Heating assembly for aerosol generating device

Abstract

A heating assembly (200) for an aerosol generating device (100) is disclosed. The heating assembly (200) comprises a heating chamber (202) having an opening (204) for receiving an aerosol substrate. A coating of an electrically insulating material (206) is formed on the surface of the heating chamber (202). A coating of an electrically conductive material (208) at least partially coats the coating of the electrically insulating material (206). The coating of the electrically conductive material (208) is configured to act as a Joule heater when current is supplied. The coating of the electrically insulating material (206) prevents any contact between the coating of the electrically conductive material (208) and the heating chamber (202).

Description

Technology Field

[0001] The present invention relates to a heating assembly for an aerosol generating device. The present disclosure is particularly applicable to a portable aerosol generating device that may be self-leaded and low temperature. Such a device may heat tobacco or other suitable aerosol-based material by conduction, convection, and / or radiation instead of burning it to generate an aerosol for inhalation. Background Technology

[0002] The popularity and use of reduced-risk or modified-risk devices (also known as vaporizers) have grown rapidly over the past few years as aids to assist habitual smokers who wish to quit using conventional tobacco products such as cigarettes, cigars, cigarillos, and rolled tobacco. In contrast to burning tobacco in conventional tobacco products, various devices and systems are available that heat or warm aerosolizable materials.

[0003] Commonly available reduced-risk or modified-risk devices are heated substrate aerosol generating devices or heat-not-burn (HNB) devices. These types of devices generate aerosols or vapors by heating an aerosol substrate (i.e., consumable)—typically containing moist leaf tobacco or other suitable aerosolizable material—to a temperature typically ranging from 150°C to 300°C. By heating the aerosol substrate but not burning or burning it, they release an aerosol containing the components desired by the user but without the unwanted byproducts that occur during combustion. Additionally, the aerosol generated by heating tobacco or other aerosolizable material generally does not contain a burnt or bitter taste that may result from combustion and could be unpleasant to the user.

[0004] In known non-combustion heating devices, it is desirable to improve the efficiency of the heating process while also ensuring reliable operation of the device. It is also desirable to improve the ease of fabricating the heating assembly. means of solving the problem

[0005] According to a first aspect of the present invention, a heating assembly for an aerosol generating device is provided, the heating assembly comprises: a heating chamber having an opening for receiving an aerosol substrate; a coating of an electrically insulating material formed on the surface of the heating chamber; and a coating of an electrically conductive material that at least partially coats the coating of the electrically insulating material, wherein the coating of the electrically conductive material is configured to function as a Joule heater when current is supplied, and the coating of the electrically insulating material prevents any contact between the coating of the electrically conductive material and the heating chamber.

[0006] In this manner, the energy efficiency of the heating assembly is significantly improved. In particular, when layers of electrically insulating and electrically conductive materials are formed as coatings that form a direct bond (e.g., chemical bond) to the underlying layer, there are no air gaps or other thermal breakdown points beneath the layer that would otherwise cause heat loss. This results in improved heating and cooling times for the heating chamber, while also providing a reliable and compact heating assembly. In contrast, in conventional heating assemblies for aerosol generation devices, the heating element is typically placed on a dielectric backing film and attached to the heating chamber using a polymer wrapping, such as a heat-shrink film. The composition of this wrapped layer results in significant heat loss due to the presence of air gaps. Furthermore, the requirement to wrap the conventional assembly with a plastic film necessitates a manual production process. By utilizing a coating of electrically conductive material as the heating element, the plastic wrapping is no longer required to secure the heating layer to the heating assembly, allowing the production of the heating assembly to occur using an automated process instead of a manual one. In addition, the use of a coating instead of a separate pre-formed heating element allows for improved flexibility regarding the shape and resulting characteristics of the heating layer. For example, a coating of an electrically conductive material follows the specific morphology of the underside, in contrast to a pre-formed heating element that is not formed closely to the surface and causes poor heat transfer.

[0007] The term "coating" refers to a layer formed during the application of a coating on a substrate. For example, a coating of an electrically insulating material is formed during the application of the electrically insulating material to the surface of a heating chamber. Similarly, a coating of an electrically conductive material is formed during the application of the electrically conductive material to a coating of the electrically insulating material. Each coating does not exist as a dielectric layer prior to the application of the coating. In particular, a coating can be defined as a layer formed by the application of a liquid, vapor, or gaseous material to the underlying substrate. This contrasts with films such as PEEK or polyimide films or conventional heating tracks, which are pre-formed and exist as distinct layers prior to their application.

[0008] Preferably, a coating of an electrical insulating material is formed as a hard layer on the surface of the heating chamber. In contrast, a conventional electrical insulating film, such as PEEK or polyimide, is attached as a flexible layer on the surface of the heating chamber.

[0009] Preferably, a coating of an electrically conductive material is formed on a coating of an electrically insulating material.

[0010] Preferably, the heating chamber is tubular, and a coating of an electrically insulating material is formed on the circumferential surface of the heating chamber.

[0011] Alternatively, the heating chamber is formed as a plate or has a "C" shape. In this case, a coating of an electrically insulating material can be formed on the convex portion of the heating chamber.

[0012] Preferably, the coating of the electrically conductive material is chemically bonded to the coating of the electrically insulating material. That is, the coating of the electrically insulating conductive material (208) forms a self-chemical bond with the coating of the electrically insulating material (206), thereby eliminating the need for an adhesive or other bonding material.

[0013] Preferably, a coating of an electrically conductive material is deposited on a coating of an electrically insulating material by physical or chemical deposition.

[0014] Preferably, the coating of the electrically conductive material is a metal or a metal oxide.

[0015] In a possible alternative, the coating of the electrically conductive material is a nonmetal, preferably carbon.

[0016] Preferably, a coating of electrically conductive material is formed as a serrated pattern on a coating of electrically insulating material. In this way, the coating of electrically conductive material can maintain energy efficiency while providing a uniform heat distribution to the aerosol substrate. Furthermore, the thermal properties of the coating of electrically conductive material can be adjusted according to the operating requirements of the heating assembly by forming the coating of electrically conductive material into different patterns. Specific patterns may also be formed to provide a coating of electrically insulating material with additional functions, for example, a thermistor or antenna function. The pattern may form a single heater track or path, or two or more heater tracks or paths that can be heated independently or simultaneously.

[0017] Preferably, the coating of the electrically conductive material is formed as an unbroken surface that completely surrounds the coating of the electrically insulating material in the circumferential direction of the heating chamber. In this way, the manufacturing process is simplified, and it is ensured that the aerosol substrate contained within the heating chamber accommodates a uniform heat distribution.

[0018] Preferably, the coating of the electrically conductive material is formed as a plurality of circumferentially spaced bands extending axially along the heating chamber. In this manner, the coating of the electrically conductive material may be selectively applied, for example, by a metal evaporation process, to provide a concentrated heating zone dependent on the configuration of the heating chamber and / or the aerosol substrate. For example, the bands may be positioned corresponding to concave and / or flat zones of the heating chamber.

[0019] Preferably, the circumferential surface of the heating chamber where the coating of the electrically insulating material is formed is the outer surface of the heating chamber. In this way, the coating of the electrically conductive material is placed on the outside of the heating assembly, and during operation, heat is generated in the coating of the electrically conductive material and conducted to the heating chamber through the coating of the electrically insulating material, thereby heating the aerosol substrate contained within the heating chamber.

[0020] Preferably, the circumferential surface of the heating chamber where the coating of the electrically insulating material is formed is the inner surface of the heating chamber. The inner surface of the heating chamber is a surface facing a cavity for receiving at least a portion of the aerosol-generating article through an opening. In this way, the coating of the electrically conductive material is placed inside the heating chamber, and during operation, the aerosol substrate received inside the heating chamber interfaces with the coating of the electrically conductive material and is heated directly by the coating of the electrically conductive material.

[0021] Preferably, the heating assembly further comprises a first electrode connected to a first axial end of a coating of an electrically conductive material and a second electrode connected to a second opposing axial end of a coating of an electrically conductive material, so that when in use, current can flow from the first electrode through the coating of the electrically conductive material to the second electrode.

[0022] Preferably, the first electrode and the second electrode are each formed as rings that surround the heating chamber in a circumferential direction. In this way, electrodes of a compact and rigid configuration are provided. Furthermore, when each electrode directly interfaces with a coating of electrically conductive material around the heating chamber, a concentrated heating zone can be created.

[0023] Preferably, the heating assembly comprises local contacts of a third material on the surface of a coating of an electrically conductive material. These local contacts can form spots for easily brazing or soldering an electrical wire with a brazing material such as lead or silver. The third material is selected for its ability to be fixed, for example, as a coating and brazed with a brazing material, on the electrically conductive material. The local contacts may be gold, nickel, or other metals. The third material may be applied, for example, by electroplating.

[0024] Preferably, the coating of the electrically conductive material has a thickness of less than 100 μm. In an example, the thickness is less than 50 μm, for instance, 5 to 45 μm. In this way, a thin and energy-efficient heating layer is provided.

[0025] Preferably, the outer surface of the heating chamber has one or more concave zones extending in the axial direction of the heating chamber. In this way, the zones protrude inward toward the interior of the heating chamber, thereby increasing the level of contact between the heating chamber and the aerosol substrate contained within the heating chamber.

[0026] Preferably, a coating of an electrically conductive material is formed corresponding to one or more concave zones. In this way, the coating of the electrically conductive material can preferentially heat the portion of the aerosol substrate adjacent to the concave zone, for example, the portion of the aerosol substrate contacted by the inward protrusion. Preferably, a coating of the electrically conductive material is also formed between two or more concave zones. In this way, the coating of the electrically conductive material also heats the portion of the aerosol substrate located between the portions of the aerosol substrate contacted by the inward protrusion.

[0027] Preferably, the coating of the electrical insulating material comprises one or more of ceramics, silicon, glass, silicon oxide, carbon, and diamond-like carbon (DLC). In this manner, the coating of the electrical insulating material exhibits a high breakdown voltage and high thermal conductivity compared to, for example, polyimide, which is often used in conventional electrical insulating films. These materials also allow for the use of thin coatings, thereby providing improved heat transfer to the aerosol substrate contained within the heating chamber. This property advantageously reduces the heating and cooling times of the heating chamber and improves the energy efficiency of the heating assembly. Furthermore, these materials exhibit higher thermal stability than polyimide.

[0028] Preferably, a coating of an electrically insulating material is deposited using plasma-enhanced chemical vapor deposition. Depositing a layer of an electrically insulating material using plasma-enhanced chemical vapor deposition involves depositing a thin film containing diamond-like-carbon (DLC) or diamond using a radio frequency electric excitation source and a carrier gas containing CH4. Preferably, a coating of an electrically conductive material is deposited using one of chemical vapor deposition; physical vapor deposition; inkjet; or gravure. For example, a coating of an electrically conductive material may be applied using thermal evaporation, vacuum evaporation, metal beam evaporation, sputtering, pulsed laser deposition, chemical vapor deposition (CVD), or arc-PVD (cathode arc deposition).

[0029] Preferably, the coating of the electrically conductive material is formed as a serrated pattern on the coating of the electrically insulating material using one of etching, masking, laser cutting, or screen printing.

[0030] Preferably, the coating of the electrically conductive material comprises titanium (and optionally consists of titanium). In another example, the coating of the electrically insulating material comprises silver or silver ink (and optionally consists of silver or silver ink).

[0031] Preferably, the coating of the electrical insulating material has a thickness of 0.3 to 10 μm. In this way, the efficiency of heat transfer across the coating of the electrical insulating material is improved, ensuring that the heating chamber is properly electrically insulated.

[0032] Preferably, the heating chamber includes one or more flattened zones extending axially along the heating chamber. In this manner, the one or more flattened zones serve to compress the outer surface of the aerosol substrate contained within the heating chamber, thereby creating closer and more consistent contact between the one or more flattened zones and the aerosol substrate.

[0033] This provides improved heat transfer from the heating chamber to the aerosol substrate.

[0034] For example, the radius of the heating chamber in the direction of one or more flattened zones may be smaller than the radius of the (e.g., cylindrical) aerosol substrate contained within the heating chamber, so that one or more flattened zones compress one or more adjacent portions of the aerosol substrate. In contrast, the radius of the heating chamber in the direction of one or more curved zones (i.e., zones of the heating chamber between flattened zones that define the generally cylindrical shape of the heating chamber) may be equal to or smaller than the radius of the (e.g., cylindrical) aerosol substrate contained within the heating chamber, so that one or more curved zones do not compress adjacent portions of the aerosol substrate. Thus, advantageously, one or more airflow channels may be defined along the length of the heating chamber between one or more curved zones and the aerosol substrate.

[0035] Preferably, a coating of an electrically insulating material is formed on one or more flattened zones. Accordingly, a coating of an electrically conductive material formed on the coating of the electrically insulating material is also located adjacent to one or more flattened zones. In one example, the coating of the electrically insulating material may be formed on the inner surface of one or more flattened zones of the heating chamber. In another example, the coating of the electrically insulating material may be formed on the outer surface of one or more flattened zones of the heating chamber.

[0036] Preferably, the heating chamber includes two separable body parts.

[0037] According to a second aspect of the present invention, a method for producing a heating assembly according to a first aspect is provided.

[0038] Preferably, the manufacturing method comprises the steps of: providing a heating chamber having an opening for receiving an aerosol substrate, wherein a coating of an electrically insulating material is formed on the surface of the heating chamber; and depositing a coating of an electrically conductive material that at least partially coats the coating of the electrically insulating material, wherein the coating of the electrically conductive material is configured to act as a Joule heater when current is supplied, and the coating of the electrically insulating material prevents any contact between the coating of the conductive material and the heating chamber.

[0039] Preferably, a coating of an electrically insulating material is formed around the surface of the heating chamber by depositing a coating of an electrically insulating material around the surface of the heating chamber.

[0040] Preferably, the heating chamber is tubular, and a coating of an electrically insulating material is formed on the circumferential surface of the heating chamber.

[0041] Alternatively, the heating chamber is formed as a plate or has a "C" shape. In this case, a coating of an electrically insulating material can be formed on the convex portion of the heating chamber.

[0042] According to a third aspect of the present invention, an aerosol generating device comprising a heating assembly according to a first aspect is provided.

[0043] According to a fourth aspect of the present invention, an aerosol generating system comprising an aerosol generating device and an aerosol substrate according to a third aspect is provided. Brief explanation of the drawing

[0044] Embodiments of the present invention are now described by way of example with reference to the drawings, and in the drawings: FIG. 1 is an exemplary aerosol generating device according to an embodiment of the present invention; FIG. 2 is a schematic cross-sectional view of a heating assembly comprising a coating of an electrically insulating material and a coating of an electrically conductive material according to an embodiment of the present invention; FIG. 3 is a perspective view of a heating assembly comprising a coating of an electrically conductive material formed in a serrated pattern according to an embodiment of the present invention; FIG. 4 is a perspective view of a heating assembly comprising a coating of an electrically conductive material formed in a serrated pattern according to an embodiment of the present invention; FIG. 5 is a perspective view of a heating assembly including a coating of an electrically conductive material that completely surrounds a heating chamber in a circumferential direction according to an embodiment of the present invention; FIG. 6 is a perspective view of a heating assembly including a coating of an electrically conductive material that completely surrounds a heating chamber in a circumferential direction according to an embodiment of the present invention; FIG. 7 is a perspective view of a heating assembly comprising a coating of an electrically conductive material disposed adjacent to one or more flattened zones of a heating chamber according to an embodiment of the present invention; FIG. 8 is a perspective view of a heating assembly comprising a coating of an electrically conductive material disposed adjacent to one or more concave regions of a heating chamber according to an embodiment of the present invention; and FIGS. 9a, FIGS. 9b and FIGS. 9c are perspective views of a heating assembly comprising a coating of an electrically conductive material disposed inside a heating chamber according to an embodiment of the present invention. FIG. 10 is a perspective view of a heating assembly comprising a coating of an electrically conductive material formed in a serrated pattern on the outer surface of a heating chamber according to an embodiment of the present invention. Specific details for implementing the invention

[0045] The drawings in this specification follow a numbering convention in which first numbers or numbers correspond to drawing numbers and the remaining numbers identify elements or components of the drawings. Similar elements or components between different drawings may be identified by the use of similar numbers. For example, 206 may refer to the element "06" in Fig. 2, and a similar element may be referred to as 306 in Fig. 3. Those skilled in the art will understand that the description of the characteristics and configuration of each element may be applied equally to the corresponding elements of other embodiments.

[0046] FIG. 1 illustrates an aerosol generating device (100) according to an embodiment of the present invention. The aerosol generating device (100) is illustrated in an assembled configuration in which internal components are visible. The aerosol generating device (100) is a non-combustible heating device which may also be referred to as a tobacco-vapor device and comprises a heating assembly (200) configured to receive an aerosol substrate, e.g., a rod of aerosol generating material, e.g., a cigarette. The heating assembly (200) is operable to heat the rod of aerosol generating material without burning it to generate vapor or aerosol for inhalation by a user. Of course, those skilled in the art will understand that the aerosol generating device (100) illustrated in FIG. 1 is merely an exemplary aerosol generating device according to the present invention. Other types and configurations of tobacco-vapor products, vaporizers, or electronic cigarettes may also be used as an aerosol generating device according to the present invention.

[0047] FIG. 2 shows a schematic cross-sectional view of a heating assembly (200) according to an embodiment of the present invention. The heating assembly (200) includes a heating chamber (202), also referred to as a thermally conductive shell configured to hold an aerosol material, also referred to as a consumable, inside. In particular, the heating chamber (202) defines a substantially cylindrical cavity in which a rod of the aerosol material can be placed. The heating chamber (202) is tubular, for example, cylindrical, and has an opening (204) placed at the longitudinal end of the heating chamber (202). In use, the user can insert the aerosol material through the opening (204) of the heating chamber (202), so that the aerosol material is placed inside the heating chamber (202) and interfaces with the inner surface (201) of the heating chamber (202). The length of the heating chamber (202) can be configured so that a portion of the aerosol material protrudes through the opening (204) of the heating chamber (202), that is, outside the heating assembly (200), and can be received in the user's mouth.

[0048] The heating chamber (202) comprises a metal, preferably made of metal, so that efficient heat transfer is provided to the aerosol substrate through the side walls of the heating chamber (202) and the heating chamber (202) has sufficient structural stability and durability. Examples of suitable metals include steel, stainless steel, or aluminum.

[0049] The thickness of the (circumferential) sidewall of the heating chamber (202) is preferably 0.1 mm or less, or more preferably 0.07 to 0.09 mm. This allows for efficient heat transfer to the consumable through the sidewall of the heating chamber (202) while maintaining sufficient structural stability. The heating chamber (202) has a closed end opposite the opening (204), and the closed end preferably has a thickness of 0.2 to 0.6 mm, which adds additional structural rigidity to the heating chamber (202). A method for manufacturing the heating chamber (202) is described in PCT / EP2020 / 074147, which is concurrently pending.

[0050] Those skilled in the art will understand that the heating chamber (202) is not limited to being cylindrical. For example, the heating chamber (202) may be formed as a cubic, conical, hemispherical, or other shaped cavity and may be configured to accommodate an aerosol substrate of a complementary shape. Furthermore, in some embodiments, the heating chamber (202) may not completely surround the aerosol substrate but instead may only come into contact with a limited area of ​​the aerosol substrate.

[0051] For example, the heating chamber (202) may be substantially cylindrical, but may include one or more elongated concave regions that protrude inward to form an elongated protrusion on the inner surface (201) of the heating chamber (202), as described later with reference to FIGS. 6 and FIGS. 8. The concave regions may be created by being pushed into the outer surface (203) of the heating chamber (202) when a fluid is injected into the heating chamber (202) under pressure, thereby providing a plurality of corresponding elongated protrusions extending longitudinally on the inner surface (201) of the heating chamber.

[0052] In another example, the heating chamber (202) may be substantially cylindrical but may include one or more flattened sections extending axially of the heating chamber (202), as described later with reference to FIGS. 5 and 7. In this case, the heating chamber (202) may be configured such that a rod of aerosol material contained within the heating chamber (202) is compressed by one or more flattened sections of the heating chamber (202). Other sections of the circumferential surface of the heating chamber (i.e., parts of the heating chamber connecting one or more flattened sections) may be configured so as not to come into contact with the rod of aerosol material contained therein, thereby forming one or more airflow channels along the length of the heating chamber. A coating of an electrical insulating material (206), also referred to as an electrical insulating layer, surrounds the outer surface (203) of the heating chamber (202). In particular, the coating of the electrical insulating material (206) is adjacent to (i.e., adjacent to, in contact with) the circumferential outer surface (203) of the heating chamber (202). The coating of the electrical insulating material (206) is directly bonded to the outer surface (203) of the heating chamber (202), that is, a chemical bond is formed between the coating of the electrical insulating material (206) and the heating chamber (202). In FIG. 2, the coating of the electrical insulating material (206) is shown as extending only along a portion of the length of the outer surface (203) of the heating chamber (202). However, those skilled in the art will understand that in other embodiments, the coating of the electrical insulating material (206) may extend along the entire length of the heating chamber (202). Furthermore, those skilled in the art will understand that the coating of the electrical insulating material (206) may only partially surround the outer surface of the heating chamber (202).

[0053] The coating of the electrical insulating material (206) preferably comprises a material exhibiting a high electrical breakdown voltage (e.g., about 100 V or more) and high thermal conductivity. For example, the coating of the electrical insulating material (206) may comprise ceramic, silicon, glass, silicon oxide, carbon, or a combination thereof. In another example, the coating of the electrical insulating material (206) may comprise diamond-like-carbon (DLC) (or optionally may consist of diamond-like-carbon). Preferably, the coating of the electrical insulating material (206) has a thickness of 0.3 to 10 μm, more preferably 0.5 to 6 μm. These characteristics ensure that the heating chamber (202) is electrically insulated while providing improved heat transfer to the aerosol substrate contained within the heating chamber (202). Advantageously, the heating and cooling times of the heating chamber (202) are reduced, thereby improving the energy efficiency of the heating assembly (200).

[0054] A coating of electrically conductive material (208) is placed on top of (i.e., coated over) a coating of electrically insulating material (206). That is, the coating of electrically conductive material (208) is directly bonded to the coating of electrically insulating material (206) on the opposite side of the coating of electrically insulating material (206) toward the heating chamber (202). In this way, a chemical bond is formed between the coating of electrically conductive material (208) and the coating of electrically insulating material (206) to ensure complete adhesion between the layers.

[0055] The coating of the electrically conductive material (208) is configured to function as a Joule heater. That is, the coating of the electrically conductive material (208) is configured to emit heat in response to the flow of current. This physical effect may be referred to as Joule heating, resistive heating, or ohmic heating. When in use, power may be supplied to the coating of the electrically conductive material (208) from a power source, e.g., a battery (not shown), so that the temperature of the coating of the electrically conductive material (208) increases and thermal energy is transferred to the heating chamber (202) across the coating of the electrically insulating material (206). An aerosol substrate contained within the heating chamber (202) is conductively heated by the heating chamber (202) to produce an aerosol for inhalation by the user.

[0056] The coating of the electrically conductive material (208) preferably comprises a metal. For example, the coating of the electrically conductive material (208) may preferably comprise primarily titanium (and optionally consist of titanium). In another example, the coating of the electrically insulating material may comprise silver or silver ink (and optionally consist of silver or silver ink). In particular, the coating of silver ink may be formed by applying silver ink flakes of butyl carbitol onto the coating of the electrically insulating material, for example, by screen printing this composition and subsequently curing, for example, by curing at 340°C for 20 minutes. The coating may also comprise a carbon or metal oxide semiconductor or conductor. Examples of metal oxides are TiO2, NiO, TiN, or TiB2. The electrical conductivity of the material is 10 (at 20°C). -3 Exceeding S / m, preferably 10 2 Exceeding S / m, most preferably 10 -3 to 10 7 It is S / m.

[0057] The coating of the electrically conductive material (208) can be deposited or printed using various techniques including chemical deposition (CVD), physical deposition (PVD), thermal evaporation, vacuum evaporation, metal beam evaporation, sputtering, pulsed laser deposition, arc-PVD (cathode arc deposition), inkjet, gravure, or screen printing.

[0058] A person skilled in the art will understand that the heating chamber (202) is not a resistive heater and therefore should not receive current. Accordingly, a coating of electrical insulating material (206) advantageously allows for efficient heat transfer from the coating of electrically conductive material (208) to the heating chamber (202), while preventing a short circuit between the heating element (208) and the heating chamber (202) by preventing contact between the coating of electrically conductive material (208) and the heating chamber (202). That is, the coating of electrical insulating material (206) separates the coating of electrically conductive material (208) from the heating chamber (202) and ensures that current does not flow from the coating of electrically conductive material (208) to the heating chamber (202).

[0059] When the heating chamber (202), the coating of the electrically insulating material (206), and the coating of the electrically conductive material (208) form a direct bond with each other (i.e., they are chemically bonded at their interface), no air gap or other thermal breakdown area exists between the components. Advantageously, this limits heat loss during operation and significantly improves the energy efficiency of the heating assembly (200).

[0060] In the embodiment illustrated in FIG. 2, the coating of the electrically conductive material (208) is formed as a continuous surface that completely surrounds the coating of the electrically insulating material (206) in the circumferential direction of the heating chamber. That is, the coating of the electrically conductive material (208) covers the coating of the electrically insulating material (206) so that a portion of the coating of the electrically insulating material (206) is not exposed at least in the circumferential direction. However, as will be discussed below, in an alternative embodiment, the coating of the electrically conductive material (208) may only partially cover the coating of the electrically insulating material (206) and may be arranged in various patterns and configurations.

[0061] FIG. 3 illustrates a heating assembly (300) according to another embodiment of the present invention. In this embodiment, a coating of an electrically conductive material (308) is formed as a serpentine or spiral pattern on a coating of an electrically insulating material (306). For example, the coating of the electrically conductive material (308) may be formed by etching, masking, laser cutting, or screen printing to form the illustrated pattern. Of course, those skilled in the art will understand that the specific pattern formed by the coating of the electrically conductive material (308) may vary depending on the functional requirements of the heating assembly (300). The pattern forms an electrical path, so that when in use, current supplied to the coating of the electrically conductive material (308) travels along the electrical path and generates thermal energy.

[0062] FIG. 4 shows a heating assembly according to another embodiment of the present invention, in which a coating of an electrically conductive material (408) is formed as a serpentine pattern in a different arrangement from the pattern of FIG. 3. The coating of the electrically conductive material (408) is patterned to form a serpentine strip of the electrically conductive material across the coating of the electrically insulating material (406). The path formed by the coating of the electrically conductive material (408) serves as an electrical path to supply current and can provide a uniform heat distribution to an aerosol substrate contained within the heating chamber (402).

[0063] In another example, a coating of the electrically conductive material (308, 408) may be patterned and / or molded for one or more additional functions. For example, a coating of the electrically conductive material (308, 408) may be molded to create a specific pattern that functions, for example, as a thermistor or antenna.

[0064] FIGS. 5 and 6 illustrate two alternative embodiments in which a coating of an electrically conductive material (508, 608) is applied as a continuous surface of an electrically conductive material that completely covers a coating of an electrically insulating material (506, 606). That is, the coating of the electrically conductive material (508, 608) surrounds the heating chamber (502, 602) in a circumferential direction so that the coating of the electrically insulating material (506, 606) is not exposed.

[0065] In FIG. 5, the heating chamber (502) is a tubular member comprising two flattened sections (512) formed on opposite sides of the heating chamber (502) that extend in the axial direction of the heating chamber (502). However, those skilled in the art will understand that the number of flattened sections (512) may be three or more, and that the flattened sections (512) are spaced apart around the circumference of the heating chamber (502). The sections of the heating chamber (502) between the flattened sections (512) may be referred to as curved sections.

[0066] Advantageously, when an aerosol substrate (e.g., a cylindrical aerosol substrate) having a diameter longer than the distance between flattened sections (512) is accommodated in the heating chamber (502), the flattened sections (512) will compress adjacent sections of the aerosol substrate. Thus, an interface of the same height is formed between each flattened section (512) and the aerosol substrate, resulting in improved heat transfer. At the same time, since the diameter of the aerosol substrate may be less than the radial distance between the curved sections of the heating chamber (502), the curved sections do not come into contact with the aerosol substrate, and two airflow channels are defined along the length of the heating chamber (502) between the curved sections of the heating chamber (502) and the aerosol substrate.

[0067] The heating assembly (510) also includes two electrodes (510) (also referred to as electrical connectors) located in an axially distant region of the electrically conductive material (508), for example, at opposite ends of the electrically conductive material (508) in the axial direction of the heating chamber (502). Each electrode (510) is configured as a wire or band forming a ring that circumferentially surrounds the coating of the electrically conductive material (508) and interfaces with it. In this way, an electrical path can be formed from one electrode (510) to the other electrode (510) through the coating of the electrically conductive material (508). Thus, when current is supplied to one of the electrodes (510), the current travels through the coating of the electrically conductive material (508) and generates heat around the entire circumference of the heating chamber (502).

[0068] In FIG. 6, the heating chamber (602) is a tubular member comprising a plurality of concave sections (614), which may also be referred to as longitudinal indentations. The concave sections (614) extend parallel to the length of the heating chamber (602) and form elongated protrusions on the inner surface (601) of the heating chamber (602). That is, the protrusions protrude toward the interior of the cavity. Thus, when an aerosol material is contained within the heating chamber (602), the elongated protrusions provide increased contact with the aerosol material, thereby generating a concentrated heating effect. A coating of an electrically conductive material (608) is formed as a uniform layer over the coating of an electrically insulating material (606). In particular, the coating of the electrically conductive material (608) is also formed within the concave sections (614). Similar to FIG. 5, the heating assembly (600) includes an annular electrode (610) that surrounds and interfaces with a coating of an electrically conductive material (608). In both embodiments, when the electrode (510, 610) interfaces with a coating of an electrically conductive material (508, 608), they can create a concentrated heating area.

[0069] FIGS. 7 and 8 illustrate two alternative embodiments in which a coating of an electrically conductive material (708, 808) is formed only on selected areas of a heating chamber (702, 802). In particular, the coating of the electrically conductive material (708, 808) is formed as a plurality of circumferentially spaced bands extending in the axial direction of the heating chamber (702, 802).

[0070] In FIG. 7, the heating chamber (702) has the same shape as the heating chamber (502) of FIG. 5, but the coating of the electrically conductive material (708) (and the coating of the lower electrically insulating material (706), as shown by reference numeral (206) in FIG. 2) is located only adjacent to the flattened area (712) of the heating chamber (702) and does not extend around the entire circumference of the heating chamber (702). That is, the coating of the electrically conductive material (708) is formed as a plurality (e.g., two) axial bands that coincide with the flattened area (712) of the heating chamber (702). In this way, when current is supplied through the electrode (710), the coating of the electrically conductive material (708) provides a concentrated heating effect that preferentially heats the area of ​​the aerosol substrate contained within the heating chamber (702) adjacent to the flattened area (712). The electrode (710) is formed as a substantially annular band or wire that surrounds the heating chamber (702) and interfaces with a coating of electrically conductive material (708) on each side of the heating chamber (702) corresponding to a flattened area (712) at a point axially distant along the length of the heating chamber (702). In the illustrated embodiment, a coating of electrically insulating material (706) is also formed on the flattened area (712) that corresponds only to (i.e., exactly underneath) the coating of electrically conductive material (708) and does not surround the heating chamber (702). As a result, the electrode (710) is positioned so that the electrode (710) contacts only the heating chamber (702) and, in particular, the coating of electrically conductive material (708) adjacent to the flattened area (712) of the heating chamber (702). In this way, the electrode (710) does not come into direct contact with the outer surface of the heating chamber (702), and an air gap is provided between the outer surface of the heating chamber (702) and the electrode (710) around the rest of the circumference of the heating chamber (702).

[0071] However, those skilled in the art will understand that in an alternative embodiment, a coating of the electrical insulating material (706) may completely surround the heating chamber (702) in a circumferential direction. In this case, the electrode (710) may come into contact with the electrical insulating material (706) and the electrically conductive material (708) on the heating chamber (702), and particularly around the entire circumference of the heating chamber (702).

[0072] In FIG. 8, the heating chamber (802) has the same shape as the heating chamber (602) of FIG. 6, but the coating of the electrically conductive material (808) (and the coating of the lower electrically insulating material (806)) is positioned to coincide with the concave area (814) (e.g., within the concave area) and does not extend around the entire circumference of the heating chamber (802). That is, the coating of the electrically conductive material (808) is formed as a plurality of axial bands extending adjacent to the concave area (814). In this manner, when current is supplied through the electrode (810), the coating of the electrically conductive material (808) provides a concentrated heating effect that preferentially heats the aerosol substrate contained within the heating chamber (802) in the portion of the aerosol substrate adjacent to the concave area (814). That is, each portion of the aerosol substrate contacted by the elongated protrusion formed on the inner surface (801) of the heating chamber (802) receives a large amount of thermal energy. Again, the electrode (810) is formed as an annular band or wire that interfaces with a coating of an electrically conductive material (808) in a concave area (814) surrounding the heating chamber (802) and in an axially distant area along the length of the heating chamber (802).

[0073] In the illustrated embodiment, the coating of the electrically insulating material (806) is formed only within a concave area (814) that corresponds to (i.e., exactly underneath) the coating of the electrically conductive material (808) and does not surround the heating chamber (802). As a result, the electrode (810) is positioned so that the electrode (810) contacts only the heating chamber (802) and, in particular, the coating of the electrically conductive material (808) adjacent to the concave area (814) of the heating chamber (802). In particular, the electrode may be formed as a ring including a radial protrusion, for example, a small strip or tab, which is positioned circumferentially around the heating chamber and contacts the concave area (814) far from the heating chamber. In this way, the electrode (810) does not contact the outer surface of the heating chamber (802) directly, and an air gap is provided between the outer surface of the heating chamber (802) and the electrode (810) around the rest of the circumference of the heating chamber (802).

[0074] However, those skilled in the art will understand that in an alternative embodiment, a coating of electrical insulating material (806) may completely surround the heating chamber (802) in a circumferential direction. In this case, the electrode (810) may come into contact with the electrical insulating material (906) and the electrically conductive material (908) of the heating chamber (802), particularly around the entire circumference of the heating chamber (802).

[0075] The axial bands of the coating of the electrically conductive material (708, 808) can be formed using various deposition or printing techniques, such as metal evaporation or screen printing, as previously discussed.

[0076] Those skilled in the art will understand that in an alternative embodiment, a plurality of circumferentially spaced bands of electrically conductive material (708, 808) and lower electrically insulating material (706, 806) may instead be formed on the inner surface (701, 801) of each heating chamber (702, 802). For example, a coating of electrically insulating material (706) may be formed as a plurality (e.g., two) axial bands on the inner surface (701) of the flattened area (712) of the heating chamber (702). A coating of electrically conductive material (708) may be formed on the coating of electrically insulating material (706) to form a corresponding axial band and an upper axial band of electrically conductive material exposed to the interior of the heating chamber (702). Similarly, a coating of electrical insulating material (806) may be formed as a plurality (e.g., two) axial bands on the inner surface (801) of the heating chamber (808) corresponding to the concave area (814). A coating of electrically conductive material (808) may be formed on the coating of electrical insulating material (806) to form a corresponding axial band and an upper axial band of electrically conductive material exposed to the interior of the heating chamber (802). That is, the electrically conductive material (808) protrudes into the interior of the heating chamber (802).

[0077] FIGS. 9a, 9b, and 9c illustrate various perspective views of a heating assembly (900) according to another embodiment of the present invention. In contrast to the previously illustrated embodiment, the heating assembly (900) comprises a coating of an electrically insulating material (906) formed on the inner surface (901) of a heating chamber (902). A coating of an electrically conductive material (908) is positioned over the coating of the electrically insulating material (906), such that the coating of the electrically conductive material (908) is located within the interior of the heating chamber (902). Thus, when an aerosol substrate is contained within the heating chamber (902), the coating of the electrically conductive material (908) comes into direct contact with heat and transfers heat to the aerosol substrate.

[0078] As illustrated in FIG. 9a, the coating of the electrically conductive material (908) is formed as a wavy pattern adjacent to each flattened area (912) of the heating chamber (902). However, in an alternative embodiment, the coating of the electrically conductive material (908) may be formed as a continuous surface that completely surrounds the inner surface (901) of the heating chamber (902). Furthermore, those skilled in the art will understand that the shape of the heating chamber (902) may be changed, as previously discussed.

[0079] In this embodiment, the coating of the electrical insulating material (906) is located directly beneath the coating of the electrically conductive material (908), that is, since the two coatings match exactly, the coating of the electrical insulating material (906) is not exposed. However, in an alternative embodiment, the coating of the electrically conductive material (908) may only partially cover the coating of the electrical insulating material (906). For example, the coating of the electrical insulating material (906) may extend circumferentially around the entire inner surface (901) of the heating chamber (902).

[0080] As illustrated in FIGS. 9a and 9b, the heating chamber (902) comprises two separable body parts. A coating of an electrically conductive material (908) is placed to form an electrical path that enters and exits the interior of the heating chamber (902) through the interface between the body parts. Thus, the coating of the electrically conductive material (908) can be safely connected to a power source without exposing the coating of the electrically conductive material (908) at the opening (904) of the heating chamber (902).

[0081] The separate body parts of the heating chamber may be formed from a heat-resistant polymer material, such as PEEK. These may be produced by injection molding. They may be assembled to form the heating chamber by press fitting and / or adhesive, such as ultrasonic welding or gluing. Each body may include a joining element along the assembly joint to provide appropriate guidance and fitting during assembly.

[0082] Those skilled in the art will understand that in an alternative embodiment, the heating chamber (902) may be formed as a single unit instead of a separable body part. Those skilled in the art will also understand that the heating chamber of all previous embodiments may include two separable body parts.

[0083] FIG. 10 shows a perspective view of a heating assembly (1000) according to another embodiment of the present invention. The heating assembly (1000) corresponds to the heating assembly (900) of FIG. 9a, 9b, and 9c in that a coating of an electrically conductive material (1008) is formed in a wavy pattern adjacent to each flattened area (1012) of the tubular heating chamber (1002). However, in this embodiment, a coating of an electrically insulating material (1006) is formed on the outer surface (1008) of the heating chamber (100). A coating of an electrically conductive material (1008) is formed on the coating of an electrically insulating material (1006) such that the coating of the electrically conductive material (1008) is directly above the coating of the electrically insulating material (1006) and follows the same wavy pattern.

[0084] In FIG. 10, the heating chamber (1002) is illustrated as being formed as a single unit, but those skilled in the art will understand that in an alternative embodiment, the heating chamber (1002) may also include two separable body parts as described for FIG. 9a, 9b, and 9c.

Claims

Claim 1 A heating assembly for an aerosol generating device, comprising: a heating chamber having an opening for receiving an aerosol substrate; a coating of an electrically insulating material formed on the surface of the heating chamber; and a coating of an electrically conductive material that at least partially coats the coating of the electrically insulating material, wherein the coating of the electrically conductive material is configured to function as a Joule heater when current is supplied, the coating of the electrically insulating material prevents any contact between the coating of the electrically conductive material and the heating chamber, and the coating of the electrically conductive material is deposited on the coating of the electrically insulating material by physical or chemical deposition. Claim 2 A heating assembly according to claim 1, wherein the heating chamber is tubular and the coating of the electrical insulating material is formed on the circumferential surface of the heating chamber. Claim 3 A heating assembly according to claim 1 or 2, wherein the coating of the electrically conductive material is chemically bonded to the coating of the electrically insulating material. Claim 4 delete Claim 5 A heating assembly according to claim 1 or 2, wherein the coating of the electrically conductive material is a metal, a metal oxide, or carbon. Claim 6 A heating assembly according to claim 1 or 2, wherein the coating of the electrically conductive material is formed as a serrated pattern on the coating of the electrically insulating material. Claim 7 A heating assembly according to paragraph 2, wherein the coating of the electrically conductive material is formed as an unbroken surface that completely surrounds the coating of the electrically insulating material in the circumferential direction of the heating chamber. Claim 8 A heating assembly according to paragraph 2, wherein the coating of the electrically conductive material is formed as a plurality of circumferentially spaced bands extending in the axial direction of the heating chamber. Claim 9 A heating assembly in which, in paragraph 2, the circumferential surface of the heating chamber on which the coating of the electrical insulating material is formed is the outer surface of the heating chamber. Claim 10 A heating assembly in which, in paragraph 2, the circumferential surface of the heating chamber on which the coating of the electrical insulating material is formed is the inner surface of the heating chamber. Claim 11 A heating assembly according to claim 1 or 2, further comprising a first electrode connected to a first axial end of the coating of the electrically conductive material and a second electrode connected to a second opposing axial end of the coating of the electrically conductive material, such that when in use, current can flow from the first electrode through the coating of the electrically conductive material to the second electrode. Claim 12 A heating assembly according to claim 11, wherein the first electrode and the second electrode are each formed as rings surrounding the heating chamber in a circumferential direction. Claim 13 A heating assembly according to claim 1 or 2, wherein the heating assembly comprises a local contact of a third material disposed on the surface of a coating of the electrically conductive material, and the local contact is configured to be connected to an electric wire using a brazing material. Claim 14 In claim 9, the heating assembly, wherein the outer surface of the heating chamber has one or more concave zones extending in the axial direction of the heating chamber. Claim 15 A method for manufacturing a heating assembly for an aerosol generating device, comprising the steps of: providing a heating chamber having an opening for receiving an aerosol substrate; forming a coating of an electrically insulating material on the surface of the heating chamber; and forming a coating of an electrically conductive material on the coating of the electrically insulating material, wherein the coating of the electrically conductive material at least partially coats the coating of the electrically insulating material, and the coating of the electrically conductive material is configured to function as a Joule heater when current is supplied, and the coating of the electrically insulating material prevents any contact between the coating of the electrically conductive material and the heating chamber, and the coating of the electrically conductive material is deposited on the coating of the electrically insulating material by physical or chemical deposition.

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