A sensor for measuring temperature gradient distribution and a manufacturing method thereof

Abstract

The application provides a sensor for realizing temperature gradient distribution measurement and a preparation method, wherein the sensor comprises a needle-shaped temperature measuring head at the front end and a pad area at the rear end; the sensor comprises a substrate layer and a thermocouple film layer from bottom to top; the thermocouple film layer comprises a single first thermocouple film and a plurality of second thermocouple films as positive and negative electrodes respectively; the first thermocouple film and the second thermocouple film are connected with the pad area, and the single first thermocouple film and the plurality of second thermocouple films are overlapped at a plurality of nodes to form a plurality of thermocouple temperature measuring nodes arranged along the needle-shaped direction at intervals. The needle-shaped temperature measuring head has small invasion damage, which reduces the damage to the measured material / structure to the maximum, is beneficial to high-precision measurement, and forms a plurality of thermocouple temperature measuring nodes arranged along the needle-shaped direction at intervals, so that the accurate measurement of the temperature gradient distribution in the same direction is realized.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a sensor for measuring temperature gradient distribution and its fabrication method. Background Technology

[0002] Temperature measurement, especially high-temperature in-situ and online measurement, is a key technology required for the optimized design and performance evaluation of high-temperature and demanding components of aerospace vehicles. For example, obtaining the temperature gradient distribution from the outside to the inside of the thermal protection layer is of great significance for thermal protection material / structure modeling, optimization design improvement, and thermal insulation performance evaluation.

[0003] Existing technologies for measuring the temperature of aircraft thermal protection layers mainly include embedded optical fibers, embedded thin-film thermocouples, and perforated thermocouple probes. Embedded optical fibers disrupt the original material / structural properties of the thermal protection layer and pose reliability issues such as interface failure. Embedded thin-film thermocouples offer advantages such as in-situ measurement and rapid response, but they are typically placed at the interfaces of different materials within the protection layer, have limited measurement points, and complex leads, thus remaining largely confined to the laboratory stage. Perforated thermocouple probes are a commonly used method in ground tests for measuring the temperature gradient distribution of the thermal protection layer from the outside in. However, this method usually requires drilling multiple holes at different thicknesses to install the thermocouple probes, introducing measurement errors from various sources. It is difficult to measure the gradient at different points along the same direction, and it causes significant damage to the thermal protection layer, making high-precision measurements challenging. Summary of the Invention

[0004] This invention provides a sensor and its fabrication method for measuring temperature gradient distribution, which solves the problem of difficulty in measuring the gradient at different measuring points in the same direction in the prior art, and enables high-precision measurement of the temperature gradient at different measuring points in the same direction.

[0005] The present invention provides a sensor for measuring temperature gradient distribution, comprising: a needle-shaped temperature probe at the front end and a pad area at the rear end, wherein the sensor comprises, from bottom to top, a substrate layer and a thermocouple thin film layer.

[0006] The thermocouple thin film layer includes a single first thermocouple thin film and a plurality of second thermocouple thin films, which serve as positive and negative electrodes respectively.

[0007] Both the first thermocouple film and the second thermocouple film are connected to the pad area, and a single first thermocouple film and multiple second thermocouple films overlap at multiple nodes to form multiple thermocouple temperature measurement nodes arranged at intervals along the needle-shaped direction.

[0008] According to a sensor provided by the present invention, the sensor further includes a protective thin film layer disposed on the thermocouple thin film layer.

[0009] According to a sensor provided by the present invention, the pad area is provided with a plurality of pads;

[0010] The number of pads is the same as the sum of the number of the first thermocouple film and the second thermocouple film, and the first thermocouple film and the second thermocouple film are respectively connected to the corresponding pads.

[0011] According to a sensor provided by the present invention, the protective film layer has an opening in the pad area for external output leads.

[0012] According to a sensor provided by the present invention, the pad area is further provided with a thermistor connected to the pad for cold junction temperature compensation.

[0013] The present invention also provides a method for fabricating a sensor for measuring temperature gradient distribution, comprising:

[0014] Substrate pretreatment;

[0015] A single first thermocouple film is formed by deposition and patterning on the substrate layer;

[0016] A plurality of second thermocouple films are deposited and patterned on a substrate layer on which the first thermocouple film is deposited; wherein, each of the first thermocouple film and the plurality of second thermocouple films are connected to the pad area and overlap at multiple nodes to form multiple thermocouple temperature measuring nodes arranged at intervals along the needle direction.

[0017] The sensor is obtained by laser cutting the substrate on which the first thermocouple film and the second thermocouple film are deposited.

[0018] According to a method for fabricating a sensor provided by the present invention, a single first thermocouple thin film is formed by deposition and patterning on a substrate layer, comprising:

[0019] Photoresist is spin-coated onto the substrate layer to form a first photoresist layer having a first opening region;

[0020] A first thermocouple thin film material is deposited on the substrate layer;

[0021] By using a wet stripping process, the substrate layer covered with the first thermocouple film material is immersed in an acetone solution for wet stripping to remove the first photoresist layer and form a patterned first thermocouple film.

[0022] According to a sensor fabrication method provided by the present invention, a plurality of second thermocouple films are formed by deposition and patterning on a substrate layer on which a first thermocouple film is deposited, including:

[0023] Photoresist is further spin-coated onto the substrate layer to form a second photoresist layer with multiple second opening regions in the needle-shaped temperature probe portion; wherein, at least a portion of the first thermocouple film is present in the second opening regions;

[0024] Deposit a second thermocouple thin film material on the substrate layer;

[0025] By using a wet stripping process, the substrate layer on which the second thermocouple film material is deposited is immersed in an acetone solution for wet stripping to remove the second photoresist layer and form a patterned second thermocouple film; wherein the second thermocouple film and the first thermocouple film overlap at multiple second opening regions to form multiple thermocouple temperature measurement nodes.

[0026] According to a method for fabricating a sensor provided by the present invention, after depositing a second thermocouple thin film material, the method further includes:

[0027] A protective layer material is deposited on a substrate layer on which a first thermocouple film and a second thermocouple film are deposited to form a protective film layer.

[0028] According to a method for manufacturing a sensor provided by the present invention, the method further includes:

[0029] The protective film layer forms an opening in the pad area through photoresist mask patterning and dry etching, and external output leads are connected.

[0030] The sensor and preparation method for measuring temperature gradient distribution provided by this invention have minimal invasive damage to the needle-shaped temperature probe, minimizing damage to the measured material / structure and facilitating high-precision measurement. Furthermore, the needle-shaped temperature probe is formed by overlapping a single first thermocouple film and multiple second thermocouple films at multiple nodes, creating multiple thermocouple temperature measurement nodes spaced apart along the needle direction, thereby achieving accurate measurement of the temperature gradient distribution in the same direction. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of the sensor for measuring temperature gradient distribution provided in an embodiment of the present invention;

[0033] Figure 2 This is a flowchart illustrating the sensor fabrication method provided in this embodiment of the invention. Figure 1 ;

[0034] Figure 3 This is a flowchart illustrating the sensor fabrication method provided in this embodiment of the invention. Figure 2 ;

[0035] Figure 4 This is a flowchart illustrating the sensor fabrication method provided in this embodiment of the invention. Figure 3 ;

[0036] Figures 5a to 5i This is a schematic diagram of the sensor fabrication method provided in an embodiment of the present invention.

[0037] Figure label:

[0038] 11: Needle-shaped temperature probe; 12: Solder pad area;

[0039] 101: Substrate layer; 102: Alumina film;

[0040] 103: First opening area; 104: Second opening area;

[0041] 201: Solder pad;

[0042] 202: Second thermocouple film; 203: First thermocouple film;

[0043] 301: Protective thin film layer; 401: Thermocouple temperature measuring node;

[0044] 501: First photoresist layer; 502: Second photoresist layer; 601: Laser cutting. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0046] The following is combined Figure 1 This describes a sensor for measuring temperature gradient distribution according to an embodiment of the present invention. See also... Figure 1 The sensors include:

[0047] The sensor comprises a needle-shaped temperature probe 11 at the front end and a pad area 12 at the rear end. From bottom to top, the sensor includes a substrate layer 101 and a thermocouple thin film layer.

[0048] Furthermore, the width or diameter of the needle-shaped temperature probe 11 of the aforementioned sensor is between 50 μm and 5000 μm. For example, in one specific embodiment, the width of the needle-shaped temperature probe 11 for measuring the temperature gradient distribution is 900 μm and the length is 40 mm.

[0049] The thermocouple film layer includes a single first thermocouple film 203 and a plurality of second thermocouple films 202, which serve as positive and negative electrodes, respectively.

[0050] Specifically, the first thermocouple film 203 can be set as the positive electrode and the multiple second thermocouple films 202 as the negative electrode; or the first thermocouple film 203 can be set as the negative electrode and the multiple second thermocouple films 202 as the positive electrode.

[0051] There can be multiple temperature sensing nodes; this example uses four. Correspondingly, there are four second thermocouple films 202, which overlap with the first thermocouple film 203 at intervals along the needle-like direction. As shown in the figure, the first thermocouple film 203 is located in the middle, and the other four second thermocouple film layers 202 are respectively placed on both sides of the first thermocouple film 203. The thickness of the first thermocouple film 203 and the second thermocouple film 202 is between 50 nm and 5000 nm.

[0052] The thermocouple temperature sensing nodes 401 distributed on the needle-shaped temperature probe are square with a side length of 100μm, and there are 4 nodes with a spacing of 1mm. The tip of the needle-shaped temperature probe 11 can be inserted into the material / structure such as the thermal protection layer of the aircraft to sense the temperature gradient distribution in the direction perpendicular to the plane of the thermal protection layer.

[0053] In addition, both the first thermocouple film 203 and the second thermocouple film 202 are connected to the pad area 12, and a single first thermocouple film 203 and multiple second thermocouple films 202 overlap at multiple nodes to form multiple thermocouple temperature measuring nodes 401 arranged at intervals along the needle direction.

[0054] Specifically, the pad area 12 is provided with a plurality of pads 201. The number of pads 201 is the same as the sum of the number of the first thermocouple film 203 and the second thermocouple film 202, and the first thermocouple film 203 and the second thermocouple film 202 are respectively connected to the corresponding pads 201.

[0055] In this embodiment, the number of pads 201 is 5. Among them, the middle pad 201 and the first thin-film thermocouple electrode 203 thereon are shared by four thermocouple temperature measurement nodes 401, thereby reducing the total number of pads.

[0056] Optionally, in addition to the substrate layer 101 and the thermocouple film layers 202 and 203, the sensor also includes a protective film layer 301, which is disposed on the thermocouple film layer to provide protection.

[0057] The protective film layer 301 has an opening in the pad area 12 for connecting external output leads.

[0058] Optionally, the pad area 12 is also provided with a thermistor connected to the pad 201 for cold junction temperature compensation.

[0059] The sensor provided in this embodiment of the invention has minimal invasive damage to the needle-shaped temperature probe, minimizing damage to the measured material / structure and facilitating high-precision measurement. Furthermore, the needle-shaped temperature probe is formed by overlapping a single first thermocouple film and multiple second thermocouple films at multiple nodes, creating multiple thermocouple temperature measurement nodes spaced apart along the needle-shaped direction, thereby achieving accurate measurement of the temperature gradient distribution in the same direction.

[0060] Furthermore, these thermocouples are typically made of bulk material and have a long thermal response time. The sensor in this embodiment can simultaneously measure different measuring points in the same direction, further ensuring high measurement accuracy.

[0061] This invention also discloses a method for fabricating a sensor for measuring temperature gradient distribution, see [link to relevant documentation]. Figure 2 This includes the following steps 21-24:

[0062] 21. Base layer pretreatment.

[0063] In this embodiment, the substrate 101 is cleaned by ultrasonic cleaning with deionized water, dried, and then a 100nm thick aluminum oxide thin film 102 is deposited on the substrate 101 by magnetron sputtering. Figure 5a As shown.

[0064] In this embodiment, the substrate 101 is a 4-inch alumina ceramic sheet.

[0065] 22. Deposition and patterning are performed on the substrate layer to form a single first thermocouple film.

[0066] In this embodiment, the deposition process adopts physical or chemical vapor deposition methods, and the patterning process can be achieved by wet stripping, dry / wet etching or laser etching, respectively.

[0067] Specifically, in a particular instance, see [reference needed]. Figure 3 Step 22 includes the following steps 31 to 33:

[0068] 31. Spin-coating photoresist onto the substrate layer to form a first photoresist layer having a first opening region.

[0069] Specifically, a mask for the first thermocouple thin film material 203, i.e., the first photoresist layer 501, is formed on the substrate layer 101 by spin-coating photoresist, followed by exposure, development, and drying. The photoresist provided in this embodiment has a thickness of 2 μm.

[0070] like Figure 5b As shown, the first opening region 103 is no longer coated with photoresist.

[0071] 32. Deposit the first thermocouple thin film material on the substrate layer.

[0072] Specifically, a first thermocouple thin film material 203, namely Pt, with a thickness of 500 nm is deposited on the substrate layer 101 by magnetron sputtering.

[0073] In this embodiment, pad 201 is completed simultaneously during this processing, so the material is also Pt with a thickness of 500nm.

[0074] like Figure 5c As shown, the first thermocouple thin film material 203 is not only deposited on the photoresist, but also deposited on the bottom layer of the first opening region 103.

[0075] 33. By means of a wet stripping process, the substrate layer covered with the first thermocouple film material is immersed in an acetone solution for wet stripping to remove the first photoresist layer and form a patterned first thermocouple film.

[0076] The first thermocouple film 203 formed, as shown Figure 5d As shown.

[0077] It should be explained that the wet stripping process removes the first photoresist layer 501 and the first thermocouple film deposited on the first photoresist layer 501, and the remaining first thermocouple film material on the substrate forms a patterned first thermocouple film 203.

[0078] Through steps 31 to 33, a single first thermocouple film can be formed on the substrate layer.

[0079] 23. A plurality of second thermocouple films are formed by deposition and patterning on the substrate on which the first thermocouple film is deposited.

[0080] In this process, a single first thermocouple film 203 and multiple second thermocouple films 202 are connected to the pad area 12 and overlap at multiple nodes to form multiple thermocouple temperature measuring nodes 401 arranged at intervals along the needle-shaped direction.

[0081] Specifically, see Figure 4Step 23 includes:

[0082] 41. Continue to spin-coat photoresist on the substrate layer to form a second photoresist layer with multiple second opening regions in the needle-shaped temperature probe portion; wherein, at least a portion of the first thermocouple film is present in the second opening regions.

[0083] Specifically, such as Figure 5e As shown, a mask for the second thermocouple thin film material, namely the second photoresist layer 502, is formed by spin-coating photoresist on the substrate layer, followed by exposure, development, and drying.

[0084] like Figure 5e As shown, the second opening region 104 is no longer coated with photoresist.

[0085] It should be noted that the second opening region 104 needs to have a portion of the first thermocouple film 203 so that the deposited second thermocouple film 202 material can be bonded to the first thermocouple film 203 in subsequent steps.

[0086] 42. Deposit a second thermocouple thin film material on the substrate layer.

[0087] Specifically, the second thermocouple thin film 202 material can be deposited on the substrate 101 by magnetron sputtering.

[0088] like Figure 5f As shown, the second thermocouple film 202 material is not only deposited on the second photoresist layer 502, but also deposited on the bottom of the second opening region 104.

[0089] 43. By using a wet stripping process, the substrate layer on which the second thermocouple film material is deposited is immersed in an acetone solution for wet stripping to remove the second photoresist layer and form a patterned second thermocouple film.

[0090] The second thermocouple film 202 and the first thermocouple film 203 overlap at multiple second opening regions 104 to form multiple thermocouple temperature measurement nodes 401.

[0091] See Figure 5g , Figure 5g A schematic diagram of one of the thermocouple temperature measurement nodes 401 is shown. As can be seen from the figure, at the thermocouple temperature measurement node 401, the second thermocouple film 202 and the first thermocouple film 203 overlap.

[0092] Through steps 41 to 43, a plurality of second thermocouple films 202 can be formed on the substrate layer 101.

[0093] Optionally, after depositing the second thermocouple thin film material, the method further includes: depositing a protective layer material on the substrate layer on which the first thermocouple thin film 203 and the second thermocouple thin film 202 are deposited by magnetron sputtering to form a protective thin film layer 301, such as... Figure 5h As shown.

[0094] The protective film layer 301 can be aluminum oxide with a thickness of 500 nm.

[0095] The protective thin film layer 301 forms an opening in the pad area through photoresist mask patterning and dry etching, and external output leads are connected.

[0096] Alternatively, the opening in the pad 201 region can be selectively removed by a photoresist-based wet stripping process.

[0097] 24. The substrate layer on which the first thermocouple film and the second thermocouple film are deposited is laser-cut to obtain the sensor.

[0098] See Figure 5i To accurately preserve the unique shape and contour of the sensor, the sensor is cut using laser cutting 601 or other physical / chemical through-etching methods.

[0099] In use, a blind hole can be drilled on the heat protection layer to be measured at the required depth, with a diameter slightly larger than the width of the sensor needle-shaped temperature probe. Then, the sensor is inserted vertically into the blind hole, thereby realizing the simultaneous measurement of the temperature gradient distribution along the thickness direction of the heat protection layer.

[0100] The method for fabricating a sensor for measuring temperature gradient distribution provided in this invention has minimal invasive damage to the needle-shaped temperature probe, minimizing damage to the measured material / structure and facilitating high-precision measurement. Furthermore, the needle-shaped temperature probe is formed by overlapping a single first thermocouple film and multiple second thermocouple films at multiple nodes to create multiple thermocouple temperature measurement nodes spaced apart along the needle direction, thereby achieving accurate measurement of the temperature gradient distribution in the same direction.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sensor for measuring temperature gradient distribution, characterized in that, include: The sensor comprises a needle-shaped temperature probe at the front end and a pad area at the rear end. From bottom to top, the sensor includes a substrate layer and a thermocouple thin film layer. The thermocouple thin film layer includes a single first thermocouple thin film and a plurality of second thermocouple thin films, which serve as positive and negative electrodes respectively. Both the first thermocouple film and the second thermocouple film are connected to the pad area, and a single first thermocouple film and multiple second thermocouple films overlap at multiple nodes to form multiple thermocouple temperature measurement nodes arranged at intervals along the needle-shaped direction. The pad area is provided with multiple pads; The number of pads is the same as the sum of the number of the first thermocouple film and the second thermocouple film, and the first thermocouple film and the second thermocouple film are respectively connected to the corresponding pads.

2. The sensor according to claim 1, characterized in that, The sensor further includes a protective thin film layer disposed on the thermocouple thin film layer.

3. The sensor according to claim 2, characterized in that, The protective film layer has an opening in the pad area for connecting external output leads.

4. The sensor according to claim 1, characterized in that, include: The pad area is also provided with a thermistor connected to the pad for cold junction temperature compensation.

5. A method for fabricating a sensor for measuring temperature gradient distribution, characterized in that, include: Substrate pretreatment; A single first thermocouple film is formed by deposition and patterning on the substrate layer; Multiple second thermocouple films are deposited and patterned on a substrate layer on which the first thermocouple film is deposited. Each of the first thermocouple film and the multiple second thermocouple films is connected to a pad area and overlaps at multiple nodes to form multiple thermocouple temperature measurement nodes spaced apart along a needle-like direction. The pad area is provided with multiple pads. The number of pads is the same as the sum of the number of the first and second thermocouple films, and each of the first and second thermocouple films is connected to its corresponding pad. The sensor is obtained by laser cutting the substrate on which the first thermocouple film and the second thermocouple film are deposited.

6. The preparation method according to claim 5, characterized in that, Deposition and patterning are performed on the substrate layer to form a single first thermocouple film, including: Photoresist is spin-coated onto the substrate layer to form a first photoresist layer having a first opening region; A first thermocouple thin film material is deposited on the substrate layer; By using a wet stripping process, the substrate layer covered with the first thermocouple film material is immersed in an acetone solution for wet stripping to remove the first photoresist layer and form a patterned first thermocouple film.

7. The preparation method according to claim 6, characterized in that, Multiple second thermocouple films are formed by deposition and patterning on a substrate on which the first thermocouple film is deposited, including: Photoresist is further spin-coated onto the substrate layer to form a second photoresist layer with multiple second opening regions in the needle-shaped temperature probe portion; wherein, at least a portion of the first thermocouple film is present in the second opening regions; Deposit a second thermocouple thin film material on the substrate layer; By using a wet stripping process, the substrate layer on which the second thermocouple film material is deposited is immersed in an acetone solution for wet stripping to remove the second photoresist layer and form a patterned second thermocouple film; wherein the second thermocouple film and the first thermocouple film overlap at multiple second opening regions to form multiple thermocouple temperature measurement nodes.

8. The preparation method according to claim 7, characterized in that, After depositing the second thermocouple thin film material, the method further includes: A protective layer material is deposited on a substrate layer on which a first thermocouple film and a second thermocouple film are deposited to form a protective film layer.

9. The preparation method according to claim 8, characterized in that, The method further includes: The protective film layer forms an opening in the pad area through photoresist mask patterning and dry etching, and external output leads are connected.

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