A novel atomic layer thermopile heat flux sensor with high sensitivity coefficient and its packaging process

Abstract

The invention discloses a novel atomic layer thermopile heat flow sensor with high sensitivity coefficient and its packaging process, comprising: a base, on which an electrical insulating oxide layer is arranged, a wire groove is arranged on the side of the base, and a lead hole II is arranged on the upper end face of the base; a sensitive element is bonded and fixed on the upper end face of the base; a packaging sleeve is arranged outside the base; a silver wire is fixed in the wire groove; the structure of the sensitive element comprises: a strontium titanate wafer, on which a lead hole I is arranged, and at least two yttrium barium copper oxide films are deposited on the surface of the strontium titanate wafer; the yttrium barium copper oxide films are connected in series end to end through a conductive gold film; two lead gold films, one end of which is connected to the yttrium barium copper oxide film, and the other end covers the area around the lead hole I; the silver wire passes through the lead hole II and the lead hole I, and is electrically connected with the lead gold film. The atomic layer thermopile heat flow sensor can physically amplify the sensor output under the same size, and can be used for wind tunnel heat measurement test.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat flux sensors, and more specifically, relates to a novel atomic layer thermopile heat flux sensor with a high sensitivity coefficient and a packaging process thereof. Background Art

[0002] Boundary layer transition is one of the few basic scientific problems left over from classical mechanics, and together with the turbulence problem, it is called the "problem of the century". For hypersonic flight, after the hypersonic boundary layer changes from laminar flow to turbulent flow, the wall heat flux and friction will increase sharply. Therefore, theoretical and experimental research on hypersonic boundary layer transition is an important means to understand the transition mechanism and further control the transition. Combined with the understanding of current theoretical research on hypersonic boundary layer transition, the evolution and development of incoming flow disturbances are considered to be the core of the boundary layer transition mechanism. Correspondingly, wind tunnel experimental research has also paid more and more attention to the testing and analysis of high-frequency pulsating heat flux. The total temperature of the airflow under the flow field state commonly used in conventional hypersonic wind tunnels and hypersonic silent wind tunnels is not high, and the heat flux in the corresponding wind tunnel test is small; for this type of invasive heat flow test method, in order to reduce the influence of the sensor on the flow field, it is often hoped that the sensor size will be as small as possible. Therefore, under the same sensor size, a sensor with a higher sensitivity coefficient can be obtained by physically amplifying the test signal, which can be used in wind tunnel test environments with lower heat flow. For smaller sensors, the sensor sensitivity coefficient can be made not too low by physically amplifying the test signal, which can also meet the test requirements. 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 purposes and other advantages according to the present invention, a novel atomic layer thermopile heat flow sensor with high sensitivity coefficient is provided, comprising:

[0005] A base, the surface of which is provided with an electrical insulating oxide layer, a side of the base is provided with a wire groove, and an upper end surface of the base is provided with a lead hole II connected to the wire groove;

[0006] A sensitive element is bonded and fixed to the upper end surface of the base; a packaging sleeve is sleeved outside the base; and a silver wire is fixedly arranged in the wire groove;

[0007] The structure of the sensitive element includes:

[0008] A circular tilted strontium titanate wafer is provided with a lead hole I which is aligned with the lead hole II, and at least two yttrium barium copper oxide films are deposited on the surface of the strontium titanate wafer, and the yttrium barium copper oxide films are oriented and grown on the tilted strontium titanate wafer by matching the characteristic parameters of the unit cell; the yttrium barium copper oxide films are connected in series end to end by a conductive gold film;

[0009] Two lead gold films, one end of which is connected to the yttrium barium copper oxide film, and the other end covers the area around the lead hole I; the silver wire passes through the lead hole II and the lead hole I, and is electrically connected to the lead gold film.

[0010] Preferably, the end surface of the silver wire is flush with the outer surface of the sensitive element.

[0011] Preferably, the base is an aluminum alloy base, and the aluminum alloy base is anodized to obtain an electrically insulating oxide layer.

[0012] Preferably, the packaging sleeve is preferably one of a polyetheretherketone packaging sleeve, a silicon nitride ceramic packaging sleeve, an alumina ceramic packaging sleeve or a silicon nitride ceramic packaging sleeve.

[0013] Preferably, the silver wire is fixed in the wire groove by glue; and the silver wire and the lead gold film are electrically connected by conductive silver paste.

[0014] Preferably, the packaging process of the atomic layer thermopile heat flow sensor includes the following steps:

[0015] Step 1, performing an anodic surface treatment on the base; opening a lead hole I on the square strontium titanate wafer along the edge of the crystal orientation, and then processing the square strontium titanate wafer into a circular sheet; depositing a yttrium barium copper oxide film, a conductive gold film, and a lead gold film on the strontium titanate wafer;

[0016] Step 2: Fix the sensitive element on the surface of the base by gluing, and ensure that the lead hole I and the lead hole II of the base are aligned;

[0017] Step 3: Pass the silver wire through the lead hole II and the lead hole I, and pour glue into the wire groove to fix the silver wire by curing and bonding the glue;

[0018] Step 4: Apply conductive silver paste between the silver wire and the lead gold film to form electrical conduction between the silver wire and the lead gold film. At the same time, the end surface of the silver wire should be flush with the outer surface of the sensitive component.

[0019] Step 5: Put the packaging sleeve on the base and ensure that the upper end surface of the packaging sleeve is flush with the outer surface of the sensitive element; at this point, the new atomic layer thermopile thermal flow sensor is packaged.

[0020] Preferably, the yttrium barium copper oxide film, the conductive gold film and the lead gold film can be deposited by one of pulsed laser physical deposition, magnetron sputtering deposition or chemical vapor deposition.

[0021] The present invention includes at least the following beneficial effects: The present invention provides a new atomic layer thermopile heat flow sensor with a high sensitivity coefficient, which can meet the requirements of small sensor size and high sensitivity coefficient for high-frequency pulsating heat flow testing in test environments such as shock wind tunnels, conventional hypersonic wind tunnels and hypersonic silent wind tunnels. The beneficial results are: the sensor output is physically amplified, and under the same size conditions, the sensor sensitivity coefficient is higher and can be used to test lower heat flows; under smaller size requirements, the sensor sensitivity coefficient is not too low, which can reduce the impact of invasive sensors on local flow fields.

[0022] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part 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 A schematic diagram of the structure of a sensitive element of a novel atomic layer thermopile heat flow sensor with a high sensitivity coefficient provided by the present invention;

[0024] Figure 2 Schematic diagram of the packaging structure of the new atomic layer thermopile thermal flow sensor with high sensitivity coefficient provided by the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in 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] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0027] like Figure 1-2 As shown: A novel atomic layer thermopile heat flow sensor with high sensitivity coefficient of the present invention comprises:

[0028] A base 8, the surface of which is provided with an electrical insulating oxide layer, a side surface of the base 8 is provided with a wire groove 10, and an upper end surface of the base 8 is provided with a lead hole II 11 connected to the wire groove 10;

[0029] A sensitive element 6 is bonded and fixed to the upper end surface of the base 8; a packaging sleeve 7 is sleeved outside the base 8; a silver wire 9 is fixedly arranged in the wire groove 10;

[0030] The structure of the sensitive element includes:

[0031] A circular tilted strontium titanate wafer 4 is provided with a lead hole I3 which is aligned with the lead hole II11, and three yttrium barium copper oxide films 1 are deposited on the surface of the strontium titanate wafer 4, and the yttrium barium copper oxide films 1 are oriented and grown on the tilted strontium titanate wafer by matching the characteristic parameters of the unit cell; the yttrium barium copper oxide films 1 are connected in series in pairs by a conductive gold film 2;

[0032] Two lead gold films 5 have one end connected to the yttrium barium copper oxide film 1 and the other end covering the area around the lead hole Ⅰ3; the silver wire 9 passes through the lead hole Ⅱ11 and the lead hole Ⅰ3 and is electrically connected to the lead gold film 5.

[0033] Working principle: This atomic layer thermopile heat flow sensor is used to lead out the electrical signals directly related to the high-frequency heat flow test from the shock tunnel and the conventional hypersonic wind tunnel. According to the electrical output characteristics of the yttrium barium copper oxide film 1 under the gradient temperature field, the three yttrium barium copper oxide films 1 are connected in series two by two using the conductive gold film 2. Therefore, this atomic layer thermopile heat flow sensor has a very high sensitivity coefficient. When there is a temperature gradient on the upper and lower surfaces of the three yttrium barium copper oxide films 1, due to the lateral Seebeck effect, a thermoelectric potential is generated that is transverse and perpendicular to the temperature gradient direction of the upper and lower surfaces of the yttrium barium copper oxide film 1. The silver The wire 9 is connected to the lead gold film 2 of the sensitive element 6, and the amplified output generated by the series connection of the yttrium barium copper oxide film 1 is transmitted to the data acquisition device; the base 8 provides a fixing mechanism for the sensitive element 6, which plays the role of fixing, supporting and protecting the sensitive element 6; under the same size conditions, the sensor sensitivity coefficient is higher and can be used to test lower heat flow; under smaller size requirements, the sensor sensitivity coefficient is not too low, which can reduce the impact of the intrusive sensor on the local flow field; the packaging sleeve 7 can further form protection for the sensitive element and achieve the purpose of electrical insulation from the test model during the use of the sensor. The new atomic layer thermopile heat flow sensor obtained in this way needs to be statically calibrated to obtain its sensitivity coefficient, and its dynamic response time and other parameters can be dynamically calibrated using pulse-type experimental equipment such as shock tubes.

[0034] In the above technical solution, the end surface of the silver wire 9 is flush with the outer surface of the sensitive element 6 .

[0035] In the above technical solution, the base 8 is preferably an aluminum alloy base, and the aluminum alloy base is anodized to obtain an electrically insulating oxide layer.

[0036] In the above technical solution, the packaging sleeve 7 is preferably one of a polyetheretherketone packaging sleeve, a silicon nitride ceramic packaging sleeve, an alumina ceramic packaging sleeve or a silicon nitride ceramic packaging sleeve.

[0037] In the above technical solution, the silver wire 9 is fixed in the wire groove 10 by glue; the silver wire 9 and the lead gold film 5 are electrically connected by conductive silver paste.

[0038] In the above technical solution, the packaging process of the atomic layer thermopile heat flow sensor includes the following steps:

[0039] Step 1: perform an anodic surface treatment on the base 8; open a lead hole Ⅰ3 on the square strontium titanate wafer along the edge of the crystal orientation, and then process the square strontium titanate wafer into a circular sheet; deposit a yttrium barium copper oxide film 1, a conductive gold film 2, and a lead gold film 5 on the strontium titanate wafer 4;

[0040] Step 2: fix the sensitive element 6 on the surface of the base 8 by gluing, and ensure that the lead hole I3 is aligned with the lead hole II11 of the base;

[0041] Step 3: Pass the silver wire 9 through the lead hole II 11 and the lead hole I 3, and pour glue into the wire groove 10 to fix the silver wire 9 by curing and bonding the glue;

[0042] Step 4: Apply conductive silver paste between the silver wire 9 and the lead gold film 5 to form electrical conduction between the silver wire 9 and the lead gold film 5. At the same time, the end surface of the silver wire 9 should be flush with the outer surface of the sensitive element 6.

[0043] Step 5: Put the packaging sleeve 7 on the base and ensure that the upper end surface of the packaging sleeve 7 is flush with the outer surface of the sensitive element 6; at this point, the atomic layer thermopile heat flow sensor is packaged.

[0044] In the above technical solution, the deposition method of the yttrium barium copper oxide film 1, the conductive gold film 2 and the lead gold film 5 can be one of pulsed laser physical deposition, magnetron sputtering deposition or chemical vapor deposition.

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

[0046] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and 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 the illustrations shown and described herein.

Claims

1. A novel atomic layer thermopile heat flow sensor with high sensitivity coefficient, characterized in that: include: A base, the surface of which is provided with an electrical insulating oxide layer, a side of the base is provided with a wire groove, and an upper end surface of the base is provided with a lead hole II connected to the wire groove; A sensitive element, which is bonded and fixed to the upper end surface of the base; A packaging sleeve, which is sleeved outside the base; A silver wire, which is fixedly disposed in the wire groove; The structure of the sensitive element includes: A circular tilted strontium titanate wafer is provided with a lead hole I which is aligned with the lead hole II, and at least two yttrium barium copper oxide films are deposited on the surface of the strontium titanate wafer, and the yttrium barium copper oxide films are oriented and grown on the tilted strontium titanate wafer by matching the characteristic parameters of the unit cell; the yttrium barium copper oxide films are connected in series end to end by a conductive gold film; Two lead gold films, one end of which is connected to the yttrium barium copper oxide film, and the other end covers the area around the lead hole I; the silver wire passes through the lead hole II and the lead hole I, and is electrically connected to the lead gold film; The packaging process of the novel atomic layer thermopile heat flow sensor comprises the following steps: Step 1, performing an anodic surface treatment on the base; opening a lead hole I on the square strontium titanate wafer along the edge of the crystal orientation, and then processing the square strontium titanate wafer into a circular sheet; depositing a yttrium barium copper oxide film, a conductive gold film, and a lead gold film on the strontium titanate wafer; Step 2: Fix the sensitive element on the surface of the base by gluing, and ensure that the lead hole I and the lead hole II of the base are aligned; Step 3: Pass the silver wire through the lead hole II and the lead hole I, and pour glue into the wire groove to fix the silver wire by curing and bonding the glue; Step 4: Apply conductive silver paste between the silver wire and the lead gold film to form electrical conduction between the silver wire and the lead gold film. At the same time, the end surface of the silver wire should be flush with the outer surface of the sensitive component. Step 5: Put the packaging sleeve on the base and ensure that the upper end surface of the packaging sleeve is flush with the outer surface of the sensitive element; at this point, the new atomic layer thermopile thermal flow sensor is packaged.

2. The novel atomic layer thermopile heat flow sensor with high sensitivity coefficient as claimed in claim 1, characterized in that: The end surface of the silver wire is flush with the outer surface of the sensitive element.

3. The novel atomic layer thermopile heat flow sensor with high sensitivity coefficient as claimed in claim 1, characterized in that: The base is an aluminum alloy base, and the aluminum alloy base is subjected to anodizing surface treatment to obtain an electrical insulating oxide layer.

4. The novel atomic layer thermopile heat flow sensor with high sensitivity coefficient as claimed in claim 1, characterized in that: The packaging sleeve is one of a polyetheretherketone packaging sleeve, a silicon nitride ceramic packaging sleeve, an alumina ceramic packaging sleeve or a silicon nitride ceramic packaging sleeve.

5. The novel atomic layer thermopile heat flow sensor with high sensitivity coefficient as claimed in claim 1, characterized in that: The silver wire is fixed in the wire slot by glue; the silver wire and the lead gold film are electrically connected by conductive silver paste.

6. The novel atomic layer thermopile heat flow sensor with high sensitivity coefficient as claimed in claim 1, characterized in that: The deposition method of the yttrium barium copper oxide film, the conductive gold film and the lead gold film is one of pulsed laser physical deposition, magnetron sputtering deposition or chemical vapor deposition.

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