A high-precision micro-nano temperature sensor for near-space exploration

Abstract

The application relates to a high-precision micro-nano temperature sensor for near-space detection and belongs to the technical field of temperature measurement. The application adopts a micro-bridge type structure, uses a platinum (Pt) resistance as a temperature measurement sensitive element, and is coated with a radiation-proof plating film on the outer surface of the sensor, and specifically comprises a sensing component, a first electrode, a second electrode, a power supply and a wire; the sensing component comprises a base, an insulating layer, a thermistor and a radiation-proof silver film; the base plays a bearing and external mounting role, the thermistor is attached to the insulating layer which is attached to the base, the thermistor is a platinum film, temperature measurement is realized, the radiation-proof aluminum film is plated on the outer layer, external interference is shielded, and the aluminum film is connected with the wire and the electrode as an electrode. The application has the characteristics of small volume, good resistance linearity, small heat capacity and strong radiation-proof capability, can achieve high measurement precision and very small response time, and solves the problems of temperature precision and response time of near-space detection.

Description

TECHNICAL FIELD

[0001] The application relates to a high-precision micro-nano temperature sensor for near-space exploration. BACKGROUND

[0002] When measuring the temperature in situ in the near space, a sensor needs to be carried by an air-based platform such as a near-space airship or a sounding rocket for in-situ measurement, and the temperature sensor needs to be small and integrated to reduce the gravity load of the air-based platform; the near-space environment is complex, has the characteristics of solar radiation, cloud scattering, low and fast temperature change, low air pressure and high wind speed, and a conventional temperature sensor is difficult to accurately measure in such a complex atmospheric environment.

[0003] The thermal error of the temperature sensor will affect the measurement accuracy and response time: on the one hand, the irradiation of the radiation light on the temperature sensor will heat the entire temperature sensor and the fixed parts, causing temperature rise, and the part in contact with the thermistor will conduct heat to the thermistor, affecting the temperature of the thermistor; on the other hand, due to the thin atmosphere and low air pressure, the heat obtained by the thermistor through heat conduction and its own Joule heat is exchanged with the outside slowly, which also affects the accuracy and rapid response of the temperature sensor.

[0004] At present, the commonly used bead-shaped thermistor temperature sensor for sounding has a large volume, a large heat capacity, a large radiation and slow heat dissipation, low precision and cannot quickly respond. SUMMARY

[0005] The application aims to provide a high-precision micro-nano temperature sensor for near-space exploration, which adopts a micro-bridge structure, uses a platinum (Pt) resistance as a temperature measuring sensitive element, has a size in the micro-nano level, and is coated with an anti-radiation plating film on the outer surface of the sensor, has the characteristics of small volume, good resistance linearity, small heat capacity and strong anti-radiation capability, can achieve high measurement accuracy and very small response time, and solves the problems of temperature measurement accuracy and response time in near-space exploration.

[0006] The application is achieved by the following technical scheme:

[0007] The application relates to a high-precision micro-nano temperature sensor for near-space exploration, which comprises a sensing component, a first electrode, a second electrode, a power supply and a wire.

[0008] The sensing component comprises a base, an insulating layer, a thermistor and an anti-radiation silver film.

[0009] The insulating layer is attached to the upper surface of the base, and the thermistor is attached to the insulating layer.

[0010] The base is a sapphire material, a cuboid, with a through hole in the middle, and the upper and lower surfaces are polished, and the lower surface is used as a fixed mounting surface;

[0011] The through hole of the base is preferably a circular hole or a square hole;

[0012] After etching the base, the middle part of the insulating layer is suspended, the shape of the middle part is the same as that of the through hole of the base, the shape of the outer ring part is the same as that of the middle part, and the middle part is connected to the outer ring part by four micro-bridges, and the size of the outer ring part is smaller than that of the through hole of the base;

[0013] As a preferred, the insulating layer is a silicon dioxide material, which is generated on the upper surface of the base by inductively coupled plasma enhanced chemical vapor deposition;

[0014] The thermistor is a platinum thin film, which is directly exposed to the air, and is preferably a multi-bend serpentine or spiral shape;

[0015] The resistance value of the thermistor is shown as formula (1), and the resistance value of the thermistor is not less than 100Ω;

[0016]

[0017] Wherein, U is the voltage, R is the resistance, I is the current, ρ is the platinum film resistivity, k is the platinum film resistance temperature coefficient, T is the temperature, L is the platinum film resistance length, S is the platinum film resistance cross-sectional area, R0 is the platinum film resistance value at 0℃;

[0018] The heat dissipation model of the platinum film of the thermistor is shown as formula (2), and the larger the surface of the platinum film, the better the heat dissipation;

[0019] Q=a(t w -t0)F (2)

[0020] Wherein, Q is the heat dissipation, a is the heat transfer coefficient, t w is the surface temperature of the platinum film, t0 is the environmental temperature, and F is the surface area of the platinum film;

[0021] The platinum film of the thermistor is deposited and shaped on the middle position of the upper surface of the insulating layer by direct current magnetron sputtering process;

[0022] The anti-radiation silver film is plated on the four peripheral surfaces of the base and the upper surface of the outer ring part of the insulating layer;

[0023] The anti-radiation silver film on the upper surface of the insulating layer is divided into three parts, which are not connected to each other, and two of them are used as electrodes and are connected to the two ends of the platinum film of the thermistor respectively;

[0024] The power supply is connected with the formed electrode of the anti-radiation silver film through the wire, and a loop is formed.

[0025] Preferably, the power supply is a constant current source, and a four-wire connection method is adopted.

[0026] Beneficial effects:

[0027] 1. The high-precision micro-nano temperature sensor for near space exploration has a micro-bridge structure, reduces heat conduction between a platinum thin film and a base, realizes large resistance in a very small volume, and improves sensitivity and precision of temperature measurement.

[0028] 2. The high-precision micro-nano temperature sensor for near space exploration has a platinum thin film of micro-nano size and adopts a good heat dissipation structure to reduce response time.

[0029] 3. The high-precision micro-nano temperature sensor for near space exploration adopts a surface plated anti-radiation aluminum film to reduce radiation interference in the near space environment, and the anti-radiation aluminum film also serves as an electrode in the loop to reduce complexity of the structure. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a structural component schematic view of the high-precision micro-nano temperature sensor for near space exploration.

[0031] Among them, 1 is a power supply, 2 is a wire, 3 is a first electrode, 4 is a second electrode, and 5 is a sensing component.

[0032] Figure 2 It is a three-dimensional structure schematic view of the high-precision micro-nano temperature sensor for near space exploration.

[0033] Among them, 6 is a base, 61 is a through hole, 9 is a side anti-radiation silver film, and 10 is an upper surface anti-radiation silver film.

[0034] Among them, 7 is an insulating layer, and 8 is a thermistor.

[0035] Figure 3 It is an insulating layer schematic view of the high-precision micro-nano temperature sensor for near space exploration.

[0036] Among them, 71 is an intermediate part, 72 is a micro-bridge, 73 is an outer ring part, and 74 is an outer ring inner hole.

[0037] Figure 4 It is a platinum thin film structure schematic view of the high-precision micro-nano temperature sensor for near space exploration.

[0038] Figure 5It is a structure diagram of a radiation-proof silver film and electrode for a high-precision micro-nano temperature sensor for near-space exploration according to the present application;

[0039] Wherein, 101 is a first part of the radiation-proof silver film, 102 is a second part of the radiation-proof silver film, and 103 is a third part of the radiation-proof silver film.

[0040] Figure 6 It is an exploded view of a high-precision micro-nano circular structure temperature sensor for near-space exploration according to the present application; DETAILED DESCRIPTION

[0041] In order to better illustrate the purposes and advantages of the present application, the following further illustrates the content of the application in combination with the drawings and examples.

[0042] Example 1

[0043] As shown in the drawings, Figure 1 a high-precision micro-nano temperature sensor for near-space exploration according to the present application comprises a power supply 1, a wire 2, a first electrode 3, a second electrode 4, and a sensing component 5.

[0044] As shown in the drawings, Figure 2 , Figure 5 the sensing component 5 comprises a substrate 6, an insulating layer 7, a thermistor 8, a side radiation-proof silver film 9, and an upper surface radiation-proof silver film 10.

[0045] As shown in the drawings, Figure 2 , Figure 5 the insulating layer 7 is attached to the upper surface of the substrate 6, and the thermistor 8 is attached to the insulating layer 7.

[0046] As shown in the drawings, Figure 2 in the example, the substrate 6 is a sapphire material, is a cuboid, has a size of 1000 μm x 1000 μm x 500 μm, has a square through hole 61 in the middle, and the upper and lower surfaces are polished.

[0047] As shown in the drawings, Figure 3 in the example, the insulating layer 7 is a silicon dioxide material, is generated on the upper surface of the substrate 6 by an inductively coupled plasma enhanced chemical vapor deposition method, after etching of the substrate 6, a suspended middle part 71 is formed, the middle part 71 has the same shape as the through hole 61 of the substrate 6, an outer ring part 73 has the same shape as the middle part 71, the middle part 71 is connected to the outer ring part 73 through four micro-bridges 72, and the size of the outer ring part 73 is smaller than the size of the through hole of the substrate 6, which is conducive to heat insulation.

[0048] The insulating layer 7 is arranged between the substrate 6 and the thermistor 8, reduces heat transfer between the thermistor 8 and the substrate 6, and realizes electrical insulation.

[0049] AsFigure 4 As shown in the embodiment, the thermistor 8 is a multi-bend serpentine platinum thin film, which is deposited and formed in the middle position of the upper surface of the insulating layer by DC magnetron sputtering process to increase adhesion;

[0050] The platinum film of the thermistor 8 is directly exposed to the air, which allows it to better sense the external temperature, improve sensor accuracy, and dissipate heat better, thus improving response time.

[0051] The resistance value of thermistor 8 is shown in equation (1):

[0052]

[0053] Where U is voltage, R is resistance, I is current, ρ is resistivity of platinum film, k is temperature coefficient of platinum film resistance, T is temperature, L is length of platinum film resistor, S is cross-sectional area of ​​platinum film resistor, and R0 is resistance value of platinum film at 0℃.

[0054] The heat dissipation model of the platinum thin film of thermistor 8 is shown in Equation (2). The larger the heat dissipation surface of the platinum thin film, the better the heat dissipation.

[0055] Q = a(t) w -t0)F (2)

[0056] Where Q is the heat dissipation, a is the heat transfer coefficient, and t w t is the surface temperature of the platinum thin film, t0 is the ambient temperature, and F is the heat dissipation surface of the platinum thin film;

[0057] In this embodiment, the platinum film of the thermistor 8 has a thickness of 200 nm, a width of 10 μm, and a resistance of 120 Ω.

[0058] like Figure 5 As shown, in this embodiment, the side radiation-shielding silver film 9 is deposited on the four sides of the substrate 6, and the upper surface radiation-shielding silver film 10 is deposited on the upper surface of the outer ring portion 73 of the insulating layer 7. The thickness of the prepared silver film is 50 nm.

[0059] The upper surface anti-radiation silver film 10 is divided into three parts, which are not connected to each other. The first part 101 of the anti-radiation silver film acts as the first electrode 3, the second part 102 of the anti-radiation silver film acts as the second electrode 4; 103 is the third part of the anti-radiation silver film.

[0060] like Figure 1 As shown in the embodiment, the power supply 1 is a constant current source and uses a four-wire connection. The first electrode 3 and the second electrode 4 are respectively connected to the two ends of the platinum film of the thermistor 8 and form a circuit with the power supply 1.

[0061] Example 2:

[0062] like Figure 6As shown, the embodiment 2 is completely identical with the structure of the embodiment 1, the technical parameters of the power supply 1, the wire 2, the first electrode 3, the sensing component 5 are completely same, the connecting modes of the second electrode 4 and the sensing component 5 are completely same, the difference between the embodiment 2 and the embodiment 1 is only that the thermal resistor 8 is spiral, and the inner ring, the outer ring of the insulating layer 7 and the through hole 61 of the base 6 corresponding to the thermal resistor 8 are all circular.

[0063] The above detailed description is further detailed for the purpose, technical scheme and beneficial effects of the application, and it should be understood that the above description is only a specific embodiment of the application and is not used to limit the protection scope of the application, and any modification, equivalent replacement, improvement, etc. within the spirit and principle of the application should be included in the protection scope of the application.

Claims

1. A high-precision micro-nano temperature sensor for near-space exploration, characterized in that: The micro-bridge structure is adopted, and a platinum (Pt) resistance is used as a temperature measuring sensitive element, and the size is in the micro-nano level, and a radiation-proof coating film is coated on the outer surface of the sensor, and the sensor comprises a power supply (1), a lead wire (2), a first electrode (3), a second electrode (4) and a sensing component (5). The sensing component (5) comprises a substrate (6), an insulating layer (7), a thermistor (8) and a radiation-proof silver film. The insulating layer (7) is attached to the upper surface of the substrate (6), and the thermistor (8) is attached to the insulating layer (7). The substrate (6) is made of sapphire material and is a cuboid with a through hole in the middle, and the upper and lower surfaces are polished, and the lower surface is used as a fixed mounting surface. After etching of the substrate (6), the middle part (71) of the suspended insulating layer (7) is formed, the middle part (71) has the same shape as the through hole (61) of the substrate (6), the outer ring part (73) has the same shape as the middle part (71), and the middle part (71) is connected to the outer ring part (73) through four micro-bridges (72), and the size of the outer ring part (73) is smaller than the size of the through hole (61) of the substrate (6). The thermistor (8) is a platinum thin film directly exposed to the air. The resistance value of the thermistor (8) is shown in formula (1), and the resistance value of the thermistor (8) is not less than 100Ω. Wherein, U is the voltage, R is the resistance, I is the current, ρ is the platinum thin film resistivity, k is the platinum thin film resistance temperature coefficient, T is the temperature, L is the platinum thin film resistance length, S is the platinum thin film resistance cross-sectional area, and R0 is the platinum thin film resistance value at 0℃. The heat dissipation model of the platinum thin film of the thermistor (8) is shown in formula (2), and the larger the platinum thin film surface is, the more conducive to heat dissipation. Q = a(t w -t0)F (2) Wherein, Q is the heat dissipation, a is the heat transfer coefficient, t w is the platinum film surface temperature, t0 is the ambient temperature, F is the platinum film surface area; The platinum thin film of the thermistor (8) is deposited and shaped at the middle position of the upper surface of the insulating layer (7) through a direct current magnetron sputtering process. The radiation-proof silver film is plated on the four peripheral surfaces of the substrate (6) and the upper surface of the outer ring part (73) of the insulating layer (7). The radiation-proof silver film on the upper surface of the insulating layer (7) is divided into three parts, which are not connected to each other, and two of them serve as electrodes and are connected to the two ends of the platinum thin film of the thermistor (8). The power supply (1) is connected to the electrodes formed by the radiation-proof silver film through the lead wire (2) to form a loop.

2. The high-precision micro / nano temperature sensor for near-space exploration according to claim 1, characterized in that: The through hole (61) of the substrate (6) is preferably a circular hole or a square hole.

3. The high-precision micro / nano temperature sensor for near-space exploration according to claim 1, characterized in that: The insulating layer (7) is made of silicon dioxide material and is generated on the upper surface of the substrate (6) by an inductively coupled plasma enhanced chemical vapor deposition method.

4. The high-precision micro / nano temperature sensor for near-space exploration according to claim 1, characterized in that: The thermistor (8) is a multi-bend serpentine or spiral shape.

5. The high-precision micro / nano temperature sensor for near-space exploration according to claim 1, characterized in that: The power supply (1) is a constant current source and adopts a four-wire connection method.

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