A new atomic layer thermopile heat flow sensor with bulk metal as sensitive element substrate and its packaging process

Abstract

The present invention discloses a novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate and its packaging process, comprising: a packaging sleeve with a bulk metal substrate disposed therein; a transition film layer and a thermoelectric effect film deposited above the bulk metal substrate, with both ends of the thermoelectric effect film respectively connected to a lead gold film; a silver wire fixedly disposed in a wire groove, and the lead gold film and the silver wire being electrically conductive. The atomic layer thermopile heat flow sensor of the present invention utilizes the good thermal conductivity and high heat capacity of metal, allowing the sensor to conduct heat away in a timely manner during long-term use, ensuring that the sensor temperature is within a controlled range; utilizing the good remachinability of metal, the electrical conductive node between the lead gold film and the silver wire is arranged on the side of the bulk metal substrate, making the sensor sensing surface flat, reducing the impact of the intrusive sensor on the local flow field; the sensor sensitive element is more compact as a whole, reducing the dimensional redundancy required for machining.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat flow sensors, and more specifically, relates to a novel atomic layer thermopile heat flow sensor with bulk metal as a sensitive element substrate and a packaging process thereof. Background Art

[0002] Boundary layer transition is one of the few fundamental scientific problems left from classical mechanics, and along with turbulence, is considered a "century-old problem." In hypersonic flight, when the hypersonic boundary layer transitions from laminar to turbulent flow, both wall heat flux and friction increase dramatically. Therefore, theoretical and experimental research on hypersonic boundary layer transition is crucial for understanding the transition mechanism and, ultimately, controlling it. Based on current theoretical research on hypersonic boundary layer transition, the evolution and development of incoming flow disturbances are considered central to the boundary layer transition mechanism. Consequently, wind tunnel and flight testing are increasingly focusing on testing and analyzing high-frequency pulsating heat flux. Conventional hypersonic wind tunnels have low heat flux, but the test duration is long and the temperature accumulation effect is significant. Flight testing, conducted in a realistic, complete aerodynamic environment, involves long test times and high heat flux, creating an urgent need for high-frequency pulsating heat flux testing. Currently, high-frequency pulsating heat flux testing primarily relies on atomic layer thermopile heat flux sensors. However, the sensitive element of the atomic layer thermopile heat flow sensor is primarily based on a strontium titanate sheet as the carrier of the thermoelectric effect film. However, the strontium titanate sheet has poor thermal conductivity and small heat capacity, making the atomic layer thermopile heat flow sensor unsuitable for long-term high-frequency pulsating heat flow testing, even in the test environment where the heat flow is low. The strontium titanate sheet is difficult to process and is extremely susceptible to damage. As a result, the sensor transmits the electrical signal sensed by the thermoelectric effect film directly by brushing conductive silver paste on the sensor surface to form electrical conductivity between the lead gold film and the silver wire. This causes unevenness in the small area around the lead hole on the sensor surface, which will cause local flow field interference. In addition, when using methods such as water-cooled insulation sleeves to achieve sensor temperature control, the sensor size is inevitably greatly increased, which greatly increases the local flow field interference caused by such invasive heat flow testing methods. Therefore, using bulk metal as the sensor substrate leverages the metal's excellent thermal conductivity to conduct heat away promptly, and its large heat capacity keeps the thermoelectric film within a consistently low temperature range. Furthermore, the metal's excellent machinability allows the contact point between the gold film and the silver wire to be located laterally, enhancing the overall integrity of the sensor. The resulting new atomic layer thermopile heat flux sensor has a flat sensing surface, meeting the requirements of long-term, high-frequency, pulsating heat flux testing in conventional hypersonic wind tunnels and flight tests. Summary of the Invention

[0003] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0004] In order to achieve these objectives and other advantages according to the present invention, a novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate is provided, comprising:

[0005] The packaging sleeve has an internal fixed sleeve provided with a block metal base;

[0006] A transition film layer and a lead gold film are deposited on the bulk metal substrate, a thermoelectric effect film is deposited on the transition film layer, and both ends of the thermoelectric effect film are respectively connected to the lead gold film;

[0007] The wire groove is arranged on the side of the block metal base, a silver wire is fixedly arranged in the wire groove, and the lead gold film transitions to the side of the block metal base to be electrically connected with the silver wire.

[0008] Preferably, a positioning threaded hole is provided on the side of the block metal base, and a through hole adapted to the positioning threaded hole is provided on the packaging sleeve, and the positioning and fixation of the packaging sleeve and the block metal base are achieved by providing top screws in the through hole and the positioning threaded hole.

[0009] Preferably, the upper end surface of the block metal substrate is provided with a transition fillet.

[0010] Preferably, the wire groove is filled with high-temperature glue, and the silver wire is fixed in the wire groove by the high-temperature glue; and electrical conduction is achieved between the silver wire and the lead gold film by brushing high-temperature silver paste.

[0011] Preferably, the packaging sleeve may be one of a silicon nitride ceramic packaging sleeve and an alumina ceramic packaging sleeve.

[0012] Preferably, the material of the bulk metal substrate is one of nickel-based alloy steel, nickel, nickel-tungsten alloy, copper and silver.

[0013] Preferably, the thermoelectric effect film is a yttrium barium copper oxide film or a lanthanum manganese copper oxide film.

[0014] Preferably, the packaging process of the novel atomic layer thermopile heat flow sensor of the present invention using bulk metal as the sensitive element substrate includes the following steps:

[0015] Step 1: Perform surface finishing treatment on the area where the transition film layer is deposited on the bulk metal substrate and the area where the lead gold film is deposited, and then deposit the transition film layer on the bulk metal substrate; perform surface treatment on the contact area between the bulk metal substrate and the lead gold film and the bulk metal substrate and the silver wire to form an electrically insulating surface; deposit a thermoelectric effect film on the surface of the transition film layer, and deposit lead gold films on both ends of the thermoelectric effect film; and process transition fillets on the bulk metal substrate;

[0016] Step 2: pouring high-temperature glue into the wire groove of the bulk metal substrate, and fixing the silver wire on the bulk metal substrate by curing the high-temperature glue;

[0017] Step 3: Apply high-temperature silver paste between the silver wire and the lead gold film to achieve electrical conduction between the silver wire and the lead gold film;

[0018] Step 4: Place the bulk metal substrate into the packaging sleeve, and ensure that the through hole of the packaging sleeve is aligned with the positioning threaded hole of the bulk metal substrate. Install screws in the through hole and the positioning threaded hole to achieve positioning and fixation between the packaging sleeve and the bulk metal substrate.

[0019] Preferably, the surface finishing treatment of the bulk metal substrate can be polishing; the surface treatment of the bulk metal substrate can be achieved by applying an insulating coating on the contact surface area between the bulk metal substrate and the lead gold film and the bulk metal substrate and the silver wire.

[0020] Preferably, the deposition technology of the transition film layer can be ion beam assisted deposition technology or inclined substrate deposition technology.

[0021] The present invention has at least the following beneficial effects: the present invention provides a novel atomic layer thermopile heat flow sensor using bulk metal as a sensitive element substrate, which can be used for long-term high-frequency pulsating heat flow testing in conventional hypersonic wind tunnels, flight tests and other test environments. The beneficial results are: using bulk metal as the sensitive element substrate utilizes the metal's good thermal conductivity and high heat capacity, allowing the sensor to conduct heat away in a timely manner during long-term use, ensuring that the sensor temperature is within a controlled range; using bulk metal as the sensitive element substrate utilizes the metal's good remachinability, allowing the electrical conduction node between the lead gold film and the silver wire to be arranged on the side of the bulk metal substrate, resulting in a flat sensor sensing surface and reducing the impact of the intrusive sensor on the local flow field; the sensor sensitive element is more compact as a whole, reducing the dimensional redundancy required for mechanical processing, and allowing the sensor size to be designed to be smaller.

[0022] Other advantages, objectives and features of the present invention will be reflected in part from the following description and will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the top view of the novel atomic layer thermopile heat flow sensor provided by the present invention, which uses bulk metal as the sensitive element substrate;

[0024] Figure 2 for Figure 1 Schematic diagram of the cross-sectional structure at AA in the middle. DETAILED DESCRIPTION

[0025] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0026] like Figure 1-2 As shown: A novel atomic layer thermopile heat flow sensor of the present invention using bulk metal as a sensitive element substrate comprises:

[0027] The packaging sleeve 1 has a fixed sleeve inside which is provided with a block metal base 6;

[0028] A transition film layer 7 and a lead gold film 5 are deposited on the bulk metal substrate 6, and a thermoelectric effect film 8 is deposited on the transition film layer 7. Both ends of the thermoelectric effect film 8 are respectively connected to the lead gold film 5;

[0029] The wire groove 3 is arranged on the side of the bulk metal base 6. The silver wire 2 is fixedly arranged in the wire groove 3, and the lead gold film 5 transitions to the side of the bulk metal base 6 and is electrically connected to the silver wire 2.

[0030] Working principle: This atomic layer thermopile heat flux sensor is used to extract electrical signals directly related to high-frequency heat flux testing from shock wind tunnels and conventional hypersonic wind tunnels; when there is a temperature gradient on the upper and lower surfaces of the thermoelectric effect film 8, due to the transverse Seebeck effect, a thermoelectric potential is generated that is transverse and perpendicular to the direction of the temperature gradient on the upper and lower surfaces of the thermoelectric effect film 8; the silver wire 2 is connected to the lead gold film 5, and the test signal is extracted from the shock wind tunnel and the conventional hypersonic wind tunnel, so that high-frequency pulsating heat flux can be directly obtained; the purpose of depositing the transition film layer 7 is to ensure the oriented growth of the thermoelectric effect film 8, the electrical insulation between the thermoelectric effect film 8 and the bulk metal substrate 6, and to prevent the metal atoms of the bulk metal substrate 6 from diffusing into the thermoelectric effect film 8. Because this atomic layer thermopile heat flux sensor uses bulk metal as the substrate for its sensitive element, it leverages the metal's excellent thermal conductivity and high heat capacity, allowing the sensor to conduct heat away promptly during prolonged use, ensuring the sensor temperature remains within a controlled range. By using bulk metal as the substrate for its sensitive element and utilizing its excellent remachinability, the electrical connection points between the lead gold film and the silver wire are located on the side of the bulk metal substrate, resulting in a flat sensor sensing surface and reducing the impact of the intrusive sensor on the local flow field. The sensor's sensitive element is more compact overall, reducing the dimensional redundancy required for machining and enabling a smaller sensor design. The resulting new atomic layer thermopile heat flux sensor requires static calibration to obtain its sensitivity coefficient, and dynamic calibration of parameters such as its dynamic response time can be performed using pulsed experimental equipment such as shock tubes.

[0031] In the above technical solution, a positioning threaded hole 4 is provided on the side of the block metal base 6, and a through hole adapted to the positioning threaded hole 4 is provided on the packaging sleeve. The positioning and fixation of the packaging sleeve 1 and the block metal base 6 are achieved by setting a top screw in the through hole and the positioning threaded hole 4.

[0032] In the above technical solution, the upper end surface of the bulk metal substrate 6 is provided with a transition fillet 9, which is provided to ensure that the lead gold film 5 transitions well from the upper surface of the bulk metal substrate 6 to the side surface of the bulk metal substrate 6.

[0033] In the above technical solution, the wire groove 3 is filled with high-temperature glue, and the silver wire 2 is fixed in the wire groove 3 by the high-temperature glue; the silver wire 2 and the lead gold film 5 are electrically conductive by brushing high-temperature silver paste.

[0034] In the above technical solution, the packaging sleeve 1 can be one of a silicon nitride ceramic packaging sleeve, an alumina ceramic packaging sleeve or a silicon nitride ceramic packaging sleeve.

[0035] In the above technical solution, the material of the block metal substrate 6 can be one of nickel-based alloy steel, nickel, nickel-tungsten alloy, copper, and silver.

[0036] In the above technical solution, the thermoelectric effect film 8 can be a yttrium barium copper oxide film or a lanthanum manganese copper oxide film.

[0037] In the above technical solution, the packaging process of the novel atomic layer thermopile heat flow sensor of the present invention using bulk metal as the sensitive element substrate includes the following steps:

[0038] Step 1: The area where the transition film layer is deposited and the area where the lead gold film is deposited on the bulk metal substrate 6 are subjected to surface finishing treatment, and then the transition film layer 7 is deposited on the bulk metal substrate; the contact area between the bulk metal substrate 6 and the lead gold film 5 and the bulk metal substrate 6 and the silver wire 2 is subjected to surface treatment to form an electrically insulating surface; a thermoelectric effect film 8 is deposited on the surface of the transition film layer 7, and the lead gold film 5 is deposited on both ends of the thermoelectric effect film 8; and a transition fillet 9 is processed on the bulk metal substrate 6;

[0039] Step 2: Pour high-temperature glue into the wire groove 3 of the bulk metal base 6, and fix the silver wire 2 on the bulk metal base 6 by curing the high-temperature glue;

[0040] Step 3: Apply high-temperature silver paste between the silver wire 2 and the lead gold film 5 to achieve electrical conduction between the silver wire 2 and the lead gold film 5;

[0041] Step 4: Install the block metal substrate 6 into the packaging sleeve 1, and ensure that the through hole of the packaging sleeve 1 is aligned with the positioning threaded hole 4 of the block metal substrate 6, and install top screws in the through hole and the positioning threaded hole 4 to achieve positioning and fixation between the packaging sleeve 1 and the block metal substrate 6.

[0042] In the above technical solution, the surface of the bulk metal base 6 can be smoothed by polishing; the surface treatment method of the bulk metal base 6 can be to apply an insulating coating to the contact surface area between the bulk metal base 6 and the lead gold film 5 and the bulk metal base 6 and the silver wire 2.

[0043] In step 1, the surface of the area where the transition film layer 7 is deposited on the bulk metal substrate 6 and the area where the lead gold film 5 is deposited is smoothed to ensure good bonding between the transition film layer 7, the lead gold film 5 and the bulk metal substrate 6; the surface treatment of the corresponding area of ​​the bulk metal substrate 6 is to ensure electrical insulation between the lead gold film 5 and the bulk metal substrate 6, and between the silver wire 2 and the bulk metal substrate 6, to form an electrically insulating surface.

[0044] In the above technical solution, the deposition technology of the transition film layer 7 can be selected from ion beam assisted deposition technology or inclined substrate deposition technology.

[0045] The number of devices and processing scales described herein are intended to simplify the description of the present invention. Applications, modifications, and variations of the present invention will be readily apparent to those skilled in the art.

[0046] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A new atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate, characterized in that: include: The packaging sleeve has an internal fixed sleeve provided with a block metal base; A transition film layer and a lead gold film are deposited on the bulk metal substrate, a thermoelectric effect film is deposited on the transition film layer, and both ends of the thermoelectric effect film are respectively connected to the lead gold film; A wire groove is provided on the side of the bulk metal substrate, a silver wire is fixedly provided in the wire groove, and the lead gold film transitions to the side of the bulk metal substrate and is electrically connected to the silver wire; The material of the bulk metal substrate is one of nickel-based alloy steel, nickel, nickel-tungsten alloy, copper, and silver; The packaging process of the new atomic layer thermopile heat flow sensor includes the following steps: Step 1: Perform surface finishing treatment on the area where the transition film layer is deposited on the bulk metal substrate and the area where the lead gold film is deposited, and then deposit the transition film layer on the bulk metal substrate; perform surface treatment on the contact area between the bulk metal substrate and the lead gold film and the bulk metal substrate and the silver wire to form an electrically insulating surface; deposit a thermoelectric effect film on the surface of the transition film layer, and deposit lead gold films on both ends of the thermoelectric effect film; and process transition fillets on the bulk metal substrate; Step 2: pouring high-temperature glue into the wire groove of the bulk metal substrate, and fixing the silver wire on the bulk metal substrate by curing the high-temperature glue; Step 3: Apply high-temperature silver paste between the silver wire and the lead gold film to achieve electrical conduction between the silver wire and the lead gold film; Step 4: Place the bulk metal substrate into the packaging sleeve, and ensure that the through hole of the packaging sleeve is aligned with the positioning threaded hole of the bulk metal substrate. Install screws in the through hole and the positioning threaded hole to achieve positioning and fixation between the packaging sleeve and the bulk metal substrate.

2. The novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate as claimed in claim 1 is characterized in that: The side of the block metal base is provided with a positioning threaded hole, and the packaging sleeve is provided with a through hole adapted to the positioning threaded hole. The packaging sleeve and the block metal base are positioned and fixed by setting top screws in the through hole and the positioning threaded hole.

3. The novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate as claimed in claim 1 is characterized in that: The upper end surface of the block metal substrate is provided with a transition fillet.

4. The novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate as claimed in claim 1 is characterized in that: The wire groove is filled with high-temperature glue, and the silver wire is fixed in the wire groove by the high-temperature glue; the silver wire and the lead gold film are electrically connected by brushing high-temperature silver paste.

5. The novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate as claimed in claim 1 is characterized in that: The packaging sleeve is one of a silicon nitride ceramic packaging sleeve and an alumina ceramic packaging sleeve.

6. The novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate as claimed in claim 1, characterized in that: The thermoelectric effect film is a yttrium barium copper oxide film or a lanthanum manganese copper oxide film.

7. The novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate as claimed in claim 1, characterized in that: The surface of the bulk metal substrate is smoothed by polishing. The surface of the bulk metal substrate is treated by applying an insulating coating on the contact areas between the bulk metal substrate and the lead gold film and between the bulk metal substrate and the silver wire.

8. The novel atomic layer thermopile heat flow sensor with bulk metal as the sensitive element substrate as claimed in claim 1 is characterized in that: The transition film layer is deposited using an ion beam assisted deposition technique or an inclined substrate deposition technique.

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