Heater tubes with thermal and electrical insulation

Abstract

The present invention relates to a heating assembly for an aerosol generating device. The heating assembly includes a substrate layer. The substrate layer is an electrically insulating substrate layer. The heating assembly further includes a heating element. The heating element is disposed on a first portion of the substrate layer. The substrate layer further includes a second portion where the heating element is not disposed. The substrate layer is rolled into a tubular shape such that the first portion of the substrate layer is positioned as an inner layer. The second portion of the substrate layer is positioned as an outer layer surrounding the first portion of the substrate layer. The heating element is disposed between the first portion of the substrate layer and the second portion of the substrate layer. The present invention also relates to an aerosol generating device and an aerosol generating system.

Description

[Technical field]

[0001] The present invention relates to a heating assembly for an aerosol generating device.The present invention further relates to an aerosol generating device.The present disclosure further relates to an aerosol generating system comprising an aerosol generating device and an aerosol-forming substrate. [Background technology]

[0002] It is known to provide an aerosol-generating device for generating an inhalable vapour. Such a device may heat an aerosol-forming substrate contained in an aerosol-generating article without combusting the aerosol-forming substrate. The aerosol-generating article may have a rod shape for inserting the aerosol-generating article into a heating chamber of the aerosol-generating device. The heating element of the heating assembly may typically be located in or around the heating chamber for heating the aerosol-forming substrate after the aerosol-generating article is inserted into the heating chamber of the aerosol-generating device.

[0003] The heat generated by the heating element may be inadvertently dissipated to components of the device that are not intended to be heated. Generally, dissipation of heat from the heating chamber may result in heat loss within the heating chamber, resulting in reduced heating efficiency. An excessive amount of energy may be required to heat the heating chamber to the desired temperature. At the same time, the heating element must be electrically insulated from the heating chamber to prevent shorting of the heating element.

[0004] It would be desirable to have a heating assembly for an aerosol generating device that can reduce heat loss from the heating chamber. It would be desirable to have a heating assembly that can reduce heating of an outer housing of the device held by a user. It would be desirable to have a heating assembly that can provide effective thermal insulation. It would be desirable to have a heating assembly that can provide thermal insulation at a low manufacturing cost. It would be desirable to have a heating assembly that can electrically isolate the heating element of the heating assembly from the heating chamber. It would be desirable to have a heating assembly with optimized thermal insulation and optimized electrical insulation at a low manufacturing cost. It would be desirable to have a heating assembly that can simultaneously provide thermal insulation and electrical insulation. Summary of the Invention

[0005] According to one embodiment of the present invention, a heating assembly for an aerosol generating device is provided. The heating assembly may include a substrate layer. The substrate layer may be an electrically insulating substrate layer. The heating assembly may include a heating element. The heating element may be disposed on a first portion of the substrate layer. The substrate layer may include a second portion on which the heating element is not disposed. The substrate layer may be rolled into a tubular shape such that the first portion of the substrate layer may be positioned as an inner layer. The second portion of the substrate layer may be positioned as an outer layer surrounding the first portion of the substrate layer. The heating element may be disposed between the first portion of the substrate layer and the second portion of the substrate layer.

[0006] According to one embodiment of the present invention, there is provided a heating assembly for an aerosol generating device. The heating assembly includes a substrate layer. The substrate layer is an electrically insulating substrate layer. The heating assembly further includes a heating element. The heating element is disposed on a first portion of the substrate layer. The substrate layer further includes a second portion on which the heating element is not disposed. The substrate layer is rolled into a tubular shape such that the first portion of the substrate layer is positioned as an inner layer. The second portion of the substrate layer is positioned as an outer layer surrounding the first portion of the substrate layer. The heating element is disposed between the first portion of the substrate layer and the second portion of the substrate layer.

[0007] By providing the first and second portions on the substrate layer, a single substrate layer can be used to sandwich the heating element between the two portions of the substrate layer. As a result, the heating element is protected by the portions of the substrate layer. A separate inner layer or a separate outer layer is no longer necessary. Protection of the heating element, such as one or both of thermal protection from the outside and electrical insulation from the inside, can be achieved by a single substrate layer having the inventive configuration described herein. Manufacturing costs can be reduced by using a single substrate layer. Manufacturing can be simplified by using a single substrate layer.

[0008] The electrically insulating substrate layer may be made from polyimide. The substrate layer may be configured to withstand temperatures between 220° C. and 320° C., preferably between 240° C. and 300° C., preferably about 280° C. The substrate layer may be made from Pyralux.

[0009] The substrate layer may be flexible. A flexible substrate layer has the advantage that the substrate layer can be rolled or formed into a desired shape. The desired shape is preferably a tubular shape. The flexibility of the substrate layer allows a first portion of the substrate layer to be rolled as a first step and then a second portion of the substrate layer to be rolled around the first portion as a second step. The flexibility of the substrate layer allows the first portion of the substrate layer to conform to the desired tubular shape during the first step. The flexibility of the substrate layer allows the second portion of the substrate layer to conform to the first portion of the tubular shape of the substrate layer during rolling the second portion of the substrate layer around the first portion of the substrate layer in the second step.

[0010] The substrate layer may be provided as a sheet before being rolled into the tubular shape. The substrate layer may be provided as a planar sheet before being rolled into the tubular shape. The substrate layer may be provided as a rectangular sheet before being rolled into the tubular shape. Such substrate layers in sheet form may be readily available and therefore may reduce manufacturing costs.

[0011] The substrate layer may have a length greater than the width of the substrate layer before being rolled into a tubular shape. The substrate layer may have a length that may be approximately twice the width of the substrate layer before being rolled into a tubular shape. Alternatively, the substrate layer may have a length less than the width of the substrate layer before being rolled into a tubular shape. The length and width of the substrate layer may be selected depending on one or both of the diameter of the aerosol-generating article to be heated and the length of the substrate portion of the article. The length of the substrate layer refers to the length along the longitudinal axis of the substrate layer before being rolled into a tubular shape. The width of the substrate layer refers to the width measured perpendicular to the longitudinal axis of the substrate layer and in the plane of the substrate layer before being rolled into a tubular shape.

[0012] The substrate layer may have a length twice the circumference of the tube of the heating arrangement, which is described in more detail below.

[0013] More generally, the length of the substrate layer may be selected such that, during rolling of the second portion of the substrate layer around the first portion of the substrate layer, the second portion of the substrate layer can completely surround the first portion of the substrate layer.

[0014] The length of the first portion of the substrate layer may be the same as or similar to the width of the first portion of the substrate layer. The length of the second portion of the substrate layer may be the same as or similar to the width of the second portion of the substrate layer. The dimensions of the first portion of the substrate layer may be the same as or similar to the dimensions of the second portion of the substrate layer. The length and width of the first portion of the substrate layer may be the same as or similar to the length and width of the second portion of the substrate layer.

[0015] The surface area of ​​the second portion of the substrate layer can be equal to or greater than the surface area of ​​the first portion of the substrate layer. The surface area of ​​the third surface of the second portion of the substrate layer can be equal to or greater than the surface area of ​​the second surface of the first portion of the substrate layer.

[0016] After rolling the substrate layer, the outer diameter of the first portion of the substrate layer may correspond to the inner diameter of the second portion of the substrate layer.

[0017] The heating element may comprise a heating track. The heating track may be configured to generate heat. The heating track may be an electrical resistive heating track. The heating element may comprise electrical contacts for electrically contacting the heating track. The electrical contacts may be attached to the heating track by any known means, for example by soldering or welding. A first electrical contact may be attached to a first end of the heating track and a second electrical contact may be attached to a second end of the heating track. The first end of the heating track may be a proximal end of the heating track and the second end of the heating track may be a distal end of the heating track or vice versa.

[0018] The heating track may be made from stainless steel. The heating track may be made from stainless steel with a thickness of about 50 μm. The heating track may preferably be made from stainless steel with a thickness of about 25 μm. The heating track may be made from Inconel with a thickness of about 50.8 μm. The heating track may be made from Inconel with a thickness of about 25.4 μm. The heating track may be made from copper with a thickness of about 35 μm. The heating track may be made from constantan with a thickness of about 25 μm. The heating track may be made from nickel with a thickness of about 12 μm. The heating track may be made from brass with a thickness of about 25 μm.

[0019] The heating tracks may be photoprinted onto the substrate layer. The heating tracks may be chemically etched onto the substrate layer.

[0020] The term "heat track" encompasses a single heating track. The heating element or heating track may be printed on the first portion of the substrate layer.

[0021] The heating track may be centrally located on the first portion of the substrate layer. The heating track may have a bench shape. The heating track may have a curved shape. The heating track may be flat before the substrate layer is rolled into a tubular shape. The heating track or heating element may be flexible. The heating track or heating element may conform to the tubular shape of the substrate layer when the substrate layer is rolled into a tubular shape.

[0022] The heating element may be sandwiched between a first portion of the substrate layer and a second portion of the substrate layer. After rolling the substrate layer, the first portion of the substrate layer may be disposed axially inside the heating element. After rolling the substrate layer, the second portion of the substrate layer may be disposed axially outside the heating element.

[0023] The first portion of the substrate layer may electrically insulate the heating element from the inside of a tube formed by the tubular shaped substrate layer.

[0024] The heating arrangement may include a tube, preferably a metal tube, around which the substrate layer may be wound or rolled. The metal tube is preferably a stainless steel tube. Alternatively, the tube may be a ceramic tube. The tube may define a tubular shape of the heating arrangement. An outer diameter of the tube may correspond to an inner diameter of the first portion of the substrate layer after rolling of the substrate layer.

[0025] Alternatively, the tube may be formed by providing a metal layer on a first portion of the substrate layer opposite the heating element in such a way that upon rolling of the substrate layer, the tube is formed. Typically, rolling of the substrate layer may be facilitated by rolling the substrate layer around a temporary cylindrical or conical support element. As a further alternative, the first portion of the substrate layer may be made of PEEK, which may directly form the tube.

[0026] The second portion of the substrate layer may insulate the heating element from the environment outside the tube formed by the tubular shaped substrate layer, in other words, the second portion of the substrate layer may insulate the heating element from the environment external to the heating assembly.

[0027] The heating assembly may include only a single substrate layer. The heating assembly may not include a separate insulating layer. Preferably, the substrate layer has a dual functionality of electrically insulating the heating element from the tube surrounded by a first portion of the substrate layer, and the substrate layer insulates the heating element from the environment outside the heating assembly. Because both of these functions can be accomplished by a single substrate layer, the structurally simple heating assembly reduces manufacturing costs while improving the functionality of the heating assembly.

[0028] The heating assembly may further comprise a heating chamber formed by a tube. The substrate layer may be rolled at least twice around the heating chamber, preferably around the outside of the heating chamber. Rolling the substrate layer around the heating chamber a first time means that a first portion of the substrate layer is rolled around the heating chamber. Rolling the substrate layer around the heating chamber a second time means that a second portion of the substrate layer is rolled around the first portion of the substrate layer.

[0029] The tube may be made of stainless steel. The tube may have a length of 10 mm to 35 mm, preferably 12 mm to 30 mm, preferably 13 mm to 22 mm. The tube may be a hollow tube. The hollow tube may have an inner diameter of 4 mm to 9 mm, preferably 5 mm to 6 mm, or 6.8 mm to 7.5 mm, preferably about 5.35 mm or about 7.3 mm. The tube may have a thickness of 70 μm to 110 μm, preferably 80 μm to 100 μm, preferably about 90 μm. The tube may have a cylindrical cross section. The tube may have a circular cross section.

[0030] The first portion of the substrate layer may include a first surface and an opposing second surface. The first surface of the first portion of the substrate layer may be disposed in direct contact with the heating chamber. The second surface of the first portion of the substrate layer may be in direct contact with the heating element. The second surface of the first portion of the substrate layer may be in direct contact with the second portion of the substrate layer.

[0031] Similarly, the second portion of the substrate layer may include a third surface and an opposing fourth surface. The third surface of the second portion of the substrate layer may be disposed in direct contact with the heating element. The third surface of the second portion of the substrate layer may be disposed in direct contact with the second surface of the first portion of the substrate layer. The fourth surface of the second portion of the substrate layer may form an outer surface of the heating arrangement.

[0032] The second portion of the substrate layer and one or more of the heating element may be spaced apart from the heating chamber by the first portion of the substrate layer.

[0033] The length of the first portion of the substrate layer may be equal to or less than the circumference of the tube. The first portion may be completely wrapped around the tube. The first portion may be wrapped once around the tube such that after the first portion of the substrate layer is wrapped around the tube, the surface of the tube is covered by the first portion of the substrate layer. The length of the second portion of the substrate layer may be equal to the circumference of the first portion of the substrate layer, such that the second portion covers the heating element and the first portion.

[0034] The circumference of the heating chamber may be approximately half the length of the substrate layer. The circumference of the heating chamber may be equal to the circumference of the tube forming the heating chamber.

[0035] The first portion of the substrate layer may have a length equal to or less than the circumference of the tube. The second portion of the substrate layer may have a length equal to or greater than the circumference of the tube, such that it can be wrapped at least once around the circumference of one or both of the tube and the first portion of the substrate layer. The second portion of the substrate layer may have a length equal to or greater than the circumference of the first portion of the substrate layer, such that it can be wrapped at least once around the circumference of one or both of the tube and the first portion.

[0036] The tube of the heating chamber may have a thickness of 70 μm to 110 μm, preferably 80 μm to 100 μm, preferably about 90 μm.

[0037] The heating assembly may further comprise a temperature sensor. The temperature sensor may be an NTC, Pt100, or preferably a Pt1000 temperature sensor. The temperature sensor may be welded to the heater. The temperature sensor may comprise a connection. The temperature sensor may comprise a metal connection. The connection, preferably a stainless steel connection, may be etched directly onto the substrate layer. The temperature sensor metal connection may then be welded onto the stainless steel connection of the substrate layer. This may simplify the manufacturing process. An exemplary manufacturing process is described below. The substrate layer may be laminated with a sheet of stainless steel, which results in a "sandwich" made of two layers, the bottom layer being polyimide and the top layer being a stainless steel sheet. Then, a heating track may be photoprinted on a first part of this sandwich (the stainless steel side) and at the same time, a second part of this sandwich (the stainless steel side) may be photoprinted with an electrical connection for the temperature sensor. Thus, both the heating track and the electrical connection of the temperature sensor may be photoprinted at the same time. The entire sandwich may then be chemically etched (only the stainless steel is etched, since the polyimide resists chemical etching), so that both the heating track and the stainless steel connection of the temperature sensor (here we refer to the connection on the sandwich) can be etched simultaneously in the same step. Then, in a later assembly step, the temperature sensor metal connection (which may be copper, or something else) may be welded onto the stainless steel connection located on the surface of the "flexible heater sandwich" of that second part.

[0038] The temperature sensor may be disposed on an outer surface of the second portion of the substrate layer. The temperature sensor may be disposed adjacent to the heating element and separated from the heating element by the second portion of the substrate layer.

[0039] The temperature sensor may be positioned on the second portion such that when the substrate layer is rolled, the temperature sensor may be positioned in an area corresponding to the center of the first portion. By positioning the temperature sensor in this manner, the heating element may be mapped such that the temperature sensor is positioned adjacent to the hottest portion of the heating element. The hottest portion adjacent to the temperature sensor may be the center of the first portion. The heating element may be located at the center of the first portion. The temperature sensor may be located directly adjacent to the heating element, separated from the heating element by the thickness of the second portion of the substrate layer. The temperature sensor may be precisely aligned to the hottest point of the heating track after an infrared image of the entire assembly identifies this hottest point and defines the mechanical location of this hottest point. This information may then be fed back into the heating assembly design, allowing for very precise alignment of the temperature sensor.

[0040] One or both of the adhesive layer and the glue layer may be provided on a first surface of the first portion of the base layer. In other words, the adhesive or glue layer may be provided on a surface of the first portion opposite a side on which the heating element may be disposed. The adhesive or glue layer may be configured to hold the first portion of the base layer firmly onto the outer circumference of the tube.

[0041] The adhesive layer may have a thickness of from 15 μm to 50 μm, preferably from 20 μm to 30 μm, more preferably about 25 μm.

[0042] The adhesive layer may be a silicone-based adhesive layer. The adhesive layer may include one or both of a PEEK-based adhesive and an acrylic adhesive.

[0043] One or both of an adhesive layer and a glue layer may be provided on a third surface of the second portion of the substrate layer, the adhesive layer or glue layer may be configured to securely hold the second portion of the substrate layer to the first portion of the substrate layer.

[0044] The heat shrink layer may be disposed around the heating assembly as it is rolled into a tubular shape. The heat shrink layer may be configured to shrink upon application of heat to the heat shrink layer. The heat shrink layer may hold the heating assembly tightly together. The heat shrink layer may be configured to apply a uniform inward pressure to the heating assembly. The heat shrink layer may improve contact between one or both of the tube and the first portion of the substrate layer and the first portion of the substrate layer and the second portion of the substrate layer. The heat shrink layer may hold most or all of the components of the heating assembly tightly together. The heat shrink layer may be used in place of the glue or adhesive layers described herein. Alternatively, the heat shrink layer may be used in addition to the glue or adhesive layers described herein.

[0045] The thickness of the heat shrink layer may be between 100 μm and 300 μm, preferably about 180 μm.

[0046] The heat shrink layer may be made of PEEK. The heat shrink layer may be made of or include one or more of Teflon and PTFE.

[0047] The substrate layer may have a thickness of from 15 μm to 50 μm, preferably from 20 μm to 30 μm, more preferably about 25 μm.

[0048] The heating element, preferably when made of stainless steel, may have a thickness of 12 μm to 60 μm, preferably 45 μm to 55 μm, more preferably about 50 μm. The heating track, preferably when made of stainless steel, may have a thickness of 12 μm to 60 μm, preferably 45 μm to 55 μm, more preferably about 50 μm. The heating element, preferably when made of brass, may have a thickness of 20 μm to 30 μm, preferably about 25 μm. The heating track, preferably when made of brass, may have a thickness of 20 μm to 30 μm, preferably about 25 μm.

[0049] The present invention further relates to an aerosol generating device comprising the heating assembly described herein.

[0050] The present invention further relates to an aerosol-generating system comprising an aerosol-generating device as described herein, and an aerosol-generating article comprising an aerosol-forming substrate as described herein.

[0051] The proximal end of a heating assembly according to the present invention is configured to be placed within an aerosol generation device in a direction towards the oral or downstream end of the device, and the distal end of a heating assembly according to the present invention is configured to be placed within an aerosol generation device in a direction towards the distal or upstream end of the device.

[0052] As used herein, the terms "upstream" and "downstream" are used to describe the relative location of components or parts of components of an aerosol generating device with respect to the direction in which air flows through the aerosol generating device during use. An aerosol generating device according to the invention comprises a proximal end through which the aerosol exits the device during use. The proximal end of an aerosol generating device may also be referred to as the mouth end or downstream end. The mouth end is downstream of the distal end. The distal end of an aerosol-generating article may also be referred to as the upstream end. Components or parts of components of an aerosol generating device may be described as being upstream or downstream of one another based on their relative location with respect to the airflow path of the aerosol generating device.

[0053] In all aspects of the present disclosure, the heating element may include an electrically resistive material. Suitable electrically resistive materials include, but are not limited to, semiconductors such as doped ceramics, "conductive" ceramics (e.g., molybdenum disilicide, etc.), carbon, graphite, metals, alloys, and composites made of ceramic and metallic materials. Such composites may include doped or undoped ceramics.

[0054] As described, in any of the aspects of the present disclosure, the heating element may comprise an external heating element, where "external" refers to the aerosol-forming substrate. The external heating element may take any suitable form. For example, the external heating element may take the form of one or more flexible heating foils or heating tracks on a dielectric substrate, such as polyimide. The dielectric substrate is the substrate layer. The flexible heating foils or heating tracks may be shaped to fit the periphery of the heating chamber. Alternatively, the external heating element may take the form of a metal grid, a flexible printed circuit board, a molded integrated circuit device (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed using a coating technique such as plasma deposition on a suitably shaped substrate layer. The external heating element may also be formed using a metal that has a well-defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between a first portion of the substrate layer and a second portion of the substrate layer. An external heating element formed in this manner may be used to both heat the external heating element and monitor its temperature during operation.

[0055] The heating element advantageously heats the aerosol-forming substrate by means of conduction. Alternatively, heat from either an internal or external heating element may be conducted to the substrate by a thermally conductive element.

[0056] In operation, the aerosol-forming substrate may be completely contained within the aerosol-generating device, in which case a user may puff on the mouthpiece of the aerosol-generating device. Alternatively, in operation, a smoking article containing the aerosol-forming substrate may be partially contained within the aerosol-generating device, in which case a user may puff on the smoking article directly.

[0057] The heating element may be configured as an induction heating element. The induction heating element may include an induction coil and a susceptor. Generally, the susceptor is a material that has the ability to generate heat when penetrated by an alternating magnetic field. According to the present invention, the susceptor may be conductive, or magnetic, or both conductive and magnetic. The alternating magnetic field generated by one or several induction coils heats the susceptor, which then transfers the heat to the aerosol-forming substrate so that the aerosol is formed. The heat transfer may be mainly by thermal conduction. Such heat transfer is best when the susceptor is in intimate thermal contact with the aerosol-forming substrate. When an induction heating element is employed, the induction heating element may be configured as an external heater as described herein. When the induction heating element is configured as an external heating element, the susceptor element is preferably configured as a cylindrical susceptor that at least partially surrounds the heating chamber. The heating track described herein may be configured as a susceptor. The susceptor may be disposed between a first portion of the substrate layer and a second portion of the substrate layer. The second portion of the substrate layer may be surrounded by an induction coil. The susceptor and the induction coil may be part of a heating assembly.

[0058] Preferably, the aerosol generating device comprises a power supply configured to provide power to one or both of the heating element and the heating assembly. Preferably, the power supply comprises a power source. Preferably, the power source is a battery, such as a lithium ion battery. Alternatively, the power source may be another form of charge storage device, such as a capacitor. The power source may require recharging. For example, the power source may have a capacity sufficient to allow continuous generation of aerosol for approximately six minutes, or a multiple of six minutes. In another example, the power source may have a capacity sufficient to allow a predetermined number of puffs, or discontinuous activation of the heating assembly.

[0059] The power supply may comprise control electronics. The control electronics may comprise a microcontroller. The microcontroller is preferably a programmable microcontroller. The electrical circuit may include further electronic components. The electrical circuit may be configured to regulate the supply of power to the heating assembly. Power may be supplied to the heating assembly continuously after activation of the system or may be supplied intermittently (e.g., between puffs). Power may be supplied to the heating assembly in the form of pulses of current.

[0060] The term "aerosol-forming substrate" as used herein refers to a substrate capable of releasing a volatile compound capable of forming an aerosol. The volatile compound may be released by heating or burning the aerosol-forming substrate. As an alternative to heating or burning, in some cases the volatile compound may be released by a chemical reaction or by mechanical stimulation such as ultrasound. The aerosol-forming substrate may be solid or liquid, or may include both solid and liquid components. The aerosol-forming substrate may be part of an aerosol-generating article.

[0061] As used herein, the term "aerosol-generating article" refers to an article that includes an aerosol-forming substrate capable of emitting a volatile compound capable of forming an aerosol. The aerosol-generating article may be disposable.

[0062] The term "aerosol-generating device" as used herein refers to a device that interacts with an aerosol-forming substrate to generate an aerosol. The aerosol-generating device may interact with one or both of an aerosol-generating article that includes an aerosol-forming substrate and a cartridge that includes an aerosol-forming substrate. In some examples, the aerosol-generating device may heat the aerosol-forming substrate to facilitate the release of volatile compounds from the substrate. An electrically operated aerosol-generating device may include an atomizer, such as an electric heater, for heating the aerosol-forming substrate to form an aerosol.

[0063] As used herein, the term "aerosol-generating system" refers to the combination of an aerosol-generating device and an aerosol-forming substrate. The aerosol-forming substrate forms part of an aerosol-generating article, and an aerosol-generating system refers to the combination of an aerosol-generating device and an aerosol-generating article. In an aerosol-generating system, the aerosol-forming substrate and the aerosol-generating device work together to generate an aerosol.

[0064] Below is provided a non-exhaustive list of non-limiting examples, any one or more of the features of these examples may be combined with any one or more features of other examples, embodiments, or aspects described herein.

[0065] Example A: 1. A heating assembly for an aerosol generating device, comprising: a substrate layer, the substrate layer being an electrically insulating substrate layer; a heating element disposed on the first portion of the substrate layer; the substrate layer includes a second portion in which the heating element is not disposed, A heating assembly, wherein a substrate layer is rolled into a tubular shape such that a first portion of the substrate layer is positioned as an inner layer and a second portion of the substrate layer is positioned as an outer layer surrounding the first portion of the substrate layer, and a heating element is disposed between the first portion of the substrate layer and the second portion of the substrate layer. Example B: The heating assembly of example A, wherein the substrate layer is flexible. Example C: The heating assembly of any of Examples A-B, wherein the substrate layer is provided as a sheet prior to being rolled into a tubular shape. Example D: The heating assembly of any of embodiments A-C, wherein a surface area of ​​the second portion is equal to or greater than a surface area of ​​the first portion. Example E: The heating assembly of any of embodiments A-D, wherein the heating element comprises a heating track. Example F: The heating assembly of any of Examples A-E, wherein the heating element is printed on the first portion of the substrate layer. Example G: The heating assembly of any of embodiments A-F, wherein the heating element is sandwiched between a first portion of the substrate layer and a second portion of the substrate layer. Example H: The heating assembly of any of embodiments A-G, wherein the first portion of the substrate layer electrically insulates the heating element from the inside of a tube formed by the tubular shaped substrate layer. Example I: The heating assembly of any of embodiments A-H, wherein the second portion of the substrate layer insulates the heating element from an environment external to a tube formed by the tubular shaped substrate layer. Example J: The heating assembly of any of Examples A-I, wherein the heating assembly includes only a single substrate layer and does not include a separate insulation layer. Example K: The heating assembly of any of Examples A-J, wherein the heating assembly further comprises a heating chamber formed by a tube, and wherein the substrate layer is rolled around the heating chamber, preferably around the outside of the heating chamber, at least twice. Example L: The heating assembly of example K, wherein the first portion of the substrate layer has a first surface and an opposing second surface, the first surface of the first portion of the substrate layer being positioned in direct contact with the heating chamber, and preferably the second surface being in direct contact with the second portion of the substrate layer. Example M: The heating assembly of any one of embodiments K or L, wherein the second portion of the substrate layer and one or more of the heating elements are spaced from the heating chamber by the first portion of the substrate layer. Example N: The heating assembly of any of embodiments KM, wherein the perimeter of the heating chamber is approximately half the length of the substrate layer. Example O: The heating assembly of any of embodiments A-N, wherein the heating assembly further comprises a temperature sensor. Example P: The heating assembly of embodiment O, wherein the temperature sensor is disposed on an exterior surface of the second portion of the substrate layer. Example Q: The heating assembly of any one of embodiments O or P, wherein the temperature sensor is positioned adjacent to the heating element and separated from the heating element by a second portion of the substrate layer. Example R: The heating assembly of any of Examples A-Q, wherein one or both of the adhesive layer and the glue layer are provided on the first portion of the substrate layer opposite the side on which the heating element is disposed. Example S: The heating assembly of any of embodiments A-R, wherein a heat shrink layer is disposed around the heating assembly when the heating assembly is rolled into a tubular shape. Example T: The heating assembly of example S, wherein the heat shrink layer is made of PEEK. Example U: An aerosol generating device comprising a heating assembly according to any one of Examples A to T. Example V: An aerosol generating system comprising the aerosol generating device of Example U and an aerosol-generating article comprising an aerosol-forming substrate.

[0066] Features described with respect to one embodiment may equally be applied to other embodiments of the invention. [Brief description of the drawings]

[0067] The invention will now be further described, by way of example only, with reference to the accompanying drawings in which:

[0068] [Figure 1] FIG. 1 shows a cross-sectional view of the heating assembly after it has been rolled into a tubular shape. [Diagram 2] FIG. 2 illustrates an embodiment of a heating assembly prior to being rolled into a tubular shape. [Diagram 3] FIG. 3 shows the embodiment of FIG. 2 of the heating assembly before the substrate layer of the heating assembly is rolled into a tubular shape with the tube being wrapped. [Figure 4]FIG. 4 shows a further embodiment of a temperature sensor for a heating assembly. [Diagram 5] FIG. 5 shows an aerosol generation system including an aerosol-generating device and an aerosol-forming substrate provided within the aerosol-generating article. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] FIG. 1 shows a heating assembly. The heating assembly is rolled into a tubular shape. The heating assembly includes a substrate layer 10. The substrate layer 10 includes a first portion 12 and a second portion 14. The substrate layer 10 is made from polyimide. The substrate layer 10 is flexible. The substrate layer 10 is first provided as a sheet as shown in FIGS. 2 and 3 and is then rolled into a tubular shape. The substrate layer 10 is rectangular. The length of the substrate layer 10 is approximately twice the width of the substrate layer 10.

[0070] A heating element 16 is disposed on the first portion 12. The heating element 16 is disposed between the first portion 12 of the substrate layer 10 and the second portion 14 of the substrate layer 10 after the heating assembly is rolled into a tubular shape. The heating element 16 is centrally disposed within the first portion 12.

[0071] The first portion 12 of the substrate layer 10 is configured to be rolled or wound around a tube 18. The tube 18 forms a heating chamber 20. The heating chamber 20 is a hollow interior of the tube 18. The heating chamber 20 is configured to receive an aerosol-forming substrate 46, shown in more detail in FIG. 5. Upon heating of the aerosol-forming substrate 46 in the heating chamber 20 by the action of the heating element 16, an inhalable aerosol is generated. The tube 18 is configured as a hollow cylindrical tube 18. The tube 18 is made of metal. The heating element 16 is disposed on a surface of the first portion 12 of the substrate layer 10 opposite a surface of the first portion 12 of the substrate layer 10 that contacts the tube 18. The first portion 12 of the substrate layer 10 is in direct contact with the tube 18.

[0072] A glue or adhesive layer may be provided between the first portion 12 of the substrate layer 10 and the tube 18 to improve the connection between the substrate layer 10 and the tube 18. A further glue or adhesive layer may be provided between the first portion 12 of the substrate layer 10 and the second portion 14 of the substrate layer 10 to improve the connection between the first portion 12 of the substrate layer 10 and the second portion 14 of the substrate layer 10. The first portion 12 of the substrate layer 10 is in direct contact with the second portion 14 of the substrate layer 10 except in the area where the heating element 16 is disposed. In the area of ​​the first portion 12 of the substrate layer 10 where the heating element 16 is disposed, the heating element 16 is in direct contact with the second portion 14 of the substrate layer 10.

[0073] FIG. 1 further shows a temperature sensor 38. The temperature sensor 38 is a Pt100 or Pt1000 temperature sensor 38. The temperature sensor 38 is disposed on the outside of the second portion 14 of the substrate layer 10 after the second portion 14 of the substrate layer 10 is wrapped around the first portion 12 of the substrate layer 10. The temperature sensor 38 is disposed adjacent to the heating element 16 and is separated from the heating element 16 by the thickness of the second portion 14 of the substrate layer 10. The heating element 16 is disposed in the center of the first portion 12 of the substrate layer 10. The temperature sensor 38 is disposed on the second portion 14 of the substrate layer 10 such that after wrapping, the temperature sensor 38 rests next to the heating element 16 to measure the hottest area of ​​the heating assembly during operation of the heating assembly.

[0074] Figure 2 shows the heating assembly prior to being wrapped around the tube 18 that surrounds the heating chamber 20. As seen in Figure 2, the heating assembly is provided as a sheet. A first portion 12 of the substrate layer 10 is disposed next to a second portion 14 of the substrate layer 10. A heating element 16 is centrally disposed on the first portion 12 of the substrate layer 10. A temperature sensor 38 is disposed on the second portion 14 of the substrate layer 10.

[0075] The heating assembly includes a first heating element contact area 22 and a second heating element contact area 24. The first heating element contact area 22 and the second heating element contact area 24 are disposed on the first portion 12 of the substrate layer 10. The first heating element contact area 22 and the second heating element contact area 24 are electrically connected to the heating element 16. In particular, the first heating element contact area 22 is provided in contact with a first portion of the heating element 16 and the second heating element contact area 24 is provided in contact with a second portion of the heating element 16 such that an electrical current can be provided between the first portion of the heating element 16 and the second portion of the heating element 16.

[0076] A first electrical contact 26 is provided to contact the first heating element contact area 22. A second electrical contact 28 is provided to contact the second heating element contact area 24. The first heating element contact area 22, the second heating element contact area 24, the first electrical contact 26, and the second electrical contraction are provided such that the heating element 16 is in electrical contact and electrical current can be supplied to the heating element 16. The supply of electrical current is described in conjunction with FIG. 5. A power supply 50 is configured to supply electrical energy to the heating element 16. A controller 52 (also shown in FIG. 5) is configured to contact the temperature sensor 38 and to operate the temperature sensor 38 or to receive the output of the temperature sensor 38. The operation of the heating assembly by the controller 52 may be controlled by a feedback loop that takes into account the output of the temperature sensor 38, or may be controlled by the controller 52 using a predetermined look-up table stored in the controller 52 by comparing the output of the temperature sensor 38 to the look-up table.

[0077] The heating assembly includes a first temperature sensor contact area 30 and a second temperature sensor contact area 32. The first temperature sensor contact area 30 and the second temperature sensor contact area 32 are disposed on the second portion 14 of the substrate layer 10. The heating assembly includes a third electrical contact 34 and a fourth electrical contact 36. The third electrical contact 34 is provided to contact the first temperature sensor contact area 30. The fourth electrical contact 36 is provided to contact the second temperature sensor contact area 32. The first temperature sensor contact area 30, the second temperature sensor contact area 32, the third electrical contact 34, and the fourth electrical contact are provided such that the temperature sensor 38 may be electrically contacted and operated.

[0078] 2, the temperature sensor 38 includes a third temperature sensor contact area 40 and a fourth temperature sensor contact area 42. The third temperature sensor contact area 40 and the fourth temperature sensor contact area 42 are disposed on the second portion 14 of the substrate layer 10 proximate the temperature sensor 38. The first temperature sensor contact area 30 is electrically connected to the third temperature sensor contact area 40, and the second temperature sensor contact area 32 is electrically connected to the fourth temperature sensor contact area 42.

[0079] Figure 3 shows the heating assembly of Figure 2 before the heating assembly is wrapped around the tube 18. Figure 3 also shows the tube 18 positioned next to the heating assembly prior to the wrapping process. The heating assembly can be wrapped around the tube 18 such that the first portion 12 of the substrate layer 10, on which the heating assembly is disposed, is first wrapped around the tube 18. After the first portion 12 of the substrate layer 10 is wrapped around the tube 18, the second portion 14 of the substrate layer 10, on which the temperature sensor 38 is disposed, is wrapped around the first portion 12 of the substrate layer 10.

[0080] FIG. 4 shows different embodiments for contacting the temperature sensor 38. In FIG. 4A, the third temperature sensor contact area 40 and the fourth temperature sensor contact area 42 are arranged next to each other and are away from the temperature sensor 38 in the direction of the third and fourth contacts. In contrast, in FIG. 2 and FIG. 3, the third temperature sensor contact area 40 and the fourth temperature sensor contact area 42 are arranged perpendicular to the longitudinal axis of the substrate layer 10 away from the temperature sensor 38. As a further option, as shown in FIG. 4B, the third temperature sensor contact area 40 and the fourth temperature sensor contact area 42 are along the longitudinal axis of the substrate layer 10 away from the temperature sensor 38. As a final option, shown in FIG. 4C, the temperature sensor 38 is in direct contact with the first temperature sensor contact area 30 and the second temperature sensor contact area 32.

[0081] As with the contacting of temperature sensor 38, heating element 16 may also be contacted differently than shown in FIG. 2 or FIG. 3, as specifically shown with respect to temperature sensor 38.

[0082] FIG. 5 shows an aerosol generation system including an aerosol generating device 44 and an aerosol-forming substrate 46 contained in an aerosol-generating article 48. The heating assembly described herein is disposed around a tube 18 forming a heating chamber 20 of the aerosol generating device. The aerosol-generating article 48 may be inserted into the heating chamber 20 of the aerosol generating device 44. The heating assembly may be operated to heat the aerosol-forming substrate 46 of the aerosol-generating article 48. Heating of the aerosol-forming substrate 46 to generate an inhalable aerosol. A user may be drawn directly into the proximal end 54 of the aerosol-generating article 48. The heating assembly is powered by a power supply 50. The power supply 50 may be disposed within the aerosol generating device 44. The supply of electrical energy from the power supply 50 to the heating assembly is controlled by a controller 52.

Claims

1. 1. A heating assembly for an aerosol generating device, comprising: a substrate layer, the substrate layer being an electrically insulating substrate layer, the substrate layer being a single substrate layer; a heating element disposed on a first portion of the substrate layer; the base layer includes a second portion where the heating element is not disposed, a heating assembly, the heating assembly comprising one of: the substrate layer is rolled into a tubular shape such that the first portion of the substrate layer is positioned as an inner layer and the second portion of the substrate layer is positioned as an outer layer surrounding the first portion of the substrate layer, the heating element is disposed between the first portion of the substrate layer and the second portion of the substrate layer, the heating assembly comprising one of: the substrate layer is made of polyimide, the substrate layer is made of Pyralux, and the first portion of the substrate layer is made of PEEK.

2. The heating assembly of claim 1 , wherein the substrate layer is flexible.

3. 3. The heating assembly of claim 1 or 2, wherein a surface area of ​​the second portion is equal to or greater than a surface area of ​​the first portion.

4. The heating assembly of any of claims 1 to 3, wherein the heating element comprises a heating track.

5. The heating assembly of any of claims 1 to 4, wherein the heating element is printed onto the first portion of the substrate layer.

6. The heating assembly of any of claims 1 to 5, wherein the first portion of the substrate layer electrically insulates the heating element from an inside of a tube formed by the tubular shaped substrate layer.

7. 7. The heating assembly of any one of claims 1 to 6, wherein the heating assembly further comprises a heating chamber formed by a tube, and the substrate layer is rolled around the heating chamber, preferably around the outside of the heating chamber, at least twice.

8. 8. The heating assembly of claim 7, wherein the first portion of the substrate layer comprises a first surface and an opposing second surface, the first surface of the first portion of the substrate layer being disposed in direct contact with the heating chamber, and preferably the second surface being in direct contact with the second portion of the substrate layer.

9. The heating assembly of any preceding claim, wherein the heating assembly further comprises a temperature sensor.

10. The heating assembly of claim 9 , wherein the temperature sensor is disposed on an exterior surface of the second portion of the substrate layer.

11. An aerosol generating device comprising a heating assembly according to any one of claims 1 to 10.

12. 12. An aerosol generating system comprising the aerosol generating device of claim 11 and an aerosol-generating article comprising an aerosol-forming substrate.

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