Mounting structure and mounting method for large-area thin film sensor for strain testing

Abstract

The application discloses a mounting structure and a mounting method of a large-area thin film sensor for strain testing, which comprises a mounting adhesive, a protective adhesive and adhesive tape; the bottom of the large-area thin film sensor is glued to the surface of a to-be-mounted surface through the mounting adhesive, the mounting adhesive between a testing area and the to-be-mounted surface adopts a patch adhesive or an adhesive film, and the mounting adhesive between a circuit area and the to-be-mounted surface adopts a fixing adhesive; the protective adhesive covers the top of the large-area thin film sensor, the protective adhesive completely wraps the top and the side of the whole large-area thin film sensor, the outside of the protective adhesive is covered with the adhesive tape, and the adhesive tape completely wraps the outside of the whole protective adhesive. The mounting structure adopts a regional mounting mode, the circuit area is fixed by using the fixing adhesive which is easy to use, and the testing area is mounted by using the patch adhesive which needs to be pressurized and heated to be solidified, so that the testing precision is ensured, the area needing to be pressurized and heated is reduced, the problem that a large-area pressurization and heating are needed when the whole "meter-level" sensor is mounted is avoided, and the mounting speed is improved.

Description

Technical Field

[0001] This invention belongs to the field of thin-film sensors and relates to an installation structure and installation method for a large-area thin-film sensor for strain testing. Background Technology

[0002] Both resistance strain gauges and large-area thin-film sensors are sensitive elements used for strain testing, and their materials, manufacturing processes, and subsequent application methods are largely the same. Resistance strain gauges are relatively small (≤20cm × 20cm), while large-area thin-film sensors are often on the order of meters. Resistance strain gauges are mostly used for short-term stress testing in relatively good or harsh environments, while large-area thin-film sensors need to meet the requirements for long-term stable operation in outdoor environments. Therefore, a complete mounting and protective structure for large-area thin-film sensors is needed to meet the application requirements of this sensor.

[0003] However, the current mounting structure of large-area thin-film sensors has the problem of requiring large-area pressure and heating when mounting "meter-level" sensors, which makes installation inconvenient, time-consuming and labor-intensive. Summary of the Invention

[0004] The purpose of this invention is to overcome the disadvantages of the existing installation structure, such as inconvenience, time and labor, and to provide an installation structure and method for a large-area thin-film sensor for strain testing, which reduces the area that needs to be pressurized and heated and improves installation efficiency.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A mounting structure for a large-area thin-film sensor for strain testing includes mounting adhesive, protective adhesive, adhesive-resistant film, and tape.

[0007] The bottom of the large-area thin-film sensor is attached to the surface to be mounted using mounting adhesive. The mounting adhesive between the test area and the surface to be mounted uses patch adhesive or film, while the mounting adhesive between the circuit area and the surface to be mounted uses fixing adhesive. Protective adhesive covers the top of the large-area thin-film sensor, completely wrapping the top and sides of the entire sensor. The protective adhesive is then covered with tape, which completely wraps the outside of the protective adhesive.

[0008] Preferably, when installing on a concrete surface, a primer is applied between the bottom of the adhesive and the surface to be installed.

[0009] Furthermore, the bonding strength between the primer and concrete is ≥2.5MPa, the tensile modulus of elasticity is ≥3Gpa, the elongation is ≥1%, the thickness is 1mm~5mm, and the area is 1.5 times to 3 times the area of ​​the large-area thin-film sensor.

[0010] Preferably, when using adhesive patch, the thickness is 0.5mm to 1mm, and when using adhesive film, the thickness is 5 to 15μm. The area of ​​the adhesive patch is 1.5 to 3 times the area of ​​the test area.

[0011] Preferably, the protective adhesive is made of butyl rubber film, liquid butyl rubber, room temperature vulcanizing silicone rubber, or polyamide adhesive.

[0012] Preferably, the thickness of the protective adhesive is 2mm to 5mm.

[0013] Preferably, a barrier film is provided between the top of the test area and the protective adhesive, and the barrier film is made of polytetrafluoroethylene, polyester or polyimide film.

[0014] Preferably, the thickness of the resist film is 20μm to 100μm, and the area of ​​the resist film is 1.5 to 2 times the area of ​​the test area.

[0015] Preferably, the edge of the tape extends 5cm to 10cm beyond the edge of the protective adhesive.

[0016] An installation method for a large-area thin-film sensor mounting structure for strain testing involves first applying a layer of adhesive to the installation location of the large-area thin-film sensor test area, then applying fixing adhesive to the circuit area of ​​the large-area thin-film sensor. The large-area thin-film sensor is then aligned with the installation location and pressed onto the sensor until its surface is flat. A soldering iron and hot plate are used to heat-press the large-area thin-film sensor test area according to the pressure, temperature, and time parameters for adhesive curing, until the adhesive or film is completely cured. Protective adhesive is then used to cover the entire large-area thin-film sensor and manually pressed until fully adhered. If there are gaps at the edges of the protective adhesive, liquid butyl rubber is used to seal them. Finally, aluminum foil tape is applied to the protective adhesive, with the edge of the aluminum foil tape extending beyond the edge of the protective adhesive.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] This invention adopts a segmented installation method. The circuit area is fixed with easy-to-use adhesive, while the test area is installed with a patch adhesive that requires pressure and heat curing. While ensuring test accuracy, it reduces the area that needs pressure and heat, avoiding the problem of large-area pressure and heat application when mounting a meter-level sensor as a whole, and improving the installation speed.

[0019] Furthermore, applying a primer can effectively resist moisture and isolate the effects of moisture and water vapor that may come into contact with the mounting surface and the cover surface.

[0020] Furthermore, a barrier film is used to isolate the protective adhesive layer from the test area, preventing the protective adhesive layer from sticking to the test area and affecting the test data.

[0021] Furthermore, the use of a highly weather-resistant base layer and protective layer ensures the long-term stable operation of the sensor in harsh outdoor environments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the large-area thin-film sensor of the present invention;

[0023] Figure 2 This is a schematic diagram of the large-area thin-film sensor mounting structure of the present invention;

[0024] Figure 3 This is a flowchart illustrating the installation process of the large-area thin-film sensor of the present invention.

[0025] Figure 4 This is a graph showing the daily sensor test data variation under outdoor conditions according to the present invention.

[0026] Wherein: 1-Line area; 2-Test area; 3-Primer adhesive; 4-Fixing adhesive; 5-Patch adhesive; 6-Protective adhesive; 7-Resistant film; 8-Aluminum foil tape; 9-Surface to be installed. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] It should be noted that the terms “front,” “back,” “left,” “right,” “up,” and “down” used in the following description refer to the directions shown in the attached diagrams, while the terms “inner” and “outer” refer to the directions toward or away from the geometric center of a specific component, respectively.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0030] In the mounting structure of the large-area thin-film sensor for strain testing described in this invention, such as... Figure 1 As shown, the large-area thin-film sensor consists of two parts: test area 2 and circuit area 1.

[0031] In this embodiment, multiple test areas 2 are arranged at various locations of the large-area thin-film sensor, and the remaining area of ​​the large-area thin-film sensor is the circuit area 1.

[0032] like Figure 2 As shown, the bottom of the large-area thin-film sensor is attached to the surface of the mounting surface 9 with mounting adhesive. The mounting adhesive between the test area 2 and the mounting surface 9 is a patch adhesive 5 or a film, and the mounting adhesive between the circuit area 1 and the mounting surface 9 is a fixing adhesive 4. The mounting adhesive can be either liquid adhesive or solid film.

[0033] The installation adopts a zoned approach: the circuit area 1 is fixed with easy-to-use, heat-free adhesive or tape that can be pressed by hand, while the test area 2 is installed with a special patch adhesive 5 that requires pressure and heat curing. This approach ensures test accuracy while avoiding the problem of large-area pressure and heating required when mounting a meter-level sensor.

[0034] When installing on a concrete surface, a primer 3 is placed between the bottom of the adhesive and the surface 9 to be installed. This effectively resists moisture and isolates the moisture and water vapor that may come into contact with the surface from the installation surface to the cover surface, thereby preventing water seepage from the concrete and causing large-area thin-film sensor failure.

[0035] The top of the large-area thin-film sensor is covered with a protective adhesive 6 as a protective layer. The protective adhesive 6 completely wraps the top of the entire large-area thin-film sensor. The protective adhesive 6 can be either liquid adhesive or solid adhesive film.

[0036] The protective adhesive 6 is covered with aluminum foil tape 8, which completely wraps the entire exterior of the protective adhesive 6.

[0037] like Figure 3 As shown, the large-area thin-film sensor is installed according to the following structure, starting from the surface to be installed, in the following order: ① Primer 3 (used when installing on concrete surfaces, not needed on metal surfaces) → ② Mounting adhesive → ③ Large-area thin-film sensor → ④ Protective adhesive 6 → ⑤ Aluminum foil tape 8. This installation method ensures the long-term stable operation of the large-area thin-film sensor in harsh outdoor environments.

[0038] The primer adhesive 3 used must be a concrete-specific epoxy repair adhesive. This adhesive must meet the following requirements: small filler particles, easy application, no dripping after application, no shrinkage after curing, high weather resistance, and good resistance to media corrosion. Simultaneously, the adhesive's bond strength to concrete should be ≥2.5MPa, its tensile modulus of elasticity should be ≥3GPa, and its elongation should be ≥1%. Before applying the primer, use tools to roughly level the surface to be installed 9, removing protrusions and impurities. During primer application, the adhesive thickness should be controlled between 1mm and 5mm, and the application area should be controlled between 1.5 and 3 times the area of ​​the large-area thin-film sensor. Curing should be carried out at room temperature or with heating according to the curing conditions, and then finely sanded until it is ready for patch installation.

[0039] The adhesive used (5) must be an epoxy or acrylic adhesive film that cures at room temperature or ≤80℃. When using the film, its thickness should be 5–15 μm. When applying the adhesive, only apply it to the test area 2 of the large-area thin-film sensor where the patch will be attached, controlling the adhesive thickness to 0.5 mm–1 mm. The adhesive film and the area covered by the adhesive should be 1.5 to 3 times the area of ​​the test area 2. Press the sensor test area 2 onto the adhesive-covered area and cure it under room temperature and pressure or with heat and pressure, according to the curing conditions.

[0040] Simultaneously with the patch installation, the circuit area 1 on the large-area thin-film sensor can be flattened and fixed to the surface to be installed using hot melt adhesive, nail-free adhesive, or double-sided tape.

[0041] The protective adhesive 6 used must be one of the following: high-weather-resistant butyl rubber film, liquid butyl rubber, room temperature vulcanizing silicone rubber, or polyamide adhesive. When using a film, its thickness should be 2mm to 5mm. During application, the adhesive thickness should be controlled between 2mm and 5mm. The area of ​​the film / adhesive application should be 1.5 to 3 times the area of ​​the primer 3. Curing should be carried out at room temperature or by baking under heat according to the curing conditions. If the adhesive has high fluidity, 2 to 5 applications are required, allowing each application to allow the previous layer to cure.

[0042] To avoid the thick protective adhesive layer 6 adhering to the test area 2 and affecting the test results, a resist film 7 can be used in the test area 2 to separate the test area 2 from the protective adhesive 6. The resist film 7 can be one of polytetrafluoroethylene, polyester and polyimide films with a thickness of 20μm to 100μm. The area of ​​the resist film 7 is controlled to be 1.5 times to 2 times the area of ​​the test area 2 of the large-area thin film sensor.

[0043] Finally, cover the entire installation area with a layer of aluminum foil tape 8. The edge of the aluminum foil tape 8 should extend 5cm to 10cm beyond the edge of the protective adhesive 6 to form an installation structure for a large-area thin-film sensor.

[0044] The large-area thin-film sensor is wrapped with a highly weather-resistant base layer and a protective layer, ensuring long-term stable operation of the sensor in harsh outdoor environments.

[0045] The installation process for the large-area thin-film sensor mounting structure for strain testing described above is as follows:

[0046] First, the surface to be installed needs to be treated. If the surface is metal, use 300-400 grit sandpaper to sand away the coating and rust until the metal is exposed. Then, sand at a 45° angle to create texture, and wipe away any loose powder with anhydrous ethanol or acetone. This completes the treatment. If the surface is concrete, it needs to be waterproofed and leveled. The specific method is as follows: Use a stonemason's chisel, a concrete rough planer with a diamond grinding wheel, etc., to remove protrusions and impurities from the concrete surface, and wipe away any loose powder with anhydrous ethanol or acetone for rough leveling. Then, evenly apply 1mm-5mm of concrete-specific epoxy repair adhesive to the rough leveled surface, controlling the application area to be 1.5 to 3 times the area of ​​the large-area thin-film sensor. Allow the leveling adhesive to cure at room temperature or by baking. After the leveling adhesive has cured, use a concrete rough planer with a hard plastic grinding wheel to sand the surface, and wipe away any loose powder with anhydrous ethanol or acetone. This completes the treatment.

[0047] Next, the large-area thin-film sensor is mounted. During installation, first apply a layer of low-temperature (≤80℃) curing adhesive 5 to the installation location of the test area 2 of the large-area thin-film sensor. The adhesive thickness should be controlled between 0.5mm and 1mm, and the adhesive area should be controlled between 1.5 and 3 times the area of ​​test area 2. Alternatively, use a soldering iron to hot-press a layer of high-modulus thermosetting adhesive film (5μm to 15μm) at a temperature higher than the softening temperature but lower than the curing temperature. The adhesive film area should be controlled between 1.5 and 3 times the area of ​​test area 2. Then, apply double-sided tape or adhesive glue to the circuit area 1 of the large-area thin-film sensor. Align the test area 2 of the large-area thin-film sensor with the installation location and manually press it onto the sensor until the surface is flat, thus securing it. Next, use a soldering iron and hot plate to hot-press the test area 2 of the large-area thin-film sensor according to the pressure, temperature, and time parameters for curing the adhesive 5 or adhesive film until the adhesive 5 or adhesive film is completely cured. This completes the mounting of the large-area thin-film sensor.

[0048] Next, the large-area thin-film sensor is protected. First, a resistive film 7, approximately 1.5 to 2 times the area of ​​the large-area thin-film sensor test area 2, is applied over it. The resistive film 7 can be made of polytetrafluoroethylene, polyester, or polyimide. This step prevents the subsequent protective adhesive layer 6 from affecting the test area 2. Then, a 2mm to 5mm butyl sealant film, 1.5 to 3 times the area of ​​the primer adhesive 3, is used to cover the entire mounting surface and manually pressed until it is completely adhered. If there are gaps at the edges of the sealant strip, liquid butyl rubber is used to seal the edges.

[0049] Finally, use aluminum foil tape 8 to attach it to the butyl sealant film. The edge of the aluminum foil tape 8 should extend 5cm to 10cm beyond the edge of the butyl sealant film to complete the installation of the large-area thin-film sensor.

[0050] After installation as described above, the large-area thin-film sensor was subjected to a high-temperature and high-humidity treatment at 60℃ and 90%RH for 168 hours. The resistance changes of the large-area thin-film sensor before and after the treatment are as follows:

[0051] Table 1. Data Record of Sensor Resistance Changes After 168 hours of High Temperature and High Humidity Treatment at 60℃ and 90%RH

[0052]

[0053] After outdoor installation as described above, remote data observation is performed on the sensors, and data changes within 6 days are as follows: Figure 4 As shown (reading time interval is 1 hour), by Figure 4 It can be seen that the data fluctuation of the large-area thin-film sensor is within the allowable range.

[0054] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0055] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A mounting structure for a large-area thin-film sensor for strain testing, characterized in that, Includes mounting adhesive, protective adhesive (6) and tape; The bottom of the large-area thin-film sensor is glued to the surface of the mounting surface (9) with mounting adhesive. The mounting adhesive between the test area (2) and the mounting surface (9) is a patch adhesive (5) or a film, and the mounting adhesive between the circuit area (1) and the mounting surface (9) is a fixing adhesive (4). Protective adhesive (6) covers the top of the large-area thin-film sensor. The protective adhesive (6) completely wraps the top and sides of the entire large-area thin-film sensor. The protective adhesive (6) is covered with tape, which completely wraps the outside of the protective adhesive (6).

2. The mounting structure of the large-area thin-film sensor for strain testing according to claim 1, characterized in that, When installing on a concrete surface, a primer (3) is placed between the bottom of the adhesive and the surface to be installed (9).

3. The mounting structure of the large-area thin-film sensor for strain testing according to claim 2, characterized in that, The bonding strength between the primer (3) and concrete is ≥2.5MPa, the tensile modulus of elasticity is ≥3Gpa, the elongation is ≥1%, the thickness is 1mm~5mm, and the area is 1.5 times to 3 times the area of ​​the large-area thin film sensor.

4. The mounting structure of the large-area thin-film sensor for strain testing according to claim 1, characterized in that, When using adhesive patch (5), the thickness is 0.5mm to 1mm, and when using adhesive film, the thickness is 5 to 15μm. The area of ​​adhesive patch (5) is 1.5 to 3 times the area of ​​test area (2).

5. The mounting structure of the large-area thin-film sensor for strain testing according to claim 1, characterized in that, The protective adhesive (6) is made of butyl rubber film, liquid butyl rubber, room temperature vulcanizing silicone rubber or polyamide adhesive.

6. The mounting structure of the large-area thin-film sensor for strain testing according to claim 1, characterized in that, The thickness of the protective adhesive (6) is 2mm to 5mm.

7. The mounting structure of the large-area thin-film sensor for strain testing according to claim 1, characterized in that, A barrier film (7) is provided between the top of the test area (2) and the protective adhesive (6). The barrier film (7) is made of polytetrafluoroethylene, polyester or polyimide film.

8. The mounting structure of the large-area thin-film sensor for strain testing according to claim 1, characterized in that, The thickness of the resist film (7) is 20μm to 100μm, and the area of ​​the resist film (7) is 1.5 to 2 times the area of ​​the test area (2).

9. The mounting structure of the large-area thin-film sensor for strain testing according to claim 1, characterized in that, The edge of the tape extends 5cm to 10cm beyond the edge of the protective adhesive (6).

10. A method for mounting a large-area thin-film sensor for strain testing based on the mounting structure of any one of claims 1-9, characterized in that, First, apply a layer of adhesive (5) to the installation position of the large-area thin-film sensor test area (2). Then, apply fixing adhesive (4) to the circuit area (1) of the large-area thin-film sensor. Align the large-area thin-film sensor with the installation position and press it down until the surface of the large-area thin-film sensor is flat. Use a soldering iron and hot plate to heat press the large-area thin-film sensor test area (2) according to the pressure, temperature and time parameters of the adhesive (5) curing until the adhesive (5) or adhesive film is completely cured. Use protective adhesive (6) to cover the entire large-area thin-film sensor and manually press it until it is completely adhered. If there are gaps at the edge of the protective adhesive (6), use liquid butyl rubber to seal the edges. Finally, use aluminum foil tape (8) to stick on the protective adhesive (6), with the edge of the aluminum foil tape (8) extending beyond the edge of the protective adhesive (6).

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