Heating element and aerosol generating device

Abstract

This application provides a heating element and an aerosol generating device, belonging to the field of aerosol generating devices. The heating element includes a composite substrate layer and a heat source structure. The composite substrate layer includes a first thermally conductive layer, a second thermally conductive layer, and a third thermally conductive layer stacked sequentially. The area of ​​the second thermally conductive layer is smaller than that of the first thermally conductive layer and also smaller than that of the third thermally conductive layer. The thermal conductivity of the second thermally conductive layer is greater than that of the first and third thermally conductive layers. The heat source structure is located on the side of the third thermally conductive layer away from the second thermally conductive layer, and at least a portion of the heat source structure overlaps with the second thermally conductive layer. The non-uniform thermal conductivity distribution of the composite substrate layer allows for changes in the temperature distribution on the surface of the heating element, both through the shape of the heat source structure and through parameters related to the second thermally conductive layer. This enriches the means of changing the temperature distribution and helps to adjust the temperature distribution on the surface of the heating element and simplify the shape of the heat source structure.

Description

Technical Field

[0001] This application relates to the field of aerosol generating devices, and particularly to a heating element and an aerosol generating device. Background Technology

[0002] The heating element is the core component of the aerosol generating device, used for heating during operation. It is typically manufactured using a thick-film process. The heating element is usually rolled into a cylindrical shape to heat the columnar aerosol generating medium inserted within it.

[0003] A heating element typically consists of a substrate layer and a heat source structure disposed on the surface of the substrate layer. When the heating element is in operation, the heat generated by the heat source structure is conducted to the substrate layer, causing the entire heating element to heat up and thus heating the aerosol-generating medium.

[0004] When a heating element generates heat, the temperature distribution is not uniform. To achieve the desired heating effect, it is generally desirable for the temperature distribution on the surface of the heating element to meet specific requirements. In designing heating elements, the shape of the heat source structure is typically altered to change the temperature distribution on its surface. However, the shape of the heat source structure has limited impact on the temperature distribution, and overly complex shapes increase the difficulty of design and manufacturing. Utility Model Content

[0005] This application provides a heating element and an aerosol generating device, which helps to adjust the temperature distribution on the surface of the heating element and simplifies the shape of the heat source structure. The technical solution is as follows: In a first aspect, embodiments of this application provide a heating element, which includes a composite substrate layer and a heat source structure. The composite substrate layer includes a first thermally conductive layer, a second thermally conductive layer, and a third thermally conductive layer stacked together. The second thermally conductive layer is located between the first thermally conductive layer and the third thermally conductive layer. The area of ​​the second thermally conductive layer is smaller than the area of ​​the first thermally conductive layer and smaller than the area of ​​the third thermally conductive layer. The thermal conductivity of the second thermally conductive layer is greater than the thermal conductivity of the first thermally conductive layer and greater than the thermal conductivity of the third thermally conductive layer. The heat source structure is located on the side of the third heat-conducting layer away from the second heat-conducting layer, and at least a portion of the heat source structure overlaps with the second heat-conducting layer.

[0006] In some examples, the heat source structure includes a first heating line, at least a portion of which overlaps with the second heat-conducting layer.

[0007] In some examples, the orthographic projection of the first heating line onto the surface of the first heat-conducting layer lies within the orthographic projection of the second heat-conducting layer onto the surface of the first heat-conducting layer.

[0008] In some examples, the heat source structure further includes a second heating circuit, the orthographic projection of which onto the surface of the first heat-conducting layer is located outside the orthographic projection of which onto the surface of the first heat-conducting layer.

[0009] In some examples, the heat source structure further includes a common line and a pad, with one end of the first heating line and one end of the second heating line respectively connected to the common line, and the other end of the first heating line, the other end of the second heating line, and the common line each connected to a pad.

[0010] In some examples, the edge of the first thermally conductive layer coincides with the edge of the third thermally conductive layer, and at most part of the edge of the second thermally conductive layer coincides with the edge of the first thermally conductive layer.

[0011] In some examples, at least one of the first and third thermally conductive layers has a thinned region, and the second thermally conductive layer is located in the thinned region.

[0012] In some examples, the composite substrate layer includes a plurality of second thermally conductive layers, which are spaced apart.

[0013] In some examples, the material of the first thermal conductive layer is the same as that of the third thermal conductive layer, and one side of the first thermal conductive layer is connected to one side of the third thermal conductive layer.

[0014] In some examples, the second thermally conductive layer is a nickel metal layer or a pyrolytic graphite layer.

[0015] In some examples, the first thermally conductive layer and the third thermally conductive layer are stainless steel metal layers.

[0016] In some examples, the composite substrate layer further includes a transition thermally conductive layer, which is located at at least one of the following: Between the first thermally conductive layer and the second thermally conductive layer, the coefficient of thermal expansion of the transition thermally conductive layer is located between the coefficients of thermal expansion of the first thermally conductive layer and the coefficients of thermal expansion of the second thermally conductive layer; The thermal expansion coefficient of the transition thermal conductive layer is located between the thermal expansion coefficients of the second thermal conductive layer and the third thermal conductive layer.

[0017] Secondly, embodiments of this application also provide an aerosol generating device, which includes a power supply component and a heating element as described in the first aspect. The heating element is rolled into a cylindrical shape for inserting an aerosol generating medium, and the power supply component is used to supply power to the heating element.

[0018] The beneficial effects of the technical solutions provided in this application include at least the following: By employing a composite substrate layer comprising a first, second, and third heat-conducting layer stacked together, where the second heat-conducting layer has a smaller area than the first and third layers but a higher thermal conductivity, different regions of the composite substrate layer exhibit varying thermal conductivity, with the region containing the second heat-conducting layer exhibiting the highest thermal conductivity. By arranging the heat source structure on the side of the third heat-conducting layer away from the second heat-conducting layer, and with at least a portion of the heat source structure overlapping the second heat-conducting layer, the heat generated by the heat source structure can be conducted more quickly in the region containing the second heat-conducting layer, and more slowly in areas outside the second heat-conducting layer. The non-uniform thermal conductivity distribution of the composite substrate layer allows for modifications to the surface temperature distribution of the heating element not only through the shape of the heat source structure but also through parameters related to the second heat-conducting layer. This enriches the methods for altering the surface temperature distribution of the heating element, facilitates its adjustment, and simplifies the shape of the heat source structure. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of a heating element provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a heating element provided in an embodiment of this application; Figure 3 This is a cross-sectional schematic diagram of a composite substrate layer provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of a heating element provided in an embodiment of this application; Figure 5 This is a schematic diagram of the structure of a composite substrate layer provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of a heating element provided in an embodiment of this application; Figure 7 This is a cross-sectional schematic diagram of a composite substrate layer provided in an embodiment of this application.

[0021] Icon labels: 10-Substrate layer, 20-Heat source structure, 21-Common line, 22-Common electrode pad, 23-Heating line, 231-First heating line, 232-Second heating line, 24-Non-common electrode pad, 220-Pad, 25-Conductor line, 30-Composite substrate layer, 30a-Thinning region, 31-First thermally conductive layer, 32-Second thermally conductive layer, 33-Third thermally conductive layer, 34-Transition thermally conductive layer. Detailed Implementation

[0022] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0023] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0024] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0025] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They 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. Therefore, they should not be construed as limitations on this application.

[0026] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means two or more.

[0028] In the process of using an aerosol generating device, the aerosol generating medium is inserted into the device, and a heating element inside the device heats the medium. By heating at a low temperature without combustion, the aerosol generating medium releases aerosols. The heating element is typically electrically heated. Figure 1 This is a schematic diagram of the structure of a heating element provided in an embodiment of this application. The heating element is typically rolled into a cylindrical shape and installed in an aerosol generating device. Figure 1 The image shows a heating element in a flat state. Figure 1 As shown, the heating element includes a substrate layer 10 and a heat source structure 20, wherein the heat source structure 20 includes a common line 21, a common electrode pad 22, and multiple heating lines 23. The common line 21 is connected to one end of each of the multiple heating lines 23, and the common line 21 is also electrically connected to the common electrode pad 22. The other end of the heating line 23 is also connected to a non-common electrode pad 24. The common electrode pad 22 and the non-common electrode pad 24 are used for soldering leads. The leads are used to supply power to the heating element. During the operation of the heating element, current flows through the multiple heating lines 23, and the heating lines 23 generate heat, thereby heating the aerosol generating medium. By changing the shape of the heat source structure 20, mainly changing the shape of the heating lines 23, the temperature distribution on the surface of the heating element can be changed to meet specific requirements, thereby achieving the desired heating effect. However, changing the shape of the heat source structure 20 has a limited impact on the temperature distribution, and usually results in an overly complex shape of the heat source structure 20, increasing the difficulty of design and manufacturing.

[0029] In order to facilitate the regulation of surface temperature distribution of the heating element and simplify the shape of the heat source structure 20, this application provides a heating element. Figure 2 This is a schematic diagram of the structure of a heating element provided in an embodiment of this application, as shown below. Figure 2 As shown, the heating element includes a composite substrate layer 30 and a heat source structure 20.

[0030] Figure 3This is a cross-sectional schematic diagram of a composite substrate layer provided in an embodiment of this application, as shown below. Figure 3 As shown, the composite substrate layer 30 includes a first thermally conductive layer 31, a second thermally conductive layer 32 and a third thermally conductive layer 33 stacked together, with the second thermally conductive layer 32 located between the first thermally conductive layer 31 and the third thermally conductive layer 33. Figure 2 The second thermally conductive layer 32, which is stacked between the first thermally conductive layer 31 and the third thermally conductive layer 33, is shown in dashed lines.

[0031] The area of ​​the second heat-conducting layer 32 is smaller than the area of ​​the first heat-conducting layer 31 and smaller than the area of ​​the third heat-conducting layer 33. The thermal conductivity of the second heat-conducting layer 32 is greater than the thermal conductivity of the first heat-conducting layer 31 and greater than the thermal conductivity of the third heat-conducting layer 33. The heat source structure 20 is located on the side of the third heat-conducting layer 33 away from the second heat-conducting layer 32. (Refer to...) Figure 2 At least a portion of the heat source structure 20 overlaps with the second heat-conducting layer 32.

[0032] In the composite substrate layer 30, each layer is relatively thin. Unless otherwise specified, the area mentioned in the embodiments of this application refers to the area projected along the thickness direction. For example, the area of ​​the second thermally conductive layer 32 refers to the area of ​​the second thermally conductive layer 32 projected onto the surface of the first thermally conductive layer 31.

[0033] The overlap of at least a portion of the heat source structure 20 with the second heat-conducting layer 32 means that at least a portion of the orthographic projection of the heat source structure 20 onto the surface of the first heat-conducting layer 31 is located within the orthographic projection of the second heat-conducting layer 32 onto the surface of the first heat-conducting layer 31.

[0034] By constructing a composite substrate layer 30 comprising a first thermally conductive layer 31, a second thermally conductive layer 32, and a third thermally conductive layer 33 stacked together, wherein the second thermally conductive layer 32, although smaller in area than the first and third thermally conductive layers 31 and 33, has a higher thermal conductivity than the first and third thermally conductive layers 31 and 33, different regions of the composite substrate layer 30 exhibit different thermal conductivity, with the region containing the second thermally conductive layer 32 exhibiting a higher thermal conductivity. By arranging the heat source structure 20 on the side of the third thermally conductive layer 33 away from the second thermally conductive layer 32, and with at least a portion of the heat source structure 20 overlapping the second thermally conductive layer 32, the heat generated by the heat source structure 20 can be conducted at a faster rate in the region containing the second thermally conductive layer 32, and at a slower rate in areas outside the second thermally conductive layer 32. The non-uniform thermal conductivity distribution of the composite substrate layer 30 allows the design of the heating element to not only change the temperature distribution on the surface of the heating element by the shape of the heat source structure 20, but also by the parameters related to the second thermal conductive layer 32. This enriches the means of changing the temperature distribution on the surface of the heating element, helps to adjust the temperature distribution on the surface of the heating element, and also helps to simplify the shape of the heat source structure.

[0035] The parameters related to the second heat-conducting layer 32 may include, but are not limited to, the thermal conductivity, shape, area, and position of the second heat-conducting layer 32 within the composite substrate layer 30. For example, Figure 4 is a schematic diagram of a heating element provided in an embodiment of this application. Figure 4 As shown, in this example, both the second thermally conductive layer 32 and the composite substrate layer 30 are rectangular, with one long side of the second thermally conductive layer 32 parallel to one long side of the composite substrate layer 30. The second thermally conductive layer 32 is arranged adjacent to one long side of the composite substrate layer 30, and is centrally located along the long side of the composite substrate layer 30.

[0036] In some examples, the heat source structure 20 may be formed on the surface of the composite substrate layer 30 using a thick film process.

[0037] The heat source structure 20 may include a heating circuit 23, which may include one heating circuit 23 or multiple heating circuits 23.

[0038] For example, such as Figure 2 As shown, the heat source structure 20 may include a first heating circuit 231. At least a portion of the first heating circuit 231 overlaps with the second heat-conducting layer 32. That is, at least a portion of the orthographic projection of the first heating circuit 231 onto the surface of the first heat-conducting layer 31 lies within the orthographic projection of the second heat-conducting layer 32 onto the surface of the first heat-conducting layer 31.

[0039] At least a portion of the first heating line 231 overlaps with the second heat-conducting layer 32, allowing the heat generated in the overlapping area to be conducted more quickly across the surface of the heating element. This results in a smaller temperature gradient in the area corresponding to the second heat-conducting layer 32 and a larger temperature gradient in areas outside the area containing the second heat-conducting layer 32. Furthermore, the temperature distribution on the surface of the heating element can be further altered by adjusting the shape of the first heating line 231 and the length of the overlap between the first heating line 231 and the second heat-conducting layer 32.

[0040] As an example, the orthographic projection of the first heating line 231 on the surface of the first heat-conducting layer 31 is located within the orthographic projection of the second heat-conducting layer 32 on the surface of the first heat-conducting layer 31.

[0041] The first heating circuit 231 is arranged as a whole in the area where the second heat-conducting layer 32 is located, so that all the heat generated by the first heating circuit 231 is concentrated in the area corresponding to the second heat-conducting layer 32 on the surface of the heating element, so that the temperature in this area can rise rapidly and the temperature gradient is small and the temperature distribution is relatively uniform; while the area outside the area where the second heat-conducting layer 32 is located exhibits a large temperature gradient.

[0042] like Figure 2As shown, the heat source structure 20 may further include a second heating circuit 232. The orthographic projection of the second heating circuit 232 onto the surface of the first heat-conducting layer 31 is located outside the orthographic projection of the second heat-conducting layer 32 onto the surface of the first heat-conducting layer 31.

[0043] The second heating circuit 232 is mainly used to conduct heat to areas outside the region where the second heat-conducting layer 32 is located in the heating element. Through the combined action of the first heating circuit 231 and the second heating circuit 232, the heating element can exhibit a more complex temperature distribution. Furthermore, by adjusting the circuit of the second heating circuit 232, the temperature distribution on the surface of the heating element can be changed, which is beneficial for more precise adjustment of the temperature distribution.

[0044] In some other possible implementations, the heat source structure 20 may include more heating circuits, for example, it may include two or more first heating circuits 231; or for example, it may include two or more second heating circuits 232, thereby enabling more precise adjustment of the temperature distribution on the surface of the heating element.

[0045] Figure 5 This is a schematic diagram of the structure of a composite substrate layer provided in an embodiment of this application, as shown below. Figure 5 As shown, the composite substrate layer 30 may include a plurality of second thermally conductive layers 32, which are spaced apart.

[0046] Multiple second thermally conductive layers 32 can be arranged arbitrarily within the composite substrate layer 30. Figure 5 The image only schematically shows two second thermally conductive layers 32 arranged side by side along one side of the composite substrate layer 30.

[0047] By arranging multiple second heat-conducting layers 32 at intervals, the temperature distribution on the surface of the heating element can be further altered.

[0048] The number of first heating lines 231 and second heat-conducting layers 32 can be the same or different. For example, the first heating lines 231 can be arranged in a one-to-one correspondence with the second heat-conducting layers 32, with at least a portion of each first heating line 231 overlapping with its corresponding second heat-conducting layer 32; or, for another example, one first heating line 231 can correspond to several second heat-conducting layers 32, with overlapping portions between the first heating line 231 and each of the corresponding several second heat-conducting layers 32; or, for yet another example, several first heating lines 231 can correspond to one second heat-conducting layer 32, with overlapping portions between the several first heating lines 231 and their corresponding second heat-conducting layers 32.

[0049] The heating circuit may have at least two ends, and the heating circuit may be a curved structure.

[0050] like Figure 2As shown, the heat source structure 20 also includes a common line 21 and a pad 220. One end of the first heating line 231 and one end of the second heating line 232 are respectively connected to the common line 21, and the other end of the first heating line 231, the other end of the second heating line 232, and the common line 21 are each connected to a pad 220.

[0051] The pad 220 may include a common electrode pad 22 and non-common electrode pads 24. As an example, the heat source structure 20 may include one common electrode pad 22 and two non-common electrode pads 24. The common electrode pad 22 is connected to a common line 21, one non-common electrode pad 24 is connected to a first heating line 231, and the other non-common electrode pad 24 is connected to a second heating line 232.

[0052] The common electrode pad 22 and the non-common electrode pad 24 can be made of the same material, so that the common electrode pad 22 and the non-common electrode pad 24 can be prepared together, thereby saving steps and reducing process costs.

[0053] The common line 21 mainly serves to split or collect current. By setting up the common line 21 and multiple pads 220, when controlling the operation of the heating element, all or part of the multiple pads 220 can be connected to the power supply, so that the first heating line 231 and the second heating line 232 can be connected in parallel or in series. They can heat together or heat independently, which makes it convenient to adjust the heating power of the heating element.

[0054] For example, the first heating line 231 and the second heating line 232 can be formed using resistive paste. After the composite substrate layer 30 is prepared, resistive paste is formed on the composite substrate layer 30 by means of printing or other processes, and then the resistive paste is sintered to form the first heating line 231 and the second heating line 232.

[0055] The heat source structure 20 may also include a conductor line 25, through which the first heating line 231 can be connected to the non-common electrode pad 24. The resistance of the conductor line 25 is less than that of the first heating line 231. The conductor line 25 is not used for heating; during the operation of the heating element, the heat generated by the conductor line 25 is much less than that generated by the first heating line 231. The conductor line 25 mainly serves as a connection, and using the conductor line 25 for connection makes the relative position of the first heating line 231 and the pad 220 less restricted.

[0056] Conductor circuit 25 can be made of metallic silver. Metallic silver has low resistance, resulting in low heat generation when connected in series with the first heating circuit 231. Conductor circuit 25 can be formed by sintering conductive silver paste. Common circuit 21 can also be made of metallic silver. Conductor circuit 25 and common circuit 21 can be fabricated together to save steps and reduce manufacturing costs.

[0057] In other possible implementations, the heat source structure 20 may also include a heating element, a heating coil, or other heating elements capable of generating heat. The heating element or heating coil may be attached to the surface of the composite substrate layer 30.

[0058] like Figure 3 As shown, at least one of the first thermal conductive layer 31 and the third thermal conductive layer 33 is provided with a thinning region 30a, and the second thermal conductive layer 32 is located in the thinning region 30a.

[0059] Since the area of ​​the second heat-conducting layer 32 is smaller than that of the first heat-conducting layer 31 and the third heat-conducting layer 33, the first heat-conducting layer 31, the second heat-conducting layer 32, and the third heat-conducting layer 33 cannot completely overlap. By thinning the first heat-conducting layer 31 and / or the third heat-conducting layer 33 to form a thinning region 30a, and arranging the second heat-conducting layer 32 in the thinning region 30a, the thickness difference between the area where the second heat-conducting layer 32 is located and other areas in the heating element can be reduced, making the surface of the heating element smoother.

[0060] In addition, the thinning region 30a also helps the heat emitted by the heat source structure 20 to be conducted to the second heat-conducting layer 32 more quickly, and the heat of the second heat-conducting layer 32 can also be conducted to the surface of the heating element more quickly.

[0061] In some examples, the edges of the first thermally conductive layer 31 and the third thermally conductive layer 33 coincide. This overlap helps to make the overall thickness of the heating element more uniform. At most, the edges of the second thermally conductive layer 32 coincide with the edge of the first thermally conductive layer 31.

[0062] For example, Figure 2 and Figure 5 In the example shown, the edge of the second thermally conductive layer 32 does not coincide with the edge of the first thermally conductive layer 31. Figure 6 This is a schematic diagram of the structure of a heating element provided in an embodiment of this application, as shown below. Figure 6 As shown, in this example, a portion of the edge of the second thermally conductive layer 32 coincides with the edge of the first thermally conductive layer 31.

[0063] Whether the edge of the second heat-conducting layer 32 overlaps with the edge of the first heat-conducting layer 31 affects the range of action of the second heat-conducting layer 32 and can also adjust the temperature distribution on the surface of the heating element.

[0064] By making the edge of the second heat-conducting layer 32 not coincide with the edge of the first heat-conducting layer 31, a larger temperature gradient can be achieved in the region on the surface of the heating element located between the edges of the second heat-conducting layer 32 and the first heat-conducting layer 31. By making a portion of the edge of the second heat-conducting layer 32 coincide with the edge of the first heat-conducting layer 31, a smaller temperature gradient can be achieved near the corresponding edge on the surface of the heating element. In some examples, the material of the first thermally conductive layer 31 is the same as that of the third thermally conductive layer 33. One side of the first thermally conductive layer 31 is connected to one side of the third thermally conductive layer 33.

[0065] The first thermally conductive layer 31 and the third thermally conductive layer 33 are both made of the same material, which facilitates fabrication and helps reduce costs. Furthermore, the first thermally conductive layer 31 and the third thermally conductive layer 33 are connected by a side, meaning that a single thermally conductive layer can be folded to form both the first and third thermally conductive layers 31, making fabrication even more convenient and cost-effective.

[0066] As an example, the first thermally conductive layer 31 and the third thermally conductive layer 33 can be metal layers, that is, the first thermally conductive layer 31 and the third thermally conductive layer 33 are formed of metal materials.

[0067] Metallic materials can withstand higher temperatures and have a longer service life. Furthermore, metallic materials have good thermal conductivity, which is beneficial for heat conduction during the operation of the heating element.

[0068] For example, both the first thermally conductive layer 31 and the third thermally conductive layer 33 are stainless steel metal layers.

[0069] The first heat-conducting layer 31 and the third heat-conducting layer 33 are formed of stainless steel. For example, they can be made of 430 stainless steel, 444 stainless steel, 304 stainless steel, or 2205 stainless steel. Stainless steel is resistant to high temperatures and has good thermal conductivity. For example, the thermal conductivity of 2205 stainless steel can reach about 15 W / m•K, that of 430 stainless steel can reach 23W / m•K~25W / m•K, and that of 444 stainless steel can reach 25W / m•K~26W / m•K. Moreover, stainless steel is relatively inexpensive.

[0070] In some other possible implementations, the first heat-conducting layer 31 and the third heat-conducting layer 33 may also be made of metal materials other than stainless steel. The materials of the first heat-conducting layer 31 and the third heat-conducting layer 33 may also be different.

[0071] In some examples, the second thermally conductive layer 32 may also be a metal layer.

[0072] For example, the second thermally conductive layer 32 can be a nickel metal layer. Nickel has a high thermal conductivity, reaching 90 W / m•K, which facilitates heat conduction within the second thermally conductive layer 32. Furthermore, nickel is relatively inexpensive, contributing to cost reduction.

[0073] In other examples, the second thermally conductive layer 32 may also be a non-metallic layer.

[0074] For example, the second thermally conductive layer 32 can be a pyrolytic graphite layer. Pyrolytic graphite has a very high thermal conductivity, which is stronger than that of metallic nickel, reaching 1200 W / m•K to 2000 W / m•K, which can greatly improve the thermal conductivity of the second thermally conductive layer 32.

[0075] The nickel metal layer and the pyrolytic graphite layer are only examples; the second thermally conductive layer 32 can also be other structures with good thermal conductivity besides the nickel metal layer and the pyrolytic graphite layer.

[0076] The composite substrate layer 30 has a stacked structure. By selecting appropriate material combinations, the first thermally conductive layer 31, the second thermally conductive layer 32, and the third thermally conductive layer 33 can be prepared respectively to avoid deformation of the heating element when it expands due to heat.

[0077] As an example, both the first thermally conductive layer 31 and the third thermally conductive layer 33 are metal layers, such as stainless steel. The second thermally conductive layer 32 is a pyrolytic graphite layer.

[0078] Pyrolytic graphite is a graphite material and has the super-lubricating properties of graphite. Even if the coefficients of thermal expansion of the second thermally conductive layer 32 are significantly different from those of the first thermally conductive layer 31 and the third thermally conductive layer 33, the pyrolytic graphite layer will not affect the expansion of the first thermally conductive layer 31 and the third thermally conductive layer 33, thereby avoiding the formation of stress in the heating element and preventing the heating element from deforming when it expands due to heat.

[0079] In other examples, the first thermally conductive layer 31, the second thermally conductive layer 32, and the third thermally conductive layer 33 are all metal layers. The first thermally conductive layer 31, the second thermally conductive layer 32, and the third thermally conductive layer 33 can be made of materials with similar coefficients of thermal expansion. As some exemplary combinations, the first thermally conductive layer 31 and the third thermally conductive layer 33 are both stainless steel metal layers made of stainless steel, such as 430 stainless steel, 444 stainless steel, 304 stainless steel, or 2205 stainless steel, and the second thermally conductive layer 32 can be a nickel metal layer made of nickel. At temperatures ranging from 20°C to 100°C, the coefficient of thermal expansion of nickel is 13 × 10⁻⁶. -6 / ℃~14.5×10 -6 At / ℃, the coefficient of thermal expansion for 430 and 444 stainless steel is 10.4×10⁻⁶. -6 / ℃~12×10 -6At / ℃, the coefficient of thermal expansion of 2205 stainless steel is 13×10⁻⁶. -6 / ℃~14×10 -6 The coefficients of thermal expansion are relatively similar at / ℃.

[0080] Figure 7 This is a cross-sectional schematic diagram of a composite substrate layer provided in an embodiment of this application. In some examples, Figure 7 As shown, the composite substrate layer 30 also includes a transition thermally conductive layer 34.

[0081] For example, the transition thermal conductive layer 34 may include at least one of the first transition thermal conductive layer 341 and the second transition thermal conductive layer 342.

[0082] The first transition heat-conducting layer 341 is located between the first heat-conducting layer 31 and the second heat-conducting layer 32, and the thermal expansion coefficient of the first transition heat-conducting layer 341 is between the thermal expansion coefficient of the first heat-conducting layer 31 and the thermal expansion coefficient of the second heat-conducting layer 32.

[0083] The second transition heat-conducting layer 342 is located between the second heat-conducting layer 32 and the third heat-conducting layer 33, and the coefficient of thermal expansion of the second transition heat-conducting layer 342 is between the coefficient of thermal expansion of the second heat-conducting layer 32 and the coefficient of thermal expansion of the third heat-conducting layer 33.

[0084] The transition thermal conductive layer 34 can be a single-layer structure or a multi-layer structure.

[0085] By setting a transition heat-conducting layer 34, the stress generated by the expansion of the heating element during heating can be reduced, which helps to avoid deformation of the heating element.

[0086] For example, both the first transition thermal conductive layer 341 and the second transition thermal conductive layer 342 can be metal layers.

[0087] In some examples, the composite substrate layer 30 may also include an insulating layer, which is located at least on the side of the third thermally conductive layer 33 away from the second thermally conductive layer 32, separating the third thermally conductive layer 33 from the heat source structure 20.

[0088] When the third heat-conducting layer 33 is made of a conductive material, such as a metal material, the insulating layer can prevent the heat source structure 20 from being short-circuited.

[0089] The heating element may also include a protective layer, which may cover at least the surface of the heat source structure 20 away from the composite substrate layer 30 to protect the heat source structure 20 and extend the service life of the heating element. For example, it can reduce the risk of the heat source structure 20 being scratched by foreign objects; or, for example, it can delay the oxidation of the heat source structure 20.

[0090] For example, the protective layer can be formed by printing a paste followed by sintering. The protective layer can be made of an insulating material.

[0091] In some examples, the heating element may also include leads that can be connected to the heat source structure 20. For example, the leads may include common electrode leads and non-common electrode leads, with the common electrode leads soldered to common electrode pad 22 and the non-common electrode leads soldered to non-common electrode pad 24.

[0092] For example, the lead can be brazed to the pad 220 or welded using common metal welding processes, such as laser welding, friction welding, cold welding, and resistance welding.

[0093] The leads can be made of metallic materials. For example, the common electrode lead can be stainless steel or nickel wire, or it can be a composite material wire, such as nickel-clad copper wire or silver-clad stainless steel wire.

[0094] The current in the common electrode lead is the sum of the currents flowing through multiple heating circuits. The current is relatively large. Stainless steel wire, nickel wire, nickel-clad copper wire, or silver-clad stainless steel wire can withstand a large current and are not easily damaged by excessive current, which helps to extend the service life.

[0095] The material of the non-common electrode lead can be the same as or different from that of the common electrode lead. For example, both the common electrode lead and the non-common electrode lead can be made of silver wire.

[0096] In the fabrication of the heating element, the heat source structure 20 can be directly formed on the surface of the composite substrate layer 30 after the composite substrate layer 30 is prepared. The composite substrate layer 30 can be prepared using a hot rolling composite process.

[0097] For example, a first thermally conductive layer 31, a second thermally conductive layer 32, and a third thermally conductive layer 33 can be prepared first. The first thermally conductive layer 31 and the third thermally conductive layer 33 can be processed, for example, by thinning the first thermally conductive layer 31 and the third thermally conductive layer 33 respectively to form a thinned region 30a. The second thermally conductive layer 32 is stacked in the thinned region 30a of the first thermally conductive layer 31, and then the third thermally conductive layer 33 is covered, so that the second thermally conductive layer 32 is located in the thinned region 30a of the first thermally conductive layer 31 and the thinned region 30a of the third thermally conductive layer 33. The composite substrate layer 30 is formed by hot rolling composite process.

[0098] In aerosol generating devices, the heating element is typically rolled into a cylindrical shape. After forming the composite substrate layer 30 using a hot rolling composite process, the composite substrate layer 30 can be wound into a cylindrical shape and shaped to improve roundness. Then, a heat source structure 20 is formed on the outer surface of the rolled cylindrical composite substrate layer 30.

[0099] In some examples, the composite substrate layer 30, wound into a cylindrical shape, can be stretched before forming the heat source structure 20 to reduce the thickness of the heating element. After stretching, it can also be shaped to improve roundness.

[0100] The heating element can be manufactured using a precision welding and drawing tube-making process. This process involves rolling metal strips into a tubular shape using high-frequency welding, laser welding, or plasma welding, and then thinning the wall thickness through cold or warm drawing to form ultra-thin-walled seamless or smoothly welded tubes.

[0101] This application also provides an aerosol generating device, which includes a power supply component and the aforementioned heating element. The heating element is rolled into a cylindrical shape and is used to insert the aerosol generating medium. The power supply component is used to supply power to the heating element.

[0102] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A heat generating body, characterized by comprising: The system includes a composite substrate layer (30) and a heat source structure (20). The composite substrate layer (30) includes a first thermally conductive layer (31), a second thermally conductive layer (32), and a third thermally conductive layer (33) stacked together. The second thermally conductive layer (32) is located between the first thermally conductive layer (31) and the third thermally conductive layer (33). The area of ​​the second thermally conductive layer (32) is smaller than the area of ​​the first thermally conductive layer (31) and smaller than the area of ​​the third thermally conductive layer (33). The thermal conductivity of the second thermally conductive layer (32) is greater than the thermal conductivity of the first thermally conductive layer (31) and greater than the thermal conductivity of the third thermally conductive layer (33). The heat source structure (20) is located on the side of the third heat-conducting layer (33) away from the second heat-conducting layer (32), and at least a portion of the heat source structure (20) overlaps with the second heat-conducting layer (32).

2. The heat generating body according to claim 1, characterized by The heat source structure (20) includes a first heating line (231), at least a portion of which overlaps with the second heat-conducting layer (32).

3. The heat generating body according to claim 2, characterized by The heat source structure (20) further includes a second heating circuit (232), the orthographic projection of the second heating circuit (232) on the surface of the first heat-conducting layer (31) is located outside the orthographic projection of the second heat-conducting layer (32) on the surface of the first heat-conducting layer (31).

4. The heat generating body according to claim 3, wherein The heat source structure (20) further includes a common line (21) and a pad (220). One end of the first heating line (231) and one end of the second heating line (232) are respectively connected to the common line (21). The other end of the first heating line (231), the other end of the second heating line (232), and the common line (21) are each connected to a pad (220).

5. The heat generating body according to claim 1, wherein The edge of the first thermal conductive layer (31) coincides with the edge of the third thermal conductive layer (33), and at most part of the edge of the second thermal conductive layer (32) coincides with the edge of the first thermal conductive layer (31).

6. The heat generating body according to claim 1, wherein At least one of the first thermally conductive layer (31) and the third thermally conductive layer (33) is provided with a thinning region (30a), and the second thermally conductive layer (32) is located in the thinning region (30a).

7. The heat generating body according to any one of claims 1 to 6, characterized by The composite substrate layer (30) includes a plurality of second thermally conductive layers (32), which are spaced apart.

8. The heat generating body according to any one of claims 1 to 6, characterized by The material of the first heat-conducting layer (31) is the same as that of the third heat-conducting layer (33), and one side of the first heat-conducting layer (31) is connected to one side of the third heat-conducting layer (33).

9. The heat generating body according to any one of claims 1 to 6, characterized by The second thermally conductive layer (32) is a nickel metal layer or a pyrolytic graphite layer.

10. The heat generating body according to claim 9, wherein The first thermal conductive layer (31) and the third thermal conductive layer (33) are stainless steel metal layers.

11. The heat generating body according to any one of claims 1 to 6, characterized by The composite substrate layer (30) further includes a transition thermally conductive layer (34), which is located at at least one of the following locations: Between the first thermally conductive layer (31) and the second thermally conductive layer (32), and the coefficient of thermal expansion of the transition thermally conductive layer (34) is located between the coefficient of thermal expansion of the first thermally conductive layer (31) and the coefficient of thermal expansion of the second thermally conductive layer (32); The thermal expansion coefficient of the transition heat conductive layer (34) is between the thermal expansion coefficient of the second heat conductive layer (32) and the thermal expansion coefficient of the third heat conductive layer (33).

12. An aerosol-generating device comprising: The heating element according to any one of claims 1 to 11 is wound in a cylindrical shape for insertion of an aerosol generating medium, and the power supply assembly is configured to supply power to the heating element.

Images