Heating body, preparation method thereof and aerosol generating device

Abstract

The invention belongs to the technical field of heating, and particularly relates to a heating body, a preparation method thereof and an aerosol generating device. The heating body comprises a substrate layer and a heating resistance layer which are arranged in a stacked mode. The substrate layer comprises a semi-metal material; the heating resistance layer comprises a semi-metal material and doping elements dispersed in the semi-metal material, and the doping elements comprise one or more of a third main group element and a fifth main group element. According to the heating body, the doped semi-metal material is used as the heating resistance layer, and the heating resistance layer and the substrate layer are the same in main component and are both semi-metal materials, so that the thermal expansion coefficients of the heating resistance layer and the substrate layer are similar. In the heating process, the volume expansion of the heating resistance layer and the volume expansion of the substrate layer are similar, so that cracking between the heating resistance layer and the substrate layer can be relieved, and the service life of the heating body is prolonged.

Description

Technical Field

[0001] This application belongs to the technical field of heating, and particularly relates to a heating element, a preparation method thereof, and an aerosol generating device. Background Art

[0002] The heating element is an important component of the aerosol generating device. A common heating element is a metal alloy heating element, which includes an insulating layer and a metal alloy layer provided on the surface of the insulating layer. The insulating layer can protect the metal alloy layer from contacting the substance to be heated (such as the aerosol generating matrix), so that the metal alloy layer is not easily corroded by the substance to be heated, and at the same time the substance to be heated is not directly heated and burned by the metal alloy layer. After the heating element is connected to the circuit and powered on, the metal alloy layer generates heat, and the heat is conducted through the insulating layer into the substance to be heated, thereby heating the substance to be heated.

[0003] Due to the different thermal expansion coefficients of the metal alloy layer and the insulating layer, their volume expansion degrees are different during the heating process, and the phenomenon of cracking of the heating element often occurs, shortening the service life of the heating element. Summary of the Invention

[0004] The purpose of this application is to provide a heating element, a preparation method thereof, and an aerosol generating device, aiming to solve the problem that the heating element is prone to cracking.

[0005] To achieve the above application purpose, the technical solution adopted in this application is as follows:

[0006] In the first aspect, this application provides a heating element, including a stacked substrate layer and a heating resistance layer; the substrate layer includes a semi-metallic material; the heating resistance layer includes a semi-metallic material and doping elements dispersed in the semi-metallic material, and the doping elements include one or more of the elements in the third main group and the fifth main group.

[0007] The heating element in the embodiment of this application uses a doped semi-metallic material as the heating resistance layer. The main components of the heating resistance layer and the substrate layer are the same, both are semi-metallic materials, so that their thermal expansion coefficients are similar. Then, during the heating process, the volume expansions of the heating resistance layer and the substrate layer are similar, so that the cracking between the heating resistance layer and the substrate layer can be alleviated, and the service life of the heating element can be prolonged.

[0008] In some embodiments, the semi-metallic material includes one or more of silicon and germanium. Silicon and germanium can be used alone or in combination. Usually, they can be in the form of silicon crystals and germanium crystals.

[0009] Silicon and germanium have good stability and insulation properties, and can be used as the substrate layer of the heating element to separate the heating resistance layer from the substance to be heated, protect the heating resistance layer from being corroded by the substance to be heated, and protect the substance to be heated from being directly contacted and heated by the heating resistance layer and catching fire.

[0010] In some embodiments, the doping element includes one or more of phosphorus, boron, aluminum, and gallium. Doping phosphorus in the semimetal material can form an n-type semiconductor, while doping boron, aluminum, or gallium can form a p-type semiconductor. By doping phosphorus, boron, aluminum, and gallium in the semimetal material, the heating resistance layer can have a certain resistivity, thereby achieving resistive heating.

[0011] In some embodiments, the doping concentration of the doping element in the heating resistance layer is 1×10 15 cm -3 ~5×10 19 cm -3 , optionally 1×10 15 cm -3 ~5×10 17 cm -3 . At this doping concentration, the heating resistance layer has a certain resistivity and can effectively achieve resistive heating.

[0012] In some embodiments, the heating resistance layer includes a first heating resistance layer and a second heating resistance layer in adjacent contact; the doping concentration C1 of the doping element in the first heating resistance layer is 1×10 15 cm -3 ~5×10 17 cm -3 (lightly doped); the doping concentration C2 of the doping element in the second heating resistance layer is greater than C1, optionally C2 is 1×10 17 cm -3 ~5×10 19 cm -3 (heavily doped).

[0013] The resistivity ρ1 of the first heating resistance layer is 0.1 Ω·cm to 4000 Ω·cm, and the resistivity ρ2 of the second heating resistance layer is greater than ρ1, optionally ρ2 is 0.3 Ω·cm to 10 Ω·cm.

[0014] The conductivity of the semimetal material increases with the increase of the doping element concentration. The first heating resistance layer has a low doping concentration and a high resistivity, which can effectively achieve resistive heating; while the second heating resistance layer has a high doping concentration and good conductivity, which is beneficial to connect the first heating resistance layer with a high resistivity to the external circuit and is beneficial to the current passing through the first heating resistance layer.

[0015] In some embodiments, the thickness of the heating resistance layer is less than or equal to 10 μm, optionally 0.01 μm to 10 μm. The thickness of the substrate layer is 50 μm to 300 μm, optionally 100 μm to 200 μm.

[0016] The embodiments of the present application use a heating resistance layer with a small thickness as the heating element of the heating body, and a substrate layer with a low thickness, which is conducive to realizing the lightweight and small-size of the heating device.

[0017] In a first aspect, the present application provides a method for preparing a heating body, including:

[0018] Disperse doping elements into the surface layer of a semimetal material to obtain a heating body;

[0019] The heating body includes a substrate layer and a heating resistance layer arranged in a stacked manner; the substrate layer includes a semimetal material; the heating resistance layer includes a semimetal material and doping elements dispersed in the semimetal material, and the doping elements include one or more of the elements in the third main group and the fifth main group.

[0020] By doping elements on the surface layer of the semimetal material, a heating body with a substrate layer and a heating resistance layer can be obtained. The formed substrate layer and heating resistance layer are integrally formed and are a whole tightly combined together, and the main components between the two are the same, so that the thermal expansion systems of the two are similar. Then, during the heating process, the volume expansions of the heating resistance layer and the substrate layer are similar, so that the cracking between the heating resistance layer and the substrate layer can be alleviated, and the service life of the heating body can be prolonged.

[0021] Moreover, the preparation method of the embodiments of the present application can obtain the substrate layer and the heating resistance layer at the same time. Compared with the common metal alloy heating body structure in which a metal alloy and a glass enamel insulating layer are combined together, the preparation process of the insulating layer can be omitted, that is, there is no need to specially set up an insulating layer separately, which is conducive to simplifying the process.

[0022] In a third aspect, the present application provides an aerosol generating device, including the heating body of the first aspect.

[0023] The heating body of the embodiments of the present application has good stability, and it is not easy to crack between the heating resistance layer and the substrate layer, which is conducive to prolonging the service life of the aerosol generating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0025] Figure 1 It is a schematic structural diagram of the heating body provided in Embodiment 1 of the present application;

[0026] Figure 2Schematic structural diagram of the heating element provided in Embodiment 3 of the present application;

[0027] Figure 3 Schematic structural diagram of the heating element provided in Embodiment 5 of the present application.

[0028] Reference numerals:

[0029] 10 - Substrate layer, 20 - Heating resistance layer, 21 - First heating resistance layer, 22 - Second heating resistance layer, 30 - Electrode layer, 40 - ITO transparent oxide conductive layer. Detailed implementation manners

[0030] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application clearer and more understandable, the present application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0031] In the present application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Wherein A and B may be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0032] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or its similar expression means any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can both represent: a, b, c, a - b (that is, a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or plural respectively.

[0033] It should be understood that in various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the order of execution. Some or all of the steps may be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0034] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms of "a", "the", and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0035] In the description of the embodiments of the present application, the weight of the relevant components mentioned not only can refer to the specific content of each component, but also can represent the proportional relationship between the weights of each component. Therefore, as long as the content of the relevant components in the description of the embodiments of the present application is scaled up or down proportionally, it is within the scope disclosed in the description of the embodiments of the present application. Specifically, the mass described in the description of the embodiments of the present application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0036] The terms "first" and "second" are only used for descriptive purposes to distinguish objects such as substances from each other, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. For example, without departing from the scope of the embodiments of the present application, the first XX can also be referred to as the second XX, and similarly, the second XX can also be referred to as the first XX. Thus, the features defined with "first" and "second" can explicitly or implicitly include one or more of such features.

[0037] The first aspect of the embodiments of the present application provides a heating element, including a substrate layer and a heating resistance layer arranged in a stacked manner; the substrate layer includes a semimetal material; the heating resistance layer includes a semimetal material and doping elements dispersed in the semimetal material, and the doping elements include one or more of elements in the third main group and elements in the fifth main group.

[0038] Term interpretation:

[0039] The heating element includes a substrate layer and a heating resistance layer arranged in a stacked manner, which means that the substrate layer and the heating resistance layer are stacked together, or it can be said that the heating resistance layer is arranged on the surface of the substrate layer.

[0040] Semimetals are also called "metalloids" or "semi-metals". Generally, semimetal materials include elements in the fourth main group, specifically including one or more of silicon, boron, arsenic, antimony, tellurium, germanium, and antimony, and optionally including one or more of silicon and germanium. These materials can also be called silicon group materials.

[0041] In the embodiments of the present application, the substrate layer includes a semimetal material, that is, the main component of the substrate layer is a semimetal material, and the semimetal material therein usually does not contain doping elements. Such a semimetal material usually has good stability and insulation. That is, the substrate layer of the embodiments of the present application includes an insulating semimetal material, which can separate the heating resistance layer from the substance to be heated, protect the heating resistance layer from being corroded by the substance to be heated, and protect the substance to be heated from being directly heated by the heating resistance layer and catching fire.

[0042] The heating resistance layer of the embodiment of the present application includes a semimetal material and a doping element. The semimetal material therein may be the same as or different from the substrate layer. The doping element includes one or more elements from Group IIIA and Group VA. The elements from Group IIIA include one or more of boron, aluminum, gallium, indium, and thallium. The elements from Group VA include one or more of nitrogen, phosphorus, arsenic, antimony, and bismuth. These doping elements are dispersed in the semimetal material, usually in the form of a solid solution. After doping the elements from Group IIIA and Group VA in the semimetal material, a p-type semiconductor or an n-type semiconductor can usually be formed, which has certain conductivity and resistance and can be used as a heating resistance.

[0043] The heating resistance layer of the embodiment of the present application is disposed on the surface of the substrate layer, and it can be of any shape. For example, it can be continuous, or there may be discontinuities. For another example, it can be in the shape of a loop, a circle, a square, etc.

[0044] The heating element provided by the embodiment of the present application has the following technical effects:

[0045] This heating element directly uses a doped semimetal material as the heating resistance layer. The main components of the heating resistance layer and the substrate layer are the same, both being semimetal materials, so that their thermal expansion coefficients are similar. Then, during the heating process, the volume expansions of the heating resistance layer and the substrate layer are similar, which can relieve the cracking between the heating resistance layer and the substrate layer and extend the service life of the heating element.

[0046] In some embodiments, the semimetal material includes one or more of silicon and germanium. Silicon and germanium can be used alone or in combination. Usually, they can be in the form of silicon crystals and germanium crystals.

[0047] Silicon and germanium have good stability and insulation properties, and can be used as the substrate layer of the heating element to separate the heating resistance layer from the substance to be heated, protecting the heating resistance layer from being corroded by the substance to be heated, and protecting the substance to be heated from being directly heated by the heating resistance layer and catching fire.

[0048] At the same time, after doping the elements from Group IIIA and Group VA in silicon and germanium, they can be used as the heating resistance layer. After being powered on, not only can a certain amount of resistive heat be generated through Ohm's law to convert electrical energy into heat energy, but also infrared light can be radiated (having good infrared radiation characteristics at 500K - 1000K), achieving the effect of infrared heating.

[0049] In some embodiments, the doping element includes one or more of phosphorus, boron, aluminum, and gallium. Doping phosphorus in the semimetal material can form an n-type semiconductor, while doping boron, aluminum, and gallium can form a p-type semiconductor. By doping phosphorus, boron, aluminum, and gallium in the semimetal material, the heating resistance layer can have a certain resistivity, thereby realizing resistive heating.

[0050] In some embodiments, the doping concentration of the doping element in the heating resistance layer is 1×10 15 cm -3 ~5×10 19 cm -3 , optionally 1×10 15 cm -3 ~5×10 17 cm -3 , and further optionally 1×10 15 cm -3 ~5×10 16 cm -3 , such as 1×10 15 cm -3 , 5×10 15 cm -3 , 1×10 16 cm -3 , 5×10 16 cm -3 , 1×10 17 cm -3 , 5×10 17 cm -3 , 1×10 18 cm -3 , 5×10 18 cm -3 , 1×10 19 cm -3 , 5×10 19 cm -3 Any point value or the range between any two point values among them. The doping concentration of the doping element in the heating resistance layer is usually expressed by the number of atoms of the doping element per cubic centimeter. At this doping concentration, the heating resistance layer has a certain resistivity and can effectively achieve resistance heating.

[0051] In some embodiments, the heating resistance layer includes a first heating resistance layer and a second heating resistance layer in adjacent contact; the doping concentration C1 of the doping element in the first heating resistance layer is 1×10 15 cm -3 ~5×10 17 cm -3 (lightly doped), optionally C1 is 1×10 15 cm -3 ~5×10 16 cm -3 ; the doping concentration C2 of the doping element in the second heating resistance layer is greater than C1, optionally C2 is 1×10 17 cm -3 ~5×10 19 cm -3(Heavily doped), and then optionally 1×10 18 cm -3 ~5×10 19 cm -3 。

[0052] In this case, the resistivity ρ1 of the first heating resistance layer is 0.1 Ω·cm to 4000 Ω·cm, optionally ρ1 is 10 Ω·cm to 500 Ω·cm, and further optionally ρ1 is 10 Ω·cm to 200 Ω·cm, such as any one of 0.1 Ω·cm, 1 Ω·cm, 10 Ω·cm, 100 Ω·cm, 200 Ω·cm, 300 Ω·cm, 500 Ω·cm, 1000 Ω·cm, 2000 Ω·cm, 3000 Ω·cm, 4000 Ω·cm or the range between any two point values. The resistivity ρ2 of the second heating resistance layer is greater than ρ1, optionally ρ2 is 0.3 Ω·cm to 10 Ω·cm, such as any one of 0.3 Ω·cm, 1 Ω·cm, 2 Ω·cm, 4 Ω·cm, 6 Ω·cm, 8 Ω·cm, 10 Ω·cm or the range between any two point values.

[0053] Wherein, the first heating resistance layer and the second heating resistance layer are adjacent in contact, which means there is an interface contact between the two. Their positions in the heating element can include: both the first heating resistance layer and the second heating resistance layer are disposed on the surface of the substrate layer, or, the first heating resistance layer is disposed on the surface of the substrate layer, and the second heating resistance layer is disposed on the surface of the first heating resistance layer.

[0054] The conductivity of the half-metal material increases with the increase of the doping element concentration. The first heating resistance layer has a low doping concentration and a relatively high resistivity, which can effectively realize resistive heating; while the second heating resistance layer has a high doping concentration and good conductivity, which is beneficial to connecting the first heating resistance layer with a relatively high resistivity to the external circuit and facilitating the current to pass through the first heating resistance layer. It can be understood that the second heating resistance layer also has a certain resistivity and can also generate a certain resistive heating effect, so it can also be classified as a heating resistance layer.

[0055] In some embodiments, the thickness of the heating resistance layer is less than or equal to 10 μm, optionally 0.01 μm to 10 μm, and further optionally 0.5 μm to 3 μm. For example, it can be any one of 0.01 μm, 0.05 μm, 0.1 μm, 0.5 μm, 1 μm, 3 μm, 5 μm, 7 μm, 9 μm, 10 μm or the range between any two of these point values. It can be understood that the heating resistance layer includes a half-metal material and doping elements dispersed in the half-metal material. The thickness of the heating resistance layer can be understood as the doping depth of the doping elements therein, and can also be referred to as the junction depth. In the case where the heating resistance layer includes a first heating resistance layer and a second heating resistance layer, the thicknesses of the first heating resistance layer and the second heating resistance layer can be independently selected from the foregoing thickness ranges.

[0056] The thickness of the substrate layer is 50 μm to 300 μm, optionally 100 μm to 200 μm. For example, it can be any one of 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm or the range between any two of these point values.

[0057] In the embodiments of the present application, a heating resistance layer with a small thickness is used as the heating element of the heating body, and a substrate layer with a low thickness is used, which is beneficial to realizing the lightweight and small size of the heating device.

[0058] In some embodiments, the heating body further includes a conductive layer disposed on the surface of the heating resistance layer. The conductive layer can include one or more of indium tin oxide (ITO), zinc oxide, tin oxide, copper, silver, gold, and aluminum. In the case where the heating resistance layer includes the foregoing first heating resistance layer and second heating resistance layer, the conductive layer can be disposed on the surface of the second heating resistance layer and not on the surface of the first heating resistance layer.

[0059] By providing the conductive layer, the heating resistance layer can be connected to an external circuit, which is beneficial to the passage of current through the heating resistance layer, thereby promoting the heating of the heating resistance layer.

[0060] In some embodiments, the heating body further includes an electrode layer, and the electrode layer is disposed on the surface of the heating resistance layer; or the electrode layer is disposed on the surface of the conductive layer. In the case where the heating resistance layer includes the foregoing first heating resistance layer and second heating resistance layer, the electrode layer can be disposed on the surface of the second heating resistance layer and not on the surface of the first heating resistance layer. The heating body can be connected to an external circuit through the electrode layer.

[0061] In some embodiments, the form of the heating body includes one or more of a heating wire, a heating plate, a heating sheet, and a heating tube. The heating body in the embodiments of the present application can be applied in multiple forms to meet different application requirements.

[0062] A second aspect of an embodiment of the present application provides a method for preparing a heating element, which is used to prepare the heating element of the first aspect.

[0063] The preparation method of the heating element comprises:

[0064] The doping elements are dispersed in the surface layer of the semi-metal material to obtain a heating element; the heating element includes a stacked substrate layer and a heating resistor layer; the substrate layer includes the semi-metal material; the heating resistor layer includes the semi-metal material and the doping elements dispersed in the semi-metal material.

[0065] By doping the surface layer of the semi-metallic material with elements, a heating element having a substrate layer and a heating resistor layer can be obtained. The substrate layer and the heating resistor layer are formed in one piece, and are tightly combined into a whole. The main components of the two are the same, which makes the thermal expansion systems of the two similar. During the heating process, the volume expansion of the heating resistor layer and the substrate layer is similar, which can alleviate the cracking between the heating resistor layer and the substrate layer and extend the service life of the heating element.

[0066] Moreover, the preparation method of the embodiment of the present application can simultaneously obtain the substrate layer and the heating resistor layer. Compared with the common metal alloy heating element structure that combines a metal alloy with a glass enamel insulating layer, the preparation process of the insulating layer can be omitted, that is, there is no need to specially set up an insulating layer, which is conducive to simplifying the process.

[0067] In some embodiments, the method of dispersing doping elements into the surface layer of the semi-metallic material can refer to the existing commonly used impurity doping methods, for example, one or more of diffusion method, ion implantation method, vapor deposition method, and solid phase reaction method can be used.

[0068] For example, the diffusion method is to diffuse a gas source or solid source containing doping elements into the semi-metal material under high temperature conditions. For example, POCl3 (or a gas source or solid source containing other doping elements such as BCl3, AlCl3) can be applied to the surface of the semi-metal material at high temperature to achieve diffusion of the doping elements in the surface layer of the semi-metal material.

[0069] During the doping process, the desired doping concentration and doping depth can be obtained by controlling the flow rate, temperature, time or other parameters of the raw materials.

[0070] In some embodiments, the semi-metallic material used in the preparation process does not contain doping elements (understandably, due to the influence of the smelting process, it may contain some unavoidable impurities), and is usually in block or sheet form. Before the doping elements are dispersed on the surface of the semi-metallic material, the semi-metallic material may also be sliced, ground and polished.

[0071] In some embodiments, the method for preparing the heating element further includes: printing electrode grid lines on the surface of the heating resistance layer and sintering them to form an electrode layer. Or it includes: coating a conductive layer on the surface of the heating resistance layer, then printing electrode grid lines on the surface of the conductive layer and sintering them to form an electrode layer.

[0072] The third aspect of the embodiments of the present application provides an aerosol generating device, including the heating element of the first aspect.

[0073] The heating element of the embodiments of the present application has good stability, and it is not easy to crack between the heating resistance layer and the substrate layer, which is beneficial to extending the service life of the aerosol generating device.

[0074] In the aerosol generating device, the substrate layer in the heating element can be in direct contact with the substance to be heated (such as the aerosol generating matrix), or there can also be a certain distance interval between the heating element and the substance to be heated, so that the substance to be heated can be heated without combustion.

[0075] The following will be described in conjunction with specific embodiments.

[0076] Embodiment 1

[0077] Please refer to Figure 1 , this embodiment provides a silicon-based heating element, including a substrate layer 10, a heating resistance layer 20, and an electrode layer 30 that are sequentially stacked. Among them, the substrate layer 10 is an undoped silicon crystal layer. The heating resistance layer 20 is a phosphorus lightly doped silicon crystal layer (n-type silicon crystal layer), and the doping concentration of phosphorus in it is about 1×10 15 cm -3 , and the thickness of the heating resistance layer is about 0.8 μm.

[0078] The silicon-based heating element of this embodiment can be prepared by the following method:

[0079] 1) Slice and grind and polish the undoped silicon crystal to obtain a silicon wafer with a thickness of about 50 μm.

[0080] 2) Apply POCl3 on one surface of the silicon wafer for phosphorus deposition and diffusion, so as to form a phosphorus lightly doped layer on the surface layer of the silicon wafer.

[0081] There is no phosphorus doping in the bottom layer of the silicon wafer, and this part of the silicon wafer without phosphorus doping serves as the substrate layer, while the phosphorus lightly doped layer serves as the heating resistance layer.

[0082] 3) Print electrode grid lines on the surface of the phosphorus lightly doped layer and sinter them to form an electrode layer.

[0083] Embodiment 2

[0084] The difference between this embodiment and Embodiment 1 is that silicon is replaced by germanium. That is, the heating element in this embodiment is a germanium-based heating element, the substrate layer is an undoped germanium crystal layer, and the heating resistance layer is a phosphorus lightly doped germanium crystal layer.

[0085] Embodiment 3

[0086] Please refer to Figure 2 , this embodiment provides a silicon-based heating element, including a substrate layer 10, a heating resistance layer, and an electrode layer 30 stacked in sequence. The heating resistance layer includes a first heating resistance layer 21 and a second heating resistance layer 22 in adjacent contact. Both the first heating resistance layer 21 and the second heating resistance layer 22 are disposed on the surface of the substrate layer 10, and the electrode layer 30 is disposed on the surface of the second heating resistance layer 22, while there is no electrode layer 30 on the surface of the first heating resistance layer 21.

[0087] Among them, the substrate layer 10 is an undoped silicon crystal layer. The first heating resistance layer 21 is a phosphorus lightly doped silicon crystal layer, and the doping concentration of phosphorus is about 5×10 17 cm -3 ; the second heating resistance layer 22 is a phosphorus heavily doped silicon crystal layer, and the doping concentration of phosphorus is about 5×10 18 cm -3 ; the thicknesses of both the first heating resistance layer 21 and the second heating resistance layer 22 are about 2 μm.

[0088] The silicon-based heating element of this embodiment can be prepared by the following method:

[0089] 1) Slice, grind, and polish the undoped silicon crystal to obtain a silicon wafer with a thickness of about 300 μm.

[0090] 2) Apply POCl3 on one surface of the silicon wafer for phosphorus deposition and diffusion, so as to form a phosphorus lightly doped layer on the surface layer of the silicon wafer. Then, perform secondary phosphorus deposition and diffusion locally on the phosphorus lightly doped layer to form a phosphorus heavily doped layer locally.

[0091] There is no phosphorus doping on the bottom layer of the silicon wafer, and this undoped part of the silicon wafer serves as the substrate layer. The phosphorus lightly doped layer is the first heating resistance layer, and the phosphorus heavily doped layer is the second heating resistance layer.

[0092] 3) Print electrode grid lines on the surface of the phosphorus heavily doped layer and sinter them to form the electrode layer.

[0093] Embodiment 4

[0094] The difference between this embodiment and Embodiment 3 is that silicon is replaced by germanium. That is, the heating element in this embodiment is a germanium-based heating element, the substrate layer is an undoped germanium crystal layer, the first heating resistance layer is a phosphorus lightly doped germanium crystal layer, and the second heating resistance layer is a phosphorus heavily doped germanium crystal layer.

[0095] Embodiment 5

[0096] The difference between this embodiment and Embodiment 1 is that an ITO transparent oxide conductive layer 40 is provided between the heating resistance layer 20 and the electrode layer 30.

[0097] Please refer to Figure 3 , the silicon-based heating element of this embodiment includes a substrate layer 10, a heating resistance layer 20, an ITO transparent oxide conductive layer 40, and an electrode layer 30 which are sequentially stacked.

[0098] Embodiment 6

[0099] The difference between this embodiment and Embodiment 3 is that an ITO transparent oxide conductive layer is provided between the second heating resistance layer and the electrode layer.

[0100] Embodiment 7

[0101] The difference between this embodiment and Embodiment 1 is that the doping element phosphorus in the heating resistance layer is replaced by boron. That is, in the silicon-based heating element of this embodiment, the heating resistance layer is a boron lightly doped silicon crystal layer, and the doping concentration of boron is about 1×10 16 cm -3 , and the thickness of the heating resistance layer is about 3 μm.

[0102] Embodiment 8

[0103] The difference between this embodiment and Embodiment 3 is that the doping element phosphorus in the first heating resistance layer and the second heating resistance layer is replaced by boron. That is, in the silicon-based heating element of this embodiment, the first heating resistance layer is a boron lightly doped silicon crystal layer, and the doping concentration of boron in this layer is about 5×10 16 cm -3 , and the thickness is about 0.5 μm; the second heating resistance layer is a boron heavily doped silicon crystal layer, and the doping concentration of boron in this layer is about 5×10 19 cm -3 .

[0104] The thicknesses of both the first heating resistance layer and the second heating resistance layer are about 5 μm.

[0105] Embodiment 9

[0106] The difference between this embodiment and Embodiment 5 is that the doping element phosphorus in the heating resistance layer is replaced by boron. That is, in the silicon-based heating element of this embodiment, the heating resistance layer is a boron lightly doped silicon crystal layer, and the doping concentration of boron in this layer is about 1×10 15 cm -3 , and the thickness is about 3 μm.

[0107] When the above-mentioned heating element is applied to a heat-not-burn aerosol generating device, at a working temperature of 400°C to 600°C, the heating element has a service life of up to 5000 to 10000 hours. Commercially available aerosol generating devices usually use stainless steel thick film heating elements. Such heating elements include a glass enamel insulating layer and a stainless steel heating layer provided on the surface of the glass enamel insulating layer, and their service life at the same working temperature is only 2000 to 5000 hours. By comparison, it can be seen that the heating element of the embodiment of the present application has a longer service life.

[0108] The above are only the preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A heating element, characterized in that, It includes a substrate layer and a heating resistance layer which are stacked; the substrate layer includes a semimetal material; the heating resistance layer includes the semimetal material and doping elements dispersed in the semimetal material, and the doping elements include one or more of group III elements and group V elements.

2. The heating element according to claim 1, wherein The semimetal material includes one or more of silicon and germanium.

3. The heating element according to claim 1 or 2, characterized in that, The doping elements include one or more of phosphorus, boron, aluminum, and gallium.

4. The heating element according to claim 1 or 2, characterized in that, The doping concentration of the doping element in the heating resistance layer is 1×10 15 cm -3 ~5×10 19 cm -3 .

5. The heating element according to claim 4, wherein The doping concentration of the doping element in the heating resistance layer is 1×10 15 cm -3 ~5×10 17 cm -3 .

6. The heating element according to claim 4, wherein The heating resistance layer includes a first heating resistance layer and a second heating resistance layer in adjacent contact; the doping concentration C1 of the doping element in the first heating resistance layer is 1×10 15 cm -3 ~5×10 17 cm -3 ; the doping concentration C2 of the doping element in the second heating resistance layer is greater than C1; And / or, the resistivity ρ1 of the first heating resistance layer is 0.1 Ω·cm to 4000 Ω·cm, and the resistivity ρ2 of the second heating resistance layer is greater than ρ1.

7. The heating element according to claim 6, wherein, C2 is 1×10 17 cm -3 ~5×10 19 cm -3 ; and / or, ρ2 is 0.3 Ω·cm to 10 Ω·cm.

8. The heating element according to claim 1, wherein The thickness of the heating resistance layer is less than or equal to 10 μm; And / or, the thickness of the substrate layer is 50 μm to 300 μm.

9. A method for preparing a heating element, characterized in that, It includes: Dispersing doping elements into the surface layer of the semimetal material to obtain the heating element; The heating element includes a substrate layer and a heating resistance layer which are stacked; the substrate layer includes the semimetal material; the heating resistance layer includes the semimetal material and doping elements dispersed in the semimetal material, and the doping elements include one or more of group III elements and group V elements.

10. An aerosol generating device, characterized in that, It includes the heating element according to any one of claims 1 to 8.

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