Thick film heating device

Abstract

The application relates to the technical field of heating equipment, and discloses a thick-film heating device which comprises a substrate, a first insulating layer, a composite heating layer, a second insulating layer and a protective layer. The substrate has opposite first and second surfaces along the thickness direction thereof; the first insulating layer is arranged on the first surface; the composite heating layer is arranged on the side of the first insulating layer away from the substrate; the second insulating layer is arranged on the side of the composite heating layer away from the first insulating layer, and the thickness of the second insulating layer is smaller than that of the first insulating layer along the thickness direction; and the protective layer is arranged on the side of the second insulating layer away from the first insulating layer. The thick-film heating device of the application increases the insulating impedance of the surface of the second insulating layer by arranging the protective layer on the surface of the second insulating layer, so that the thick-film heating device can pass the temperature-resistant heating test, the safety and reliability are improved, and the other performances of the thick-film heating device are not deteriorated; the preparation process is simple, and the production efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of heating equipment technology, and in particular to a thick film heating device. Background Technology

[0002] With the development of new energy vehicles, their functions and performance have been further improved. For example, a thick film heating device used in new energy vehicles mainly heats liquids to heat the battery pack and prevent the battery pack from getting too cold.

[0003] The existing fabrication process for thick-film heating devices generally involves printing a paste onto a substrate using thick-film screen printing technology. This paste includes an insulating dielectric layer, a conductor material layer, a heating resistance layer, and a surface protective insulating dielectric layer, followed by high-temperature sintering to form a film layer with a thickness ranging from tens to hundreds of micrometers. The insulating dielectric layer is typically printed four or five times, while the surface protective insulating dielectric layer is usually printed one or two times, followed by high-temperature sintering. However, the thickness of the surface protective insulating dielectric layer often results in insufficient insulation resistance, making it unsuitable for high-temperature resistance testing. Utility Model Content

[0004] This application provides a thick film heating device, a heating module, and a battery pack device, which can improve the pass rate of the temperature resistance test of the thick film heating device and improve product quality.

[0005] To solve the above-mentioned technical problems, one technical solution adopted in this application embodiment is: providing a thick film heating device, including a substrate, a first insulating layer, a composite heating layer, a second insulating layer, and a protective layer. The substrate has a first surface and a second surface opposite to each other along its thickness direction; the first insulating layer is disposed on the first surface; the composite heating layer is disposed on the side of the first insulating layer opposite to the substrate; the second insulating layer is disposed on the side of the composite heating layer opposite to the first insulating layer, and the thickness of the second insulating layer is less than the thickness of the first insulating layer along its thickness direction; the protective layer is disposed on the side of the second insulating layer opposite to the first insulating layer.

[0006] In some embodiments, the first insulating layer comprises glass-ceramic; and / or, the second insulating layer comprises glass-ceramic; and / or, the protective layer comprises one of a high-temperature resistant ink layer, a ceramic glaze layer, and a high-temperature resistant adhesive layer.

[0007] In some embodiments, the second surface of the substrate is used to contact the liquid to be heated, and the second surface of the substrate is provided with a reinforcement portion to increase the thermal conductivity area of ​​the second surface.

[0008] In some embodiments, the reinforcement includes a groove that is recessed from the second surface toward the direction of the first surface; and / or, the reinforcement includes a boss that protrudes from the second surface toward the direction of the first surface.

[0009] In some embodiments, the thick film heating device further includes a thermally conductive layer disposed on the second surface, wherein the thermal conductivity of the thermally conductive layer is greater than that of the substrate.

[0010] In some embodiments, the substrate comprises a stainless steel plate; and / or, the thermally conductive layer comprises one of a copper layer, an aluminum layer, or a high-temperature resistant graphene coating.

[0011] In some embodiments, along the thickness direction of the substrate, the ratio of the projected area S1 of the thermally conductive layer on the substrate to the projected area S2 of the second surface satisfies: 85% ≤ S1 / S2 ≤ 100%.

[0012] In some embodiments, the composite heating layer includes a heating resistance layer and a conductor material layer. The heating resistance layer includes a plurality of heating elements extending along a first direction, and the conductor material layer connects the plurality of heating elements end to end in sequence. The first direction is perpendicular to the thickness direction.

[0013] The beneficial effects of the embodiments of this application are as follows: The thick film heating device of this application increases the insulation resistance of its surface by adding a protective layer to the surface of the second insulating layer, so as to pass the temperature resistance test, improve safety and reliability, and will not cause other performance degradation of the thick film heating device. Its preparation process is simple and improves production efficiency. Adding a protective layer can enhance the corrosion resistance of the outer surface of the thick film heating device. Setting a reinforcing part can increase the contact area between the second surface of the substrate and the liquid, improve heating efficiency, and setting an uneven reinforcing part can reduce the flow rate of the liquid and increase the turbulence of the liquid, so that the hot and cold liquids are fully mixed and the heat transfer is more uniform. On the other hand, it can reduce the large bubbles formed on the second surface during heating, thereby reducing the noise during heating. Adding a thermally conductive layer, the thermal conductivity of the thermally conductive layer is greater than that of the substrate, which can further improve the heating effect of the substrate on the liquid. In addition, the thermally conductive layer makes the heat conduction of each area of ​​the substrate more uniform. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the specific embodiments of this application, the accompanying drawings used in the description of the specific embodiments will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0015] Figure 1 This is an exploded view of the thick film heating device according to an embodiment of this application;

[0016] Figure 2 This is an exploded view of another embodiment of the thick film heating device of this application;

[0017] Figure 3 yes Figure 2 A magnified schematic diagram of part A in the middle. Detailed Implementation

[0018] To facilitate understanding of this application, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as "connected" to another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "inner," "outer," "vertical," "horizontal," etc., used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0020] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0021] Please see Figure 1 This application provides a thick-film heating device 100, comprising a substrate 10, a first insulating layer 20, a composite heating layer 30, a second insulating layer 40, and a protective layer 50 sequentially disposed in the thickness direction X. In this embodiment, the substrate 10 is generally flat. Along the thickness direction X of the substrate 10, the substrate 10 has a first surface 11 and a second surface 12 disposed opposite to each other. The first insulating layer 20 is disposed on the first surface 11, and the composite heating layer 30 is disposed on the side of the first insulating layer 20 facing away from the substrate 10. The second insulating layer 40 is disposed on the side of the composite heating layer 30 facing away from the first insulating layer 20. Along the thickness direction X of the substrate 10, the thickness of the second insulating layer 40 is less than the thickness of the first insulating layer 20; the protective layer 50 is disposed on the side of the second insulating layer 40 facing away from the first insulating layer 20.

[0022] The composite heating layer 30 is electrically connected to an external power source to generate heat when energized. Both the first insulating layer 20 and the second insulating layer 40 can be achieved through printing, coating, or other methods. For example, a microcrystalline glass layer is printed on the first surface 11 of the substrate 10, sintered at 800°C to 900°C, and cured. This process is repeated 4-5 times to obtain the first insulating layer 20. Then, the composite heating layer 30 is placed on the surface of the first insulating layer 20, and another microcrystalline glass layer is printed on its surface. This is then sintered at 800°C to 900°C and cured. This process is repeated 1-2 times to obtain the second insulating layer 40. When preparing the first insulating layer 20, since the composite heating layer 30 is not present, it can be repeatedly sintered at high temperatures 4-5 times. However, when preparing the second insulating layer 40, the presence of the composite heating layer 30 makes repeated high-temperature sintering unsuitable; otherwise, the high temperature of 800°C to 900°C will affect the structure and performance of the composite heating layer 30.

[0023] Because the second insulating layer 40 is printed fewer times than the first insulating layer 20, its thickness is also less. During electrical strength testing, the insulation resistance of the second insulating layer 40 is less than 50 MΩ, indicating low insulation resistance, poor safety and reliability, and failure to meet electrical strength requirements. Increasing the thickness of the second insulating layer 40 simply by increasing the number of printing cycles would lead to other defects in the thick-film heating device 100, such as deformation and increased overall resistance.

[0024] Therefore, to solve the above problems, the thick film heating device 100 of this application adds a protective layer 50 to the surface of the second insulating layer 40. As an example, high-temperature resistant ink, ceramic glaze, or high-temperature resistant adhesive is applied to the surface of the second insulating layer 40 by spraying or coating techniques, and then sintered and cured at an environment of 100°C to 200°C to form the protective layer 50. On the one hand, compared to increasing the thickness of the second insulating layer 40 by simply increasing the number of printing and sintering cycles at an environment of 800°C to 900°C, the protective layer 50 produced in this application at an environment of 100°C to 200°C is easier to process, and the firing environment has less impact on the composite heating layer 30; on the other hand, the cost of preparing the protective layer 50 using materials such as high-temperature resistant ink, ceramic glaze, or high-temperature resistant adhesive is lower than that of the second insulating layer 40 made of microcrystalline glass.

[0025] The thick film heating device 100 of this application embodiment increases the surface insulation resistance of the second insulating layer 40 by adding a protective layer 50, so as to pass the temperature resistance test, improve safety and reliability, and will not cause other performance degradation of the thick film heating device 100. Its preparation process is simple and improves production efficiency.

[0026] In some embodiments, the substrate 10 includes a stainless steel plate, giving it sufficient structural strength to support the first insulating layer 20, the composite heating layer 30, the second insulating layer 40, and the protective layer 50. It is understood that the substrate 10 in this embodiment is a flat plate; in other embodiments, the substrate 10 may also be a cylindrical plate or a curved plate.

[0027] In some embodiments, the protective layer 50 includes one of a high-temperature resistant ink layer, a ceramic lacquer layer, and a high-temperature resistant adhesive layer. These materials have good heat resistance and high impedance values, which are beneficial for enhancing the insulation impedance on the surface of the second insulating layer 40.

[0028] In some embodiments, please refer to Figure 2 The second surface 12 of the substrate 10 is for contacting the liquid to be heated, and heat is transferred from the substrate 10 to the liquid to be heated to achieve heating of the liquid. The second surface 12 of the substrate 10 can be provided with a reinforcing part 121 by means of etching, machining or stamping, etc. The reinforcing part 121 is used to increase the thermally conductive area of ​​the second surface 12, thereby increasing the contact area between the second surface 12 and the liquid and improving the heating efficiency.

[0029] As an example, please refer to Figure 3 The reinforcing portion 121 includes a groove 122, which is recessed from the second surface 12 toward the first surface 11. This structure increases the contact area between the sidewall of the groove 122 and the liquid to be heated, thereby accelerating the heating effect of the substrate 10. Multiple grooves 122 can be provided, and they can be arranged in a regular or irregular pattern.

[0030] As another example, please refer to Figure 3 The reinforcing portion 121 includes a boss 123, which protrudes from the second surface 12 in a direction away from the first surface 11. This structure increases the contact area between the sidewall of the boss 123 and the liquid to be heated, thereby accelerating the heating effect of the substrate 10. Multiple bosses 123 can be provided, and they can be arranged in a regular or irregular pattern.

[0031] In other examples, the reinforcement 121 may include both a groove 122 and a boss 123. For example, after providing a recessed groove 122 on the second surface 12 of the substrate 10, a boss 123 facing the second surface 12 is provided at the bottom of the groove 122; or, after providing a protruding boss 123 on the second surface 12 of the substrate 10, a groove 122 recessed towards the first surface 11 is provided on the boss 123. With the above structure, the heat dissipation area on the second surface 12 can be further increased, the heat dissipation efficiency of the substrate 10 can be accelerated, and the service life of the thick film heating device 100 can be improved. In addition, since the second surface 12 of the substrate 10 is used to contact the liquid to be heated, compared to the flat surface of the second surface 12 of the substrate 10, providing an uneven reinforcement 121 can reduce the flow rate of the liquid, increase the turbulence of the liquid, make the hot and cold liquids mix thoroughly, and make the heat transfer more uniform. On the other hand, it can reduce the large bubbles formed on the second surface 12 during heating, thereby reducing the noise during heating and improving the heating quality of the thick film heating device 100.

[0032] In some embodiments, please refer to Figure 1 The thick-film heating device 100 also includes a heat-conducting layer 60, which is disposed on the second surface 12 of the substrate 10. The thermal conductivity of the heat-conducting layer 60 is greater than that of the substrate 10. It is understood that the heat-conducting layer 60 can be disposed on the second surface 12 whether it is a flat surface or has a reinforcing portion 121. By disposing of a heat-conducting layer 60 with a higher thermal conductivity on the second surface 12 of the substrate 10, the heating effect of the substrate 10 on the liquid can be further improved, and the heat-conducting layer 60 makes the heat conduction more uniform in various areas of the substrate 10.

[0033] In some embodiments, a thermally conductive layer 60 can be formed on the second surface 12 of the substrate 10 using techniques such as thermal spraying or sputtering, electroplating, or printing. The thermally conductive layer 60 includes one of a copper layer, an aluminum layer, or a high-temperature resistant graphene coating. Compared to the stainless steel material of the substrate 10, the aforementioned material of the thermally conductive layer 60 has a better thermal conductivity and stronger heat conduction capability. Furthermore, forming a thermally conductive layer 60 of the aforementioned material on the second surface 12 of the substrate 10 can reduce the corrosion of the substrate 10 by the liquid to be heated, thereby extending the lifespan of the thick-film heating device 100.

[0034] In some embodiments, along the thickness direction X of the substrate 10, the ratio of the projected area S1 of the thermally conductive layer 60 on the substrate 10 to the projected area S2 of the second surface 12 satisfies: 85% ≤ S1 / S2 ≤ 100%. That is, the thermally conductive layer 60 occupies 85% or more of the area of ​​the second surface 12 of the substrate 10, ensuring that most of the area of ​​the substrate 10 can conduct heat more quickly through the thermally conductive layer 60, thereby improving heating efficiency.

[0035] In some embodiments, please refer to Figure 1 The composite heating layer 30 includes a heating resistance layer 31 and a conductor material layer 32. The heating resistance layer 31 includes several heating elements extending along a first direction Y. The conductor material layer 32 connects the heating elements end-to-end in sequence. The first direction Y is perpendicular to the thickness direction X. This structure allows the heating elements to form a serpentine structure with their ends connected, resulting in uniform heating. In other embodiments, the heating elements connected by the conductor material layer 32 can also form other shapes, such as wavy, spiral, M-shaped, or grid-shaped.

[0036] It is understood that the thick-film heating device 100 of this application embodiment can be applied to new energy vehicles. For example, the thick-film heating device 100 is used to heat liquids, and the heated liquids are then passed into the battery pack to heat the battery pack. Alternatively, the thick-film heating device 100 of this application embodiment can be applied to other electrical equipment with heating requirements. The structure and function of the thick-film heating device 100 can be referred to the above embodiments, and will not be repeated here.

[0037] The thick-film heating device 100 of this application embodiment includes a substrate 10, a first insulating layer 20, a composite heating layer 30, a second insulating layer 40, and a protective layer 50. The substrate 10 has opposing first surfaces 11 and second surfaces 12 along its thickness direction X; the first insulating layer 20 is disposed on the first surface 11; the composite heating layer 30 is disposed on the side of the first insulating layer 20 facing away from the substrate 10; the second insulating layer 40 is disposed on the side of the composite heating layer 30 facing away from the first insulating layer 20, and the thickness of the second insulating layer 40 is less than the thickness of the first insulating layer 20 along the thickness direction X; the protective layer 50 is disposed on the side of the second insulating layer 40 facing away from the first insulating layer 20. By adding a protective layer 50 to the surface of the second insulating layer 40, the thick-film heating device 100 of this application embodiment can increase the surface insulation resistance, thereby passing temperature resistance tests, improving safety and reliability, and without causing other performance degradation of the thick-film heating device 100. Its preparation process is simple and improves production efficiency.

[0038] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A thick film heating device, characterized in that, include: A substrate having opposing first and second surfaces along its thickness direction; A first insulating layer is disposed on the first surface; A composite heating layer is disposed on the side of the first insulating layer that is away from the substrate; A second insulating layer is disposed on the side of the composite heating layer opposite to the first insulating layer, and the thickness of the second insulating layer is less than the thickness of the first insulating layer along the thickness direction. A protective layer is disposed on the side of the second insulating layer opposite to the first insulating layer.

2. The thick film heating device according to claim 1, characterized in that, The first insulating layer comprises microcrystalline glass; and / or, The second insulating layer comprises microcrystalline glass; and / or, The protective layer includes one of the following: a high-temperature resistant ink layer, a ceramic coating layer, or a high-temperature resistant adhesive layer.

3. The thick film heating device according to claim 1, characterized in that, The second surface of the substrate is used to contact the liquid to be heated, and the second surface of the substrate is provided with a reinforcement portion, which is used to increase the thermal conductivity area of ​​the second surface.

4. The thick film heating device according to claim 3, characterized in that, The reinforcement includes a groove that is recessed from the second surface toward the first surface; and / or The reinforcement includes a boss that protrudes from the second surface in a direction away from the first surface.

5. The thick film heating device according to any one of claims 1-4, characterized in that, The thick film heating device further includes a thermally conductive layer disposed on the second surface, the thermal conductivity of the thermally conductive layer being greater than that of the substrate.

6. The thick film heating device according to claim 5, characterized in that, The substrate includes a stainless steel plate; And / or, The thermally conductive layer includes one of a copper layer, an aluminum layer, or a high-temperature resistant graphene coating.

7. The thick film heating device according to claim 5, characterized in that, Along the thickness direction of the substrate, the ratio of the projected area S1 of the thermally conductive layer on the substrate to the projected area S2 of the second surface satisfies: 85% ≤ S1 / S2 ≤ 100%.

8. The thick film heating device according to claim 1, characterized in that, The composite heating layer includes a heating resistance layer and a conductor material layer. The heating resistance layer includes a plurality of heating elements extending along a first direction. The conductor material layer connects the plurality of heating elements end to end in sequence. The first direction is perpendicular to the thickness direction.

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