Integrated anti-interference temperature sensing module and packaging method thereof

Abstract

The application provides an integrated anti-interference temperature sensing module, which comprises a temperature sensing module, a control module and a lead wire. The temperature sensing module comprises a printed circuit board, a first filter unit, a temperature sensing unit and a sealing unit. The sealing unit comprises a first encapsulation layer, a second encapsulation layer and a third encapsulation layer. The material of the third encapsulation layer is consistent with that of the second encapsulation layer. The thermal conductivity of the second encapsulation layer is higher than that of the first encapsulation layer. The insulation of the first encapsulation layer is higher than that of the second encapsulation layer. The sealing unit is provided in a layered structure, and the insulation, thermal conductivity, thermal insulation and stress of different encapsulation layers are designed differently, so that the requirements of high insulation, low stress and high thermal conductivity can be met simultaneously in the same temperature sensing area, and the functional loss caused by a single encapsulation material is avoided. The problems of low anti-interference precision and decreased thermal management reliability in the prior art are solved.

Description

Technical Field

[0001] This application relates to the field of temperature sensor technology, and more specifically, to an integrated anti-interference temperature sensing module and its packaging method for use in battery packs or battery modules in new energy vehicles. Background Technology

[0002] Currently, the battery pack of new energy vehicles, as the core of the vehicle's power, relies heavily on the accurate sensing of the battery management system for its safety and reliability. Temperature sensors distributed throughout the cells and key connection points are the direct "nerve endings" for preventing thermal runaway, optimizing thermal management, and ensuring lifespan. However, the battery pack's interior constitutes an extremely harsh electromagnetic compatibility environment: high-power switching devices such as the motor drive inverter and the onboard DC-DC converter continuously generate high-intensity, wide-spectrum conducted and radiated interference. This electromagnetic noise can easily couple to the analog signal transmission harness of the temperature sensors, causing distortion and fluctuations in the weak voltage signal transmitted to the battery management controller, resulting in inaccurate temperature monitoring.

[0003] While traditional "end-point countermeasures" (i.e., filtering and protection at the controller circuit board port) have some effect, interference has already taken hold during long-distance transmission, and it is difficult to achieve uniform and efficient protection for numerous temperature sensors that are distributed widely. Therefore, the temperature sensors currently used in battery packs or battery modules of new energy vehicles still cannot uniformly and efficiently solve the problem of external interference signals.

[0004] Furthermore, existing technologies do not consider the different encapsulation requirements of various components. This means that within the same temperature sensing area, the requirements for high insulation and low stress, as well as high thermal conductivity, cannot be simultaneously met by a single encapsulation material. This leads to mutual constraints between the encapsulation needs of the high-insulation protective elements and the high-thermal-conductivity elements inside the temperature sensor. When only a temperature sensor exists in the temperature sensing area, there is no functional conflict in the encapsulation materials, thus avoiding the aforementioned performance degradation problem. However, when the temperature sensing area contains both a temperature sensor and other components such as a filter unit with high insulation protection, using the existing uniform encapsulation method may result in reduced insulation strength and leakage resistance of the filter unit or other components due to the use of thermally conductive adhesive, or insufficient thermal conductivity and slower response speed of the temperature sensing unit due to the use of high-insulation adhesive. This ultimately affects the overall battery pack's anti-interference accuracy and thermal management reliability. Summary of the Invention

[0005] In view of this, embodiments of this application provide a packaging method for an integrated anti-interference temperature sensing module, comprising the following steps: S1, a temperature sensing module is provided, the temperature sensing module includes a printed circuit board, a first filtering unit disposed on the top layer of the printed circuit board and a temperature sensing unit, the printed circuit board has a signal input pad and a conductive via; S2, forming a first encapsulation layer having first thermal conductivity and first insulation properties, encapsulating the first filter unit, and completely curing it; S3, forming a second encapsulation layer having second thermal conductivity and second insulation, encapsulating the temperature sensing unit, and then completely curing it; S4, forming a third encapsulation layer with third thermal conductivity and third insulation, encapsulating the first filter unit, the temperature sensing unit, and the printed circuit board with the same material as the second encapsulation layer, and then completely curing them; wherein, the first thermal conductivity is lower than the second thermal conductivity; the first thermal conductivity is lower than the third thermal conductivity; the first insulation is higher than the second insulation, and the first insulation is higher than the third insulation; S5, Install the housing, insert the temperature sensing module into the housing, and allow part of the leads to extend out of the housing; S6, forming a potting layer, using epoxy resin material, filling the space between the housing and the temperature sensing module through a potting process, and encapsulating all of the third encapsulation layer, all of the printed circuit board and part of the leads, and completing the preparation after the epoxy resin is completely cured.

[0006] In one embodiment, the thermal conductivity of the material of the second encapsulation layer is more than 8 times that of the material of the first encapsulation layer; The dielectric strength of the first encapsulation layer material is 1.5 times or more than that of the dielectric strength of the second encapsulation layer material, or the volume resistivity of the first encapsulation layer material is 100 to 10,000 times that of the second encapsulation layer material.

[0007] In one embodiment, when forming the first encapsulation layer in S2, an organic silicone conformal coating with an insulation strength ≥20kV / mm and low stress is applied by spraying or dipping. The coating thickness is controlled between 0.1mm and 0.3mm. Before coating, the printed circuit board and the surface of the first filter unit are subjected to plasma cleaning or solvent cleaning to remove oil and moisture. The curing conditions are: leave at room temperature for 15 to 30 minutes, and then bake at 80℃ to 100℃ for 30 to 60 minutes to ensure complete curing and no low molecular weight silicone oil precipitation.

[0008] In one embodiment, when forming the second encapsulation layer in step S3, a precision dispensing process is used to uniformly cover the top and sides of the temperature sensing unit with a high thermal conductivity adhesive with a thermal conductivity ≥2.0W / m·K, and the encapsulation thickness is controlled between 0.2mm and 0.4mm. After dispensing, vacuum degassing is required to prevent residual air bubbles in the adhesive layer from forming a heat insulation layer. The curing conditions are: room temperature curing for 24 hours or curing at 80°C for 1 to 2 hours.

[0009] In one embodiment, when forming the third encapsulation layer in S4, the same high thermal conductivity adhesive as in S3 is used. The first filter unit and the temperature sensing unit are simultaneously encapsulated by secondary dispensing or molding, so that the third encapsulation layer completely covers the first encapsulation layer and the second encapsulation layer and extends to the edge and / or back of the printed circuit board. Before curing, it needs to stand for 10 to 20 minutes to remove interface air bubbles.

[0010] In one embodiment, when forming the potting layer in S6, a vacuum potting process is used: the semi-finished product with the shell installed is placed in a vacuum chamber, and a vacuum of 2.0 × 10⁻⁶ is drawn. 4 Pa ~ 1.0 × 10 3 Pa and hold for 5-10 minutes, then inject pre-mixed and degassed epoxy resin potting compound. After the injection is completed, vacuum again to remove residual gas inside. Finally, cure at 60℃-80℃ for 4-8 hours. The thickness of the potting layer is at least 1.0 mm higher than the highest point of the third encapsulation layer and completely fills all gaps between the housing and the temperature sensing module.

[0011] In one embodiment, before forming each encapsulation layer in steps S2 to S4, the surface of the printed circuit board and the surface of the cured encapsulation layer are subjected to surface activation treatment; and before forming the potting layer in step S6, the roots of the cured first encapsulation layer, the second encapsulation layer, the third encapsulation layer, and the lead are cleaned.

[0012] This application also provides an integrated anti-interference temperature sensing module, the integrated anti-interference temperature sensing module comprising: A temperature sensing module is located in the temperature detection area; the temperature sensing module further includes: a printed circuit board, a first filter unit and a temperature sensing unit disposed on the top layer of the printed circuit board, and a sealing unit for sealing the first filter unit and the temperature sensing unit; The control module is located away from the temperature detection area; and, Lead wires electrically connect the temperature sensing module and the control module; The sealing unit includes: The first encapsulation layer has a first thermal conductivity and a first insulation, and is used to encapsulate the first filter unit; A second encapsulation layer, having a second thermal conductivity and a second insulating property, is used to encapsulate the temperature sensing unit; and The third encapsulation layer has third thermal conductivity and third insulation properties, and is used to encapsulate the first filter unit and the temperature sensing unit; Wherein, the first thermal conductivity is lower than the second thermal conductivity; the first thermal conductivity is lower than the third thermal conductivity; the first insulation is higher than the second insulation, and the first insulation is higher than the third insulation.

[0013] In one embodiment, the thermal conductivity of the material of the second encapsulation layer is more than 8 times that of the material of the first encapsulation layer; The dielectric strength of the first encapsulation layer material is 1.5 times or more than that of the dielectric strength of the second encapsulation layer material, or the volume resistivity of the first encapsulation layer material is 100 to 10,000 times that of the second encapsulation layer material.

[0014] In one embodiment, the first filtering unit is connected in parallel with the temperature sensing unit; The control module includes: The control circuit supplies power and transmits signals to the temperature sensing module through the signal input pad; and, The second filtering unit is electrically connected to the control circuit and is used to perform noise reduction processing on the return signal of the temperature sensing module. One end of the lead is electrically connected to the signal input pad, and the other end of the lead is electrically connected to the control circuit; The second filter unit is located at the other end of the lead. The second filter unit is used to allow DC and low-frequency temperature acquisition signals to pass through without attenuation, while performing a second noise reduction process on external high-frequency interference signals. The noise frequency filtered out by the second filter unit is higher than the noise frequency filtered out by the first filter unit.

[0015] In one embodiment, the shortest interval between the first encapsulation layer and the second encapsulation layer on the printed circuit board is between 1 mm and 2 mm. The first encapsulation layer, which has higher insulation properties, encapsulates the conductive via.

[0016] In one embodiment, it further includes: a housing disposed on the temperature sensing module for enclosing the sealing unit and part of the lead wire; the housing is a 3.6mm × 15mm plastic housing.

[0017] In one embodiment, the device further includes: a potting layer, which is disposed between the housing and the temperature sensing module by potting, and encapsulates all of the sealing unit, all of the printed circuit board and part of the leads; the hardness of the potting layer is greater than the hardness of the first encapsulation layer and also greater than the hardness of the second encapsulation layer; the thermal conductivity of the potting layer is greater than the thermal conductivity of the first encapsulation layer, and the thermal conductivity of the potting layer is comparable to that of the second encapsulation layer.

[0018] In one embodiment, the thicknesses of the first encapsulation layer, the second encapsulation layer, and the third encapsulation layer are all set to 0.1 mm-0.4 mm, and the thickness of the potting layer is set to 0.5 mm-2 mm.

[0019] In this embodiment, the packaging method for the integrated anti-interference temperature sensing module provided by the application forms a layered packaging process for different component functional requirements by sequentially executing steps S1 to S6. Specifically, S2 forms a first encapsulation layer with first thermal conductivity and first insulation to encapsulate the first filter unit; S3 forms a second encapsulation layer with second thermal conductivity and second insulation to encapsulate the temperature sensing unit; and S4 forms a third encapsulation layer of the same material as the second encapsulation layer to encapsulate the entire module. The first thermal conductivity is lower than the second and third thermal conductivity, and the first insulation is higher than the second and third insulation. This achieves the differentiated requirements of high insulation and low stress protection for the filter unit and high thermal conductivity and fast response for the temperature sensing unit within the same temperature sensing module. Finally, S6 uses an epoxy resin potting layer to provide outer rigid protection, forming a composite packaging structure of inner functional partition encapsulation + outer overall rigid potting. This avoids the problem that a single material cannot simultaneously address multiple contradictory properties such as insulation, thermal conductivity, and stress, significantly improving the module's anti-interference capability, temperature measurement accuracy, and long-term reliability in the harsh environment of new energy vehicle battery packs.

[0020] Therefore, in the above embodiments, while achieving miniaturized packaging, anti-interference capability, environmental adaptability, and temperature measurement accuracy are also taken into account, providing reliable technical support for thermal runaway early warning and thermal management optimization of new energy vehicle battery packs. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating the steps of the packaging method for the integrated anti-interference temperature sensing module provided in the embodiments of this application. Figure 2 This is a top view of the integrated anti-interference temperature sensing module provided in the embodiments of this application; Figure 3 This is a bottom view of the integrated anti-interference temperature sensing module provided in the embodiments of this application.

[0023] Explanation of reference numerals in the attached figures: Integrated anti-interference temperature sensing module 100: Temperature sensing module 10: Printed circuit board 11, signal input pad 101, conductive via 102; first filter unit 12, temperature sensing unit 13; sealing unit 14: first encapsulation layer 141, second encapsulation layer 142, third encapsulation layer 143; housing 15: potting layer 151; Control module 20: control circuit 21, second filter unit 22; Lead wire 30. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0025] Please see Figure 1 This application provides a packaging method for an integrated anti-interference temperature sensing module, used to package the integrated anti-interference temperature sensing module 100 in any of the above embodiments. The packaging method includes the following steps: S1, a temperature sensing module 10 is provided: The temperature sensing module 10 includes a printed circuit board 11, a first filtering unit 12 disposed on the top layer of the printed circuit board 11, and a temperature sensing unit 13. The printed circuit board 11 has a signal input pad 101 and a conductive via 102. The printed circuit board 11 extends along a first direction. The temperature sensing unit 13, the conductive via 102, the first filtering unit 12, and the signal input pad 101 are arranged sequentially from left to right in the first direction.

[0026] S2, forming a first encapsulation layer 141 with first thermal conductivity and first insulation properties: encapsulating the first filter unit 12 and allowing it to fully cure. In this step, the first encapsulation layer 141 can be a silicone conformal coating with an insulation strength ≥20kV / mm and low stress. The first encapsulation layer 141 simultaneously encapsulates the first filter unit 12 and the conductive via 102.

[0027] S3, a second encapsulation layer 142 with second thermal conductivity and second insulation is formed to encapsulate the temperature sensing unit 13 and is then fully cured. The second encapsulation layer 142 is spaced apart from the first encapsulation layer 141 in a first direction. In this step, the second encapsulation layer 142 may be made of a high thermal conductivity adhesive with a thermal conductivity ≥2.0 W / m·K.

[0028] S4, a third encapsulation layer 143 with third thermal conductivity and third insulation is formed: encapsulating the first filter unit 12, the temperature sensing unit 13, and the printed circuit board 11, and completely curing it. The third encapsulation layer 143 can simultaneously encapsulate both the front (surface where the top layer is located) and the back (surface where the bottom layer is located) of the printed circuit board 11. In this step, in one embodiment, the third encapsulation layer 143 can be made of the same material as the second encapsulation layer 142, such as a high thermal conductivity adhesive. The first thermal conductivity is lower than the second thermal conductivity; the first thermal conductivity is lower than the third thermal conductivity. The first insulation is higher than the second insulation, and the first insulation is higher than the third insulation. In other embodiments, the third encapsulation layer 143 can also be made of a different material than the second encapsulation layer 142. Specifically, the first thermal conductivity may be lower than the second thermal conductivity; the second thermal conductivity may be lower than the third thermal conductivity; the first insulation may be higher than the second insulation, and the second insulation may be higher than the third insulation.

[0029] In the above steps, the thermal conductivity of the second encapsulation layer 142 material and / or the third encapsulation layer 143 material can be set to be more than 8 times that of the first encapsulation layer 141 material. Further, the thermal conductivity of the first encapsulation layer 141 material can be set to 0.2-0.3 W / m·K.

[0030] In the above steps, the dielectric strength of the first encapsulation layer 141 material can be set to be 1.5 times or more than the dielectric strength of the second encapsulation layer 142 material and / or the third encapsulation layer 143 material. The volume resistivity of the first encapsulation layer 141 material is 100 times to 10000 times the volume resistivity of the second encapsulation layer 142 material and / or the third encapsulation layer 143 material. Further, the dielectric strength of the second encapsulation layer 142 material can be set to be between 15 kV / mm and 18 kV / mm. Further, the volume resistivity of the second encapsulation layer 142 material can be set to be between 1.0 × 10⁻⁶ kV / mm. 11 ~3.5×10 11 Ω·cm.

[0031] S5, Install housing 15: Install the temperature sensing module 10 into housing 15, and allow part of the lead wire 30 to extend out of housing 15. For example... Figure 2 and Figure 3 As shown, the shell 15 is rectangular in the top and bottom views. In reality, the shell 15 can be a cuboid or a cylinder.

[0032] S6, Forming the potting layer 151: Using epoxy resin material, the potting process is used to fill the space between the housing 15 and the temperature sensing module 10, and to wrap all the first encapsulation layer 141, the second encapsulation layer 142, the third encapsulation layer 143, all the printed circuit board 11 and part of the leads 30. The preparation is completed after the epoxy resin is completely cured.

[0033] In this embodiment, a complete encapsulation process is formed by sequentially performing the steps of providing the temperature sensing module 10, forming the first encapsulation layer 141, forming the second encapsulation layer 142, forming the third encapsulation layer 143, mounting the housing 15, and forming the potting layer 151. The first encapsulation layer 141 is specifically used to encapsulate the first filter unit 12 using a material with first thermal conductivity and first insulation. The second encapsulation layer 142 and the third encapsulation layer 143 are respectively used to encapsulate the temperature sensing unit 13 and the entire unit using materials with second thermal conductivity and second insulation, and third thermal conductivity and third insulation, respectively. In some embodiments, the following conditions are met: the thermal conductivity of the second encapsulation layer material is more than 8 times that of the first encapsulation layer material; the dielectric strength of the first encapsulation layer material is 1.5 times or more that of the second encapsulation layer material; or, the volume resistivity of the first encapsulation layer material is 100 to 10,000 times that of the second encapsulation layer material. Finally, an epoxy resin potting layer 151 provides an outer rigid protection, which combines differentiated encapsulation of different functional components with overall potting. This avoids the contradiction that a single material cannot simultaneously meet the high insulation and low stress requirements of the filter unit and the high thermal conductivity requirements of the temperature sensing unit, while ensuring the reliability of the module in multiple dimensions such as mechanical, electrical and thermal aspects.

[0034] In one embodiment, when the first encapsulation layer 141 is formed in S2, an organosilicon conformal coating is applied by spraying or dipping, with the coating thickness controlled between 0.1 mm and 0.3 mm. Before coating, the surfaces of the printed circuit board 11 and the first filter unit 12 are subjected to plasma cleaning or solvent cleaning to remove oil and moisture. The curing conditions are: leave at room temperature for 15 to 30 minutes, then bake at 80°C to 100°C for 30 to 60 minutes to ensure complete curing and no low-molecular-weight silicone oil precipitation.

[0035] In this embodiment, silicone conformal coating is applied in step S2 using spraying or dipping, with the thickness controlled between 0.1 mm and 0.3 mm. Prior to coating, the surfaces of the printed circuit board 11 and the first filter unit 12 are subjected to plasma cleaning or solvent cleaning to remove oil and moisture. A segmented curing process, involving room temperature exposure followed by high-temperature baking, is then employed. On one hand, surface cleaning significantly improves the adhesion between the conformal coating and the substrate and components, preventing blistering or insufficient adhesion due to contamination. On the other hand, precise thickness control and the segmented curing process ensure complete curing of the first encapsulation layer 141 without the precipitation of low-molecular-weight silicone oil, thereby guaranteeing its high insulation strength and low stress characteristics, and preventing residual silicone oil from causing interface contamination or adhesion failure in subsequent encapsulation or potting layers.

[0036] In one embodiment, when forming the second encapsulation layer 142 in S3, a precision dispensing process is used to uniformly cover the top and sides of the temperature sensing unit 13 with high thermal conductivity adhesive, and the encapsulation thickness is controlled between 0.2 mm and 0.5 mm. Vacuum degassing is required after dispensing to prevent residual air bubbles in the adhesive layer from forming a heat insulation layer. The curing conditions are: room temperature curing for 24 hours or curing at 80°C for 1 to 2 hours.

[0037] In this embodiment, on the one hand, precision dispensing achieves accurate encapsulation of the temperature sensing unit 13 (a miniature temperature-sensing element such as an NTC thermistor), preventing the adhesive from overflowing into the adjacent filter unit (the first filter unit 12). On the other hand, vacuum degassing completely eliminates air bubbles in the adhesive layer, preventing them from forming a localized heat insulation layer that would reduce thermal conductivity or generate hot spots. Combined with suitable curing conditions, this improves the thermal response speed and strong mechanical adhesion of the temperature sensing unit 13.

[0038] In one embodiment, when the third encapsulation layer 143 is formed in S4, the same high thermal conductivity adhesive as in S3 is used. Through secondary dispensing or molding, the first filter unit 12 and the temperature sensing unit 13 are simultaneously encapsulated, so that the third encapsulation layer 143 completely covers the first encapsulation layer 141 and the second encapsulation layer 142, extending to the edge and / or back of the printed circuit board 11. Before curing, it needs to stand for 10-20 minutes to remove interface air bubbles, ensuring that there is no delamination or air gaps between the third encapsulation layer 143 and the first and second encapsulation layers 141 and 142.

[0039] In this embodiment, on the one hand, the third encapsulation layer 143 connects the encapsulation areas of different materials in the inner layer into a continuous thermally conductive and mechanically protective layer, avoiding local weak points. On the other hand, static venting ensures that there is no delamination or air gap between the third encapsulation layer 143 and the first encapsulation layer 141 and the second encapsulation layer 142, thereby ensuring the sealing integrity and thermal conductivity continuity of the overall structure and preventing the penetration of humid and hot gases or contaminants along the interface.

[0040] In one embodiment, when forming the potting layer 151 in S6, a vacuum potting process is used: the semi-finished product with the housing 15 installed is placed in a vacuum chamber, and a vacuum of 2.0 × 10⁻⁶ is drawn. 4 Pa ~ 1.0 × 10 3 Pa and hold for 5-10 minutes, then inject pre-mixed and degassed epoxy resin potting compound. After potting, vacuum again to remove residual gas. Finally, cure at 60-80°C for 4-8 hours. The thickness of the potting layer 151 is at least 1.0 mm higher than the highest point of the third encapsulation layer 143, and completely fills all gaps between the housing 15 and the temperature sensing module 10.

[0041] In this embodiment, on the one hand, vacuum potting completely eliminates air bubbles inside and at the interface of the potting compound, avoiding partial discharge, reduced insulation strength, or poor heat dissipation caused by air bubbles. On the other hand, precise curing conditions and thickness requirements ensure that the potting layer 151 has a low coefficient of thermal expansion (10-25ppm / ℃) and high hardness (>80D), enabling it to achieve thermal matching with the FR-4 printed circuit board 11, while providing sufficient mechanical protection and environmental isolation.

[0042] In one embodiment, before forming each encapsulation layer in S2 to S4, the surface of the printed circuit board 11 and the surface of the cured encapsulation layer are subjected to surface activation treatment. Furthermore, before forming the potting layer 151 in S6, the cured first encapsulation layer 141, second encapsulation layer 142, third encapsulation layer 143, and the root of the lead 30 are cleaned. During the cleaning process, the use of silicone-based release agents or silicone oil-containing substances is prohibited to prevent curing inhibition or adhesion failure of the epoxy resin potting layer 151 due to interface contamination.

[0043] In this embodiment, surface activation treatment is performed on the printed circuit board 11 and the surface of the cured encapsulation layer before the formation of each encapsulation layer in S2 to S4. Before forming the potting layer 151 in S6, the cured first encapsulation layer 141, second encapsulation layer 142, third encapsulation layer 143, and the root of the lead 30 are cleaned, and the use of silicone-based release agents or silicone-containing substances is prohibited. On the one hand, the surface activation treatment improves the interlayer bonding strength between each encapsulation layer and the adhesion between the encapsulation layer and the printed circuit board 11, avoiding interface separation. On the other hand, strictly prohibiting silicone-containing substances from contaminating the interface effectively prevents the epoxy resin potting layer 151 from curing inhibited (e.g., not curing or incomplete curing) or failing to bond due to interface contamination, thereby ensuring the long-term interface stability and overall reliability of the hard-shell, soft-core three-layer protection system.

[0044] The inventors of this application prepared a total of four integrated anti-interference temperature sensing modules, namely Example 1, Example 2, Example 3 and Comparative Example 1, with 100 products in each group, by referring to the packaging method of the integrated anti-interference temperature sensing module described above.

[0045] Example 1: S11, a temperature sensing module 10 is provided: The temperature sensing module 10 includes a printed circuit board 11, a first filtering unit 12 disposed on the top layer of the printed circuit board 11, and a temperature sensing unit 13. The printed circuit board 11 has a signal input pad 101 and a conductive via 102. The printed circuit board 11 extends along a first direction. The temperature sensing unit 13, the conductive via 102, the first filtering unit 12, and the signal input pad 101 are arranged sequentially from left to right in the first direction.

[0046] S21, a first encapsulation layer 141 with first thermal conductivity and first insulation properties is formed: the first filter unit 12 is encapsulated and completely cured. In this step, the first encapsulation layer 141 is made of silicone conformal coating with an insulation strength ≥20kV / mm and low stress. The first encapsulation layer 141 simultaneously encapsulates the first filter unit 12 and the conductive via 102. The thickness of the first encapsulation layer 141 is 0.2mm.

[0047] S31, a second encapsulation layer 142 with second thermal conductivity and second insulation is formed to encapsulate the temperature sensing unit 13 and is then fully cured. The second encapsulation layer 142 is spaced apart from the first encapsulation layer 141 in a first direction. In this step, the second encapsulation layer 142 uses a high thermal conductivity adhesive with a thermal conductivity ≥2.0 W / m·K (the thermal conductivity of the high thermal conductivity adhesive is 2.2 W / m·K). The thickness of the second encapsulation layer 142 is 0.3 mm.

[0048] S41, a third encapsulation layer 143 with third thermal conductivity and third insulation is formed: encapsulating the first filter unit 12, the temperature sensing unit 13, and the printed circuit board 11, and then completely curing it. The third encapsulation layer 143 can simultaneously encapsulate both the front (surface where the top layer is located) and the back (surface where the bottom layer is located) of the printed circuit board 11. In this step, the third encapsulation layer 143 uses the same material as the second encapsulation layer 142. The thickness of the third encapsulation layer 143 is 0.2 mm.

[0049] S51, Install housing 15: Install the temperature sensing module 10 into housing 15, and extend part of the lead wire 30 out of housing 15. Housing 15 is cylindrical.

[0050] S61, Forming the potting layer 151: Using epoxy resin material, a potting process is used to fill the space between the housing 15 and the temperature sensing module 10, and to encapsulate the entire first encapsulation layer 141, the second encapsulation layer 142, the third encapsulation layer 143, the entire printed circuit board 11, and part of the leads 30. The process is completed after the epoxy resin has fully cured. The fully cured potting layer 151 is 1.0 mm higher than the highest point of the third encapsulation layer.

[0051] Example 2: The difference between Example 2 and Example 1 is that the material of the third encapsulation layer 143 is different from that of the second encapsulation layer 142. In Example 2, the second encapsulation layer 142 uses a high thermal conductivity adhesive with a thermal conductivity of 3.1 W / m·K, while the remaining steps and film thickness are the same as in Example 1.

[0052] Example 3: The difference between Example 3 and Example 1 is that the thickness of the first encapsulation layer 141 is 0.3 mm, and the thickness of the second encapsulation layer 142 is 0.2 mm. The film material, film thickness, and other steps in Example 3 are the same as in Example 1.

[0053] Comparative Example 1: S101, a temperature sensing module 10 is provided: The temperature sensing module 10 includes a printed circuit board 11, a first filtering unit 12 disposed on the top layer of the printed circuit board 11, and a temperature sensing unit 13. The printed circuit board 11 has a signal input pad 101 and a conductive via 102. The printed circuit board 11 extends along a first direction. The temperature sensing unit 13, the conductive via 102, the first filtering unit 12, and the signal input pad 101 are arranged sequentially from left to right in the first direction.

[0054] S201, an encapsulation layer is formed to simultaneously encapsulate the first filter unit 12 and the temperature sensing unit 13, and then completely cures it. The thickness of the encapsulation layer is 0.3 mm.

[0055] S301, Install housing 15: Install the temperature sensing module 10 into housing 15, and allow part of the lead wire 30 to extend out of housing 15. Housing 15 is cylindrical.

[0056] S401, Forming the potting layer 151: Using epoxy resin material, the potting layer is filled between the housing 15 and the temperature sensing module 10 through a potting process, and encapsulates the entire encapsulation layer, the entire printed circuit board 11, and part of the leads 30. The preparation is completed after the epoxy resin is completely cured. The gap between the fully cured potting layer 151 and the encapsulation layer is 1.0 mm.

[0057] The performance of the integrated anti-interference temperature sensing modules of the above four sets of embodiments 1, 2, 3 and Comparative Example 1 is listed in Table 1 below.

[0058] Table 1: Performance Comparison of Integrated Anti-interference Temperature Sensing Modules

[0059] The response time in Table 1 represents the time required for the measured resistance value to change to 63.2% within the range of 25℃ to 100℃. The response time reflects the thermal conductivity encapsulation effect of the temperature sensing unit. Table 1 clearly shows that Comparative Example 1 has the slowest response time. The response times of Examples 1-3 are all within 8 seconds.

[0060] The temperature cycling durability in Table 1 represents the product performance observed after hundreds of cycles within the range of -40℃ to 125℃. Temperature cycling durability is used to evaluate the ability of the hard-shell, soft-core three-layer protective system of this application to resist thermal stress, observing whether delamination or cracking occurs during hundreds of cycles. The high-temperature storage life in Table 1 represents 1000 hours of storage at 125℃. This describes the aging characteristics of the film material in the product under long-term high temperatures.

[0061] Table 1 clearly shows that after hundreds of cycle tests under special temperature conditions or long-term high-temperature storage, the product of Comparative Example 1 exhibited abnormalities such as epoxy cracking, abnormal insulation withstand voltage, and resistance drift > ±5%. In contrast, the products of Examples 1-3, after hundreds of cycle tests under special temperature conditions or long-term high-temperature storage, showed no abnormal resistance, normal insulation withstand voltage, or epoxy cracking. This indicates that the integrated anti-interference temperature sensing module prepared using the method provided in this application has better durability and high-temperature storage life.

[0062] Please see Figure 2 and Figure 3 This application provides an integrated anti-interference temperature sensing module 100, applied to battery packs or battery modules in new energy vehicles. The integrated anti-interference temperature sensing module 100 includes: a temperature sensing module 10, a control module 20, and leads 30 electrically connecting the temperature sensing module 10 and the control module 20. In practical applications, the length of the leads 30 is not limited, as long as it meets the temperature testing requirements of the battery packs or battery modules in new energy vehicles. The leads 30 can be configured as wires with an outer sheath, and can be configured as high-temperature resistant wires. In other embodiments, the leads electrically connecting the temperature sensing module 10 and the control module 20 can also be replaced with printed circuit boards or other structural forms. Figure 2 To clarify the internal structure, some components in the temperature sensing module 10 are shown as transparent. Furthermore, to clarify the control module 20 and its relationship with the temperature sensing module 10, the structure of the control module 20 is illustrated in the figure.

[0063] The temperature sensing module 10, located in the temperature detection area, detects the battery temperature and converts the temperature signal into an electrical signal. The control module 20, located away from the temperature detection area, processes the electrical signal. Specifically, the control module 20 is located in the control area; for example, it may be located in the same area as the battery management system of the battery pack or battery module in a new energy vehicle.

[0064] The temperature sensing module 10 includes: a printed circuit board 11, a first filtering unit 12, a temperature sensing unit 13, and a sealing unit 14.

[0065] The printed circuit board 11 extends along a first direction and has a double-sided microstructure with a top and bottom layer. The printed circuit board 11 is provided with signal input pads 101 and conductive vias 102. A first filtering unit 12 is disposed on the top layer of the printed circuit board 11, close to the signal input pads 101, and is used for initial noise reduction of external interference signals. The printed circuit board 11 may be configured to include an insulating substrate (such as fiberglass) and copper foil traces printed on it, serving as mechanical support and electrical connection. The printed circuit board 11 extends along a first direction. The first direction is... Figure 2The horizontal direction shown is... Figure 2 The temperature sensing module 10 is shown pointing towards the control module 20. The printed circuit board 11 is provided with signal input pads 101 and conductive vias 102. The signal input pads 101 are positioned closer to the control module 20.

[0066] The first filtering unit 12 is disposed on the top layer of the printed circuit board 11 and close to the signal input pad 101, and is used to perform initial noise reduction processing on external interference signals. The temperature sensing unit 13 is disposed on the top layer of the printed circuit board 11 and spaced a first distance from the first filtering unit 12 in a first direction. In some embodiments, the first filtering unit 12 may be configured as a surface-mount capacitor. In some embodiments, the temperature sensing unit 13 may be configured as a surface-mount NTC thermistor.

[0067] The temperature sensing unit 13, conductive via 102, first filter unit 12, and signal input pad 101 are arranged sequentially from left to right in the first direction. The signal input pad 101 is located in the temperature detection area closest to the control module 20. The control module 20 supplies power and transmits signals to the temperature sensing module 10 through the signal input pad 101. The externally acquired signals transmitted by the control module 20 to the temperature sensing module 10 through the signal input pad 101 reach the signal pad of the first filter unit 12 in the first order of the temperature sensing module 10. The first filter unit 12 presents extremely low transient impedance to high-frequency noise, and the high-frequency interference current undergoes initial noise reduction processing through the first filter unit 12 the moment it enters the temperature sensing module 10. The conductive via 102 is disposed between the temperature sensing unit 13 and the first filter unit 12, and the diameter of the conductive via 102 is smaller than the first distance.

[0068] The sealing unit 14 is disposed on the temperature sensing module 10. The sealing unit 14 includes: a first sealing layer 141, a second sealing layer 142 and a third sealing layer 143.

[0069] The first encapsulation layer 141 is used to encapsulate the first filter unit 12. The second encapsulation layer 142 is used to encapsulate the temperature sensing unit 13. The third encapsulation layer 143 is used to encapsulate the first filter unit 12, the temperature sensing unit 13, and the printed circuit board 11. The material of the third encapsulation layer 143 is the same as that of the second encapsulation layer 142.

[0070] The thermal insulation of the first encapsulation layer 141 is higher than that of the second encapsulation layer 142. The thermal conductivity of the second encapsulation layer 142 is higher than that of the first encapsulation layer 141. The insulation of the first encapsulation layer 141 is higher than that of the second encapsulation layer 142. Further, the thermal conductivity of the second encapsulation layer 142 material can be set to be at least 8 times that of the first encapsulation layer 141 material. The dielectric strength of the first encapsulation layer 141 material is at least 1.5 times that of the second encapsulation layer 142 material. The volume resistivity of the first encapsulation layer 141 material is 100 to 10,000 times that of the second encapsulation layer 142 material.

[0071] In some embodiments, the first encapsulation layer 141 is selected for its high thermal insulation performance (low thermal conductivity, 0.2-0.3 W / m·K) and high insulation strength (dielectric strength ≥20 kV / mm, volume resistivity 1.0×10¹³~1.6×10¹³). 5 (Ω·cm), low-stress silicone conformal coating.

[0072] In some embodiments, the second encapsulation layer 142 and the third encapsulation layer 143 are selected with high thermal conductivity (thermal conductivity ≥ 2.0 W / m·K) and low insulation strength (dielectric strength ≥ 15 kV / mm~18 kV / mm, volume resistivity ≥ 1.0 × 10⁻⁶). 11 ~3.5×10 11 High thermal conductivity adhesive (Ω·cm).

[0073] In this embodiment, firstly, a first filtering unit 12 is set on the printed circuit board 11 of the temperature sensing module 10, adjacent to the signal input pad 101, so that the high-frequency interference current carried in the externally acquired signal is bypassed in place as soon as it enters the module, thereby suppressing the source of interference and avoiding the drawbacks of interference signals being generated and coupled along long-distance transmission in traditional terminal filtering schemes. Thus, it can achieve unified and efficient anti-interference protection for numerous temperature sensors distributed in the battery pack, and greatly improve the temperature monitoring fidelity of the battery management system.

[0074] Secondly, the sealing unit 14 is configured as a layered structure of a first encapsulation layer 141, a second encapsulation layer 142, and a third encapsulation layer 143. The first encapsulation layer 141 is made of a high-insulation, low-stress, and heat-insulating material (such as silicone conformal coating) to encapsulate the first filter unit 12. The second encapsulation layer 142 and the third encapsulation layer 143 are made of materials with high thermal conductivity and relatively poor insulation (such as high thermal conductivity adhesive) to encapsulate the temperature sensing unit 13 and the whole. In this way, the requirements of the first filter unit 12 for high insulation and low stress and the performance requirements of the temperature sensing unit 13 for high thermal conductivity are met simultaneously in the same temperature sensing area. This avoids the functional loss caused by a single encapsulation material. It not only ensures the insulation and leakage resistance of the first filter unit 12 under high voltage, but also improves the thermal response speed of the temperature sensing unit 13. This effectively solves the problem of decreased anti-interference accuracy and thermal management reliability caused by functional conflicts of encapsulation materials in the prior art.

[0075] Furthermore, the temperature sensing unit 13, conductive via 102, first filtering unit 12, and signal input pad 101 are arranged sequentially on the printed circuit board 11, so that external interference signals must be processed by the first filtering unit 12 before reaching the temperature sensing unit 13 in the physical path. Combined with the optimization of the signal loop area by the conductive via 102, the sensitivity of the temperature sensing module 10 to spatial electromagnetic interference is further reduced. At the same time, in conjunction with the secondary processing of the return signal by the control module 20, a complete anti-interference link from the source to the end is formed.

[0076] Therefore, in the above embodiments, while achieving miniaturized packaging, anti-interference capability, environmental adaptability, and temperature measurement accuracy are also taken into account, providing reliable technical support for thermal runaway early warning and thermal management optimization of new energy vehicle battery packs.

[0077] In one embodiment, the first filtering unit 12 is connected in parallel with the temperature sensing unit 13. The control module 20 includes a control circuit 21 and a second filtering unit 22. The control circuit 21 supplies power and transmits signals to the temperature sensing module 10 through the signal input pad 101. The second filtering unit 22 is electrically connected to the control circuit 21 and is used to perform noise reduction processing on the feedback signal from the temperature sensing module 10. In some embodiments, the second filtering unit 22 can be configured as a first-order RC low-pass filter, a second-order RC low-pass filter, or an active low-pass filter.

[0078] In one embodiment, the first filtering unit 12 is connected in parallel with the temperature sensing unit 13. The control module 20 includes a control circuit 21 and a second filtering unit 22. The control circuit 21 supplies power and transmits signals to the temperature sensing module 10 through the signal input pad 101. The second filtering unit 22 is electrically connected to the control circuit 21 and is used to perform noise reduction processing on the feedback signal from the temperature sensing module 10. In some embodiments, the second filtering unit 22 can be configured as a first-order RC low-pass filter, a second-order RC low-pass filter, or an active low-pass filter.

[0079] One end of lead 30 is electrically connected to signal input pad 101, and the other end of lead 30 is electrically connected to control circuit 21. Since the first filter unit 12 is connected in parallel with temperature sensing unit 13, the external acquisition signal transmitted from control module 20 to temperature sensing module 10 via signal input pad 101 is input from the top layer, and its first arrival point is the signal pad of the first filter unit 12. High-frequency interference current carried in the external acquisition signal first reaches the pad of the first filter unit 12. The first filter unit 12 presents extremely low transient impedance to high-frequency noise, and the high-frequency interference current undergoes initial noise reduction processing through the first filter unit 12 the moment it enters the temperature sensing module 10.

[0080] The second filter unit 22 is located at the other end of the lead 30. The second filter unit 22 allows DC and low-frequency temperature acquisition signals to pass through without attenuation, while simultaneously performing a second noise reduction process on external high-frequency interference signals. The noise frequency filtered by the second filter unit 22 is higher than that filtered by the first filter unit 12. The synergistic effect of the first filter unit 12 and the second filter unit 22 achieves better high-frequency filtering. The first filter unit 12 bypasses noise as soon as external interference signals enter. The second filter unit 22 performs a final purification at the end of the lead 30 (signal chain). The two filter units work together to form a layered defense system from source to end. Even if a small amount of interference crosses the transmission line of the lead 30 and the defense line of the first filter unit 12, it can be finally filtered out before entering the battery pack / battery module. The high-frequency components in the signal reaching the second filter unit 22 have been significantly weakened by the first filter unit 12 and no longer possess significant transient energy. This makes the second filter unit 22 less demanding on the device's shock resistance, allowing it to use component parameters with higher precision and less extreme requirements for transient response, thus pursuing better frequency selectivity in filtering characteristics.

[0081] In this embodiment, the first filtering unit 12 is connected in parallel with the temperature sensing unit 13, and a second filtering unit 22 electrically connected to the control circuit 21 is provided in the control module 20. The second filtering unit 22 is located at the other end of the lead 30 and filters out noise frequencies higher than the first filtering unit 12, forming a hierarchical filtering architecture of front-end coarse filtering and back-end fine filtering. The first filtering unit 12 prioritizes filtering out relatively low-frequency interference at the entrance of the temperature sensing module 10, while the second filtering unit 22 further filters out residual noise at higher frequencies at the front end of the control circuit 21. The two work together to ensure the attenuation-free transmission of DC and low-frequency temperature acquisition signals and to achieve segmented and efficient suppression of wide-spectrum interference signals, significantly improving the signal fidelity of the integrated anti-interference temperature sensing module 100 in complex electromagnetic environments.

[0082] In one embodiment, the shortest spacing between the first encapsulation layer 141 and the second encapsulation layer 142 on the printed circuit board 11 is between 1 mm and 2 mm. The first encapsulation layer 141, with higher insulation, encapsulates the conductive via 102.

[0083] In this embodiment, the shortest interval between the first encapsulation layer 141 and the second encapsulation layer 142 on the printed circuit board 11 is limited to 1mm-2mm, and the conductive via 102 is encapsulated by the first encapsulation layer 141, which has higher insulation properties. On the one hand, the reasonable spacing avoids defects such as interface cracking and stress concentration caused by differences in shrinkage rate or chemical compatibility issues during the curing process of the two encapsulation layers made of different materials. On the other hand, by utilizing the high insulation properties of the first encapsulation layer 141 to focus on encapsulating the conductive via 102, leakage or creepage caused by potential concentration at the edge of the via is effectively prevented, thereby ensuring both electrical safety and the integrity of the encapsulation structure in a compact layout.

[0084] In one embodiment, the integrated anti-interference temperature sensing module 100 further includes a housing 15 disposed on the temperature sensing module 10 for enclosing the sealing unit 14 and part of the lead wires 30. The housing 15 can be a 3.6mm × 15mm plastic housing. More specifically, the housing 15 can be a circular plastic housing with a radius of 3.6mm and a length of 15mm.

[0085] In this embodiment, a circular plastic shell is used to enclose the sealing unit 14 and part of the lead wires 30, giving the temperature sensing module 10 a uniform external contour and mechanical support. On the one hand, the miniaturized size of the shell 15 allows it to be easily embedded into the narrow gaps between the cells in a new energy vehicle battery pack or battery module, achieving precise positioning of the temperature measuring point. On the other hand, the insulation and chemical corrosion resistance of the plastic shell 15 itself provide preliminary physical protection for the internal sealing unit 14, preventing it from being squeezed or contaminated by external forces during potting or installation, thus improving the assembly consistency of the module.

[0086] In one embodiment, the integrated anti-interference temperature sensing module 100 further includes a potting layer 151. The potting layer is disposed between the housing 15 and the temperature sensing module 10, and encapsulates all the sealing units 14, all the printed circuit boards 11, and a portion of the leads 30. The hardness of the potting layer 151 is greater than that of the first encapsulation layer 141 and also greater than that of the second encapsulation layer 142. The thermal conductivity of the potting layer 151 is greater than that of the first encapsulation layer 141, and is comparable to that of the second encapsulation layer 142.

[0087] The cured potting layer 151 has a hardness greater than 80D, and its coefficient of thermal expansion is between 10 ppm / ℃ and 25 ppm / ℃. The thermal conductivity of potting layer 151 is between 2.0 W / (m·K) and 2.5 W / (m·K). Potting layer 151 exhibits low thermal stress.

[0088] The coefficient of thermal expansion of the potting layer 151 is between 10 ppm / ℃ and 25 ppm / ℃, close to the coefficient of thermal expansion of the printed circuit board 11 (FR-4 PCB substrate) which is 15 ppm / ℃ to 20 ppm / ℃. In one embodiment, the coefficient of thermal expansion of the potting layer 151 can be set to 15 ppm / ℃. In one embodiment, the material of the potting layer 151 is epoxy resin. In this embodiment, the potting layer 151 has the functions of mechanical protection (impact resistance, vibration resistance), environmental isolation (waterproof and dustproof), and heat conduction / heat dissipation assistance.

[0089] The first encapsulation layer 141 serves as the initial noise reduction layer (providing electrical insulation and a low-stress environment for sensitive circuits). The second encapsulation layer 142 serves as the efficient thermal conductor (rapidly transmitting temperature signals).

[0090] In this embodiment, a potting layer 151 is provided between the housing 15 and the temperature sensing module 10, and it completely encapsulates the sealing unit 14, the printed circuit board 11 and part of the leads 30. The hardness (>80D), thermal conductivity (2.0-2.5 W / m·K) and thermal expansion coefficient (10-25ppm / ℃) of the potting layer 151 are precisely controlled. Together with the inner first encapsulation layer 141 (low hardness, low thermal conductivity, high insulation) and the second encapsulation layer 142 (high thermal conductivity, medium hardness), a three-layer protection system of hard shell and soft core is formed (more specifically, the outer side of the first filter unit 12 has a three-layer protection system of first encapsulation layer 141, third encapsulation layer 143 and potting layer 151, and the outer side of the temperature sensing unit 13 has a three-layer protection system of second encapsulation layer 142, third encapsulation layer 143 and potting layer 151). The potting layer 151 utilizes its high hardness to provide rigid armor protection against impact and vibration, while its high thermal conductivity assists the second encapsulation layer 142 in rapidly dissipating heat. Simultaneously, its coefficient of thermal expansion is highly matched to that of the FR-4 printed circuit board 11 (15-20 ppm / ℃), significantly reducing thermal stress during temperature cycling and effectively preventing delamination and cracking. Combined with the low-stress electrical insulation of the first encapsulation layer 141 and the efficient thermal conductivity of the second encapsulation layer 142, the entire module maintains long-term reliability even under harsh environments such as drastic temperature changes, high humidity, and vibration.

[0091] In one embodiment, the thicknesses of the first encapsulation layer 141, the second encapsulation layer 142, and the third encapsulation layer 143 can be set to 0.1 mm to 0.4 mm, respectively. The thickness of the potting layer 151 can be set to 0.5 mm to 2 mm.

[0092] In this embodiment, the thicknesses of the first encapsulation layer 141, the second encapsulation layer 142, and the third encapsulation layer 143 are controlled between 0.1 mm and 0.4 mm, respectively, and the thickness of the potting layer 151 is controlled between 0.5 mm and 2 mm, forming a differentiated thickness distribution of a thin inner layer and a thick outer layer. The thinner inner encapsulation ensures that the first filter unit 12 obtains low-stress electrical protection and the temperature sensing unit 13 obtains a low-thermal-resistance heat conduction path, avoiding stress increase or response delay caused by excessive encapsulation thickness. The thicker outer potting layer provides sufficient mechanical redundancy and environmental isolation capability, ensuring that all gaps within the housing 15 are fully filled, eliminating local weak points. This thickness optimization design achieves the best balance between functionality and structural strength within a miniaturized space, further improving the anti-interference stability and environmental adaptability of the integrated anti-interference temperature sensing module 100.

[0093] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0094] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application; and these modifications, changes, 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 this application. All should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims.

Claims

1. A packaging method for an integrated anti-interference temperature sensing module, characterized in that, Includes the following steps: S1, a temperature sensing module is provided, the temperature sensing module includes a printed circuit board, a first filtering unit disposed on the top layer of the printed circuit board and a temperature sensing unit, the printed circuit board has a signal input pad and a conductive via; S2, forming a first encapsulation layer with first thermal conductivity and first insulation properties, encapsulating the first filter unit, and allowing it to fully cure; when forming the first encapsulation layer in S2, an organosilicon conformal coating with an insulation strength ≥20kV / mm and low stress is applied by spraying or dipping. S3, forming a second encapsulation layer with second thermal conductivity and second insulation properties, encapsulating the temperature sensing unit, and allowing it to fully cure; when forming the second encapsulation layer in S3, a precision dispensing process is used to uniformly cover the top and sides of the temperature sensing unit with a high thermal conductivity adhesive with a thermal conductivity ≥2.0W / m·K. S4, forming a third encapsulation layer with third thermal conductivity and third insulation, encapsulating the first filter unit, the temperature sensing unit, and the printed circuit board with the same material as the second encapsulation layer, and then completely curing them; wherein, the first thermal conductivity is lower than the second thermal conductivity; the first thermal conductivity is lower than the third thermal conductivity; the first insulation is higher than the second insulation, and the first insulation is higher than the third insulation; S5, Install the housing, insert the temperature sensing module into the housing, and allow part of the leads to extend out of the housing; S6, forming a potting layer, using epoxy resin material, filling the space between the housing and the temperature sensing module through a potting process, and encapsulating all of the third encapsulation layer, all of the printed circuit board and part of the leads, and completing the preparation after the epoxy resin is completely cured; The thermal conductivity of the material of the second encapsulation layer is more than 8 times that of the material of the first encapsulation layer; The dielectric strength of the first encapsulation layer material is 1.5 times or more than that of the dielectric strength of the second encapsulation layer material, or the volume resistivity of the first encapsulation layer material is 100 to 10,000 times that of the second encapsulation layer material.

2. The packaging method for the integrated anti-interference temperature sensing module according to claim 1, characterized in that, When forming the first encapsulation layer in step S2, the coating thickness is controlled between 0.1 mm and 0.3 mm. Before coating, the printed circuit board and the surface of the first filter unit are subjected to plasma cleaning or solvent cleaning to remove oil and moisture. The curing conditions are: place at room temperature for 15 to 30 minutes and then bake at 80°C to 100°C for 30 to 60 minutes to ensure complete curing and no low molecular weight silicone oil precipitation.

3. The packaging method for the integrated anti-interference temperature sensing module according to claim 1, characterized in that, When the second encapsulation layer is formed in S3, the encapsulation thickness is controlled between 0.2 mm and 0.4 mm. After dispensing, vacuum degassing is required to prevent residual air bubbles in the adhesive layer from forming a heat insulation layer. The curing conditions are: room temperature curing for 24 hours or curing at 80°C for 1 to 2 hours.

4. The packaging method for the integrated anti-interference temperature sensing module according to claim 3, characterized in that, When forming the third encapsulation layer in step S4, the same high thermal conductivity adhesive as in step S3 is used. The first filter unit and the temperature sensing unit are simultaneously encapsulated through secondary dispensing or molding. The third encapsulation layer completely covers the first encapsulation layer and the second encapsulation layer, and extends to the edge and / or back of the printed circuit board. Before curing, it needs to stand for 10 to 20 minutes to remove interface air bubbles.

5. The packaging method for the integrated anti-interference temperature sensing module according to claim 1, characterized in that, When forming the potting layer in step S6, a vacuum potting process is used: the semi-finished product with the shell installed is placed in a vacuum chamber, and the vacuum is evacuated to 2.0 × 10⁻⁶. 4 Pa ~ 1.0 × 10 3 Pa and hold for 5-10 minutes, then inject pre-mixed and degassed epoxy resin potting compound. After the injection is completed, vacuum again to remove residual gas inside. Finally, cure at 60℃-80℃ for 4-8 hours. The thickness of the potting layer is at least 1.0 mm higher than the highest point of the third encapsulation layer and completely fills all gaps between the housing and the temperature sensing module.

6. The packaging method for the integrated anti-interference temperature sensing module according to claim 1, characterized in that, In steps S2 to S4, before forming each encapsulation layer, the surface of the printed circuit board and the surface of the cured encapsulation layer are subjected to surface activation treatment; and before forming the potting layer in step S6, the roots of the cured first encapsulation layer, the second encapsulation layer, the third encapsulation layer and the lead are cleaned.

7. An integrated anti-interference temperature sensing module, characterized in that, The integrated anti-interference temperature sensing module is formed using the packaging method described in any one of claims 1-6; The integrated anti-interference temperature sensing module includes: A temperature sensing module is located in the temperature detection area; the temperature sensing module further includes: a printed circuit board, a first filter unit and a temperature sensing unit disposed on the top layer of the printed circuit board, and a sealing unit for sealing the first filter unit and the temperature sensing unit; The control module is located away from the temperature detection area; and, Lead wires electrically connect the temperature sensing module and the control module; The sealing unit includes: The first encapsulation layer has a first thermal conductivity and a first insulation, and is used to encapsulate the first filter unit; A second encapsulation layer, having a second thermal conductivity and a second insulating property, is used to encapsulate the temperature sensing unit; and The third encapsulation layer has third thermal conductivity and third insulation properties, and is used to encapsulate the first filter unit and the temperature sensing unit; Wherein, the first thermal conductivity is lower than the second thermal conductivity; the first thermal conductivity is lower than the third thermal conductivity; the first insulation is higher than the second insulation, and the first insulation is higher than the third insulation; The thermal conductivity of the material of the second encapsulation layer is more than 8 times that of the material of the first encapsulation layer; The dielectric strength of the first encapsulation layer material is 1.5 times or more than that of the dielectric strength of the second encapsulation layer material, or the volume resistivity of the first encapsulation layer material is 100 to 10,000 times that of the second encapsulation layer material.

8. The integrated anti-interference temperature sensing module according to claim 7, characterized in that, The first filtering unit is connected in parallel with the temperature sensing unit; The control module includes: The control circuit supplies power and transmits signals to the temperature sensing module through the signal input pad; and, The second filtering unit is electrically connected to the control circuit and is used to perform noise reduction processing on the return signal of the temperature sensing module. One end of the lead is electrically connected to the signal input pad, and the other end of the lead is electrically connected to the control circuit; The second filter unit is located at the other end of the lead. The second filter unit is used to allow DC and low-frequency temperature acquisition signals to pass through without attenuation, while performing a second noise reduction process on external high-frequency interference signals. The noise frequency filtered out by the second filter unit is higher than the noise frequency filtered out by the first filter unit.

9. The integrated anti-interference temperature sensing module according to claim 8, characterized in that, The shortest interval between the first encapsulation layer and the second encapsulation layer on the printed circuit board is between 1 mm and 2 mm. The first encapsulation layer, which has higher insulation properties, encapsulates the conductive via.

10. The integrated anti-interference temperature sensing module according to claim 9, characterized in that, Also includes: A housing, disposed on the temperature sensing module, is used to enclose the sealing unit and part of the lead wire; A potting layer is disposed between the housing and the temperature sensing module by potting, and encapsulates all of the sealing unit, all of the printed circuit board and part of the leads; the hardness of the potting layer is greater than that of the first encapsulation layer and also greater than that of the second encapsulation layer; the thermal conductivity of the potting layer is greater than that of the first encapsulation layer, and the thermal conductivity of the potting layer is comparable to that of the second encapsulation layer.

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