Heat generating body and aerosol generating device

Abstract

The application provides a heating body and an aerosol generating device, comprising: a base body, the base body comprising a main body part and an extension part, the main body part being provided with a groove in the longitudinal direction; the main body part being provided with two connection areas at one end close to the extension part, the two connection areas being arranged on both sides of the groove, and the two connection areas being used for connecting electrode leads; the extension part being used for balancing the heat of the connection areas; a conductive heating film, the conductive heating film at least uniformly covering the upper surface and / or the lower surface of the base body; and a protective film, the protective film covering the conductive heating film on the surface of the base body, and the protective film not covering the conductive heating film on the surface of the connection areas. The heating body of the application forms a conductive heating film on the surface of the base body, there is no heating track, and the heating is uniform; and the local temperature at the energized place is balanced by the extension part, so that local high heat is not generated. At the same time, the conductive heating film can realize heating and temperature control sharing, the temperature of the heating body can be converted according to the resistance change after the temperature change, the temperature control is accurate and timely, the process is simple, and the user experience is improved.

Description

Technical Field

[0001] This application relates to the field of electronic cigarette technology, and more particularly to heating elements and aerosol generating devices. Background Technology

[0002] Currently, with the rapid development of heated non-combustible aerosol generating devices, the heating element has become a core component, determining the overall design and performance quality of the aerosol generating device. Existing heating elements for heated non-combustible electronic cigarettes typically print the heating circuitry and temperature sensing circuitry separately; that is, the heating circuitry is fabricated on one side of the substrate, and the temperature sensing circuitry on the other side. This distance between the temperature sensing and heating components results in low temperature control accuracy and complex manufacturing processes. Furthermore, the temperature field uniformity of the heating circuitry is poor, affecting the user experience. Additionally, localized high temperatures are easily generated at the connection point between the heating element and the power supply due to the current. Summary of the Invention

[0003] This application provides a heating element and an aerosol generating device. By forming a conductive heating film on the surface of the substrate, the heating uniformity of the heating element can be improved, and the local temperature at the energized point can be balanced by the extension, thereby enhancing the user experience.

[0004] In a first aspect, this application provides a heating element, the heating element comprising:

[0005] The substrate includes a main body and an extension. The main body has a groove along its longitudinal direction. The main body includes two connection areas, which are disposed on both sides of the groove. The two connection areas are used to connect electrode leads. The extension is used to balance the overheating temperature of the connection areas.

[0006] A conductive heating film, wherein the conductive heating film at least uniformly covers the upper surface and / or lower surface of the substrate; and

[0007] A protective film that covers the conductive heating film on the surface of the substrate, but does not cover the conductive heating film on the surface of the connection area.

[0008] In a feasible implementation, the substrate is made of at least one of metal, ceramic and high-temperature resistant glass.

[0009] In a feasible implementation, the main body and the extension are integrally formed, and the main body has an insertion end for insertion into the aerosol forming matrix of the aerosol generating device.

[0010] In a feasible implementation, the conductive heating film is formed on the entire surface of the substrate.

[0011] In a feasible implementation, the heating element satisfies at least one of the following characteristics:

[0012] (1) The material of the conductive heating film includes at least one of nickel, nickel alloy, platinum, platinum alloy, titanium, and titanium alloy;

[0013] (2) The temperature coefficient of resistance of the conductive heating film is ≥1000ppm / ℃;

[0014] (3) The initial resistance of the conductive heating film at 25°C is 0.2Ω to 1.6Ω;

[0015] (4) The thickness of the conductive heating film is 7 μm to 20 μm.

[0016] In a feasible implementation, the substrate is a conductive substrate, and the heating element further includes an insulating film formed on the surface of the conductive substrate, wherein the conductive heating film is formed on at least a portion of the surface of the insulating film.

[0017] In a feasible implementation, the conductive heating film is formed using at least one of physical vapor deposition, chemical plating, or electroplating processes.

[0018] In a feasible implementation, the thickness of the protective film is from 10 μm to 500 μm.

[0019] In a feasible implementation, the protective film is made of glass glaze.

[0020] In a second aspect, this application provides an aerosol generating device, the aerosol generating device including the heating element according to the first aspect above.

[0021] The technical solution provided in this application has at least the following beneficial effects:

[0022] This application provides a heating element and an aerosol generating device. By forming a conductive heating film on the substrate surface of the heating element, there is no heating trajectory, resulting in uniform heating. Furthermore, the extension balances the local temperature at the energized point, preventing localized overheating. Simultaneously, the conductive heating film can achieve both heating and temperature control. After the temperature changes with energization, the temperature of the heating element can be calculated based on the change in resistance, enabling accurate and timely temperature control with a simple manufacturing process, thus improving the user experience. [Attached Image Description]

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments 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.

[0024] Figure 1This is a schematic diagram of the overall structure of the heating element provided in the embodiments of this application;

[0025] Figure 2 A bottom view of the heating element provided in an embodiment of this application;

[0026] Figure 3 This is a front view of the overall structure of the heating element provided in the embodiments of this application;

[0027] Figure 4 This is a schematic diagram of the overall structure of another heating element provided in an embodiment of this application;

[0028] Figure 5 This is a temperature field distribution diagram of the heating element provided in Embodiment 1 of this application;

[0029] Figure 6 A graph showing the rate of increase of the surface average temperature of the heating element provided in Embodiment 2 of this application;

[0030] Figure 7 This is a temperature field distribution diagram of the heating element provided in Embodiment 3 of this application;

[0031] Figure 8 Temperature field distribution diagram of the heating element provided in Embodiment 4 of this application

[0032] Figure 9 This is a temperature field distribution diagram of the heating element provided in Embodiment 5 of this application;

[0033] Figure 10 Temperature field distribution diagram of the heating element in Comparative Example 1 provided in this application;

[0034] Figure 11 A curve showing the comparison of the heating rate of the surface average temperature of the heating element provided in Embodiment 2 of this application and the heating element of Comparative Example 1.

[0035] Attached image labels:

[0036] 1-Heating element;

[0037] 10-Matrix;

[0038] 11-Main body; 110-Connecting area; 111-Groove; 112-Insertion end;

[0039] 12-Extension;

[0040] 20-Conductive heating film;

[0041] 30 - Protective film. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0043] In the description of this specification, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; unless otherwise specified or stated, the term "multiple" means two or more; the terms "connection," "fixed," etc., should be interpreted broadly, for example, "connection" can be a fixed connection or a detachable connection, or an integral connection, or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium.

[0044] Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0045] In the description of this specification, it should be understood that the directional terms such as "upper" and "lower" used in the embodiments of this application are used to describe the angles shown in the accompanying drawings and should not be construed as limiting the embodiments of this application. Furthermore, in the context, it should also be understood that when it is mentioned that an element is connected "upper" or "lower" to another element, it can be directly connected to the other element "upper" or "lower," or indirectly connected to the other element "upper" or "lower" through an intermediate element.

[0046] In a first aspect, this application provides a heating element, comprising: a substrate, the substrate including a main body portion and an extension portion, the main body portion having a groove along a longitudinal direction; the main body portion including two connection areas, the two connection areas being disposed on both sides of the groove, the two connection areas being used to connect electrode leads; the extension portion being used to balance the overheating temperature of the connection areas; a conductive heating film, the conductive heating film at least uniformly covering the upper surface and / or lower surface of the substrate; and a protective film, the protective film covering the conductive heating film on the surface of the substrate, the protective film not covering the conductive heating film on the surface of the connection areas.

[0047] In the above solution, by forming a conductive heating film on the substrate surface of the heating element, there is no heating trajectory, the heating is uniform, and no localized high heat is generated. Furthermore, the conductive heating film can achieve both heating and temperature control; after energizing, the temperature change can be converted into the temperature of the heating element based on the resistance change, thus achieving accurate and timely temperature control with a simple process, improving the user experience.

[0048] Figure 1 This is a schematic diagram of the overall structure of the heating element provided in the embodiments of this application. Figure 2 A bottom view of the heating element provided in the embodiments of this application, such as... Figure 1 and Figure 2As shown, the heating element includes a substrate 10, a conductive heating film 20, and a protective film 30.

[0049] Specifically, the substrate 10 constitutes the carrier of the heating element 1, used to support the conductive heating film 20. The substrate 10 has an arrow-shaped structure, which facilitates docking with the aerosol generating device.

[0050] The substrate 10 can be classified into conductive substrates and non-conductive substrates according to their conductivity. Conductive substrates include metallic materials, while non-conductive substrates include at least one of ceramics and high-temperature resistant glass. Among these, metallic conductive substrates include iron-chromium-aluminum alloys, stainless steel, nickel-chromium alloys, nickel, and titanium. The material used to prepare the substrate 10 needs to possess characteristics such as high-temperature resistance, stable physical and chemical properties at high temperatures, and no release of harmful substances at high temperatures. The material of the substrate 10 can be determined according to actual needs and is not limited here.

[0051] It should be noted that the preparation method of the substrate 10 can be selected according to whether the substrate 10 is a conductive substrate or a non-conductive substrate. For example, a conductive substrate can be prepared by die casting or hot stamping. For example, conductive titanium metal is melted and die-cast into an elongated sheet, and then polished to obtain a conductive substrate.

[0052] The non-conductive substrate can be prepared by dry pressing the substrate 10 material and then sintering it. For example, the substrate 10 material is a ceramic substrate material, which can be dry pressed into a longitudinal sheet and then sintered at a suitable temperature. The specific sintering temperature can be adjusted according to the different materials and is not limited here.

[0053] As an optional technical solution in this application, the material of the substrate 10 can also be a composite material, namely a composite ceramic substrate formed by sintering ceramic and metal together. The composite ceramic substrate has advantages such as corrosion resistance, high temperature resistance, long service life, high efficiency and energy saving, uniform temperature, good thermal conductivity, and fast thermal compensation speed.

[0054] It should be noted that when the substrate 10 is a conductive substrate, an insulating film needs to be prepared on the outer surface of the conductive substrate during use to prevent the conductivity of the conductive substrate from affecting the use of the conductive heating film 20. Specifically, the insulating film can be an organic insulating film or an inorganic insulating film. The inorganic insulating film includes at least one of silicon oxide insulating film, silicon nitride insulating film, aluminum oxide insulating film, and aluminum nitride insulating film. The organic insulating film includes at least one of polyimide insulating film, polyethylene insulating film, polyvinylidene fluoride insulating film, and polytetrafluoroethylene insulating film. In some embodiments, a slurry containing organic insulating material can be coated on the surface of the conductive substrate and then dried. Of course, the material of the insulating film can also be selected according to actual needs, and no limitation is made here.

[0055] Figure 3This is a front view of the overall structure of the heating element 1 provided in the embodiments of this application, such as... Figure 3 As shown, the substrate 10 includes a main body 11 and an extension 12, which are integrally formed. The main body 11 includes two connection areas 110, which are used to connect electrode leads, thereby realizing the conductive heating function of the heating element 1.

[0056] It should be noted that the connection area 110 connects to the positive and negative terminals of the power supply. During power-on, the current can cause the local temperature of the connection area 110 to become excessively high, resulting in uneven heating. Therefore, by providing the extension 12, the overheating temperature of the connection area 110 can be evenly distributed, ensuring the normal operation of the heating element. In addition to the extension 12, other heat dissipation structures can also be provided, which can be selected according to actual needs and are not limited here.

[0057] To form a conductive circuit, the main body 11 has a groove 111 along its longitudinal direction, and two connecting areas 110 are disposed on both sides of the groove 111. Through the groove 111 and the connecting areas 110 of the main body 11, the substrate 10 can form a circuit when energized. The groove 111 can be obtained by dry pressing with a mold or by laser grooving, and the groove 111 can also be filled with insulating material.

[0058] The main body 11 is provided with an insertion end 112, which is used to insert into the aerosol forming matrix of the aerosol generating device, so that the heat from the heating element 1 can cause the aerosol forming matrix to form smoke. In this embodiment, the insertion end 112 is an inverted V-shaped tip, which facilitates the insertion of the heating element 1 into the aerosol forming matrix. The two sides of the insertion end 112 are sharpened to further facilitate insertion into the aerosol forming matrix.

[0059] It should be noted that the insertion end 112, besides the inverted V-shaped tip, can also be other shapes, for example, Figure 4 This is a schematic diagram of the overall structure of another heating element provided in an embodiment of this application, as shown below. Figure 4 As shown, the insertion end 112 can be trapezoidal or arc-shaped. Different structures of the insertion end 112 can be used to fully connect with the aerosol generating device; no limitation is imposed here, and the appropriate option can be selected based on actual needs.

[0060] In practical applications, after the positive and negative terminals of the power supply are connected in the connection area 110, the heating element 1 generates heat. The generated heat is transferred to the aerosol generating device through the insertion end 112 of the main body 11, thereby generating a mist that simulates smoke.

[0061] The substrate 10 used in this application is an integrated sheet structure, meaning that the main body 11 and the extension 12 are sheet structures of the same thickness. Specifically, the thickness of the substrate 10 is 0.2 mm to 1.5 mm. Optionally, the thickness of the substrate 10 can be 0.2 mm, 0.4 mm, 0.6 mm, 0.9 mm, 1.3 mm, 1.5 mm, etc., and is not limited here. If the thickness of the substrate 10 is too thick, the product size will be too large, and the manufacturing process cost will increase; if the thickness of the substrate 10 is too thin, the strength will be insufficient, and it will be easy to break during use.

[0062] In this application, a conductive heating film 20 loaded on the substrate 10 is used to provide heat to the heating element 1. The conductive heating film 20 is formed on at least a portion of the surface of the substrate 10 and extends from the main body portion 11 to the extension portion 12.

[0063] Specifically, the conductive heating film 20 is uniformly covered on the surface of the substrate 10. When the connection area 110 is connected to the positive and negative terminals of the power supply, the conductive heating film 20 can generate heat, which is then transferred to the aerosol generating device through the insertion end 112 of the main body 11.

[0064] It should be noted that when the substrate 10 is a conductive substrate, the conductive heating film 20 is formed on at least a portion of the surface of the insulating film.

[0065] As an optional technical solution in this application, the conductive heating film 20 can be formed on the entire surface of the substrate 10, thereby enabling the entire heating element 1 to heat up uniformly and avoiding excessively high local temperatures. In other embodiments, the conductive heating film 20 can be formed only on the upper and lower surfaces of the substrate 10, that is, the conductive heating film 20 is not provided on the side of the substrate 10, thereby appropriately reducing costs. Of course, the coverage area of ​​the conductive heating film 20 can also be selected according to actual needs, and is not limited here.

[0066] Specifically, the conductive heating film 20 generates heat using the principle of resistance heating. The conductive heating film 20 used in this application is made of a material with a high temperature coefficient of resistance. That is, as the energizing time of the conductive heating film 20 increases, the temperature of the conductive heating film 20 continuously rises, and the resistance value of the conductive heating film 20 will also change accordingly. Therefore, the temperature of the heating plate can be calculated based on the temperature coefficient of resistance of the conductive heating film 20, thus realizing the functions of heating and temperature measurement.

[0067] The conductive heating film 20 used in this application has a temperature coefficient of resistance ≥1000ppm / ℃, specifically 1000ppm / ℃, 2000ppm / ℃, 3000ppm / ℃, 4000ppm / ℃, 5000ppm / ℃, 6000ppm / ℃, etc., and is not limited here. Optionally, the conductive heating film 20 can be made of at least one of nickel, nickel alloy, platinum, platinum alloy, titanium, and titanium alloy. The material of the conductive heating film 20 can be selected according to actual needs, and is not limited here.

[0068] Specifically, the conductive heating film 20 can be a single-layer structure or a composite structure. For example, when the conductive heating film 20 is a single-layer structure, it can be a nickel film, etc.; when the conductive heating film 20 is a composite structure, it can be a nickel film and a titanium film stacked together.

[0069] At room temperature (25°C), the initial resistance of the conductive heating film 20 is between 0.2Ω and 1.6Ω. Optionally, the initial resistance of the conductive heating film 20 can be 0.2Ω, 0.4Ω, 0.6Ω, 0.8Ω, 1Ω, 1.2Ω, 1.4Ω, 1.6Ω, etc., and is not limited here. If the initial resistance of the conductive heating film 20 is too high, a relatively large voltage is required to test a certain power, resulting in a more complex boost circuit and higher cost; if the initial resistance of the conductive heating film 20 is too low, the current is too large at a certain power, leading to greater related losses. Preferably, the resistance of the conductive heating film 20 can be 0.6Ω.

[0070] The thickness of the conductive heating film 20 is 7 to 20 μm. Optionally, the specific thickness of the conductive heating film 20 can be 7 μm, 9 μm, 11 μm, 13 μm, 15 μm, 17 μm, 19 μm, 20 μm, etc., and is not limited here. If the conductive heating film 20 is too thick, the cost is high and it is prone to cracking; if the conductive heating film 20 is too thin, the thickness is prone to unevenness, and it is also prone to burn-out during use.

[0071] In practical applications, at least one of the following processes can be used to form a conductive heating film 20 on the substrate 10: physical vapor deposition, chemical plating, or electroplating. Preferably, a physical vapor deposition process is used to form the conductive heating film 20 on at least a portion of the surface of the substrate 10.

[0072] Furthermore, at least one protective film 30 is formed on the conductive heating film 20 on the surface of the substrate 10. The protective film 30 is used to protect the conductive heating film 20. The protective film 30 covering the conductive heating film 20 can have both good insulation and good heat resistance to adapt to the resistance heating of the conductive heating film 20 and ensure the service life of the heating element 1. In this application, the protective film 30 can be a glass glaze layer.

[0073] It should be noted that the protective film 30 can only cover the conductive heating film 20 on the surface of the connection area 110. Since the glass glaze layer used in the protective film 30 is an insulator, covering the connection area 110 will make it difficult to form a circuit when the power is applied, affecting the electrical connection between the conductive heating film 20 and the power supply electrode, so that the heating element 1 cannot work normally.

[0074] In this application, the thickness of the protective film 30 is from 10 μm to 500 μm. Optionally, the thickness of the protective film 30 can be 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 500 μm, etc., and is not limited here. If the thickness of the protective film 30 is too high, the manufacturing cost will increase; if the thickness of the protective film 30 is too thin, it will not provide good protection for the conductive heating film 20, affecting the service life of the heating element 1. Optionally, the thickness of the protective film 30 can be 200 μm.

[0075] Secondly, this application provides a method for preparing a heating element, which can be formed by physical vapor deposition, chemical plating or electroplating.

[0076] The specific preparation method includes the following steps:

[0077] Step S10: Clean the substrate and then dry it;

[0078] Step S20: Under a vacuum environment and protective atmosphere, the substrate is coated using at least one of physical vapor deposition, chemical plating, or electroplating processes until a conductive heating film with a thickness of 7 μm to 20 μm is deposited on the upper and / or lower surfaces of the substrate.

[0079] In the above scheme, the prepared heating element is used for both heating and temperature control, there is no heating trajectory, the heating is uniform, and the temperature of the heating element can be calculated based on the change in resistance after the power is applied to achieve temperature measurement. Therefore, the temperature control is accurate and timely, the process is simple, and the user experience is good.

[0080] The substrate 10 used in this preparation method includes a main body 11 and an extension 12, which are integrally formed. The main body 11 includes two connection areas 110, which are used to connect electrode leads, thereby realizing the conductive heating function of the heating element 1.

[0081] To form a conductive circuit, the main body 11 has a groove 111 along its longitudinal direction, and two connecting areas 110 are disposed on both sides of the groove 111. Through the groove 111 and the connecting areas 110 of the main body 11, the substrate 10 can form a circuit when energized. The groove 111 can be obtained by dry pressing with a mold or by laser grooving, and the groove 111 can also be filled with insulating material.

[0082] In step S10, the substrate is cleaned and dried, which can enhance the bonding force between the subsequently prepared conductive heating film and the substrate, prevent the conductive heating film from falling off during use, and extend the service life of the heating element.

[0083] After drying, the substrate is used to prepare a conductive heating film using physical vapor deposition, chemical plating, or electroplating. It should be noted that in step S20, when the substrate is conductive, an insulating film needs to be prepared on the outer surface of the conductive substrate during use to prevent the conductivity of the conductive substrate from affecting the use of the conductive heating film. Specifically, the insulating film can be an organic insulating film or an inorganic insulating film. The inorganic insulating film includes at least one of silicon oxide, silicon nitride, aluminum oxide, and aluminum nitride insulating films. The organic insulating film includes at least one of polyimide, polyethylene, polyvinylidene fluoride, and polytetrafluoroethylene. The material of the insulating film can be selected according to actual needs and is not limited here.

[0084] Preferably, a physical vapor deposition process is used to form the conductive heating film, and the specific steps include:

[0085] A protective atmosphere with a gas flow rate of 50 ml / min to 300 ml / min is introduced into a vacuum environment, and the sputtering power is set to 10 W / cm. 2 Up to 20W / cm 2 The sputtering current causes the protective atmosphere to form a gas plasma, which impacts the conductive heating film raw material target material, forming conductive heating film raw material target material atoms.

[0086] The conductive heating film is deposited on the atomic matrix of the target material for 10 min to 600 min until a conductive heating film with a thickness of 7 μm to 20 μm is formed.

[0087] In step S20, the protective atmosphere used is an argon protective atmosphere, and the inlet gas flow rate of the protective atmosphere is 50 ml / min to 300 ml / min. Optionally, the inlet gas flow rate of the protective atmosphere can be 50 ml / min, 100 ml / min, 150 ml / min, 200 ml / min, 250 ml / min, 300 ml / min, etc. The protective atmosphere is used to form gas plasma to bombard the conductive heating film raw material target. The inlet gas flow rate of the protective atmosphere can be selected according to the amount of conductive heating film raw material target used, and is not limited here.

[0088] After introducing the protective atmosphere, the sputtering power is set. The magnitude of the sputtering power affects the deposition of conductive heating film target atoms on the substrate. In this application, the sputtering power is 10W to 20W. Optionally, the sputtering power can be 10W, 12W, 14W, 16W, 18W, 20W, etc. If the sputtering power is too high, the conductive heating film target atoms will deposit too quickly on the substrate, resulting in poor uniformity of the conductive heating film. If the sputtering power is too low, the sputtering process will be difficult to perform. The sputtering power can be selected according to the amount of conductive heating film target material used, and is not limited here.

[0089] Sputtering equipment within the sputtering power range generates sputtering current, which ionizes the protective atmosphere to form gas plasma. The gas plasma impacts the conductive heating film raw material target, causing the atoms of the conductive heating film raw material target to escape. The escaped conductive heating film raw material target atoms are deposited on the rotating substrate to the target thickness to obtain a conductive heating film.

[0090] The deposition time of the escaped conductive heating film target atoms on the substrate is from 10 min to 600 min. Optionally, the deposition time can be 10 min, 100 min, 200 min, 300 min, 400 min, 500 min, 600 min, etc., and is not limited here. If the deposition time is too long, the product size will be too large, and the manufacturing process cost will increase; if the deposition time is too short, the formed conductive heating film will be too thin, resulting in insufficient strength and easy breakage during use. Preferably, the deposition time can be 200 min.

[0091] During the deposition of the escaping conductive heating film raw material target atoms on the substrate, the substrate needs to rotate at a certain speed, which is 2 mm / s to 5 mm / s. Optionally, the specific rotation speed can be 2 mm / s, 3 mm / s, 4 mm / s, 5 mm / s, etc. Rotation can ensure that the conductive heating film raw material target atoms are deposited uniformly on the substrate, improving the deposition quality. The rotation speed can be selected according to actual needs and is not limited here.

[0092] It should be noted that the conductive heating film raw material target used in the physical vapor deposition process includes at least one of nickel, nickel alloy, platinum, platinum alloy, titanium, and titanium alloy, which can be specifically selected according to the required physical properties.

[0093] The conductive heating film obtained by physical vapor deposition has a thickness of 7 to 20 μm. Specific thicknesses, such as 7 μm, 9 μm, 11 μm, 13 μm, 15 μm, 17 μm, 19 μm, and 20 μm, are optional and not limited here. Excessive thickness of the conductive heating film increases cost and increases the risk of cracking; insufficient thickness leads to uneven thickness and a higher risk of burn-out during use.

[0094] At room temperature (25°C), the initial resistance of the conductive heating film 20 is between 0.2Ω and 1.6Ω. Optionally, the initial resistance of the conductive heating film 20 can be 0.2Ω, 0.4Ω, 0.6Ω, 0.8Ω, 1Ω, 1.2Ω, 1.4Ω, 1.6Ω, etc., and is not limited here. If the initial resistance of the conductive heating film 20 is too high, a relatively large voltage is required to test a certain power, resulting in a more complex boost circuit and higher cost; if the initial resistance of the conductive heating film 20 is too low, the current is too large at a certain power, leading to greater related losses. Preferably, the resistance of the conductive heating film 20 can be 0.6Ω.

[0095] Following step S20, the preparation method further includes:

[0096] Step S30: A protective film is formed on the surface of the conductive heating film away from the substrate.

[0097] In step S30, a glass glaze layer is prepared as a protective film on the surface of the conductive heating film away from the substrate. The protective film is used to protect the conductive heating film. The protective film covering the conductive heating film can have both good insulation and good heat resistance to adapt to the resistance heating of the conductive heating film and ensure the service life of the heating element.

[0098] It should be noted that the protective film 30 can only cover the conductive heating film 20 on the surface of the connection area 110. Since the glass glaze layer used in the protective film 30 is an insulator, covering the connection area 110 will make it difficult to form a circuit when the power is applied, affecting the electrical connection between the conductive heating film 20 and the power supply electrode, so that the heating element 1 cannot work normally.

[0099] In this application, the thickness of the protective film is from 10 μm to 500 μm. Optionally, the specific thickness of the protective film can be 10 μm, 50 μm, 100 μm, 200 μm, 300 μm, 500 μm, etc., and is not limited here. If the thickness of the protective film is too high, the manufacturing cost will increase; if the thickness of the protective film is too thin, it will not provide good protection for the conductive heating film and will affect the service life of the heating element. Optionally, the thickness of the protective film can be 200 μm.

[0100] Through the above steps S10, S20 and S30, a conductive heating element is obtained.

[0101] To enable those skilled in the art to better understand the technical solution of this application, the application will be further described in detail below with reference to specific embodiments.

[0102] Example 1:

[0103] In this embodiment 1, the substrate is made of stainless steel, the conductive heating film is made of nickel metal, and the insulating and protective films are made of glass glaze. The specific steps are as follows:

[0104] Clean and dry the stainless steel substrate;

[0105] A glass glaze layer is prepared on the surface of a stainless steel substrate as an insulating film;

[0106] The substrate is first treated with an electrical conductive treatment, and then nickel metal is prepared into a conductive heating film using an electroplating process. The thickness of the conductive heating film is 20 micrometers.

[0107] A glass glaze layer with a thickness of 200 μm is prepared as a protective film in the region of the substrate excluding the bonding area.

[0108] The obtained heating element has an initial resistance of 0.2Ω at 25℃ and a temperature coefficient of resistance of 5800ppm / ℃.

[0109] test:

[0110] A conductive layer is covered in the connection area. An external circuit supplies power through the conductive layer to heat the conductive heating film. At the same time, the circuit detects the resistance value and calculates the temperature of the heating element based on the temperature coefficient of resistance. Combined with software algorithms, temperature control is achieved.

[0111] Test results:

[0112] Figure 5 This is a temperature field distribution diagram of the heating element provided in Embodiment 1 of this application, such as... Figure 5 As shown, the heating element prepared in this embodiment has a uniform temperature overall, with a temperature difference of less than 10℃.

[0113] Example 2:

[0114] In this embodiment 2, the substrate is made of alumina ceramic, the conductive heating film is made of platinum metal, and the protective film is made of glass glaze. The specific steps are as follows:

[0115] Clean and dry the alumina ceramic substrate;

[0116] A conductive heating film of platinum metal was prepared by magnetron sputtering in PVD, which was applied only to the front and back of the substrate. The thickness of the conductive heating film was 7 micrometers.

[0117] A glass glaze layer with a thickness of 100 μm is prepared as a protective film in the region of the substrate excluding the bonding area.

[0118] The heating element produced has an initial resistance of 1Ω at 25℃ and a temperature coefficient of resistance of 3700ppm / ℃.

[0119] test:

[0120] A conductive layer is covered in the connection area. An external circuit supplies power through the conductive layer to heat the conductive heating film. At the same time, the circuit detects the resistance value and calculates the temperature of the heating element based on the temperature coefficient of resistance. Combined with software algorithms, temperature control is achieved.

[0121] Test results:

[0122] Figure 6 This is a curve showing the rate of increase of the average surface temperature of the heating element provided in Embodiment 2 of this application. Figure 6 As shown, the surface heating rate of the heating element prepared in this embodiment 2 is uniform.

[0123] Example 3:

[0124] In this embodiment 3, the heating element has its sharp corners removed from the substrate. The substrate is made of zirconium oxide ceramic, the conductive heating film is made of titanium metal, and the protective film is made of glass glaze. The specific steps are as follows:

[0125] Clean and dry the alumina ceramic substrate;

[0126] A conductive heating film with a thickness of 15 micrometers was prepared from titanium metal by electron beam evaporation in PVD.

[0127] A glass glaze layer with a thickness of 10 μm is prepared as a protective film in the region of the substrate excluding the bonding area.

[0128] The heating element produced has an initial resistance of 1.6Ω at 25℃ and a temperature coefficient of resistance of 4000ppm / ℃.

[0129] test:

[0130] A conductive layer is covered in the connection area. An external circuit supplies power through the conductive layer to heat the conductive heating film. At the same time, the circuit detects the resistance value and calculates the temperature of the heating element based on the temperature coefficient of resistance. Combined with software algorithms, temperature control is achieved.

[0131] Test results:

[0132] Figure 7 This is a temperature field distribution diagram of the heating element provided in Embodiment 3 of this application, such as... Figure 7 As shown, the heating element prepared in Example 3 has a uniform overall temperature with a temperature difference of less than 10°C.

[0133] Example 4:

[0134] In this embodiment 4, the substrate is made of silicon dioxide glass, the conductive heating film is made of titanium alloy metal, and the protective film is made of glass glaze. The specific steps are as follows:

[0135] Clean and dry the silica glass substrate;

[0136] The substrate is prepared into a conductive heating film by chemical plating of titanium alloy metal, and the thickness of the conductive heating film is 8 micrometers.

[0137] A glass glaze layer with a thickness of 50 μm is prepared as a protective film in the region of the substrate excluding the bonding area.

[0138] The obtained heating element has an initial resistance of 1.6Ω at 25℃ and a temperature coefficient of resistance of 3100ppm / ℃.

[0139] test:

[0140] A conductive layer is covered in the connection area. An external circuit supplies power through the conductive layer to heat the conductive heating film. At the same time, the circuit detects the resistance value and calculates the temperature of the heating element based on the temperature coefficient of resistance. Combined with software algorithms, temperature control is achieved.

[0141] Test results:

[0142] Figure 8 This is a temperature field distribution diagram of the heating element provided in Embodiment 3 of this application, such as... Figure 8 As shown, the heating element prepared in this embodiment 4 can raise its temperature to 300°C within 5 seconds when the power supply is 30W, and the overall temperature of the heating element is uniform with a temperature difference of less than 10°C.

[0143] Example 5:

[0144] In this embodiment 5, the substrate is alumina ceramic, and the conductive heating film material is Fe. 79 Ni 21 Made of alloy material, the protective film uses a glass enamel layer. The specific steps are as follows:

[0145] Clean and dry the alumina ceramic substrate;

[0146] The substrate is first subjected to an overall conductive treatment, and then electroplating is used to coat the Fe substrate. 79 Ni 21 The alloy is used to prepare a conductive heating film with a thickness of 12 micrometers.

[0147] A glass glaze layer with a thickness of 90 μm is prepared as a protective film in the region of the substrate excluding the bonding area.

[0148] The obtained heating element has an initial resistance of 0.6Ω at 25℃ and a temperature coefficient of resistance of 1000ppm / ℃.

[0149] test:

[0150] The entire connection area is covered with a conductive layer. An external circuit supplies power through the conductive layer to heat the conductive heating film. The circuit also detects the resistance value and calculates the temperature of the heating element based on the temperature coefficient of resistance. Combined with software algorithms, temperature control is achieved.

[0151] Test results:

[0152] Figure 9 This is a temperature field distribution diagram of the heating element provided in Embodiment 5 of this application, such as... Figure 9 As shown, the heating element prepared in this embodiment has a uniform temperature overall, with a temperature difference of less than 10℃.

[0153] Comparative Example 1:

[0154] Unlike Example 2, Comparative Example 1 prepared heating trajectories on a zirconia ceramic substrate.

[0155] Test results:

[0156] Figure 10 This is a temperature field distribution diagram of the heating element in Comparative Example 1 provided in this application. Figure 11 This is a comparison curve of the heating rate of the surface average temperature of the heating element provided in Embodiment 2 of this application and the heating element in Comparative Example 1, as shown in the figure. Figure 10 and Figure 11 As shown, the heating rate of the heating element prepared with a conductive heating film is higher than that of the heating element prepared with a conductive heating trajectory.

Claims

1. A heating element, characterized in that, The heating element includes: The substrate includes a main body and an extension. The main body has a groove along its longitudinal direction. Two connection areas are provided at one end of the main body near the extension. The two connection areas are located on both sides of the groove and are used to connect electrode leads. The extension is used to balance the heat of the connection areas. A conductive heating film, wherein the conductive heating film at least uniformly covers the upper surface and / or lower surface of the substrate; and A protective film that covers the conductive heating film on the surface of the substrate, but does not cover the conductive heating film on the surface of the connection area; The conductive heating film satisfies the following characteristics: (1) The material of the conductive heating film includes at least one of nickel, nickel alloy, platinum, platinum alloy, titanium, and titanium alloy; (2) The temperature coefficient of resistance of the conductive heating film is ≥1000ppm / ℃; (3) The initial resistance of the conductive heating film at 25°C is 0.2Ω to 1.6Ω; (4) The thickness of the conductive heating film is 7 μm to 19 μm.

2. The heating element according to claim 1, characterized in that, The substrate is made of at least one of metal, ceramic and high-temperature resistant glass.

3. The heating element according to claim 1, characterized in that, The main body and the extension are integrally formed. The main body has an insertion end for insertion into the aerosol forming matrix of the aerosol generating device.

4. The heating element according to claim 3, characterized in that, The conductive heating film is formed on at least a portion of the surface of the substrate, and the conductive heating film extends from the main body to the extension portion.

5. The heating element according to claim 1, characterized in that, The substrate is a conductive substrate, and the heating element further includes an insulating film formed on the surface of the conductive substrate, wherein the conductive heating film is formed on at least a portion of the surface of the insulating film.

6. The heating element according to claim 1, characterized in that, The conductive heating film is formed using at least one of the following processes: physical vapor deposition, chemical plating, or electroplating.

7. The heating element according to claim 1, characterized in that, The thickness of the protective film is from 10 μm to 500 μm.

8. The heating element according to claim 7, characterized in that, The protective film is made of glass glaze.

9. An aerosol generating device, characterized in that, The aerosol generating device includes a heating element according to any one of claims 1 to 8.

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