Temperature sensor packaging method for flight test

Abstract

The invention provides a temperature sensor packaging method for a flight test, and the method comprises the following steps: enabling a temperature measurement sensitive unit to be connected with a wire in a welding manner, and forming a welding spot; the temperature measurement sensitive unit is arranged in the hollow shell, and the temperature measurement sensitive unit, the welding spots and part of the wires are all located in the hollow shell; high-temperature glue is poured into the hollow shell, and after it is judged that the hollow shell is filled with the high-temperature glue, pouring is stopped; the thermal expansion coefficient of the high-temperature glue and the thermal expansion coefficient of the hollow shell material are in the same magnitude; and curing the high-temperature glue, and connecting the hollow shell, the internal temperature measurement sensitive unit, the welding spots and part of the wires into a whole by the cured high-temperature glue. According to the flight test temperature sensor, the high-temperature glue is adopted for packaging, so that the reliability of the sensor in severe vibration and high-temperature environments is improved while internal welding spots are protected, the thermal expansion coordination of a packaging material is optimized, and the failure of the flight test temperature sensor in an extreme temperature environment is avoided.

Description

Technical Field

[0001] This invention relates to the field of sensor packaging technology, and in particular to a packaging method for a temperature sensor used in flight testing. Background Technology

[0002] Flight testing directly verifies aircraft performance, ensures flight safety, and promotes technological optimization and innovation. Temperature sensors play a crucial role in flight testing, and their measurement accuracy and reliability directly affect aircraft performance evaluation and safety assurance. However, the unique characteristics of the flight environment, such as severe vibration, drastic temperature changes, and extreme environmental factors like high temperatures, pose significant challenges to the packaging of temperature sensors.

[0003] Currently, common packaging methods include single-material packaging and multi-material packaging. Single-material packaging includes metal packaging, ceramic packaging, and resin packaging. Multi-material packaging uses multiple materials in the packaging process. Sensors using existing packaging methods have drawbacks such as easily broken solder joints, poor vibration resistance, poor high-temperature resistance, and poor thermal expansion coordination.

[0004] Metal encapsulation refers to directly inserting the temperature-sensing element into a hollow metal shell, with the wires connected to the element firmly compressed by the shell, thus encapsulating the sensor. Sensors using this encapsulation method typically have a hollow internal design, leaving the solder joints between the temperature-sensing element and the wires unprotected and easily damaged. During encapsulation and use, relative displacement between the solder joints and the shell can easily cause open circuits. While ceramic encapsulation can be used in high-temperature environments, it is prone to breakage due to its brittleness under the strong vibrations of flight testing, leading to sensor failure. Resin encapsulation is prone to aging in high-temperature environments, resulting in decreased adhesion between the encapsulation layer and the sensing element, causing sensor failure. Composite material encapsulation has poor thermal expansion coordination due to differences in the coefficients of thermal expansion between materials. This leads to varying degrees of expansion or contraction between different materials during temperature changes, generating thermal stress that can damage easily damaged parts such as the sensor's solder joints.

[0005] Therefore, developing a packaging method that can protect the internal solder joints of the sensor, resist vibration, withstand high temperatures, and has excellent material thermal expansion coordination has become the key to solving the application problems of temperature sensors in flight tests. Summary of the Invention

[0006] The purpose of this invention is to provide a packaging method for a temperature sensor used in flight testing. This method effectively protects the internal solder joints and improves the reliability of the sensor under severe vibration and high temperature conditions. It also optimizes the thermal expansion coordination characteristics of the packaging material to prevent the temperature sensor from failing under extreme temperature conditions during flight testing.

[0007] A first aspect of the present invention provides a method for packaging a temperature sensor for flight testing, comprising the following steps:

[0008] S1. Connect the temperature sensing unit to the wire by welding to form a solder joint;

[0009] S2. Install the temperature sensing unit into the hollow shell, so that the temperature sensing unit, solder joints and some wires are all inside the hollow shell;

[0010] S3. Pour the high-temperature adhesive into the hollow shell. Stop the potting process once the hollow shell is completely filled with high-temperature adhesive. The high-temperature adhesive is a high-temperature adhesive with a thermal expansion coefficient on the same order of magnitude as the hollow shell material.

[0011] S4. Perform high-temperature adhesive curing. The cured high-temperature adhesive will connect the hollow shell and the internal temperature sensing unit, solder joints and some wires into a whole.

[0012] Preferably, the hollow outer shell material is consistent with the outer shell material of the flight test prototype.

[0013] Preferably, in step S3, the high-temperature adhesive is placed in a syringe after being filtered, and after the gas is expelled, the high-temperature adhesive is poured into the hollow shell when it has good fluidity.

[0014] Preferably, in step S3, the sensor is inverted during potting with the measuring surface facing down, and high-temperature adhesive is poured into the hollow shell from the hollow tail end.

[0015] Preferably, in step S3, a through hole is provided at the top of the hollow shell. When a small amount of high-temperature adhesive seeps out of the through hole, it is determined that the high-temperature adhesive has filled the hollow shell, and the potting process is stopped.

[0016] Preferably, in step S4, the high-temperature adhesive curing includes:

[0017] S41. After the potting process is stopped, the sensor should be cured at room temperature.

[0018] S42. After curing at room temperature, perform high-temperature curing.

[0019] Preferably, the room temperature curing temperature is controlled above 20℃, and the room temperature curing time is 18 to 24 hours; the high temperature curing temperature is controlled above 100℃, and the high temperature curing time is not less than 4 hours; during high temperature curing, the sensor temperature rises with the heating equipment, and after the high temperature adhesive is cured, the sensor cools down with the heating equipment, and the temperature change rate during the entire curing process should not exceed 5℃ / min.

[0020] A second aspect of the present invention provides a temperature sensor for flight testing, which is packaged using the aforementioned temperature sensor packaging method for flight testing, comprising: a hollow shell; a temperature sensing unit and a wire disposed inside the hollow shell, the temperature sensing unit being connected to the wire by welding to form a solder joint; and high-temperature adhesive being injected into the hollow shell, the high-temperature adhesive connecting the hollow shell and the internal temperature sensing unit, solder joint, and part of the wire into a whole.

[0021] Preferably, the hollow outer shell has a through hole at the top, and the temperature sensing unit is inserted into the hollow outer shell from the rear hollow part, with the top of the temperature sensing unit flush with or slightly protruding from the outer end face of the through hole.

[0022] Preferably, the high-temperature adhesive is a high-temperature adhesive with a coefficient of thermal expansion on the same order of magnitude as that of the hollow shell material, and the hollow shell material is consistent with the shell material of the flight test prototype.

[0023] Compared with the prior art, the present invention has at least the following beneficial effects:

[0024] (1) This invention uses a high-temperature adhesive with a thermal expansion coefficient close to that of the outer shell for encapsulation, which ensures that the sensor can expand or contract uniformly when the temperature changes, thus avoiding thermal stress and solving the problem of thermal expansion coordination of the sensor during flight testing.

[0025] (2) The cured high-temperature adhesive connects the outer shell and the internal temperature sensing unit, solder joints, and some wires into a whole, which has good vibration resistance and solves the problem of sensor damage due to mechanical stress.

[0026] (3) The cured high-temperature adhesive has good stability and can maintain the encapsulation effect when facing high-temperature chemical environment and drastic temperature changes, thus improving the reliability of the sensor.

[0027] (4) After curing, the high-temperature adhesive forms a dense protective layer to prevent dust, moisture and other substances from entering the sensor. Attached Figure Description

[0028] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the process flow for the temperature sensor packaging method for flight testing provided by the present invention;

[0030] Figure 2 This is a schematic diagram of the temperature sensor used for flight testing provided by the present invention.

[0031] Explanation of reference numerals in the attached diagram: 1. Through hole; 2. Temperature sensing unit; 3. Hollow outer shell; 4. Solder joint; 5. Wire. Detailed Implementation

[0032] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, 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 application pertains.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form includes the plural form unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0034] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Example 1

[0036] like Figure 1 As shown, this invention provides a high-temperature sensor packaging method for flight testing. Taking the flight test prototype's housing material as GH4099 as an example, the high-temperature sensor packaging method is specifically described, including the following steps:

[0037] (1) The temperature sensing unit 2 is connected to the wire 5 by laser welding to form a solder joint 4.

[0038] (2) Insert the temperature sensing unit 2 into the hollow outer shell 3 from the hollow end, so that the top of the temperature sensing unit 2 is flush with or slightly protrudes from the outer end face of the through hole 1. At this time, the temperature sensing unit 2, the solder joint 4 and part of the wire 5 are all inside the hollow outer shell 3.

[0039] (3) The hollow outer shell 3 is made of GH4099, and the coefficient of thermal expansion of GH4099 is 13.0 × 10⁻⁶. -6 / ℃, select a high-temperature adhesive with a coefficient of thermal expansion in the same order of magnitude as the hollow shell material 3. The high-temperature adhesive model is OMEGABOND 600, which can withstand temperatures exceeding 800℃ and has a coefficient of thermal expansion of 11.9×10.-6 / ℃, prepare high-temperature adhesive (filler to curing agent ratio of 2.0~3.0:1).

[0040] (4) Invert the sensor with the measuring surface facing down. Filter the prepared high-temperature adhesive and place it in a syringe. After purging the gas, ensure the high-temperature adhesive has good fluidity, then pour the high-temperature adhesive from the hollow tail end into the gap between the temperature sensing unit 2, the solder joint 4, part of the wire 5, and the hollow outer shell 3 to achieve a seal. When a small amount of high-temperature adhesive seeps out of the through hole 1 where the temperature sensing unit 2 and the head of the hollow outer shell 3 meet, it is determined that the high-temperature adhesive has filled the hollow outer shell 3, and the potting process is stopped.

[0041] (5) After the potting is stopped, the sensor is cured at room temperature indoors for 24 hours.

[0042] (6) After the room temperature curing is completed, the sensor is placed in the oven for high temperature curing. The maximum temperature of the oven is set to 105℃. The heating starts from room temperature and the heating rate is 4℃ / min. After reaching the maximum temperature, the oven is kept warm for 5 hours.

[0043] (7) After the sensor is cured at 105°C, turn off the oven and wait for the oven to cool naturally to room temperature before taking out the sensor.

[0044] In this embodiment, the order of steps (1), (2), and (3) is adjustable and can be adjusted to (3), (1), (2) or (1), (3), (2).

[0045] Example 2

[0046] like Figure 2 As shown, this embodiment provides a temperature sensor for flight testing, which is packaged using the temperature sensor packaging method for flight testing in Embodiment 1. Specifically, it includes: a hollow shell 3; a temperature sensing unit 2 and a wire 5 are disposed inside the hollow shell 3, and the temperature sensing unit 2 is connected to the wire 5 by welding to form a solder joint 4; high-temperature adhesive is poured into the hollow shell 3, and the high-temperature adhesive connects the hollow shell 3 and the internal temperature sensing unit 2, solder joint 4 and part of the wire 5 into a whole.

[0047] In this embodiment, a through hole 1 is provided at the top of the hollow shell 3, and the temperature sensing unit 2 is inserted into the hollow shell 3 from the hollow part at the tail, so that the top of the temperature sensing unit 2 is flush with or slightly protruding from the outer end face of the through hole 1.

[0048] In this embodiment, the high-temperature adhesive is a high-temperature adhesive with a coefficient of thermal expansion on the same order of magnitude as the hollow outer shell 3 material, and the hollow outer shell 3 material is consistent with the outer shell material of the flight test prototype. Taking GH4099 as an example, the hollow outer shell 3 material is selected as GH4099, and the coefficient of thermal expansion of GH4099 material is 13.0 × 10⁻⁶.-6 / ℃, and selected a high-temperature adhesive with a thermal expansion coefficient in the same order of magnitude as the hollow shell material 3. The high-temperature adhesive model is OMEGABOND 600, with a temperature resistance exceeding 800℃ and a thermal expansion coefficient of 11.9×10. -6 / ℃.

[0049] In summary, to protect the solder joints of the temperature sensor during flight testing and meet the requirements for vibration resistance and high temperature resistance, this invention provides a temperature sensor encapsulation method for flight testing by considering the thermal expansion coordination characteristics of materials and through innovative material selection and structural design. By introducing the concept of high-temperature adhesive potting, the internal solder joints of the sensor are protected while significantly improving the reliability of the sensor under severe vibration and high temperature environments. It also optimizes the thermal expansion coordination of the encapsulation material to prevent the temperature sensor from failing under extreme temperature environments during flight testing.

[0050] 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 or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for packaging a temperature sensor for flight testing, characterized in that, Includes the following steps: S1. Connect the temperature sensing unit (2) to the wire (5) by welding to form a solder joint (4); S2. Install the temperature sensing unit (2) into the hollow shell (3) so that the temperature sensing unit (2), solder joint (4) and part of the wire (5) are all inside the hollow shell (3); S3. Pour the high-temperature adhesive into the hollow shell (3). After determining that the high-temperature adhesive has filled the hollow shell (3), stop the potting process. The high-temperature adhesive is a high-temperature adhesive with a thermal expansion coefficient on the same order of magnitude as the hollow shell (3) material. S4. High-temperature adhesive is cured. The cured high-temperature adhesive connects the hollow shell (3) and the internal temperature sensing unit (2), solder joint (4) and some wires (5) into a whole.

2. The temperature sensor packaging method for flight testing according to claim 1, characterized in that, The hollow outer shell (3) is made of the same material as the outer shell of the flight test prototype.

3. The temperature sensor packaging method for flight testing according to claim 1, characterized in that, In step S3, the high-temperature adhesive is filtered and placed in a syringe. After the gas is expelled, the high-temperature adhesive is poured into the hollow shell (3) when it has good fluidity.

4. The temperature sensor packaging method for flight testing according to claim 3, characterized in that, In step S3, the sensor is inverted during potting, with the measuring surface facing down, and high-temperature adhesive is poured into the hollow shell (3) from the hollow tail.

5. The temperature sensor packaging method for flight testing according to claim 4, characterized in that, In step S3, a through hole (1) is provided on the top of the hollow shell (3). When a small amount of high-temperature adhesive seeps out of the through hole (1), it is determined that the high-temperature adhesive has filled the hollow shell (3) and the potting process is stopped.

6. The temperature sensor packaging method for flight testing according to claim 1, characterized in that, In step S4, the high-temperature adhesive curing includes: S41. After the potting process is stopped, the sensor should be cured at room temperature. S42. After curing at room temperature, perform high-temperature curing.

7. The temperature sensor packaging method for flight testing according to claim 6, characterized in that, For room temperature curing, the temperature should be controlled above 20℃ and the curing time should be 18 to 24 hours; for high temperature curing, the temperature should be controlled above 100℃ and the curing time should be no less than 4 hours, and the temperature change rate during the curing process should not exceed 5℃ / min.

8. A temperature sensor for flight testing, characterized in that, The temperature sensor packaging method for flight testing according to any one of claims 1-7 is used for packaging, including: a hollow shell (3); a temperature sensing unit (2) and a wire (5) are disposed inside the hollow shell (3), the temperature sensing unit (2) is connected to the wire (5) by welding to form a solder joint (4); the hollow shell (3) is filled with high-temperature adhesive, the high-temperature adhesive connects the hollow shell (3) and the internal temperature sensing unit (2), solder joint (4) and part of the wire (5) into a whole.

9. The temperature sensor packaging method for flight testing according to claim 8, characterized in that, The hollow shell (3) has a through hole (1) at the top. The temperature sensing unit (2) is inserted into the hollow shell (3) from the hollow part at the tail. The top of the temperature sensing unit (2) is flush with or slightly protrudes from the outer end face of the through hole (1).

10. The temperature sensor for flight testing according to claim 8, characterized in that, The high-temperature adhesive is a high-temperature adhesive with a thermal expansion coefficient on the same order of magnitude as the hollow shell (3) material, and the hollow shell (3) material is consistent with the shell material of the flight test prototype.

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