HEATING ELEMENT AND ELECTRONIC ATOMIZATION DEVICE

Abstract

 A heating element (100) and an electronic atomization device. The heating element (100) comprises: a substrate (10), which is of a longitudinal structure, and comprises a bottom end and a top end opposite the bottom end; and a heating film (20), which is arranged on the substrate (10), and comprises at least two heating sub-films (21) successively arranged in the longitudinal direction of the substrate (10), wherein the initial heating power per unit of area of the heating sub-film (21), among the heating sub-films (21), located at the top end is greater than the initial heating power per unit of area of each of the remaining heating sub-films (21); and the change rate of the heating power of the heating sub-film (21) which is located at the top end and has the largest initial heating power per unit of area is less than the change rate of the heating power of each of the remaining heating sub-films (21). Therefore, in an initial vaping stage, an aerosol is formed by means of rapid baking in a high-temperature region at a top end, and then, the heating temperatures of regions are made to gradually become close to each other, such that the whole aerosol generation matrix is uniformly and fully baked, the situation where the temperature of a certain region is overly high for a long time and thus causes burn is prevented, and the aerosol generation matrix is effectively baked and used, thereby improving the user experience.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of atomization technologies, and in particular, to a heating element and an electronic atomization device.

BACKGROUND

[0002] An aerosol is a colloidal dispersion system formed by small solid or liquid particles dispersing and suspending in a gaseous medium. For example, the aerosol can be generated by an electronic atomization device baking and heating an aerosol-generating substrate, such as a herb or paste matrix, and can be applied in different fields, deliver a inhalable aerosol to a user, which is an alternative to a conventional product form and an inhalation mode.

[0003] Generally, the aerosol-generating substrate is typically heated by a heating element in the electronic atomization device, and the aerosol-generating substrate is a matrix material capable of generating the aerosol after heated. However, in the prior art, the heating element has a disadvantage of a low aerosol formation speed. In order to increase the aerosol formation speed, in some embodiments, a high temperature region of the heating element is arranged closer to a portion for inhalation by a mouth of the user, and a position and a volume of the high temperature region are fixed, so that the aerosol-generating substrate baked at the high temperature region is prone to be charred, thus influencing a taste. In some other embodiments, in order to increase the aerosol formation speed, more heating energy is provided to the aerosol-generating substrate at an initial stage of heating, which can also increase the aerosol formation speed. However, since the initial heating energy is relatively large, a carbonization speed of the aerosol-generating substrate is over high, a number of effective inhalations is reduced, leading to that the aerosol-generating substrate cannot be effectively baked and utilized.

[0004] Therefore, the heating element in the related art tends to cause local charring when the aerosol formation speed is increased, or the aerosol-generating substrate cannot be effectively baked and utilized, thus affecting user experience.

SUMMARY

[0005] Accordingly, it is necessary to provide a heating element and an electronic atomization device, which avoid local charring while increasing an aerosol formation speed, and can effectively bake and utilize an aerosol-generating substrate, thereby improving user experience.

[0006] A heating element is provided. The heating element includes:

a base body being of a longitudinal structure and including a bottom end and a top end opposite to the bottom end; and

a heating film arranged on the base body and including at least two sub-heating films sequentially arranged in a longitudinal direction of the base body.

[0007] In at least two sub-heating films, an initial heating power per unit area of the sub-heating film located at the top end is greater than an initial heating power per unit area of each of the remaining sub-heating films. A heating power change rate of the sub-heating film which is located at the top end and has the maximum initial heating power per unit area is less than a heating power change rate of each of the remaining sub-heating films.

[0008] In the heating element, the initial heating power per unit area of the sub-heating film located at the top end is maximum, and a high-temperature region is formed at the top end in an initial stage of inhalation, so as to increase the aerosol formation speed. Moreover, the heating power change rate of the sub-heating film with the maximum initial heating power is minimum, the heating power change rates of the other sub-heating films are large. After being energized for a period of time, a variation of the heating power of the sub-heating film at the top end is small, and a variation of the heating power of the sub-heating film at a bottom end is large, so that the heating powers of the sub-heating film at the top end and the sub-heating film at the bottom end can gradually approach each other, and even the heating power of the sub-heating film at the bottom end exceeds the heating power of the sub-heating film at the top end, and then, a temperature of the sub-heating film at the bottom end can be rapidly increased to approach a temperature of the sub-heating film at the top end, so that the whole heating film can uniformly generate heat in the longitudinal direction.

[0009] In this way, the at least two sub-heating films in the heating film ultimately heat and atomize the whole aerosol-generating substrate uniformly, thus preventing charring caused by an excessively high local temperature in a region. Meanwhile, it is also not necessary to provide a large amount of heating energy to the whole aerosol-generating substrate in an initial stage of heating, which avoids a reduction of effective inhalations caused by an excessively high carbonization speed of the entire aerosol-generating substrate, so as to sufficiently bake and utilize the aerosol-generating substrate. Equivalently, an aerosol is formed by rapid baking by the high-temperature region at the top end at the initial stage of inhalation, and then, heating temperatures of regions gradually approach each other, to uniformly and fully bake the whole aerosol-generating substrate. As such, the charring caused by a long-time excessively high temperature in a region can be avoided, the aerosol-generating substrate is effectively baked and utilized, and the user experience is improved.

[0010] In an embodiment, in a direction from the bottom end to the top end, the initial heating powers per unit area of the sub-heating films are gradually increased, and the heating power change rates of the sub-heating films are gradually decreased.

[0011] In an embodiment, each sub-heating film is a thermistor, and the at least two sub-heating films are connected in series with each other.

[0012] In the direction from the bottom end to the top end, initial resistances per unit area of the sub-heating films connected in series with each other are gradually increased, and resistance change rates of the sub-heating films are gradually decreased.

[0013] In an embodiment, each sub-heating film is a thermistor. The at least two sub-heating films are connected in parallel with each other.

[0014] In the direction from the bottom end to the top end, initial resistances per unit area of the sub-heating films connected in parallel with each other are gradually decreased, and resistance change rates of the sub-heating films are gradually decreased.

[0015] In an embodiment, all the sub-heating films are made of positive temperature-coefficient-of-resistance materials, or all the sub-heating films are made of negative temperature-coefficient-of-resistance materials.

[0016] In an embodiment, some of the at least two sub-heating films located at the bottom end are made of positive temperature coefficient materials, and some of the at least two sub-heating films located at the top end are made of negative temperature coefficient materials.

[0017] In an embodiment, the heating element further includes a first electrode layer and a second electrode layer that are arranged on the base body. The first electrode layer and the second electrode layer are in contact with two of the at least two sub-heating films at head and tail ends respectively.

[0018] In an embodiment, the heating element further includes an infrared radiation layer. The infrared radiation layer is arranged on the base body and stacked on the heating film.

[0019] A projection of the infrared radiation layer to a plane where the heating film is located on covers all the sub-heating films.

[0020] In an embodiment, the base body is configured as a central heating structure. The receiving cavity is formed on an outer periphery side of the base body. The heating film and the infrared radiation layer are sequentially stacked on an outer surface of the base body from inside out.

[0021] In an embodiment, the base body is configured as a pin. The heating film and the infrared radiation layer extend in a circumferential direction of the pin. The at least two sub-heating films in the heating film are arranged in an axial direction of the pin.

[0022] Or, the base body is configured as a sheet. The heating film and the infrared radiation layer are sequentially stacked on one of a front surface and a rear surface of the sheet from inside out, and the infrared radiation layer is stacked on the other of the front surface and the rear surface of the sheet.

[0023] In an embodiment, the base body is configured as a peripheral heating structure. The receiving cavity is formed inside the base body.

[0024] An outer periphery surface of the base body is coated with the heating film. The infrared radiation layer is formed between the heating film and the base body or on an inner periphery surface of the base body facing the receiving cavity.

[0025] In an embodiment, the base body is transparent. The infrared radiation layer is stacked between the heating film and the base body.

[0026] Or, the base body is non-transparent. The infrared radiation layer is coated on the inner periphery surface of the base body.

[0027] An electronic atomization device includes the above-mentioned heating element.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to illustrate the technical solutions in the embodiments of the present application or the prior art more clearly, the drawings required for describing the embodiments or the prior art will be described briefly. Apparently, the following described drawings are merely for the embodiments of the present application, and other drawings can be derived from the disclosed drawings by those of ordinary skill in the art without any creative effort.

FIG. 1 is a schematic cross-sectional structural view of a heating member according to an embodiment of the present application.

FIG. 2 is a schematic structural view of a base body and an electrical heating film of the heating member shown in FIG. 1.

FIG. 3 is an expanded view of the electrical heating film shown in FIG. 2.

FIG. 4 is a schematic cross-sectional structural view of a heating member according to another embodiment.

FIG. 5 is a schematic cross-sectional structural view of a heating member according to another embodiment.

FIG. 6 is a schematic cross-sectional structural view of a heating member according to another embodiment.

FIG. 7 is a schematic cross-sectional structural view of the heating member according to another embodiment.

FIG. 8 is a schematic cross-sectional structural view of a heating member according to another embodiment.

FIG. 9 is a schematic cross-sectional structural view of a heating member according to another embodiment.

FIG. 10 is a schematic structural view of a heating body and an electrical heating film shown in FIG. 8 or FIG. 9.

[0029] Reference numerals: 100: heating element; 10: base body; 11: receiving cavity; 20: heating film; 21: sub-heating film; 32: first electrode layer; 34: second electrode layer; 40: insulating layer; 50: infrared radiation layer; 60: protective layer.

DETAILED DESCRIPTION

[0030] In order to make the aforementioned objects, features and advantages of the present application more apparent, the embodiments of the present application are described below in detail with reference to the accompanying drawings. In the following description, numerous specific details are set forth, so as to provide a thorough understanding of the present application. However, the present application may be implemented in many other ways different from those described herein, those skilled in the art may make similar improvements without departing from the essence of the present application, and therefore, the present application is not limited to the examples disclosed below.

[0031] In descriptions of the present application, it should be understood that, orientations or positional relationships indicated by terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "anticlockwise", "axial", "radial", "circumferential" etc. are based on orientations or positional relationships shown in the accompanying drawings, and they are used only for describing the present application and for description simplicity, but do not indicate or imply that an indicated device or element must have a specific orientation or be constructed and operated in a specific orientation, and thus cannot be understood as a limitation on the present application.

[0032] In addition, the terms such as "first" and "second" are used herein for purposes of description and are not intended to indicate or imply relative importance or significance or to imply the number of indicated technical features. Thus, the feature defined by "first" and "second" may include at least one of the features explicitly or implicitly. In the description of the present application, "a plurality of" means at least two, such as two, three, or the like, unless otherwise specified.

[0033] In the present application, unless specified or limited otherwise, the terms "mounted", "connected", "coupled", and "fixed" and the like are used broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; or may also be mechanically or electrically connected; or may also be directly connected or indirectly connected via intermediate mediums; or may also be communication or an interaction relationship of two elements, unless otherwise specified. The above terms can be understood by those skilled in the art according to specific situations.

[0034] In the present application, unless specified or limited otherwise, a first feature being "on" or "below" a second feature may mean that the first feature is in direct contact with the second feature, and the first feature is in indirect contact with the second feature via an intermediate medium formed therebetween. Furthermore, a first feature being "on," "above," or "on top of" a second feature may mean that the first feature is right or obliquely above the second feature, or just means that the first feature is at a height higher than that of the second feature. A first feature being "below," "under," or "on bottom of' a second feature may mean that the first feature is right or obliquely below the second feature, or just means that the first feature is at a height lower than that of the second feature.

[0035] It should be noted that when an element is referred to as being "fixed on" or "provided at" another element, the element may be directly located on the other element or an intermediate element may exist. When an element is considered to be "connected to" another element, the element may be directly connected to the other element or an intermediate element may exist. As used herein, the terms "vertical", "horizontal", "upper", "lower", "left", "right", or the like, are for purposes of illustration only and do not denote unique embodiments.

[0036] Referring to FIGS. 1 to 3, in an embodiment of the present application, a heating element 100 is provided for heating and atomizing an aerosol-generating substrate, and a formed aerosol can be inhaled into the mouth of a user for inhalation by the user.

[0037] The heating element 100 includes a base body 10 and a heating film 20. The base body 10 is of a longitudinal structure and includes a bottom end and a top end opposite to the bottom end. The base body 10 is configured to carry the aerosol-generating substrate. The heating film 20 is arranged on the base body 10, and includes at least two sub-heating films 21 sequentially arranged in a longitudinal direction B of the base body 10. In the sub-heating films 21, an initial heating power per unit area of the sub-heating film 21 located at the top end is greater than an initial heating power per unit area of each of the remaining sub-heating films 21, equivalently, the initial heating power of the sub-heating film 21 located at the top end is large, and the initial heating power of the sub-heating film 21 located at the bottom end is small. As such, the sub-heating film 21 located at the top end can be heated quickly and has a relatively high initial temperature, the sub-heating film 21 at the bottom end is heated slowly and has a relatively low initial temperature. The sub-heating film 21 at the top end with the high initial temperature is closer to a portion for inhalation by the user, so that the aerosol can be quickly formed during inhalation by the user, thus improving inhaling tastes of first several inhalations by the user.

[0038] In addition, a heating power change rate of the sub-heating film 21 which is located at the top end and has the maximum initial heating power per unit area is less than a heating power change rate of each of the remaining sub-heating films 21. Equivalently, the initial heating power per unit area of the sub-heating film 21 located at the top end is maximum, and a high-temperature region is formed at the top end in an initial stage of inhalation, so as to increase an aerosol formation speed. Moreover, the heating power change rate of the sub-heating film 21 with the maximum initial heating power is minimum, the heating power change rates of the other sub-heating films 21 are large. After being energized for a period of time for a period of time, a variation of the heating power of the sub-heating film 21 at the top end is small, and a variation of the heating power of the sub-heating film 21 at the bottom end is large, so that the heating powers of the sub-heating film 21 at the top end and the sub-heating film 21 at the bottom end can gradually approach each other, and even the heating power of the sub-heating film 21 at the bottom end exceeds the heating power of the sub-heating film 21 at the top end, and then, a temperature of the sub-heating film 21 at the bottom end can be rapidly increased to approach a temperature of the sub-heating film 21 at the top end. As such, the whole heating film 20 can uniformly generate heat in the longitudinal direction.

[0039] In this way, the at least two sub-heating films 21 of the heating film 20 ultimately heat and atomize the whole aerosol-generating substrate uniformly, thus preventing charring caused by an excessively high local temperature in a region. Meanwhile, it is also not necessary to provide a large amount of heating energy for the whole aerosol-generating substrate in an initial stage of heating, which avoids a reduction of effective inhalations caused by an excessively high carbonization speed of the entire aerosol-generating substrate, so as to sufficiently bake and utilize the aerosol-generating substrate. Equivalently, an aerosol is formed by rapid baking by the high-temperature region at the top end at the initial stage of inhalation, and then, heating temperatures of the various regions gradually approach each other, to uniformly and fully bake the whole aerosol-generating substrate. As such, the charring caused by a long-time excessively high temperature in a region can be avoided, the aerosol-generating substrate is effectively baked and utilized, and the user experience is improved.

[0040] It should be noted that the heating power change rate is a vector, and the heating power change rate may be a positive value or a negative value. For example, the heating power change rate of the sub-heating film 21 at the top end is a negative value, the heating power change rate of the sub-heating film 21 at the bottom end is a positive value. The heating power of the sub-heating film 21 at the bottom end is gradually increased, and the power of the sub-heating film 21 at the top end is gradually decreased. After a period of time, the heating power of the sub-heating film 21 at the bottom end can exceed the heating power of the sub-heating film 21 at the top end. For another example, the heating power change rates of the sub-heating film 21 at the top end and the sub-heating film 21 at the bottom end are both positive values, and the heating power change rate of the sub-heating film 21 at the top end is small and the increment thereof is small, after a period of time, the heating power of the sub-heating film 21 at the bottom end can exceed the heating power of the sub-heating film 21 at the top end. For another example, resistance change rates of the sub-heating film 21 at the top end and the sub-heating film 21 at the bottom end are both negative values, and the heating power change rate of the sub-heating film 21 at the top end is small (the negative value is small, and absolute value is large), that is, an absolute value of a reduction in the heating power of the sub-heating film 21 at the top end is large, after a period of time, the heating power of the sub-heating film 21 at the bottom end can exceed the heating power of the sub-heating film 21 at the top end.

[0041] Further, in a direction from the bottom end to the top end, the initial heating powers per unit area of the sub-heating films 21 are gradually increased, and the heating power change rates of the sub-heating films 21 are gradually decreased. That is, the sub-heating film 21 located at the bottom end has a small initial heating power but a large heating power change rate; the sub-heating film 21 located downstream of an inhaling airflow is closer to the portion for inhalation by the user, and has a large initial heating power that causes the aerosol to be quickly formed, but a small heating power change rate. Thus, after dynamic adjustment for a period of time, the sub-heating film 21 with a small initial heating power is heated rapidly, the sub-heating film 21 with a large initial heating power is heated slowly, and finally, heating temperatures of the sub-heating films 21 at the top end and the bottom end approach each other, so that a temperature difference between the sub-heating films 21 can be reduced, and a whole heating temperature of the heating film 20 is uniform.

[0042] Optionally, the final temperature difference between the sub-heating films 21 is in a range from 0-5 degrees; that is, the final heating temperatures of the sub-heating films 21 are the same, or the final temperature difference between the sub-heating films 21 is small, so that the entire aerosol-generating substrate is heated uniformly.

[0043] In some embodiments, the at least two sub-heating films 21 are connected in series. Initial resistances per unit area of the sub-heating films 21 connected in series are gradually increased in the direction from the bottom end to the top end. For an entire heating circuit, when the plurality of sub-heating films 21 are connected in series, the greater the resistance of each sub-heating film 21, the greater the heating power thereof. The resistance and the heating power have a directly proportional relationship. Therefore, the sub-heating film 21 at the bottom end has a small initial resistance, a low initial heating power, and a low initial heating temperature, and the sub-heating film 21 at the top end has a large initial resistance, a large initial heating power, and a high initial heating temperature, so that the aerosol flowing to the portion for inhalation by the user is quickly formed. Optionally, two adjacent sub-heating films 21 in the heating film 20 are connected in series with each other by edge lamination, or two adjacent sub-heating films 21 in the heating film 20 are connected in series by applying a conductive material.

[0044] Each sub-heating film 21 is a thermistor. Resistance change rates of the sub-heating films 21 are gradually decreased in the direction from the bottom end to the top end. That is, a resistance value of each sub-heating film 21 changes correspondingly with a change of the temperature of the sub-heating film. Moreover, the resistance change rate of the sub-heating film 21 at the bottom end is large, equivalently, the resistance of the sub-heating film 21 at the bottom end can be increased quickly, and then, the heating temperature thereof can be increased quickly; the resistance change rate of the sub-heating film 21 at the top end is small, equivalently, the sub-heating film 21 at the top end has a small resistance increasing speed, and then, the heating temperature thereof is increased slowly. As such, the heating temperature of the sub-heating film 21 at the bottom end can catch up with the heating temperature of the sub-heating film 21 at the top end after a period of time, so that the final heating temperatures of every two adjacent sub-heating films 21 approach each other, to uniformly heat the whole aerosol-generating substrate.

[0045] Specifically, taking two sub-heating films 21 as an example, the initial resistances of the two sub-heating films 21 are R1 and R2 respectively, temperature coefficients of resistance of the two sub-heating films 21 are TCR1 and TCR2 respectively, where TCR1≠TCR2. The resistance change rate of one sub-heating film 21 is R1*TCR1, and the resistance change rate of the other sub-heating film 21 is R2*TCR2. In the initial stage of inhalation, R1>R2, and R1*TCR1<R2*TCR2; after a period of time, the resistance of R2 is increased to be greater than the resistance of R1, the heating power of R2 is then increased. A heating value of R2 is increased, a temperature of R2 can be increased to approach a temperature of R1 quickly. Int this way, a temperature difference between R1 and R2 can be reduced; for example, the heating temperatures of R1 and R2 finally reach expected temperatures respectively.

[0046] It may be understood that, under a control condition of a same total power and/or a same total resistance, a difference of time for the two sub-heating films 21 to be heated to the expected temperature can be adjusted by adjusting a difference between R1 and R2 and a difference between R1*TCR1 and R2*TCR2. The larger the difference between R1 and R2, the larger the difference of time for the two sub-heating films 21 to be heated to the expected temperature; the smaller the difference between R1*TCR1 and R2*TCR2, the larger the difference of time for the two sub-heating films 21 to be heated to the expected temperature, thus allowing a design of the heating element 100 adapted for aerosol-generating substrates with different sizes.

[0047] In a specific embodiment, all the sub-heating films 21 are made of positive temperature-coefficient-of-resistance materials; that is, with an increase of the temperature, the resistance of each sub-heating film 21 is increased gradually, and the heating power of each sub-heating film 21 is increased gradually. In addition, the sub-heating film 21 at the top end has a small resistance change rate and a small increase of the heating power, and the sub-heating film 21 at the bottom end has a large resistance increasing rate and a large increase of the heating power, so that the heating powers and the temperatures of the two sub-heating films with a large initial heating power difference can gradually approach each other. Optionally, various sub-heating films 21 are made of a mixture of metal Ag and glass or a silver palladium alloy, which is a positive temperature coefficient material. Appropriate temperature coefficients of resistances (TCRs) and resistivities of various sub-heating films 21 can be adjusted by the percentage of components.

[0048] In another specific embodiment, all the sub-heating films 21 are made of negative resistance coefficient materials; that is, with the increase of the temperature, the resistance of each sub-heating film 21 is decreased gradually, and the heating power of each sub-heating film 21 is reduced gradually; the sub-heating film 21 at the top end has a small resistance change rate. Since a large absolute value of a reduction of the resistance value in unit time, and a large absolute value of the reduction of the heating power, the sub-heating film 21 at the bottom end has a large resistance reduction rate, a small absolute value of a reduction of the resistance value in unit time, and a small absolute value of the reduction of the heating power. As such, the heating power of a region with a high initial temperature is decreased with a large absolute value, the heating power of a region with a low initial temperature is decreased with a small absolute value. The heating power of the region with a low initial temperature can be gradually greater than the heating power of the region with a high initial temperature, and then, the heating temperature of the region with a low initial temperature can be gradually increased at a high speed, and final heating temperatures of the two regions having a large initial heating temperature difference can gradually approach each other.

[0049] Optionally, each sub-heating film 21 is formed by fully mixing, molding, and sintering metal oxide of two or more selected from a group consisting of manganese, copper, silicon, cobalt, iron, nickel, and zinc. Alternatively, each sub-heating film 21 is made of a non-oxide material, such as silicon carbide, tin selenide, tantalum nitride, or the like, which is a negative temperature coefficient material. The appropriate TCR and resistivity can be adjusted by adjusting the percentage of components, a sintering atmosphere, a sintering temperature, and a structural state.

[0050] In still another specific embodiment, some of the at least two sub-heating films 21 located at the bottom end are made of positive temperature coefficient materials, and some of the at least two sub-heating films 21 located at the top end are made of negative temperature coefficient materials. A resistance change rate of the positive temperature coefficient material is greater than a resistance change rate of the negative temperature coefficient material; that is, the resistance of the sub-heating film 21 at the bottom end is gradually increased, the resistance of the sub-heating film 21 at the top end is gradually reduced until the resistance of the sub-heating film 21 at the bottom end is greater than that of the sub-heating film 21 at the top end. In this case, the heating power of the sub-heating film 21 at the bottom end is large, so that the temperature of the sub-heating film 21 at the bottom end can be rapidly increased to approach the temperature of the sub-heating film 21 at the top end, and therefore, the final temperature difference between the adjacent sub-heating films 21 can be reduced, and the aerosol-generating substrate can be uniformly heated and baked.

[0051] Optionally, part of the sub-heating films 21 is made of a mixture of metal Ag and glass or a silver palladium alloy, which is a positive temperature coefficient material. An appropriate TCR and a resistivity can be adjusted by the percentage of components. Still optionally, the other part of the sub-heating films 21 are formed by fully mixing, molding, and sintering metal oxide of two or more selected from a group consisting of manganese, copper, silicon, cobalt, iron, nickel, and zinc. Alternatively, each sub-heating film 21 is made of a non-oxide material, such as silicon carbide, tin selenide, tantalum nitride, or the like, which is a negative temperature coefficient material, and the appropriate TCR and resistivity can be adjusted by adjusting the percentage of components, a sintering atmosphere, a sintering temperature, and a structural state.

[0052] In some other embodiments, the at least two sub-heating films 21 are connected in parallel, and initial resistances per unit area of the sub-heating films 21 connected in parallel are gradually decreased in the direction from the bottom end to the top end. For an entire heating circuit, when the plurality of sub-heating films 21 are connected in parallel, the greater the resistance of each sub-heating film 21, the smaller the heating power thereof. The resistance and the heating power have an inversely proportional relationship. Therefore, the sub-heating film 21 at the bottom end has a large initial resistance, a low initial heating power, and a low initial heating temperature, and the sub-heating film 21 at the top end has a small initial resistance, a large heating power, and a high initial heating temperature, so that the aerosol flowing to the portion for inhalation by the user can be quickly formed. Optionally, two adjacent sub-heating films 21 in the heating film 20 are connected in parallel by applying a conductive material.

[0053] Each sub-heating film 21 is a thermistor. Resistance change rates of the sub-heating films 21 are gradually decreased in the direction from the bottom end to the top end. That is, a resistance value of each sub-heating film 21 changes correspondingly with a change of the temperature of this sub-heating film. Moreover, the resistance change rate of the sub-heating film 21 at the bottom end is large, equivalently, the resistance of the downstream sub-heating film 21 can be increased quickly, and then, the heating temperature can be increased quickly; the resistance change rate of the sub-heating film 21 at the top end is small, equivalently, the sub-heating film 21 at the top end has a small resistance increasing speed, and then, the heating temperature thereof is increased slowly. As such, the heating temperature of the sub-heating film 21 at the bottom end can catch up with the heating temperature of the sub-heating film 21 at the top end after a period of time, so that the final heating temperatures of every two adjacent sub-heating films 21 approach to each other, to uniformly heat the whole aerosol-generating substrate.

[0054] Specifically, taking two sub-heating films 21 as an example, the initial resistances of the two sub-heating films 21 are R1 and R2 respectively, temperature coefficients of resistance of the two sub-heating films 21 are TCR1 and TCR2 respectively, where TCR1≠TCR2. The resistance change rate of one sub-heating film 21 is R1*TCR1, and the resistance change rate of the other sub-heating film 21 is R2*TCR2. In the initial stage of inhalation, R1<R2, R1*TCR1<R2*TCR2; that is, the resistance of R2 is rapidly reduced, the heating power of R2 is rapidly increased until the heating power of R1 is less than the heating power of R2. A heating value of R2 is large, a temperature of R2 can be increased to approach a temperature of R1 quickly, and therefore, a temperature difference between R1 and R2 can be reduced; for example, the heating temperatures of R1 and R2 finally reach expected temperatures respectively.

[0055] It may be understood that, under a control condition of a same total power and/or a same total resistance, a difference of time for the two sub-heating films 21 to be heated to the expected temperature can be adjusted by adjusting a difference between R1 and R2 and a difference between R1*TCR1 and R2*TCR2. The larger the difference between R1 and R2, the larger the difference of time for the two sub-heating films 21 to be heated to the expected temperature; the smaller the difference between R1*TCR1 and R2*TCR2, the larger the difference of time for the two sub-heating films 21 to be heated to the expected temperature, thus allowing a design of the heating element 100 adapted for aerosol generating substrates with different sizes.

[0056] In a specific embodiment, all the sub-heating films 21 are made of positive temperature-coefficient-of-resistance materials; that is, with an increase of the temperature, the resistance of each sub-heating film 21 is increased gradually, and the heating power of each sub-heating film 21 is decreased gradually. In addition, the sub-heating film 21 at the bottom end has a small resistance change rate and a small decrease of the heating power, and the sub-heating film 21 at the top end has a large resistance increasing rate and a large decrease of the heating power, so that the heating powers and the temperatures of the two sub-heating films with a large initial heating power difference can gradually approach each other.

[0057] Optionally, various sub-heating films 21 are made of a mixture of metal Ag and glass or a silver palladium alloy, which is a positive temperature coefficient material. An appropriate TCR and a resistivity can be adjusted by the percentage of components.

[0058] In another specific embodiment, all the sub-heating films 21 are made of negative resistance coefficient materials; that is, with the increase of the temperature, the resistance of each sub-heating film 21 is decreased gradually, and the heating power of each sub-heating film 21 is increased gradually. In addition, the sub-heating film 21 at the bottom end has a small resistance change rate, a large reduction of the resistance value in unit time, and a large absolute value of the increase of the heating power. The sub-heating film 21 at the top end has a large resistance reduction rate, a small reduction of the resistance value in unit time, and a small absolute value of the increase of the heating power. As such, the heating power of a region with a high initial temperature is increased with a small absolute value, the heating power of a region with a low initial temperature is increased with a large absolute value. The heating power of the region with a low initial temperature can be gradually greater than the heating power of the region with a high initial temperature, and then, the heating temperature can be increased at a high speed, and final heating temperatures of the two regions having a large initial heating temperature difference can gradually approach each other.

[0059] Optionally, each sub-heating film 21 is formed by fully mixing, molding, and sintering metal oxide of two or more selected from a group consisting of manganese, copper, silicon, cobalt, iron, nickel, and zinc. Alternatively, each sub-heating film 21 is made of a non-oxide material, such as silicon carbide, tin selenide, tantalum nitride, or the like, which is a negative temperature coefficient material. The appropriate TCR and resistivity can be adjusted by adjusting the percentage of components, a sintering atmosphere, a sintering temperature, and a structural state.

[0060] In still another specific embodiment, some of the at least two sub-heating films 21 located at the bottom end are made of positive temperature coefficient materials, and some of the at least two sub-heating films 21 located at the top end are made of negative temperature coefficient materials. The initial resistance of the sub-heating film 21 at the bottom end is greater than the initial resistance of the downstream sub-heating film 21. A resistance change rate of the positive temperature coefficient material is greater than a resistance change rate of the negative temperature coefficient material; that is, the sub-heating film 21 at the top end has a gradually increased resistance and a gradually reduced heating power, and the sub-heating film 21 at the bottom end has a gradually decreased resistance and a gradually increased heating power until the heating power of the sub-heating film 21 at the top end is less than the heating power of the sub-heating film 21 at the bottom end. In this case, the heating power of the sub-heating film 21 at the bottom end is large, so that the temperature of the sub-heating film 21 at the bottom end can be rapidly increased to approach the temperature of the sub-heating film 21 at the top end, and therefore, the final temperature difference between the adjacent sub-heating films 21 can be reduced, and the aerosol-generating substrate can be uniformly heated and baked.

[0061] Optionally, part of the sub-heating films 21 is made of a mixture of metal Ag and glass or a silver palladium alloy, which is a positive temperature coefficient material. An appropriate TCR and a resistivity can be adjusted by the percentage of components. Still optionally, the other part of the sub-heating films 21 are formed by fully mixing, molding, and sintering metal oxide of two or more selected from a group consisting of manganese, copper, silicon, cobalt, iron, nickel, and zinc. Alternatively, each sub-heating film 21 is made of a non-oxide material, such as silicon carbide, tin selenide, tantalum nitride, or the like, which is a negative temperature coefficient material, and the appropriate TCR and resistivity can be adjusted by adjusting the percentage of components, a sintering atmosphere, a sintering temperature, and a structural state.

[0062] In some embodiments, the heating element 100 further includes a first electrode layer 32 and a second electrode layer 32 that are arranged on the base body 10. The first electrode layer 32 and the second electrode layer 34 are in contact with two of the at least two sub-heating films 20 at head and tail ends respectively. In this way, the first electrode layer 32 and the second electrode layer 34 are respectively arranged at the head and tail ends of the whole sub-heating films 21, to form connection terminals configured for connecting the heating film 20 to the outside, thereby facilitating power supply to the heating film 20. Moreover, all the sub-heating films 21 only require the first electrode layer 32 and the second electrode layer 34 at the head end and the tail end, so that an occupied space is small, additional electrodes are avoided, a lead wire and circuit cost can be reduced, and the structure is particularly suitable for heating an aerosol-generating substrate with a small size.

[0063] In some embodiments, the heating element 100 further includes an infrared radiation layer 50. The infrared radiation layer 50 is arranged on the base body 10 and stacked on the heating film 20. A projection of the infrared radiation layer 50 to a plane where the heating film 20 is located covers all the sub-heating films 21. That is, the infrared radiation layer 50 has at least two radiation regions corresponding to the at least two sub-heating films 21 respectively. The radiation regions can generate infrared radiation of different degrees according to the heating temperatures of the corresponding sub-heating films 21, so that the aerosol substrate can be segmentally heated.

[0064] In this way, on the one hand, the aerosol-generating substrate may be heated and atomized by the infrared radiation, such that the heating element 100 can realize a heating burning-free baking mode, and a content of harmful substances in the aerosol can be reduced. On the other hand, the infrared radiation degree is in direct proportion to a heated temperature, and after the heating temperature of the heating film 20 is set segmentally, the infrared radiation degree can be correspondingly set segmentally, so that the radiation degree of the infrared radiation region corresponding to the downstream sub-heating film 21 is high, the aerosol can be formed after the aerosol-generating substrate close to a nozzle is rapidly heated, and the aerosol formation speed during initial stage of inhalation is increased. In addition, in the subsequent stages of inhaling process, the temperatures of the sub-heating films 21 gradually approach to each other, and then, the infrared radiation degrees of the regions on the infrared radiation layer 50 corresponding to the sub-heating films 21 approach to each other, so that the radiation degrees of the regions of the infrared radiation layer 50 approach to each other, and the whole aerosol-generating substrate is uniformly and fully baked. In this way, an influence on a taste by charring caused by an over high temperature in a certain region for a long time is prevented, it can also be avoided that a carbonization speed is overhigh due to application of high initial energy to the whole aerosol-generating substrate, the aerosol-generating substrate can be fully utilized, and the number of inhalations can be effectively guaranteed.

[0065] In some embodiments, the base body 10 is made of a high temperature resistant material, such as quartz glass, mica, steel, ceramic, or the like. The first electrode and the second electrode are made of a metal material with high electric conductivity, such as silver, gold, copper, or an alloy containing gold, silver, and copper. The infrared radiation layer 50 is made of at least one of a perovskite material, a spinel material, carbide, silicide, nitride, oxide, a rare earth material or the like, having high infrared emissivity.

[0066] Referring to FIGS. 1 to 5, in some embodiments, the base body 10 is configured as a peripheral heating structure. A receiving cavity 11 is formed in the base body 10. In actual use, the aerosol-generating substrate may be placed within the receiving cavity 11 in the base body 10, so that the base body 10 surrounds the aerosol-generating substrate, and the aerosol-generating substrate is heated and atomized from a periphery thereof. An outer periphery surface of the base body 10 is coated with the heating film 20. The infrared radiation layer 50 is formed between the heating film 20 and the base body 10 or on an inner periphery surface of the base body 10 facing the receiving cavity 11. In this way, after the base body 10 is heated by the heating film 20 located on the outer periphery surface, the infrared radiation layer 50 located on an inner side of the heating film 20 generates infrared radiation, so that the aerosol-generating substrate in the receiving cavity 11 of the base body 10 is heated and atomized, which can increase the aerosol formation speed of the aerosol-generating substrate in the initial stage of inhalation. Meanwhile, the aerosol-generating substrate is uniformly and fully baked in the subsequent stages of inhaling process, thus improving the user experience.

[0067] Referring to FIG.S 4 and 5, in a specific embodiment, the base body 10 is transparent, the infrared radiation layer 50 is stacked between the heating film 20 and the base body 10. Infrared rays radiated by the infrared radiation layer 50 can be transmitted through the base body 10 to heat and atomize the aerosol-generating substrate received inside the base body 10. As such, the infrared radiation layer 50 can perform infrared radiation after heated quickly, thereby further improving an atomization efficiency. Referring to FIG. 4, optionally, the infrared radiation layer 50 is an insulating infrared radiation layer 50. Referring to FIG. 5, further optionally, the infrared radiation layer 50 is a non-insulating layer, and an insulating layer 40 is arranged between the infrared radiation layer 50 and the heating film 20 to prevent conduction between the heating film 20 and the infrared radiation layer 50.

[0068] It may be understood that when the base body 10 is transparent, the infrared radiation layer 50 can also be arranged on the inner periphery surface of the base body 10, so that after the base body 10 is heated by the heating film 20 on the outer periphery surface, the infrared radiation layer 50 is heated to emit the infrared rays to heat and atomize the aerosol-generating substrate received inside the base body 10.

[0069] Referring to FIG. 1, in another specific embodiment, the base body 10 is non-transparent, and the infrared rays cannot be transmitted through the base body 10. The infrared radiation layer 50 is coated on the inner periphery surface of the base body 10 facing the receiving cavity 11, so that after the base body 10 is heated by the heating film 20 on the outer periphery surface, the infrared radiation layer 50 is heated to emit the infrared rays to heat and atomize the aerosol-generating substrate received inside the base body 10.

[0070] Referring to FIGS. 6 to 10, in some embodiments, the base body 10 is configured as a central heating structure, and the heating film 20 and the infrared radiation layer 50 are sequentially stacked on an outer surface of the base body 10 from inside out. In use, the aerosol-generating substrate is inserted onto an outer periphery of the base body 10, and when the heating film 20 and the infrared radiation layer 50 on the outer periphery of the base body 10 work, the aerosol-generating substrate is heated and atomized from the inside of the aerosol-generating substrate.

[0071] Referring to FIGS. 6 to 7, in a specific embodiment, the base body 10 is configured as a pin, the heating film 20 and the infrared radiation layer 50 extend in a circumferential direction of the pin. The at least two sub-heating films 21 in the heating film 20 are sequentially arranged in an axial direction of the pin. As such, the heating film 20 and the infrared radiation layer 50 are sequentially arranged on an outer periphery surface of the pin from inside out. The infrared radiation layer 50 generates infrared radiation outwards after the heating film 20 at the bottom generates heat, so as to heat and bake the aerosol-generating substrate sleeved on the outer periphery of the pin, so that the aerosol can be rapidly formed in the initial stage of inhalation, and the whole aerosol-generating substrate can be evenly and fully baked in a later period, thereby improving the use experience of the user.

[0072] Referring to FIG. 6, optionally, the base body 10 is an insulator, and the heating film 20 is directly formed on the base body 10. Referring to FIG. 7, optionally, the base body 10 is a conductor, and an insulating layer 40 is arranged between the base body 10 and the heating film 20 to prevent conduction between the heating film 20 and the base body 10.

[0073] Further, the infrared radiation layer 50 is coated with a protective layer 60. The protective layer 60 serves as an outermost layer to protect film structures on the outer surface of the base body 10.

[0074] Referring to FIGS. 8 to 10, in another specific embodiment, the base body 10 is configured as a sheet. The heating film 20 and the infrared radiation layer 50 are sequentially stacked on one of a front surface and a rear surface of the sheet from inside out, and the infrared radiation layer 50 is stacked on the other of the front surface and the rear surface of the sheet. After the base body 10 is configured as a sheet, the heating film 20 can be formed on only one surface of the sheet, and balanced heating can be realized on the other surface of the sheet under the action of heat conduction, so that the infrared radiation layers 50 coated on the front and rear surfaces of the sheet can be heated to radiate infrared rays outwards to heat the aerosol generating matrices on the front and rear surfaces of the sheet.

[0075] Specifically, the base body 10 is made of a material with high thermal conductivity, such as stainless steel, ceramic, or the like. When one surface of the sheet is heated, the other surface can also be heated rapidly. Referring to FIG. 8, optionally, the base body 10 is an insulator, and the heating film 20 is directly formed on the base body 10. Referring to FIG. 9, further optionally, the base body 10 is a conductor, and front and rear surfaces of the base body 10 are coated with innermost insulating layers 40 to prevent conduction between the heating film 20 and the base body 10.

[0076] Further, the infrared radiation layer 50 is coated with a protective layer 60. The protective layer 60 serves as an outermost layer to protect film structures on the outer surface of the base body 10. Specifically, the infrared radiation layer 50 is an insulating infrared radiation layer.

[0077] Referring to FIG. 10, in some embodiments, the heating film 20 may have a U-shaped structure. An open end 22 of the U-shaped structure is located at a bottom end a1 of the base body 10, and a closed end 23 of the U-shaped structure is located at a top end a2 of the base body 10. The electrical heating film 20 includes a sub-heating film 21 located at the closed end of the U-shaped structure and another sub-heating film 21 located at the open end of the U-shaped structure. Certainly, in other embodiments, the electrical heating film 20 may also have other shapes, such as a shape covering the entire surface of the base body 10, or the like, which is not limited herein.

[0078] In any of the embodiments of the present application, the base body 10 is configured as a central heating structure or a peripheral heating structure. The infrared radiation layer 50 is arranged at a suitable position according to the structure of the base body 10. The base body 10 is designed as an infrared heating body having a significant infrared radiation heating effect, which can improve a heating efficiency of the heating element 100. Moreover, the infrared radiation layer 50 may be configured as an insulating layer 40 or a non-insulating layer. When the infrared radiation layer 50 is configured as a non-insulating layer, the insulating layer 40 is additionally arranged between the infrared radiation layer 50 and the heating film 20 to prevent conduction and electric leakage of the heating element 100.

[0079] In an embodiment of the present application, an electronic atomization device is further provided. The electronic atomization device includes the above-mentioned heating element 100, which enables the electronic atomization device to rapidly form an aerosol-generating substrate during an initial stage of inhalation, thus improving tastes of first several inhalations by the user. Furthermore, the aerosol-generating substrate may be heated and atomized uniformly and fully during subsequent inhalations, so as to prevent charring caused by a long-time excessively high local temperature of the aerosol-generating substrate, and avoid that excessive heating energy is provided for the whole aerosol-generating substrate in the initial stage of inhalation to increase the carbonization speed of the aerosol-generating substrate, so that the aerosol-generating substrate can be fully baked and heated, which can effectively guarantee the number of inhalations.

[0080] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features are described in the embodiments. However, as long as there is no contradiction in the combinations of these technical features, the combinations should be considered as in the scope of the specification.

[0081] The above-described embodiments are only several implementations of the present application, and the descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present application. It should be understood by those of ordinary skill in the art that various modifications and improvements can be made without departing from the concept of the present application, and all fall within the protection scope of the present application. Therefore, the patent protection of the present application shall be defined by the appended claims.

Claims

1. A heating element, comprising:

a base body being of a longitudinal structure and comprising a bottom end and a top end opposite to the bottom end; and

a heating film arranged on the base body and comprising at least two sub-heating films sequentially arranged in a longitudinal direction of the base body;

wherein in at least two sub-heating films, an initial heating power per unit area of the sub-heating film located at the top end is greater than an initial heating power per unit area of each of the remaining sub-heating films; and a heating power change rate of the sub-heating film which is located at the top end and has the maximum initial heating power per unit area is less than a heating power change rate of each of the remaining sub-heating films.

2. The heating element according to claim 1, wherein in a direction from the bottom end to the top end, the initial heating powers per unit area of the sub-heating films are gradually increased, and the heating power change rates of the sub-heating films are gradually decreased.

3. The heating element according to claim 2, wherein each sub-heating film is a thermistor, and the at least two sub-heating films are connected in series with each other;
in the direction from the bottom end to the top end, initial resistances per unit area of the sub-heating films connected in series with each other are gradually increased, and resistance change rates of the sub-heating films are gradually decreased.

4. The heating element according to claim 2, wherein each sub-heating film is a thermistor, and the at least two sub-heating films are connected in parallel with each other;
in the direction from the bottom end to the top end, initial resistances per unit area of the sub-heating films connected in parallel with each other are gradually decreased, and resistance change rates of the sub-heating films are gradually decreased.

5. The heating element according to claim 3 or 4, wherein all the sub-heating films are made of positive temperature-coefficient-of-resistance materials, or all the sub-heating films are made of negative temperature-coefficient-of-resistance materials.

6. The heating element according to claim 3 or 4, wherein some of the at least two sub-heating films located at the bottom end are made of positive temperature coefficient materials, and some of the at least two sub-heating films located at the top end are made of negative temperature coefficient materials.

7. The heating element according to claim 3 or 4, further comprising a first electrode layer and a second electrode layer that are arranged on the base body; and wherein the first electrode layer and the second electrode layer are in contact with two of the at least two sub-heating films at head and tail ends respectively.

8. The heating element according to any one of claims 1 to 4, further comprising an infrared radiation layer arranged on the base body and stacked on the heating film;
wherein a projection of the infrared radiation layer to a plane where the heating film is located on covers all the sub-heating films.

9. The heating element according to claim 8, wherein the base body is configured as a central heating structure, and the heating film and the infrared radiation layer are sequentially stacked on the outer surface of the base body from inside out.

10. The heating element according to claim 8, wherein the base body is configured as a pin; the heating film and the infrared radiation layer extend in a circumferential direction of the pin; and the at least two sub-heating films in the heating film are arranged in an axial direction of the pin; or,
the base body is configured as a sheet, with the heating film and the infrared radiation layer sequentially stacked on one of a front surface and a rear surface of the sheet from inside out, and the infrared radiation layer stacked on the other of the front surface and the rear surface of the sheet.

11. The heating element according to claim 8, wherein the base body is configured as a peripheral heating structure, and a receiving cavity is formed inside the base body;
the heating film is coated on the outer periphery surface of the base body; the infrared radiation layer is formed between the heating film and the base body or on the inner periphery surface of the base body facing the receiving cavity.

12. The heating element according to claim 11, wherein the base body is transparent, and the infrared radiation layer is stacked between the heating film and the base body; or,
the base body is non-transparent, and the infrared radiation layer is coated on the inner periphery surface of the base body.

13. An electronic atomization device, comprising the heating element according to any one of claims 1 to 12.

Drawing