Atomic layer thermopile heat flow sensor with water cooling and preparation and assembly method thereof

Abstract

The invention relates to the technical field of thermoelectric effect and heat flux density detection, and discloses an atomic layer thermopile heat flux sensor with water cooling and preparation and assembly methods, the heat flux sensor comprises a sensor chip and a cooling assembly, the bottom layer of the sensor chip is a substrate layer with the 001 crystal face beveled by 15 degrees, and the bottom layer of the sensor chip is a substrate layer with the 001 crystal face beveled by 15 degrees. A layered heat flow sensitive film on the substrate is a YBa2Cu3O7-delta film grown through pulse laser deposition, and double-layer metal electrodes are prepared at the two ends of the surface of the YBa2Cu3O7-delta film; and the cooling assembly is used for carrying out water cooling on the sensor chip and packaging the sensor chip. According to the invention, a YBa2Cu3O7-delta thin film with a large inclination angle is prepared on a single crystal lanthanum aluminate LaAlO3 substrate which is beveled by 15 degrees; the high-temperature-resistant Ni / Pt and Ni / W double-layer electrode is prepared on the surface of the YBa2Cu3O7-delta thin film, annealing is carried out, the contact strength of the YBa2Cu3O7-delta thin film and an electrode material is improved, the contact resistance is reduced, and the electric signal strength is improved; the cooling assembly improves the stability of the device in a large-heat-flow and long-time working scene.

Description

Technical Field

[0001] The present invention relates to the technical field of thermoelectric effect and heat flux density detection, and in particular to an atomic layer thermopile heat flux sensor with water cooling and a preparation and assembly method thereof, which is mainly used for heat flux density detection and testing. Background Art

[0002] Heat flux density, also known as heat flux, refers to the heat energy passing through a unit area per unit time and is a directional vector. It is different from the scalar temperature and can more accurately and timely reflect the thermal effect and heat distribution of an object in engineering applications. Combined with the thermophysical parameters of the object, the evolution of the temperature field can be further accurately predicted. Accurate and rapid detection of heat flow has an urgent application demand in some special engineering research fields, such as studying the heat generated by the impact and friction of high-speed airflow on the skin surface of a spacecraft during supersonic flight or re-entering the atmosphere, guiding aerodynamic layout design and thermal protection design; such as thermal damage assessment during the explosion of weapon warheads; thermal management of new energy power batteries, etc.

[0003] The mainstream heat flux detection products on the market are metal film thermopiles and semiconductor thermopiles. This type of heat flux sensor is based on the Seebeck effect, which uses the difference in Seebeck coefficient properties between different conductors or semiconductors. When the two materials with different Seebeck coefficients come into contact, a temperature difference is generated at the junction and a thermoelectric potential is output. The thermoelectric potential output by the detection device can be used to infer the measured heat flux density.

[0004] Limited by their device principles and structures, metal film thermopiles and semiconductor thermopiles cannot achieve high time resolution heat flux density measurement. Therefore, relevant studies have proposed heat flux sensors based on the atomic layer thermopile principle. In theory, atomic layer thermopile heat flux sensors can achieve faster response times and achieve higher time resolution heat flux detection. However, there are still some problems in the development and research of existing atomic layer thermopile heat flux sensors.

[0005] The defects of the prior art are as follows:

[0006] 1) Existing products of the same type (atomic layer thermopile heat flux sensor) lack continuous cooling components and cannot work for a long time in high heat flux density scenarios.

[0007] 2) Based on the working principle of the atomic layer thermopile type heat flow sensor, the film inclination angle affects the sensor sensitivity, and the thickness affects its response time. Therefore, it is necessary to solve the film structure design problems such as the film inclination angle and thickness to obtain excellent sensitivity and response time.

[0008] 3) From the material level, it is not easy to prepare high-quality single-crystal atomic layer thermopile films with large inclination angles. Summary of the invention

[0009] The purpose of the present invention is to provide a fast-response atomic layer thermopile heat flux sensor with water cooling for large heat flux density and long-time measurement, as well as a preparation and assembly method.

[0010] The present invention provides the following technical solutions:

[0011] In a first aspect, the present invention provides an atomic layer thermopile heat flow sensor with water cooling, comprising a sensor chip (1) and a cooling assembly, wherein the bottom layer of the sensor chip (1) is a 001 crystal plane with a 15° beveled substrate layer, and the layered heat flow sensitive film thereon is a YBa2Cu3O3 grown by pulsed laser deposition. 7-δ The YBa2Cu3O thin film 7-δ Double-layer metal electrodes are prepared at both ends of the film surface; the cooling component is used for water cooling the sensor chip (1) and packaging the sensor chip (1).

[0012] According to some embodiments, the cooling component includes a chassis (5), a heat sink (6) is provided on the chassis (5), a cylindrical cover (7) covers the heat sink (6) and is connected to the chassis (5), the top surface of the heat sink (6) is embedded in the sensor chip (1) and fixed by the cover (7), the lower water inlet pipe (2) and the water outlet pipe (3) pass through the chassis (5) and pass through the heat sink (6), forming a water cooling circuit under the sensor chip (1); the lower lead tube (4) passes through the chassis (5) and the heat sink (6) and is used to pass the leads of the sensor chip (1).

[0013] According to some embodiments, a cylindrical boss is provided on the bottom plate (5), and two fourth holes (54) for respectively passing the water inlet pipe (2) and the water outlet pipe (3) and a fifth hole (55) for passing the lead pipe (4) are provided in the cylindrical boss;

[0014] The heat sink (6) comprises a heat sink body (61) for heat conduction, a circular groove (67) is provided at the bottom of the heat sink body (61), and the cylindrical boss is embedded in the circular groove (67); a top groove (62) for embedding the sensor chip (1) is provided at the top center of the heat sink body (61); a waist-shaped hole (63) is provided below the top groove (62) along the radial direction of the heat sink body (61), and both ends of the waist-shaped hole (63) are blocked by metal blocks (631); two axial holes (631) for cooling water inlet and outlet are provided in the heat sink body (61) and are connected to the waist-shaped hole (63). 4), the axial hole (64) is connected with the two fourth holes (54); the opposite groove edges of the top groove (62) are each provided with a sixth hole (66); a radial transverse through hole (65) for hand operation is provided in the cross direction between the two axial holes (64); a ninth hole (69) and an eighth hole (68) for assembling the heat sink body (61) and the chassis (5) are provided on the lower side of the hole wall of the transverse through hole (65); the sixth hole (66), the transverse through hole (64), the ninth hole (69) and the fifth hole (55) are passed through to penetrate the leads of the sensor chip (1).

[0015] According to some embodiments, a cover top hole (71) corresponding to the sensor chip (1) is provided on the top of the cover (7).

[0016] According to some embodiments, the material of the heat sink body (61) is selected from metal aluminum, metal copper or stainless steel.

[0017] According to some embodiments, thermal conductive silicone grease is provided between the sensor chip (1) and the top groove (62).

[0018] According to some embodiments, the substrate layer is selected from a LaAlO3 single crystal substrate or a SrTiO3 single crystal substrate; and the double-layer metal electrode is selected from metal tungsten W or metal platinum Pt deposited on a Ni seed layer.

[0019] In a second aspect, the present invention provides a method for preparing a sensor chip of the atomic layer thermopile heat flow sensor with water cooling as described above, which comprises the following steps:

[0020] S11: Using pulsed laser deposition technology, YBa2Cu3O is deposited on a LaAlO3 single crystal substrate with a 15° bevel on the 001 crystal plane or on a SrTiO3 single crystal substrate. 7-δ film;

[0021] S12: The obtained YBa2Cu3O 7-δ The film was annealed in situ, annealing conditions: 500 °C, for 1 h;

[0022] S13: in YBa2Cu3O 7-δA 2 mm wide and 20 nm thick nickel metal Ni is deposited at both ends of the film as a seed layer;

[0023] S14: After depositing the metal Ni, depositing metal platinum Pt or metal tungsten W with a thickness of 80 nm on the surface of the metal Ni to form an electrode;

[0024] S15: After depositing the electrode, annealing is performed again to obtain the sensor chip (1) with the electrode. Annealing conditions: 500° C. for 1 hour;

[0025] S16: Using silver paste to weld the enameled silver wires onto the electrodes on both sides of the sensor chip (1).

[0026] According to some embodiments, the YBa2Cu3O prepared in step S11 7-δ The film had a tilt angle of 15° and a thickness of 200 nm.

[0027] In a third aspect, the present invention provides a method for assembling the above-mentioned atomic layer thermopile thermal flow sensor with water cooling, which comprises the following steps:

[0028] S21: Using bolts, align and assemble the chassis (5) and the heat sink (6) through the second hole (52) and the eighth hole (68). During the alignment and assembly, the fourth hole (54) on the chassis (5) and the axial hole (64) on the heat sink (6) are precisely aligned as channels for circulating water, and the contact surfaces are waterproofly sealed by a rubber ring;

[0029] S22: The water inlet and outlet pipes and the lead pipe (4) are respectively assembled with the fourth hole (54) and the fifth hole (55) on the chassis (5) through threads. During installation, the axial centers of the water inlet and outlet pipes, the fourth hole (54) on the chassis (5) and the axial hole (64) on the heat sink (6) are aligned;

[0030] S23: peel off part of the shielding layer of the signal wire with a pure silver wire core and a shielding wire, and pass the two signal wires from the bottom of the lead tube (4) from bottom to top through the two sixth holes (66) on the heat sink (6);

[0031] S24: welding the two silver wires on the sensor chip (1) to the signal wires led out from the sixth hole (66) respectively, and insulating the welding points;

[0032] S25: placing thermal conductive silicone grease on the top groove (62), and installing the sensor chip (1) in the top groove (62);

[0033] S26: Tighten the excess wire from the lead tube (4), and pour waterproof silicone rubber into the lead tube (4), waiting for solidification, so that the sensor chip (1) is fixed by the viscosity of the thermal conductive silicone grease and the tension of the signal line;

[0034] S27: welding the shielding wire of the signal wire to the lead tube (4) to form a shielding layer;

[0035] S28: The cover (7) is mounted and fixed on the chassis (5) from the top downwards. Before assembly, thermal conductive silicone grease is placed on the top of the heat sink (6);

[0036] S29: Bolts are used to assemble through the third hole (53) on the chassis (5) and the cover edge hole (72) of the cover (7). After tight assembly, the thermal conductive silicone grease between the top inner surface of the cover (7) and the top of the heat sink (6) is subjected to a pre-tightening force, which plays a role in fixing the sensor chip (1), thereby obtaining the atomic layer thermopile heat flow sensor with water cooling.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. Yttrium barium copper oxide (YBa2Cu3O) with a large tilt angle was prepared on a single crystal lanthanum aluminate (LaAlO3) substrate with a 15° bevel. 7-δ )film.

[0039] 2. In YBa2Cu3O 7-δ High temperature resistant (high temperature resistant means not easy to oxidize and fall off under high temperature environment, and can work stably) Ni / Pt and Ni / W double-layer electrodes were prepared on the surface of the film and annealed to increase the YBa2Cu3O 7-δ Improve the contact strength between the film and electrode material, reduce contact resistance, and enhance electrical signal strength.

[0040] 3. Designed a packaging structure for the sensor with water cooling. Designed and processed a water channel under the chip slot, so that circulating cooling water can pass through the inside of the packaging base, and continuously cool down through the cooling components, so that it can work for a long time in a high heat flux density scenario.

[0041] 4. Sensor packaging design materials, such as the material of the heat sink body, can be made of metal aluminum, metal copper or stainless steel. This avoids the ceramics used in existing technologies, reducing material costs and processing difficulties. In addition, metal aluminum (metal copper and stainless steel can also be used) has good thermal conductivity, which improves the heat dissipation performance of the water cooling design on the bottom of the chip, thereby 1) being able to quickly establish heat transfer balance on the upper / lower surface (hot end / cold end) of the chip and improve the response time of the sensor; 2) in the measurement scenario of the same heat flux density, it can generate a larger temperature difference on the upper / lower surface of the chip, which can improve the sensitivity compared to heat flux sensors without water cooling; 3) in the measurement scenario of high heat flux density, it can extend the service life and survival time of the chip.

[0042] 5. Optimized the heat conduction between the sensor chip and the sensor package base. Add thermal grease between the sensor chip and the chip slot to ensure heat conduction between the two.

[0043] 6. The sensor chip lead material and welding process are optimized, and the shielded signal line is welded correctly to reduce noise and ensure effective signals, thereby improving the sensor signal quality. After the signal is drawn from the chip electrode using enameled silver wire, the silver wire is welded to the Teflon-coated signal line with a shielding layer. In addition, the shielding layer of the signal line needs to be welded to the sensor package shell to form a complete shielding layer. Protect the effective signal, reduce noise, and improve the signal quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the structure of a sensor chip provided in an embodiment of the present invention.

[0045] Figure 2 Front and side cross-sectional views of an atomic layer thermopile heat flow sensor with water cooling provided in an embodiment of the present invention.

[0046] Figure 3 a is a front view of a chassis provided by an embodiment of the present invention.

[0047] Figure 3 b is a side view of the chassis provided by an embodiment of the present invention.

[0048] Figure 3 c is a top view of the chassis provided by an embodiment of the present invention.

[0049] Figure 3 d is a perspective isometric view of the chassis provided by an embodiment of the present invention.

[0050] Figure 4a A perspective isometric view of a heat sink provided in accordance with an embodiment of the present invention.

[0051] Figure 4b A cross-sectional view of a heat sink provided in an embodiment of the present invention.

[0052] Figure 4c A radial cross-sectional view of a transverse through hole provided in an embodiment of the present invention.

[0053] Figure 4d A top view of a heat sink provided in an embodiment of the present invention.

[0054] Figure 5a A perspective isometric view of a lid provided for an embodiment of the present invention.

[0055] Figure 5b A side view of a cover provided for an embodiment of the present invention.

[0056] Figure 5c A top view of a cover provided in accordance with an embodiment of the present invention.

[0057] Figure 6aThermoelectric potential curves of the atomic layer thermopile heat flow sensor structure with water cooling and without water cooling provided in the embodiments of the present invention under different heat flow conditions.

[0058] Figure 6b The linear fitting results of the sensitivity calibration of the atomic layer thermopile heat flow sensor structure with water cooling and without water cooling provided by the embodiment of the present invention under the condition of applying different heat flows are shown.

[0059] In the figure:

[0060] Sensor chip 1; water inlet pipe 2; water outlet pipe 3; lead tube 4; chassis 5; first hole 51; second hole 52; third hole 53; fourth hole 54; fifth hole 55; heat sink 6; heat sink body 61; top groove 62; waist-shaped hole 63; metal block 631; axial hole 64; transverse hole 65; sixth hole 66; circular groove 67; eighth hole 68; ninth hole 69; cover 7; cover top hole 71; cover side hole 72. DETAILED DESCRIPTION

[0061] The present invention is described in detail below in conjunction with the embodiments and drawings, but it should be understood that the embodiments and drawings are only used to exemplify the present invention and do not constitute any limitation on the protection scope of the present invention. All reasonable changes and combinations within the scope of the inventive concept of the present invention fall within the protection scope of the present invention.

[0062] The existing metal film thermocouple type heat flow sensor is based on the Seebeck effect. It uses MEMS processing technology to process thermocouples and thermal resistors and other structures on the substrate. Under the influence of heat flow, a temperature difference is generated at the hot end and the cold end. The output potential signal of the thermopile under different heat flow is detected to measure the heat flow.

[0063] In practical applications, the main focus of heat flow sensors is sensitivity (the size of the thermoelectric potential output under unit heat flux density) and response time (the time difference from the influence of heat flux density to the output of stable potential, generally 60% of the rising edge time). For metal film thermocouple heat flow sensors, the sensitivity expression is:

[0064] E=NΔS·ΔT (1)

[0065] Where N is the number of thermocouple logarithms; ΔS is the difference in Seebeck coefficients of the two materials; ΔT is the temperature difference between the hot end and the cold end. Its output sensitivity can be adjusted not only by designing the number of thermocouple logarithms, but also by the temperature difference between the hot end and the cold end. The more essential source of the temperature difference between the hot end and the cold end lies in the presence of the thermal resistance layer. In addition, its response time is related to the equilibrium time of the temperature difference established between the hot end and the cold end of the thermocouple, that is, it is related to parameters such as the material and thickness of the thermal resistance layer. Due to the presence of the thermal resistance layer, fast response time cannot be obtained on metal thin film thermopiles or semiconductor thermopiles heat flux sensors. The response time of currently reported metal thin film thermopile heat flux sensors is generally on the order of ~100ms.

[0066] However, for the high-frequency pulse heat flux density detection in the scenarios of hypersonic flight and thermal damage performance of weapon and ammunition explosion, higher requirements are placed on the response speed of the heat flux sensor. The atomic layer thermopile based on the transverse thermoelectric effect has the characteristics of fast response speed and can meet the needs of the above application scenarios. The atomic layer thermopile utilizes the anisotropy of the thermoelectric properties of layered materials. The basic principle is that the Seebeck coefficients in the ab plane and out-of-plane c-axis directions of the thin film material are anisotropic ΔS=(S ab -S c ), when the material grows at an inclination angle θ, the Seebeck effect will cause different electric fields to be generated in the x and z directions of space. x It is easy to measure, and the direction of the electric field is perpendicular to the direction of the thermal field. x The expression is:

[0067]

[0068] Where Δ z T is the temperature difference along the z direction, d is the thickness of the sensitive film, is the temperature gradient along the z direction, and l is the effective measurement length along the x direction. To obtain the transverse voltage signal, the film needs to satisfy S ab ≠S c There is an angle θ≠0° or 90° between the c-axis of the film and the normal line. By increasing the tilt angle θ of the film or appropriately reducing the film thickness d, the lateral U of the device can be improved. x At the same time, the reduction of film heat capacity can also reduce the device response time and improve the response speed. Therefore, the lateral thermoelectric thin film heat flow sensor based on the anisotropic Seebeck coefficient of a single material can achieve high sensitivity and fast response speed at the same time. In order to obtain an atomic layer thermopile heat flow sensor with better performance and stability, work was carried out based on the above background and technical defect analysis.

[0069] Therefore, the technical ideas of the present invention are as follows:

[0070] 1) Based on the working principle of the atomic layer thermopile heat flow sensor, the film inclination angle affects the sensor sensitivity, and the thickness affects its response time. Therefore, it is necessary to solve the film structure design problems such as the film inclination angle and thickness to obtain excellent sensitivity and response time.

[0071] 2) From the material level, solve the difficulty of preparing large-angle, high-quality single-crystal films.

[0072] 3) From the packaging design perspective, solve the problems of packaging structure material optimization, heat sink circulation water channel design, and signal line lead-out.

[0073] In addition, in order for the atomic layer thermopile thermal flow sensor to cope with complex working conditions such as high temperature and impact in the above scenarios, it is also necessary to research and design a reliable packaging structure for it.

[0074] The present invention aims to utilize a layered material with thermoelectric transport anisotropy to grow an epitaxial thin film on a suitable beveled single crystal substrate through pulsed laser deposition technology to prepare a sensor chip, and to improve its working stability and anti-interference performance in high heat flux density, long-term service scenarios through reliable packaging design.

[0075] The atomic layer thermopile heat flow sensor with water cooling provided by the present invention comprises a sensor chip 1 and various components that are water-cooled and packaged.

[0076] The present invention will be further described below in conjunction with the accompanying drawings.

[0077] Example 1

[0078] 1. Sensor chip

[0079] The sensor chip 1 provided in this embodiment is a layered structure. Figure 1 The bottom layer of the sensor chip 1 is a LaAlO3 substrate layer with a (001) crystal plane and a 15° bevel. The layered heat flow sensitive film on it is a YBa2Cu3O grown by pulsed laser deposition technology. 7-δ Thin film, YBa2Cu3O 7-δ Double-layer metal electrodes are prepared at both ends of the film surface.

[0080] 2. Packaging structure design

[0081] This embodiment adopts a "plug-type" packaging design (the appearance is similar to a plug), and the axial cross-section of the sensor packaging design structure is as follows: Figure 2 The material of all components is aluminum with an oxidized surface. The structure of the package design includes a water inlet pipe 2, a water outlet pipe 3, a lead pipe 4, a chassis 5, a heat sink 6 and a cover 7 from bottom to top.

[0082] Component structure introduction:

[0083] 1) If Figure 2 The lower ends of the inlet and outlet water pipes and the lead-in pipe 4 are pagoda heads, and the upper ends are provided with threads for assembly.

[0084] 2) If Figure 3 .a is a front view of the chassis 5, Figure 3 .b is a left view of chassis 5, Figure 3 .c is a top view of the chassis 5, Figure 3 .d is a perspective axonometric view of the chassis 5. The chassis 5 is a disc-shaped chassis as a whole, with a cylindrical boss protruding upward in the center, and an annular groove on the outside of the cylindrical boss; the outer periphery of the annular groove has three first holes 51 (assembly holes for test installation), two opposite second holes 52 (for assembly with the heat sink 6) on the upper and lower sides of the cylindrical boss, three grooves protruding evenly outward from the annular groove, each of which is provided with a third hole 53 (for assembly with the cover 7), two fourth holes 54 (threaded holes for assembly with the inlet and outlet water pipes) on the left and right sides of the cylindrical boss, and a center hole 55 (threaded hole for assembly with the lead-in tube 4) at the center of the cylindrical boss.

[0085] 3) As shown in FIG4.a, it is an axial perspective view of the heat sink body 61, as shown in FIG4.b, it is a front cross-sectional view of the heat sink body 61, and it is a side view of the transverse through hole 65, as shown in FIG4.c, it is a left cross-sectional view of the heat sink body 61, and as shown in FIG4.d, it is a top view of the heat sink body 61. The heat sink 6 is used to cool the sensor chip 1 and maintain a constant low temperature at the bottom of the sensor chip 1 when it is working (using cooling water at room temperature 25°C as the cooling medium). It includes a cylindrical heat sink body 61, and the material of the heat sink body 61 is metal aluminum (surface oxidation process). A rectangular top groove 62 is provided on the top of the heat sink body 61, and the sensor chip 1 is placed in the top groove 62. A waist-shaped hole 63 is opened 1mm below the top groove 62. For the convenience of processing, the waist-shaped hole 63 is designed as a through hole along the radial direction of the heat sink, and then a metal block 631 is used to seal the two ends with sealant. The two axial holes 64 in the heat sink 6 are connected to the waist-shaped hole 63 to form a cooling water channel, and are externally connected to the water inlet pipe 2 and the water outlet pipe 3. The heat sink body 61 is provided with a square transverse through hole 65 in the diameter direction to facilitate manual operation when the lead wire is led out. A sixth hole 66 is provided at the groove edge of the top groove 62 for leading out the lead wire of the sensor chip 1. A circular groove 67 with an opening downward is provided at a certain distance below the bottom of the heat sink body 61 and the transverse through hole 65. An eighth hole 68 and a ninth hole 69 are provided between the circular groove 67 and the transverse through hole 65. The ninth hole 69 in the middle is a threaded hole for assembly with the lead tube 4. The eighth hole 68 is a threaded hole for assembly with the chassis 5.

[0086] 4) As shown in Fig. 5.a, Fig. 5.b and Fig. 5.c, the cover 7 is a cylindrical shell with a skirt and cover ears at the bottom. A rectangular cover hole 71 is opened on the top, so that the sensor chip 1 can receive external heat flux through the rectangular hole after being installed in place. The size of the cover hole 71 is smaller than that of the sensor chip 1, and the cover hole 71 only exposes the sensitive material of the sensor chip 1, that is, Figure 1 The layered heat flow sensitive film in the middle of the electrodes at both ends is covered and fixed by the cover 7; the cover ears at the bottom of the cover 7 are provided with cover edge holes 72, which are assembly holes for matching the cover with the chassis.

[0087] This embodiment also provides a method for preparing the above-mentioned atomic layer thermopile heat flow sensor with water cooling, including the working steps of S1 chip preparation and S2 device assembly.

[0088] S1 includes the following steps:

[0089] S11: Using pulsed laser deposition technology, YBa2Cu3O was deposited on a LaAlO3 single crystal substrate with a 15° bevel on the (001) crystal plane. 7-δ The process parameters are set as follows: control the substrate temperature to 750-800°C; maintain the oxygen partial pressure to 40Pa; set the pulse laser output energy to 350mJ; control the laser beam area reaching the target surface to 0.02cm 2 , corresponding to laser energy density 1.8-2.0J / cm 2 , pulse frequency 3Hz. Controlling the deposition time can obtain films of different thicknesses. This embodiment preferably prepares YBa2Cu3O with an inclination angle of 15° and a thickness of 200nm 7-δ Theoretically, the larger the tilt angle of YBa2Cu3O 7-δ The film has a greater sensitivity. The YBa2Cu3O 7-δ The film is a preferred solution that has the characteristics of easy preparation, high yield and high sensitivity (sensitivity formula is shown in Formula 2).

[0090] S12: In-situ annealing is performed on the film obtained by the above preparation process to reduce internal defects of the material and obtain a film with higher quality. Annealing conditions: 500° C., for 1 hour.

[0091] S13: After the film is annealed, a 2 mm wide and 20 nm thick metal nickel Ni is deposited on both ends of the film as a seed layer using magnetron sputtering technology. The process parameters are: Ar flow rate 80 sccm, working gas pressure 0.5 Pa; sputtering power 80 W.

[0092] S14: After depositing metal Ni, a metal platinum (Pt) with a thickness of 80 nm is deposited on the surface of the metal Ni by magnetron sputtering technology to form an electrode. The process parameters for depositing Pt are: Ar flow rate 100 sccm, working gas pressure 0.5 Pa; sputtering power 80 W.

[0093] S15: After depositing the electrodes, annealing is performed again to obtain a heat flow sensor chip 1 with electrodes. Annealing conditions: 500° C., for 1 hour.

[0094] S16: Use silver paste to solder the enameled silver wire to the electrodes on both sides of the sensor chip 1. The silver paste is dried using a hot air gun at a temperature of 380° C. The enameled silver wire must be polished to expose the silver wire.

[0095] S2 includes the following steps:

[0096] S21: Use bolts to align and assemble the chassis 5 and the heat sink 6 through the second hole 52 and the eighth hole 68. During the alignment and assembly, the fourth hole 54 on the chassis 5 and the axial hole 64 on the heat sink 6 as the passage of circulating water should be accurately aligned, and their contact surfaces are waterproofly sealed by rubber rings.

[0097] S22: The water inlet and outlet pipes and the lead pipe 4 are respectively assembled with the fourth hole 54 and the fifth hole 55 on the chassis 5 by threads. During installation, the water inlet and outlet pipes, the fourth hole 54 on the chassis 5 and the axial hole 64 on the heat sink 6 are aligned with each other.

[0098] S23: peel off part of the shielding layer of the signal wire with shielding wire (the wire core is pure silver wire), and pass the two signal wires through the sixth hole 66 on the heat sink 6 from the bottom to the top from the bottom of the lead tube 4.

[0099] S24: Solder the two silver wires on the sensor chip 1 to the signal wires led out from the sixth hole 66 respectively, and insulate the welding points.

[0100] S25 : placing a piece of thermal conductive silicone grease of appropriate size on the top groove 62 , and then installing the sensor chip 1 in the top groove 62 .

[0101] S26: Tighten the redundant wires from the lead tube 4, and pour waterproof silicone rubber into the lead tube 4, and wait for curing. The sensor chip 1 is fixed by the viscosity of the thermal conductive silicone grease and the tension of the signal wire.

[0102] S27: The shielding wire of the signal wire is welded to the lead tube 4 (metal material) or other internal structures of the packaging structure. The entire packaging structure and the shielding wire form a shielding layer, which can effectively reduce the influence of noise on the effective signal.

[0103] S28: The cover 7 is mounted and fixed on the chassis 5 from the top downward. Before assembly, a piece of thermal conductive silicone grease is placed on the top of the heat sink 6.

[0104] S29: Use bolts to assemble through the third hole 53 on the chassis 5 and the cover side hole 72 of the cover 7. After tight assembly, the thermal conductive silicone grease between the top inner surface of the cover 7 and the top of the heat sink 6 is pre-tightened, which also plays a role in fixing the sensor chip 1, that is, the atomic layer thermopile heat flow sensor with water cooling is obtained.

[0105] When the heat flux sensor is working, the heat flux reaches the upper surface of the sensor chip 1, and accumulates and conducts in the sensor chip 1 and the heat flux sensor packaging structure in a short time. The surface and internal temperature of the sensor chip 1 will increase to a certain extent, causing the measured value of the heat flux sensor to deviate from the true value. When a water cooling structure is introduced into the heat flux sensor, the heat is conducted to the circulating water through the sensor cooling component and carried away by the circulating water, maintaining a constant low temperature (depending on the circulating water temperature) on the lower surface of the sensor chip 1 for a relatively long time, which is conducive to establishing a temperature difference between the upper and lower surfaces of the heat flux sensitive film of the sensor chip 1. When the measured heat flux changes, the temperature of the upper surface changes, and the voltage signal output by the sensor chip 1 changes accordingly. The introduction of the water cooling structure enables this type of heat flux sensor to perform accurate and stable measurements at a larger heat flux for a longer time.

[0106] Example 2

[0107] 1. Sensor chip

[0108] The structure of the sensor chip 1 used in this embodiment is the same as that of the embodiment 1, but the substrate material, electrode material and process of the sensor chip 1 are different. The substrate material of this embodiment is a SrTiO3 single crystal substrate; the electrode material is metal tungsten (W).

[0109] 2. Packaging structure design

[0110] The packaging structure used in this embodiment is designed the same as that in Embodiment 1, and its structural composition is as described in the component structure of Embodiment 1. However, the material of the packaging structure in this embodiment is stainless steel.

[0111] This embodiment provides a method for preparing a sensor chip of a novel atomic layer thermopile heat flow sensor with water cooling, comprising the following steps:

[0112] S11: Using pulsed laser deposition technology, YBa2Cu3O was deposited on a SrTiO3 single crystal substrate with a 15° bevel angle on the (001) crystal plane. 7-δ The process parameters are set as follows: control the substrate temperature to 750-800°C; maintain the oxygen partial pressure to 40Pa; set the pulse laser output energy to 350mJ; control the laser beam area reaching the target surface to 0.02cm 2 , corresponding to laser energy density 1.8-2.0J / cm 2, pulse frequency 3Hz. 7-δ The film has a tilt angle of 15° and a thickness of 200 nm.

[0113] S12: In-situ annealing is performed on the film obtained by the above preparation process to reduce internal defects of the material and obtain a film with higher quality. Annealing conditions: 500° C., for 1 hour.

[0114] S13: After the film is annealed, a 2 mm wide and 20 nm thick metal Ni is deposited on both ends of the film as a seed layer using magnetron sputtering technology. The process parameters are: Ar flow rate 80 sccm, working gas pressure 0.5 Pa; sputtering power 80 W.

[0115] S14: In this embodiment, metal tungsten (W) is selected as the high temperature electrode. After depositing the Ni seed layer, a 80 nm thick W is deposited on the Ni seed layer using magnetron sputtering technology to form an electrode. The process parameters for depositing W are: Ar flow rate 100 sccm, working gas pressure 0.5 Pa; sputtering power 80W.

[0116] S15: After depositing the electrodes, annealing is performed again to obtain a heat flow sensor chip 1 with electrodes. Annealing conditions: 500° C., for 1 hour.

[0117] S16: Use silver paste to solder the enameled silver wire to the electrodes on both sides of the sensor chip 1. The silver paste is dried using a hot air gun at a temperature of 380° C. The enameled silver wire must be polished to expose the silver wire.

[0118] The specific steps of S2 are:

[0119] S21: Use bolts to align and assemble the chassis 5 and the heat sink 6 through the second hole 52 and the eighth hole 68. During the alignment and assembly, the fourth hole 54 on the chassis 5 and the axial hole 64 on the heat sink 6 as the circulation water channel should be accurately aligned, and their contact surfaces should be waterproof and sealed by a rubber ring.

[0120] S22: The water inlet and outlet pipes and the lead pipe 4 are respectively assembled with the fourth hole 54 and the fifth hole 55 on the chassis 5 by threads. During installation, the water inlet and outlet pipes, the fourth hole 54 on the chassis 5 and the axial hole 64 on the heat sink 6 are aligned with each other.

[0121] S23: peel off part of the shielding layer of the signal wire with shielding wire (in this example, the shielding wire with the core of silver-plated copper wire is selected), and pass the two signal wires from the bottom of the lead tube 4 through the sixth hole 66 on the heat sink 6 from bottom to top.

[0122] S24: Solder the two silver wires on the sensor chip 1 to the signal wires led out from the sixth hole 66 respectively, and insulate the welding points.

[0123] S25 : placing a piece of thermal conductive silicone grease of appropriate size on the top groove 62 , and then installing the sensor chip 1 in the top groove 62 .

[0124] S26: Tighten the redundant wires from the lead tube 4, and pour waterproof silicone rubber into the lead tube 4, and wait for curing. The sensor chip 1 is fixed by the viscosity of the thermal conductive silicone grease and the tension of the signal.

[0125] S27: The shielding wire of the signal wire is welded to the lead tube 4 (metal material) or other internal structures of the packaging structure. The entire packaging structure and the shielding wire form a shielding layer, which can effectively reduce the influence of noise on the effective signal.

[0126] S28: The cover 7 is mounted and fixed on the chassis 5 from the top downward. Before assembly, a piece of silicone pad is placed on the top of the heat sink 6.

[0127] S29: Use bolts to assemble through the third hole 53 on the chassis 5 and the cover side hole 72 of the cover 7. After tight assembly, the silicone pad between the top inner surface of the cover 7 and the top of the heat sink 6 is pre-tightened, which also plays a role in fixing the sensor chip 1, that is, a fast response atomic layer thermopile heat flow sensor with a water cooling structure is obtained.

[0128] Compared with Example 1, Example 2 has different substrate materials, electrode materials, corresponding process methods, and signal line selections for the sensor chip 1.

[0129] The substrate material of Example 1 is a LaAlO3 single crystal substrate; the electrode material is metal platinum (Pt); and the core of the signal line is a pure silver wire.

[0130] The substrate material of Example 2 is a SrTiO3 single crystal substrate; the electrode material is metal tungsten (W); and the core of the signal line is a shielded silver-plated copper wire.

[0131] Example 3

[0132] This embodiment is comparative example 1.

[0133] 1. Sensor chip

[0134] This comparative example 1 uses the same sensor chip 1 as that of the first embodiment.

[0135] 2. The packaging structure design used in this comparative example 1 is different from that in the embodiment 1 in that no circulating water channel and pipeline are designed in the packaging structure, that is, the fourth hole 54 is not provided on the chassis 5, the waist-shaped hole 63 and the axial hole 64 are not provided on the heat sink 6, and the water inlet pipe 2 and the water inlet pipe 3 are eliminated. The rest of the structure is consistent with the component structure of the embodiment 1.

[0136] This comparative example 1 provides a method for preparing an atomic layer thermopile heat flow sensor without water cooling, which includes the working steps of S1: chip preparation and S2: device assembly.

[0137] S1 includes the following steps:

[0138] S11: Using pulsed laser deposition technology, YBa2Cu3O was deposited on a LaAlO3 single crystal substrate with a 15° bevel on the (001) crystal plane. 7-δ The process parameters are set as follows: control the substrate temperature to 750-800°C; maintain the oxygen partial pressure to 40Pa; set the pulse laser output energy to 350mJ; control the laser beam area reaching the target surface to 0.02cm 2 , corresponding to laser energy density 1.8-2.0J / cm 2 , pulse frequency 3Hz. Controlling the deposition time can obtain films of different thicknesses. This embodiment preferably prepares YBa2Cu3O with an inclination angle of 15° and a thickness of 200nm 7-δ Theoretically, the larger the tilt angle of YBa2Cu3O 7-δ The film has a greater sensitivity. The YBa2Cu3O 7-δ The film is a preferred solution that has the characteristics of easy preparation, high yield and high sensitivity (sensitivity formula is shown in Formula 2).

[0139] S12: In-situ annealing is performed on the film obtained by the above preparation process to reduce internal defects of the material and obtain a film with higher quality. Annealing conditions: 500° C., for 1 hour.

[0140] S13: After the film is annealed, a 2 mm wide and 20 nm thick metal nickel Ni is deposited on both ends of the film as a seed layer using magnetron sputtering technology. The process parameters are: Ar flow rate 80 sccm, working gas pressure 0.5 Pa; sputtering power 80 W.

[0141] S14: After depositing metal Ni, a metal platinum (Pt) with a thickness of 80 nm is deposited on the surface of the metal Ni by magnetron sputtering technology to form an electrode. The process parameters for depositing Pt are: Ar flow rate 100 sccm, working gas pressure 0.5 Pa; sputtering power 80 W.

[0142] S15: After depositing the electrodes, annealing is performed again to obtain a heat flow sensor chip 1 with electrodes. Annealing conditions: 500° C., for 1 hour.

[0143] S16: Use silver paste to solder the enameled silver wire to the electrodes on both sides of the sensor chip 1. The silver paste is dried using a hot air gun at a temperature of 380° C. The enameled silver wire must be polished to expose the silver wire.

[0144] S2 includes the following steps:

[0145] S21 : Using bolts, align and assemble the chassis 5 and the heat sink 6 through the second hole 52 and the eighth hole 68 .

[0146] S22: The lead tube 4 is assembled with the chassis 5 through threads.

[0147] S23: peel off part of the shielding layer of the signal wire with shielding wire (the wire core is pure silver wire), and pass the two signal wires through the sixth hole 66 on the heat sink 6 from the bottom to the top from the bottom of the lead tube 4.

[0148] S24: Solder the two silver wires on the sensor chip 1 to the signal wires led out from the sixth hole 66 respectively, and insulate the welding points.

[0149] S25 : placing a piece of thermal conductive silicone grease of appropriate size on the top groove 62 , and then installing the sensor chip 1 in the top groove 62 .

[0150] S26: Tighten the redundant wires from the lead tube 4, and pour waterproof silicone rubber into the lead tube 4, and wait for curing. The sensor chip 1 is fixed by the viscosity of the thermal conductive silicone grease and the tension of the signal wire.

[0151] S27: The shielding wire of the signal wire is welded to the lead tube 4 (metal material) or other internal structures of the packaging structure. The entire packaging structure and the shielding wire form a shielding layer, which can effectively reduce the influence of noise on the effective signal.

[0152] S28: The cover 7 is mounted and fixed on the chassis 5 from the top downward. Before assembly, a piece of silicone pad is placed on the top of the heat sink 6.

[0153] S29: Use bolts to assemble through the third hole 53 on the chassis 5 and the cover side hole 72 of the cover 7. After tight assembly, the silicone pad between the top inner surface of the cover 7 and the top of the heat sink 6 is pre-tightened, which also plays a role in fixing the sensor chip 1, that is, an atomic layer thermopile heat flow sensor without a water cooling structure is obtained.

[0154] The performance of Example 1 (with water-cooled heat flux sensor) and Comparative Example 1 (without water-cooled heat flux sensor) were tested using the quartz lamp array as the heat source. The heat flux densities provided by the quartz lamp array at 0.5 kW, 1 kW, 1.5 kW, 2 kW and 2.5 kW were 28.94, 98.39, 176.93, 256.17 and 330.36 kW / m 2 During the test, the vertical distance between the sensor and the quartz lamp array was 5 cm. The test method was continuous testing, and the output power of the quartz lamp array was increased in a gradient at intervals of 60 seconds. The test results are as follows: Figure 6a and 6b . Figure 6aThe curves of thermoelectric potential of the heat flux sensors of Example 1 and Comparative Example 1 over time (VT curves) recorded when the quartz lamp array continuously radiates the heat flux sensors. The heat flux sensor of Comparative Example 1 is at 0.5 kW (corresponding to a heat flux of 28.94 kW / m 2 ) and 1kW (corresponding to a heat flux of 98.39kW / m 2 ) Within the time of continuous operation of 120s under the radiation of the quartz lamp array, its thermoelectric potential output had no significant difference from the thermoelectric potential output of the heat flux sensor in Example 1. However, as the test time continued and the power of the quartz lamp array increased, the thermoelectric potential curve of the heat flux sensor in Comparative Example 1 gradually deviated from the thermoelectric potential curve of the heat flux sensor in Example 1. And when the power of the quartz lamp array was maintained at 1.5kW or 2kW (the output heat flux density remained unchanged when the power was constant), the thermoelectric potential curve of the heat flux sensor in Comparative Example 1 showed a linear growth trend, which was in sharp contrast to the stable thermoelectric potential curve of the heat flux sensor in Example 1. When the power of the quartz lamp array continued to increase to 2.5kW, the corresponding heat flux density reached 330.36kW / m 2 When the thermoelectric potential curve of the heat flux sensor of comparative example 1 drops rapidly after reaching the peak value and then starts to rise again, its measurement result is obviously distorted. However, the heat flux sensor of embodiment 1 can provide stable signal output within each power duration range when the power of the quartz lamp array increases from 0.5kW to 2.5kW within the time domain range of 360s.

[0155] Figure 6b Based on Figure 6a The heat flux density and thermoelectric potential were measured to plot the heat flux sensor sensitivity calibration results. Among them, the sensitivity linear fitting R of the heat flux sensor in comparative example 1 and the heat flux sensor in embodiment 1 is 2 The linearity of the heat flow sensor of Example 1 is better than that of the heat flow sensor of Comparative Example 1.

[0156] In the above results, the distortion or even failure of the measurement results of the heat flux sensor of comparative example 1 can be attributed to the temperature increase of the device itself during the long-term heat flux test. Since the heat flux sensor of Example 1 introduces a cooling component, its stability and linearity in the scenario of high heat flux density and long-term operation are better than those of the heat flux sensor of comparative example 1. In summary, the atomic layer thermopile heat flux sensor with water cooling provided by the present invention can overcome the shortcomings of existing products in the scenario of high heat flux density and long-term operation.

[0157] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. An atomic layer thermopile heat flow sensor with water cooling, comprising a sensor chip (1) and a cooling assembly, characterized in that: The bottom layer of the sensor chip (1) is a 001 crystal plane with a 15° bevel substrate layer, and the layered heat flow sensitive film thereon is a YBa2Cu3O 7-δ The YBa2Cu3O thin film 7-δ Double-layer metal electrodes are prepared at both ends of the film surface; the cooling component is used for water cooling the sensor chip (1) and packaging the sensor chip (1).

2. The water-cooled atomic layer thermopile heat flow sensor according to claim 1, characterized in that: The cooling assembly comprises a chassis (5), a heat sink (6) is provided on the chassis (5), a cylindrical cover (7) covers the heat sink (6) and is connected to the chassis (5), the top surface of the heat sink (6) is embedded in the sensor chip (1) and fixed by the cover (7), a water inlet pipe (2) and a water outlet pipe (3) on the lower side pass through the chassis (5) and pass through the heat sink (6), forming a water cooling circuit below the sensor chip (1); a lead pipe (4) on the lower side passes through the chassis (5) and the heat sink (6) and is used to pass the lead of the sensor chip (1).

3. The water-cooled atomic layer thermopile heat flow sensor according to claim 2, characterized in that: The bottom plate (5) is provided with a cylindrical boss, and the cylindrical boss is provided with two fourth holes (54) for respectively passing the water inlet pipe (2) and the water outlet pipe (3) and a fifth hole (55) for passing the lead pipe (4); The heat sink (6) comprises a heat sink body (61) for heat conduction, a circular groove (67) is provided at the bottom of the heat sink body (61), and the cylindrical boss is embedded in the circular groove (67); a top groove (62) for embedding the sensor chip (1) is provided at the top center of the heat sink body (61); a waist-shaped hole (63) is provided below the top groove (62) along the radial direction of the heat sink body (61), and both ends of the waist-shaped hole (63) are blocked by metal blocks (631); two axial holes (631) for cooling water inlet and outlet are provided in the heat sink body (61) and are connected to the waist-shaped hole (63). 4), the axial hole (64) is connected with the two fourth holes (54); the opposite groove edges of the top groove (62) are each provided with a sixth hole (66); a radial transverse through hole (65) for hand operation is provided in the cross direction between the two axial holes (64); a ninth hole (69) and an eighth hole (68) for assembling the heat sink body (61) and the chassis (5) are provided on the lower side of the hole wall of the transverse through hole (65); the sixth hole (66), the transverse through hole (64), the ninth hole (69) and the fifth hole (55) are passed through to penetrate the leads of the sensor chip (1).

4. The water-cooled atomic layer thermopile heat flow sensor according to claim 3, characterized in that: The top of the cover (7) is provided with a cover top hole (71) corresponding to the sensor chip (1).

5. The water-cooled atomic layer thermopile heat flow sensor according to claim 3, characterized in that: The material of the heat sink body (61) is selected from metal aluminum, metal copper or stainless steel.

6. The water-cooled atomic layer thermopile heat flow sensor according to claim 3, characterized in that: Thermal conductive silicone grease is provided between the sensor chip (1) and the top groove (62).

7. The water-cooled atomic layer thermopile heat flow sensor according to claim 1, characterized in that: The substrate layer is selected from LaAlO3 single crystal substrate or SrTiO3 single crystal substrate; the double-layer metal electrode is selected from metal tungsten W or metal platinum Pt deposited on a Ni seed layer.

8. A method for preparing a sensor chip of an atomic layer thermopile heat flow sensor with water cooling as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: S11: Using pulsed laser deposition technology, YBa2Cu3O is deposited on a LaAlO3 single crystal substrate with a 15° bevel on the 001 crystal plane or on a SrTiO3 single crystal substrate. 7-δ film; S12: The obtained YBa2Cu3O 7-δ The film was annealed in situ, annealing conditions: 500 °C, for 1 h; S13: in YBa2Cu3O 7-δ A 2 mm wide and 20 nm thick nickel metal Ni is deposited at both ends of the film as a seed layer; S14: After depositing the metal Ni, depositing metal platinum Pt or metal tungsten W with a thickness of 80 nm on the surface of the metal Ni to form an electrode; S15: annealing again after depositing the electrode to obtain the sensor chip (1) with the electrode, annealing condition: 500° C., for 1 hour; S16: Using silver paste to weld the enameled silver wires onto the electrodes on both sides of the sensor chip (1).

9. The preparation method according to claim 8, characterized in that: YBa2Cu3O prepared in step S11 7-δ The film had a tilt angle of 15° and a thickness of 200 nm.

10. An assembly method of an atomic layer thermopile heat flux sensor with water cooling as claimed in any one of claims 3 to 7, characterized in that: The following steps are involved: S21: Using bolts, align and assemble the chassis (5) and the heat sink (6) through the second hole (52) and the eighth hole (68). During the alignment and assembly, the fourth hole (54) on the chassis (5) and the axial hole (64) on the heat sink (6) are precisely aligned as channels for circulating water, and the contact surfaces are waterproofly sealed by a rubber ring; S22: The water inlet and outlet pipes and the lead pipe (4) are respectively assembled with the fourth hole (54) and the fifth hole (55) on the chassis (5) through threads. During installation, the axial centers of the water inlet and outlet pipes, the fourth hole (54) on the chassis (5) and the axial hole (64) on the heat sink (6) are aligned; S23: peel off part of the shielding layer of the signal wire with a pure silver wire core and a shielding wire, and pass the two signal wires from the bottom of the lead tube (4) from bottom to top through the two sixth holes (66) on the heat sink (6); S24: welding the two silver wires on the sensor chip (1) to the signal wires led out from the sixth hole (66) respectively, and insulating the welding points; S25: placing thermal conductive silicone grease on the top groove (62), and installing the sensor chip (1) in the top groove (62); S26: Tighten the excess wire from the lead tube (4), and pour waterproof silicone rubber into the lead tube (4), waiting for solidification, so that the sensor chip (1) is fixed by the viscosity of the thermal conductive silicone grease and the tension of the signal line; S27: welding the shielding wire of the signal wire to the lead tube (4) to form a shielding layer; S28: The cover (7) is mounted and fixed on the chassis (5) from the top downwards. Before assembly, thermal conductive silicone grease is placed on the top of the heat sink (6); S29: Bolts are used to assemble through the third hole (53) on the chassis (5) and the cover edge hole (72) of the cover (7). After tight assembly, the thermal conductive silicone grease between the top inner surface of the cover (7) and the top of the heat sink (6) is subjected to a pre-tightening force, which plays a role in fixing the sensor chip (1), thereby obtaining the atomic layer thermopile heat flow sensor with water cooling.

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