A graphene high-temperature temperature sensor with a thin-film structure

Abstract

A thin-film structure graphene high-temperature temperature sensor, the sensor comprising: a packaging housing, a ceramic end cap provided at the top of the packaging housing, and a ceramic substrate provided at the bottom end inside the packaging housing, with a plurality of through holes provided on the ceramic end cap; a detection unit, the detection unit being provided on the ceramic substrate; an interconnection component, the interconnection component being provided on both sides of the detection unit, one end of the interconnection component being connected to the detection unit and the other end being connected to the outside. The present invention uses a detection nano-film containing a graphene layer to replace other metal materials or semiconductor materials, improving the temperature measurement range of the resistive temperature sensor. Due to the high thermal conductivity of the graphene material, the response speed of the device is improved. The detection nano-film is wrapped by an alumina nano-film and a substrate, effectively eliminating interference factors in the surrounding environment and isolating the direct contact between the detection nano-film and the outside world, thereby enhancing the high-temperature resistance and stability of the device, and can be applied to extremely harsh high-temperature test environments.

Description

Technical Field

[0001] The present invention relates to the technical field of high-temperature testing, and particularly relates to a graphene high-temperature temperature sensor with a thin-film structure. Background Art

[0002] Since some components in equipment such as aero-engine, heavy gas turbine, thermal power station and smelting furnace work in a high-temperature and harsh environment for a long time, temperature sensors are needed to monitor the temperature parameters of these high-temperature components in real time, so as to accurately evaluate the health status of the equipment, improve the operation life of the equipment, and ensure safe and reliable operation.

[0003] Since graphene can withstand a high temperature of 3000 °C in an oxygen-free environment, and the thermal conductivity of graphene is as high as 5300 W / (m·K), the sensor prepared by using graphene film has an extremely short response time to temperature. Since Al2O3 can withstand a high temperature above 1500 °C, and the melting point of the substrate material α-Al2O3 can reach 2030 °C, the graphene can be stably operated in an environment above 1500 °C after being hermetically packaged with Al2O3 film and α-Al2O3 substrate.

[0004] At present, the metal thin-film high-temperature temperature sensor has a temperature measurement range of 0 - 1300 °C, high precision and stable performance; but it has large thermal inertia and long response time. For example, a certain type of thin-film high-temperature temperature sensor developed by Shanghai Aeronautical Measurement and Control Technology Research Institute for aero-engine turbine blades has a maximum measurement temperature of 1100 °C [Invention No.: CN109338290A], and a certain type of thin-film temperature sensor developed by Shaanxi Electric Apparatus Research Institute for aircraft with fast response has a temperature measurement upper limit of 1200 °C and a response time less than 50 ms [Invention No.: CN104748876A].

[0005] Developing a fast-response, small-size and high-performance high-temperature resistant thin-film temperature sensor using graphene material is a scientific and technological problem that needs to be solved urgently at present. Compared with the metal thin-film high-temperature temperature sensor, the graphene high-temperature temperature sensor with a thin-film structure described in the present invention can be used at a high temperature of 1500 °C and the response time is as low as 10 ms. Summary of the Invention

[0006] In order to effectively solve the deficiencies in the above background art, the present invention uses graphene instead of metal and other semiconductor materials to design a graphene high-temperature temperature sensor with a thin-film structure. The detection nano-film with a graphene layer has its electrical characteristics changed by temperature. Specifically, the temperature changes the conductivity of the graphene layer, and then the change in the conductivity of the detection nano-film is detected by an external detection circuit to achieve the measurement of temperature.

[0007] A graphene high-temperature temperature sensor with a thin-film structure can stably operate at a high temperature of 1500 °C for a long time. The sensor includes:

[0008] A packaging housing, a ceramic end cap provided at the top of the packaging housing, and a ceramic substrate provided at the bottom inside the packaging housing. A plurality of through holes are provided on the ceramic end cap;

[0009] A detection unit, which is arranged in an internal detection space jointly defined by the ceramic end cap, the ceramic substrate, and the packaging housing and is located on the ceramic substrate;

[0010] An interconnection component, which is arranged on both sides of the detection unit. One end of the interconnection component is connected to the detection unit, and the other end of the interconnection component is connected to the outside to lead out the electrical response in the detection unit.

[0011] Optionally, the detection unit is arranged on one side of the ceramic substrate facing the internal detection space. The detection unit includes: a detection nano-film, metal electrodes, an alumina nano-film, a substrate, and a barrier layer. The substrate is arranged on the ceramic substrate, the detection nano-film is arranged on the upper surface of the substrate, the alumina nano-film covers the upper surface of the detection nano-film, the metal electrodes are arranged on both sides of the detection nano-film and are connected to the detection nano-film, and the barrier layer is arranged between the metal electrodes and the substrate.

[0012] Optionally, the detection nano-film is composed of an upper boron nitride layer, a middle graphene layer, and a lower boron nitride layer. The upper boron nitride layer, the middle graphene layer, and the lower boron nitride layer are sequentially arranged from top to bottom, and the middle graphene layer is in a serpentine bending structure or a disc-shaped bending structure.

[0013] Optionally, the metal electrode is composed of a composite electrode, a wiring, and an internal interconnection electrode. The composite electrode is connected to the internal interconnection electrode through the wiring. The composite electrode is respectively connected to two opposite ends of the middle graphene layer. The interconnection electrode is connected to the interconnection component for leading out the electrical response in the detection nano-film.

[0014] Optionally, the barrier layer is arranged at the bottom of the composite electrode, the wiring, and the internal interconnection electrode.

[0015] Optionally, the interconnection component includes: an interconnection lead, an interconnection pad, a lead post, and an external interconnection electrode. The interconnection lead, the interconnection pad, the lead post, and the external interconnection electrode are sequentially connected.

[0016] Optionally, mounting holes for mounting the lead posts are formed in the ceramic substrate, the lead posts are disposed in the mounting holes, the interconnect pads are disposed on the ceramic substrate and connected to one end of the lead posts, interconnect bumps are provided on the interconnect pads, one end of the interconnect leads is connected to the interconnect bumps on the interconnect pads, the other end of the interconnect leads is connected to the internal interconnect electrodes, an opening for accommodating the external interconnect electrodes is provided at the bottom of the package housing, the external interconnect electrodes are disposed at the bottom of the ceramic substrate and connected to the other end of the lead posts, and the external interconnect electrodes are connected to an external detection component.

[0017] The beneficial effects of the present invention are as follows. Based on the original resistive temperature sensor, the detection nano-film containing a graphene layer is used to replace other metal materials or semiconductor materials, greatly increasing the temperature measurement range of the resistive temperature sensor. And due to the high thermal conductivity of the graphene material, the response speed of the device is effectively improved. At the same time, the detection nano-film is wrapped by an alumina nano-film and a substrate, effectively eliminating the interference factors in the surrounding environment, and the alumina nano-film isolates the direct contact between the detection nano-film and the outside world, thereby enhancing the high-temperature resistance and stability of the device. It can be applied to extremely harsh high-temperature test environments and is an ideal high-temperature temperature sensor. The device can stably work at a high temperature of 1500 °C for a long time with a response time as low as 10 ms, and is applicable to various high-temperature test environments, having high practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic external structure diagram of an embodiment of the present invention;

[0019] Figure 2 It is a schematic cross-sectional structure diagram of an embodiment of the present invention;

[0020] Figure 3 It is a top view of the detection unit structure of an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the structure of the detection nano-film and the metal electrode of an embodiment of the present invention;

[0022] Figure 5 It is a top view of the structure of the detection nano-film and the metal electrode of an embodiment of the present invention;

[0023] Figure 6 It is a schematic cross-sectional structure diagram of the detection nano-film of an embodiment of the present invention;

[0024] Figure 7 It is a top view of the structure of the middle graphene layer and the metal electrode of an embodiment of the present invention;

[0025] As shown in the figure, the list of reference numerals is as follows:

[0026] Detection of nano-film - 1; through-hole - 2; alumina nano-film - 3; composite electrode - 4, 8; wiring - 5, 9; internal interconnection electrode - 6, 10; ceramic end cap - 7; interconnection lead - 11, 13; interconnection bump - 12, 14; interconnection pad - 15, 17; lead post - 16, 18; substrate - 19; ceramic substrate - 20; package housing - 21; upper boron nitride layer - 22; middle graphene layer - 23; lower boron nitride layer - 24; barrier layer - 25, 26; external interconnection electrode - 27, 28. Detailed implementation manners

[0027] The embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation of the present invention.

[0028] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "front", "rear", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the combination or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. In addition, during the description of the embodiments of the present invention, for the positional relationships of "upper", "lower", "front", "rear", "left", "right", etc. of all the devices in the drawings, they are all based on Figure 1 as the standard.

[0029] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0030] The following further describes the present invention with reference to the drawings:

[0031] As Figure 1 , 2 shown, it is a three-dimensional external view of the first embodiment of the present invention. A graphene high-temperature temperature sensor with a thin-film structure is provided, which can work stably at a high temperature of 1500 °C for a long time. The sensor includes:

[0032] The encapsulation housing 21 can be in the shape of a cylinder, a cube, a cuboid, etc. as a whole, and no specific limitation is made. In the drawings of the present invention, only a cylindrical structure is shown. The encapsulation housing is used to isolate the external environment and support and protect the internal structure;

[0033] The ceramic end cap 7 is disposed on the top end of the encapsulation housing 21. A plurality of through holes 2 are provided on the ceramic end cap 7. The upper surface of the ceramic end cap 7 is a porous structure formed by a plurality of through holes 2, which is conducive to rapid heat transfer to the inside, thereby improving the response time. The shape of the through hole 2 is not limited to the circular shape shown in the present invention, and can also be other shapes such as a square shape, and no specific limitation is made;

[0034] The ceramic substrate 20 is disposed at the bottom end inside the encapsulation housing 21. The ceramic end cap 7, the ceramic substrate 20 and the encapsulation housing 21 jointly define an internal detection space to provide support and protection for the internal components;

[0035] The detection unit is disposed in the internal detection space and on the ceramic substrate 20;

[0036] The interconnection component is disposed on both sides of the detection unit. One end of the interconnection component is connected to the detection unit, and the other end of the interconnection component is connected to the outside.

[0037] As Figure 2 shown, it is a cross-sectional view of the overall structure of the first embodiment of the present invention. A ceramic substrate 20 is disposed at the bottom of the internal detection space. The outer peripheral side of the ceramic substrate 20 is lap-connected to the inner side surface of the encapsulation housing 21.

[0038] As Figure 2-5 shown, the detection unit is disposed on one side of the ceramic substrate 20 facing the internal detection space. The detection unit includes: a detection nano-film 1, metal electrodes, alumina nano-films 3, a substrate 19, and barrier layers 25, 26. The substrate 19 is disposed on the ceramic substrate 20. The detection nano-film 1 is disposed on the upper surface of the substrate 19. The alumina nano-film 3 covers the upper surface of the detection nano-film 1. The metal electrodes are disposed on both sides of the detection nano-film 1 and connected to the detection nano-film 1. The barrier layers 25, 26 are disposed between the metal electrodes and the substrate 19.

[0039] As Figure 2 、 4As shown in Fig. 6, the detection nano-film 1 is composed of an upper boron nitride layer 22, a middle graphene layer 23, and a lower boron nitride layer 24. The upper boron nitride layer 22, the middle graphene layer 23, and the lower boron nitride layer 24 are sequentially arranged from top to bottom. The middle graphene layer 23 is in a "folded-back" structure with serpentine bends. The middle graphene layer 23 with a folded-back structure has a relatively high sensitivity. The structural shape of the middle graphene layer 23 is not limited to the "folded-back" structure shown in the present invention and can also be in other shapes such as a "disc" shape with a similar mosquito coil spiral shape, etc., without specific limitation. The number of folds of the middle graphene layer 23 is not limited to the number shown in this embodiment and can also be other numbers without specific limitation. In other embodiments, the number of layers of the upper boron nitride layer 22 and the lower boron nitride layer 24 is greater than or equal to 1, and the middle graphene layer 23 is a single-layer structure. In the present invention, temperature is directly conducted through the upper alumina nano-film 3 to the middle graphene layer 23 of the detection nano-film 1, thereby sensing external temperature changes and greatly improving the response time.

[0040] As Figure 2-7 shown, the metal electrode is composed of composite electrodes 4, 8, wirings 5, 9, and internal interconnection electrodes 6, 10. The composite electrodes 4, 8 are connected to the internal interconnection electrodes 6, 10 through the wirings 5, 9. The composite electrodes 4, 8 are respectively connected to two opposite ends of the middle graphene layer 23. The interconnection electrode is connected to the interconnection component for exporting the electrical response in the detection nano-film 1. The barrier layers 25, 26 are arranged at the bottoms of the composite electrodes 4, 8, the wirings 5, 9, and the internal interconnection electrodes 6, 10. The barrier layers 25, 26, as the wetting layer and the protective layer, isolate the metal electrode from the substrate 19 and prevent the mutual diffusion of metal atoms and substrate atoms at high temperatures.

[0041] As Figure 2 、 3As shown, the interconnect component includes interconnect leads 11, 13, interconnect pads 15, 17, lead posts 16, 18, and external interconnect electrodes 27, 28, and the interconnect leads 11, 13, interconnect pads 15, 17, lead posts 16, 18, and external interconnect electrodes 27, 28 are connected in sequence. Mounting holes for mounting the lead posts 16, 18 are formed in the ceramic substrate 20, the lead posts 16, 18 are disposed in the mounting holes, the interconnect pads 15, 17 are disposed on the ceramic substrate 20 and connected to one ends of the lead posts 16, 18, interconnect bumps 12, 14 are provided on the interconnect pads 15, 17, one ends of the interconnect leads 11, 13 are connected to the interconnect bumps 12, 14 on the interconnect pads 15, 17, the other ends of the interconnect leads 11, 13 are connected to the internal interconnect electrodes 6, 10, an opening for accommodating the external interconnect electrodes 27, 28 is provided at the bottom of the package housing 21, the external interconnect electrodes 27, 28 are disposed at the bottom of the ceramic substrate 20 and connected to the other ends of the lead posts 16, 18, and the external interconnect electrodes 27, 28 are connected to an external detection component for transmitting and detecting the electrical response of the nano-film 1 to the temperature signal. The external detection component can be a component that constitutes a complete sensor structure in the prior art. The interconnect leads 11, 13 are formed by Pt wire bonding, and the substrate and the ceramic substrate are in close contact by Pt-Pt metal bonding technology to provide a firm support for the temperature sensor chip.

[0042] The alumina nano-film 3 can be covered on the upper surface of the detection nano-film 1 by evaporation to perform anaerobic encapsulation on the detection nano-film 1. The alumina nano-film 3 on the upper surface of the detection nano-film 1 isolates the detection nano-film 1 from direct contact with the outside world and provides anaerobic protection for the middle graphene layer 23 in the detection nano-film 1.

[0043] In the present invention, the detection nano-film is protected by the alumina nano-film and then encapsulated using a ceramic package, which is convenient for encapsulation.

[0044] In this embodiment, the substrate 19 is a cylinder, and the area of the detection nano-film 1 is smaller than the area of the upper side surface of the entire substrate 19.

[0045] In the present invention, the substrate material can be selected as α - Al2O3 material, the substrate can be made of Al2O3 material, and the metal electrodes and the internal and external interconnect electrodes can be selected as Pt material.

[0046] The package housing is connected to the ceramic end caps 7 and the ceramic substrate 20 and firmly bonded.

[0047] The principle of the present invention is:

[0048] When an external temperature signal acts on the upper surface of the sensor ceramic end cap, the temperature is transmitted to the detection unit through the upper ceramic end cap. The middle graphene layer therein is affected by the temperature, and the electro-phonon coupling strength and phonon scattering strength inside its material change, resulting in a change in the conductivity of the middle graphene layer. By detecting the current change in the plane of the middle graphene layer, the externally applied temperature value can be measured. At the same time, in this process, the alumina nano-film and the substrate isolate the detection nano-film from direct contact with the outside world, providing an oxygen-free protection for the middle graphene layer, ensuring that the detection nano-film can work in a high-temperature environment, and thus achieving high-precision measurement of temperature in a harsh and complex high-temperature environment.

[0049] In the description of this specification, the description of reference terms such as "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0050] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and purposes of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A graphene high-temperature temperature sensor with a thin-film structure that can operate stably at a high temperature of 1500°C for a long time, characterized in that, The sensor includes: a packaging housing (21), a ceramic end cap (7) provided at the top of the packaging housing (21), and a ceramic substrate (20) provided at the bottom end inside the packaging housing (21), and a plurality of through holes (2) are provided on the ceramic end cap (7); a detection unit, which is arranged in an internal detection space jointly defined by the ceramic end cap (7), the ceramic substrate (20) and the packaging housing (21) and is located on the ceramic substrate (20); an interconnection component, which is arranged on both sides of the detection unit, one end of the interconnection component is connected to the detection unit, and the other end of the interconnection component is connected to the outside to lead out the electrical response in the detection unit; The detection unit is arranged on one side of the ceramic substrate (20) facing the internal detection space. The detection unit includes: a detection nano-film (1), a metal electrode, an alumina nano-film (3), a substrate (19) and barrier layers (25, 26). The substrate (19) is arranged on the ceramic substrate (20), the detection nano-film (1) is arranged on the upper surface of the substrate (19), the alumina nano-film (3) covers the upper surface of the detection nano-film (1), the metal electrodes are arranged on both sides of the detection nano-film (1) and are connected to the detection nano-film (1), and the barrier layers (25, 26) are arranged between the metal electrodes and the substrate (19); the substrate material is α-Al2O3 material; The metal electrode is composed of composite electrodes (4, 8), wirings (5, 9) and internal interconnection electrodes (6, 10). The composite electrodes (4, 8) are connected to the internal interconnection electrodes (6, 10) through the wirings (5, 9). The composite electrodes (4, 8) are respectively connected to two opposite ends of the middle graphene layer (23). The interconnection electrodes are connected to the interconnection component for leading out the electrical response in the detection nano-film (1); The interconnection component includes: interconnection leads (11, 13), interconnection pads (15, 17), lead posts (16, 18) and external interconnection electrodes (27, 28). The interconnection leads (11, 13), the interconnection pads (15, 17), the lead posts (16, 18) and the external interconnection electrodes (27, 28) are sequentially connected; Mounting holes for mounting the lead posts (16, 18) are formed in the ceramic substrate (20). The lead posts (16, 18) are disposed in the mounting holes. The interconnection pads (15, 17) are disposed on the ceramic substrate (20) and connected to one end of the lead posts (16, 18). Interconnection bumps (12, 14) are provided on the interconnection pads (15, 17). One end of the interconnection leads (11, 13) is connected to the interconnection bumps (12, 14) on the interconnection pads (15, 17), and the other end of the interconnection leads (11, 13) is connected to the internal interconnection electrodes (6, 10). An opening for accommodating the external interconnection electrodes (27, 28) is provided at the bottom of the package housing (21). The external interconnection electrodes (27, 28) are disposed at the bottom of the ceramic substrate (20) and connected to the other end of the lead posts (16, 18). The external interconnection electrodes (27, 28) are connected to an external detection component; The detection nano-film (1) is composed of an upper boron nitride layer (22), a middle graphene layer (23), and a lower boron nitride layer (24). The upper boron nitride layer (22), the middle graphene layer (23), and the lower boron nitride layer (24) are sequentially arranged from top to bottom. The middle graphene layer (23) is in a serpentine bending structure or a disc-shaped bending structure.

2. The graphene high-temperature temperature sensor with a thin-film structure according to claim 1, characterized in that, The barrier layers (25, 26) are disposed at the bottoms of the composite electrodes (4, 8), the wirings (5, 9), and the internal interconnection electrodes (6, 10).

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