Heating assembly and aerosol generating device

Abstract

The utility model discloses a heating assembly and an aerosol generating device. The heating assembly comprises a metal base body, a heating layer and an electric insulation layer. A porous structure is formed on at least one surface of the metal matrix; the heating layer is used for switching on a power supply and heating; the electric insulation layer is at least partially located between the metal matrix and the heating layer, and the electric insulation layer is combined with the porous structure. The porous structure formed on the surface of the metal matrix increases the surface roughness of the metal matrix, and effectively improves the physical anchoring binding force of the electrical insulation layer and the metal matrix, thereby reducing the risks of falling off, cracking and the like of the adjacent layer structures of the heating assembly.

Description

Technical Field

[0001] This utility model relates to the field of heating non-combustion technology, and in particular to a heating component and an aerosol generating device. Background Technology

[0002] An aerosol generating device is an electronic product that atomizes a liquid or solid matrix into an aerosol for users to inhale. Its core component is a heating element. Some heating elements use a metal tube to contain the solid matrix, and achieve heating and heat conduction by covering the metal tube with a heating film layer. Since the heating film layer needs to be electrically conductive to generate heat, an insulating and thermally conductive layer needs to be placed between the heating film layer and the metal tube. However, based on existing processing and molding methods, there is a problem of insufficient bonding strength between the insulating and thermally conductive layer and the metal tube, which makes the heating element prone to phenomena such as adjacent layer detachment and cracking. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide an improved heating component and aerosol generating device, addressing at least one deficiency mentioned in the background art.

[0004] The technical solution adopted by this utility model to solve its technical problem is as follows: a heating component is provided, which includes a metal substrate, a heating layer and an electrical insulating layer; at least one surface of the metal substrate is formed with a porous structure; the heating layer is used to connect to a power source and generate heat; the electrical insulating layer is at least partially located between the metal substrate and the heating layer, and the electrical insulating layer and the porous structure are combined.

[0005] In some embodiments, the surface roughness Ra of the porous structure is 0.2 to 0.6 μm; and / or, the pore density of the porous structure is greater than 90%; and / or, the pore size of the porous structure is 1 to 5 μm.

[0006] In some embodiments, the metal substrate is a hollow metal tube, and the inner and / or outer wall surfaces of the metal substrate are formed with the porous structure, and the electrical insulating layer is at least partially located between the outer wall surface and the heating layer.

[0007] In some embodiments, the porous structure is formed on both the inner and outer walls of the metal substrate, and the electrical insulating layer includes a first insulating layer and a second insulating layer, wherein the first insulating layer is located between the outer wall and the heating layer, and the second insulating layer is located on the inner wall.

[0008] In some embodiments, the thickness of the metal substrate is 0.01 mm to 0.5 mm.

[0009] In some embodiments, the metal substrate is a stainless steel substrate.

[0010] In some embodiments, the heating layer includes a base film and a heating film, the base film being disposed on the surface of the electrical insulating layer opposite to the metal substrate, and the heating film being disposed on the surface of the base film opposite to the electrical insulating layer.

[0011] In some embodiments, the heating layer further includes a heat equalization layer disposed on the side of the heating film opposite to the base film.

[0012] In some embodiments, the heating layer further includes electrode leads, one end of which is connected to the heat spreader.

[0013] This utility model also provides an aerosol generating device, which includes a power supply unit and a heating component as described in any one of the above, wherein the power supply unit and the heating layer of the heating component are connected.

[0014] The present invention has at least the following beneficial effects: the porous structure formed on the surface of the metal substrate increases the surface roughness of the metal substrate, effectively improving the physical anchoring bond between the electrical insulation layer and the metal substrate, thereby reducing the risk of adjacent layer structures of the heating component falling off or cracking. Attached Figure Description

[0015] To more clearly illustrate the technical solution of this utility model, the following will further describe this utility model in conjunction with the accompanying drawings and embodiments. In the drawings:

[0016] Figure 1 This is a schematic diagram of the structure of the heating component in some embodiments of this utility model;

[0017] Figure 2 yes Figure 1 The exploded structural diagram of the heating component is shown.

[0018] Figure 3 yes Figure 2 A further exploded structural diagram of the heating component shown;

[0019] Figure 4 This is a microscopic structural diagram of the porous structure of the heating component in some embodiments of this utility model. Detailed Implementation

[0020] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model are now described in detail with reference to the accompanying drawings. Unless otherwise explicitly specified and limited, terms such as "installation," "connection," "joining," "fixing," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or a connection within two elements or an interaction between two elements. When an element is referred to as being "on" or "below" another element, the element can be located "directly" or "indirectly" on the other element, or there may be one or more intermediary elements. The terms "first," "second," etc., are used only for the convenience of describing this technical solution and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] Please see Figures 1 to 3 This utility model illustrates a heating component according to an embodiment, which includes a metal substrate 10, a heating layer 2, and an electrical insulating layer 3. This heating component is used in an aerosol generating device.

[0022] At least one surface of the metal substrate 10 has a porous structure. That is, the porous structure exists only on the surface of the metal substrate 10 and does not penetrate the two opposing surfaces of the metal substrate 10. The heating layer 2 is used to connect to a power source and generate heat. The electrically insulating layer 3 is at least partially located between the metal substrate 10 and the heating layer 2, and the electrically insulating layer 3 is integrated with the porous structure. That is, the electrically insulating layer 3 may be entirely located between the metal substrate 10 and the heating layer 2, or only a portion of the electrically insulating layer 3 may be located between the metal substrate 10 and the heating layer 2. The electrically insulating layer 3 is disposed on the porous surface of the metal substrate 10 and is tightly bonded to the metal substrate 10 by means of sintering or the like. In other words, the electrically insulating layer 3 covers the porous structure.

[0023] like Figure 4 As shown, the porous structure on the surface of the metal substrate 10 has a uniform and dense pore morphology. The porous structure formed on the surface of the metal substrate 10 increases the surface roughness of the metal substrate 10, effectively improving the physical anchoring bond between the electrical insulating layer 3 and the metal substrate 10, thereby reducing the risk of adjacent layer structure detachment and cracking of the heating component. Since this porous structure exists only on the surface of the metal substrate 10, it is not sensitive to grain boundary precipitates and defects near grain boundaries, and its morphology is more stable.

[0024] In some embodiments, the thickness of the electrical insulating layer 3 can be 10 μm to 80 μm. The electrical insulating layer 3 can be formed on the metal substrate 10 by sintering a glass glaze layer with an expansion coefficient of 9 × 10⁻⁶ (1 / K) to 13 × 10⁻⁶ (1 / K) and tightly bonded to the porous structure. The sintering temperature can be 700 to 900 °C.

[0025] The metal substrate 10 can be a stainless steel substrate, specifically a 316L stainless steel substrate. Of course, in other embodiments, the metal substrate 10 can also be made of other metal materials. Currently, chemical corrosion on 316L stainless steel mainly includes two methods: acid etching and pitting corrosion. Acid etching primarily occurs at processing defects and grain boundaries on the metal surface, mainly utilizing the Cr-depleted grain boundary theory to cause intergranular corrosion, with the main reaction being: Fe + 2H⁺ + →Fe 2+ +H2. Acid etching agents are mainly mixed acids such as HNO3 (nitric acid) or HF (hydrofluoric acid), resulting in low production efficiency, significant environmental pollution, and poor pore morphology on metal surfaces. Furthermore, the pore morphology is greatly affected by raw material processing defects and the distribution of intergranular precipitates. Traditional chemical pitting etching processes on 316L stainless steel typically produce pores on the order of tens of micrometers. If applied to thin tubes with wall thicknesses on the micrometer level, the risk of corrosion through is high. Too weak corrosion conditions result in poor morphology, limited roughening effect, or even failure to form pores; too strong corrosion conditions lead to uneven pore formation and a high risk of corrosion through.

[0026] Specifically, the porous structure on the surface of the metal substrate 10 can be formed by the following etching process:

[0027] S1. Dissolve an acidic substance in pure water to obtain an acidic solution. The acidic substance includes one or more of tartaric acid, oxalic acid, hydrochloric acid, and hydrofluoric acid.

[0028] S2. Take one of ferric chloride and copper chloride and add it to the acid solution to obtain a corrosive agent;

[0029] S3. Install the metal substrate 10 to be corroded onto the fixture, perform ultrasonic cleaning on the metal substrate 10, and rinse it clean.

[0030] S4. Immerse the metal substrate 10 in the etchant. Specifically, during the immersion process, the fixture must be rotated, or the etchant must be kept in a state of uniform flow relative to the metal substrate 10, to prevent localized over-corrosion of the surface of the metal substrate 10;

[0031] S5. Clean the metal substrate 10 after corrosion is completed, and then rinse and dry it.

[0032] The corrosion reaction between the above-mentioned corrosive agent and the metal substrate 10 mainly includes: 2Fe 3+ +Fe→

[0033] 3Fe 2+ (iron salts) or Cu 2+ +Fe→Fe 2+ +Cu (copper salt). Furthermore, guided by chloride ions with small radius and strong penetrating adsorption capacity, and under the action of a self-catalytic mechanism, the above reaction preferentially penetrates deeper into the pitting corrosion pits, forming a pore morphology with a certain depth and density. By monitoring acidity and salt concentration, adding acid and salt according to the quantity of metal substrate 10, and controlling the corrosion temperature and time, the degree of corrosion and morphology can be controlled to tend towards stability. Experiments show that the above corrosion process can form a uniform and dense pore morphology (porous structure) on the surface of the metal substrate 10. This pore morphology is generated on the surface layer of the metal substrate 10 and is not sensitive to grain boundary precipitates and defects near grain boundaries, resulting in a more stable morphology. Experiments show that the above heating element underwent three high-temperature sintering cycles at approximately 800℃ during processing. The final heating element showed no peeling or cracking in the 370℃ / 3-cycle water quenching test and the 48-hour neutral salt spray test. Moreover, compared with acid etching, the above etchant has lower acidity, a milder odor, and is more environmentally friendly; its corrosion efficiency is higher, making it more suitable for mass production.

[0034] In some embodiments, the surface roughness Ra of the porous structure is 0.2–0.6 μm. The pore density of the porous structure is greater than 90%. The pore diameter of the porous structure is 1–5 μm. Pore density refers to the ratio of the area of ​​pores to the total area of ​​a given planar region. For example, if pores occupy 90 units of a 100-unit planar region, then the pore density of the porous structure is 90%. A pore diameter of 1–5 μm means that the smallest pore diameter in the porous structure is 1 μm, the largest pore diameter is 5 μm, and the average pore diameter of the porous structure is 1–5 μm.

[0035] like Figure 2 and Figure 3 As shown, in some embodiments, the metal substrate 10 is a hollow metal tube. The metal tube encloses a heating cavity for containing an aerosol-generating matrix. The aerosol-generating matrix can be a solid matrix. The inner and / or outer wall surfaces of the metal substrate 10 have porous structures, and the electrically insulating layer 3 is at least partially located between the outer wall surface and the heating layer 2. For example, in a first embodiment, the outer wall surface of the metal substrate 10 has a porous structure, and the electrically insulating layer 3 is at least partially located between the outer wall surface and the heating layer 2; in a second embodiment, both the inner and outer wall surfaces of the metal substrate 10 have porous structures, a portion of the electrically insulating layer 3 is located between the outer wall surface and the heating layer 2, and another portion of the electrically insulating layer 3 is located on the inner wall surface of the metal substrate 10. For example... Figure 2 and Figure 3In the illustrated embodiment, both the inner and outer walls of the metal substrate 10 are formed with porous structures. The electrical insulating layer 3 includes a first insulating layer 31 and a second insulating layer 32. The first insulating layer 31 is located between the outer wall and the heating layer 2, serving both insulating and heat-conducting functions. The second insulating layer 32 is located on the inner wall, serving to uniformly conduct heat. The thicknesses of the first insulating layer 31 and the second insulating layer 32 can be 10 μm to 80 μm, respectively.

[0036] Tests have shown that the above-described corrosion process forms a porous structure on the surface of the thin metal tube. The optimized combination of acid and salt in the etchant effectively prevents the corrosion reaction from occurring only in a localized area, resulting in a very low risk of corrosion penetration. Even for thin tubes with a thickness of 0.01 mm to 0.5 mm, it is highly probable that the porous structure forms only on the surface of the tube without penetrating the tube wall. A full-scale weighing experiment was conducted on the metal tube to be corroded. The calculation results show that the maximum bilateral removal of the corroded metal tube is less than 3 μm, far less than 10 μm, providing sufficient safety margin. The full-scale weighing experiment involves weighing several metal tubes before and after corrosion, calculating the weight loss, and then combining this with the surface area and density of the metal tube material to calculate the theoretical bilateral corrosion removal, thereby assessing the risk of corrosion penetration. Therefore, it has been verified that as long as the above-described corrosion process is adopted, the risk of corrosion penetration is very low, so even with a very thin metal substrate 10, a uniformly dense porous structure can be formed on the surface of the metal substrate 10. In some embodiments, the thickness of the metal substrate 10 can be 0.01 mm to 0.5 mm. For example, when the metal substrate 10 is a metal tube, the wall thickness of the metal tube can be 0.01 mm to 0.5 mm.

[0037] The thickness of the heating layer 2 can be any value from 8μm to 20μm, including the extreme values.

[0038] like Figure 3 As shown, in some embodiments, the heating layer 2 includes a base film 21 and a heating film 22. The base film 21 is disposed on the surface of the electrically insulating layer 3 facing away from the metal substrate 10, and the heating film 22 is disposed on the surface of the base film 21 facing away from the electrically insulating layer 3. That is, the base film 21 is disposed on the outer surface of the electrically insulating layer 3, and the heating film 22 is disposed on the outer surface of the base film 21. The base film 21 serves as the molding basis for the heating film 22. The heating film 22 has a specific shape trajectory.

[0039] like Figure 3 As shown, in some embodiments, the heating layer 2 further includes a heat-spreading layer 23, which is disposed on the side of the heating film 22 facing away from the base film 21. Specifically, the heat-spreading layer 23 can be disposed on the surface of the heating film 22 facing away from the base film 21. That is, the heat-spreading layer 23 can be disposed on the outer surface of the heating film 22. Thus, the base film 21, the heating film 22, and the heat-spreading layer 23 are sequentially disposed from the inside to the outside on the outer surface of the electrically insulating layer 3. The heat-spreading layer 23 is mainly used for uniform heat conduction.

[0040] like Figure 3 As shown, in some embodiments, the heating layer 2 further includes electrode leads 24, one end of which is connected to the heat spreader 23. The other end of the electrode leads 24 extends outward for connecting to a power source. After the electrode leads 24 are connected to the power source, heat is sequentially conducted from the heating layer 2 to the first insulating layer 31, the metal substrate 10, the second insulating layer 32, and finally to the aerosol generating matrix within the heating chamber. The aerosol generating matrix generates aerosols upon heating for the user to inhale.

[0041] This invention also provides an aerosol generating device, which includes a power supply unit and a heating element of any of the above embodiments, wherein the power supply unit and the heating layer 2 of the heating element are connected. Specifically, the power supply unit is connected to the end of the electrode lead 24 away from the heating layer 2.

[0042] It is understood that the above embodiments only illustrate preferred embodiments of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present utility model patent. It should be noted that for those skilled in the art, the above technical features can be freely combined, and several modifications and improvements can be made without departing from the concept of the present utility model, all of which fall within the protection scope of the present utility model. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present utility model should fall within the coverage of the claims of the present utility model.

Claims

1. A heating element, characterized in that, include: A metal substrate (10) having at least one surface formed with a porous structure; A heating layer (2) is used to connect to a power source and generate heat. An electrical insulating layer (3) is located at least partially between the metal substrate (10) and the heating layer (2), and the electrical insulating layer (3) is combined with the porous structure.

2. The heating component according to claim 1, characterized in that, The surface roughness Ra of the porous structure is 0.2–0.6 μm; And / or, the pore density of the porous structure is greater than 90%; And / or, the pore size of the porous structure is 1 to 5 μm.

3. The heating component according to claim 1, characterized in that, The metal substrate (10) is a hollow metal tube, and the inner wall and / or outer wall of the metal substrate (10) are formed with the porous structure. The electrical insulating layer (3) is at least partially located between the outer wall and the heating layer (2).

4. The heating component according to claim 3, characterized in that, The metal substrate (10) has a porous structure on both its inner and outer walls. The electrical insulating layer (3) includes a first insulating layer (31) and a second insulating layer (32). The first insulating layer (31) is located between the outer wall and the heating layer (2), and the second insulating layer (32) is located on the inner wall.

5. The heating component according to claim 1, characterized in that, The thickness of the metal substrate (10) is 0.01 mm to 0.5 mm.

6. The heating component according to claim 1, characterized in that, The metal substrate (10) is a stainless steel substrate.

7. The heating component according to claim 1, characterized in that, The heating layer (2) includes a base film (21) and a heating film (22). The base film (21) is disposed on the surface of the electrical insulating layer (3) facing away from the metal substrate (10), and the heating film (22) is disposed on the surface of the base film (21) facing away from the electrical insulating layer (3).

8. The heating element according to claim 7, characterized in that, The heating layer (2) further includes a heat equalization layer (23), which is disposed on the side of the heating film (22) facing away from the base film (21).

9. The heating element according to claim 8, characterized in that, The heating layer (2) further includes an electrode lead (24), one end of which is connected to the heat spreader (23).

10. An aerosol generating device, characterized in that, It includes a power supply unit and a heating component as described in any one of claims 1 to 9, wherein the power supply unit and the heating layer (2) of the heating component are connected.

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