features can be used in any combination without conflict.

Claims

1. A method for fabricating a manganese cobalt nickel-based MEMS temperature sensor chip, characterized in that, include: A pre-treatment powder material is provided, wherein the pre-treatment powder material comprises at least cobalt trioxide, manganese dioxide, and nickel trioxide; The pre-powder material is mixed with an organic solvent to obtain the sensor printing paste; A substrate is provided, a pattern is formed by photolithography, an electrode layer is formed on the surface of the substrate, and then the electrode layer is patterned into interdigitated electrodes; The printing paste is patterned on an electrically polarized substrate using a patterning process; A substrate containing printing paste is sintered to obtain a sensitive film with an electrode layer; A protective layer is formed on the sensitive membrane to obtain a manganese cobalt nickel-based MEMS temperature sensor chip.

2. The method for fabricating a manganese-cobalt-nickel based MEMS temperature sensor chip according to claim 1, characterized in that, The pre-powder material also includes ferric oxide.

3. The method for fabricating a manganese-cobalt-nickel based MEMS temperature sensor chip according to claim 1, characterized in that, The process involves mixing the pre-powder material with an organic solvent to obtain a printing paste for the sensor, wherein the organic solvent is a mixture of terpineol, ethyl cellulose, and dibutyl phthalate, and the mass percentage of terpineol, ethyl cellulose, and dibutyl phthalate in the mixture is (70-90):(10-20):(5-10).

4. The method for fabricating a manganese-cobalt-nickel based MEMS temperature sensor chip according to claim 1, characterized in that, The process involves mixing the pre-powder material with an organic solvent to obtain a printing paste for the sensor, wherein the mass percentage of the pre-powder material to the organic solvent is (50-70):(30-50).

5. The method for fabricating a manganese-cobalt-nickel based MEMS temperature sensor chip according to claim 1, characterized in that, The printing paste is patterned on an electrically polarized substrate using a patterning process, wherein the patterning process employs a microelectronic printer dispensing process or a screen printing process.

6. The method for fabricating a manganese-cobalt-nickel based MEMS temperature sensor chip according to claim 1, characterized in that, The substrate containing the printing paste is sintered to obtain a sensitive film with an electrode layer, wherein the sintering temperature is 700℃~1100℃.

7. A manganese-cobalt-nickel based MEMS temperature sensor chip, characterized in that, It is prepared using the method described in any one of claims 1-6.

8. A packaging method for a manganese cobalt nickel-based MEMS temperature sensor chip, characterized in that, include: The manganese cobalt nickel-based MEMS temperature sensor chip prepared by any one of claims 1-6 or the manganese cobalt nickel-based MEMS temperature sensor chip of claim 7 is placed in the center of an insulating substrate; A cover plate is placed on the insulating substrate to enclose the temperature sensor chip in the cavity between the cover plate and the insulating substrate; The cover plate is fixedly connected to the insulating substrate at the connection point; The interdigitated electrodes on the sensor chip are connected to the package pins on the insulating substrate to achieve electrical signal output.

9. The packaging method for the manganese cobalt nickel-based MEMS temperature sensor chip according to claim 8, characterized in that, The method of fixing the cover plate and the insulating substrate at the connection point includes: using a vacuum reflow soldering process to heat-press the cover plate and the insulating substrate at the connection point.

10. The packaging method for the manganese cobalt nickel-based MEMS temperature sensor chip according to claim 8, characterized in that, Connecting the interdigitated electrodes on the sensor chip to the package pins on the insulating substrate to achieve electrical signal output includes: leading out electrodes between the interdigitated electrodes and the package pins on the insulating substrate via gold wires.

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