Aerosol generator with a fixed heater

Abstract

To provide an electrically heated aerosol-generating device.SOLUTION: An electrically heated aerosol-generating device includes a heating assembly to heat an aerosol-forming substrate to generate an inhalable aerosol. The heating assembly includes a heater and a heater mount. The heater is substantially blade-shaped for insertion into the aerosol-forming substrate. The heater mount provides structural support to the heater and allows the heater to be disposed within the aerosol-generating device. The heater mount is formed from a moldable material molded around a portion of the heater and extends through a through-hole to couple the heater to the heater mount. The use of such a through-hole improves anchoring of the heater in the heater mount.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an electrically heated aerosol generating device comprising a heating assembly for heating an aerosol-forming substrate to generate an inhalable aerosol, the heating assembly comprising a heater and a heater mount, the heater configured to have enhanced anchoring within the heater mount. [Background technology]

[0002] There is an increasing demand for handheld aerosol generating devices that can deliver an aerosol for inhalation by a user. One particular application is for heated smoking devices in which an aerosol-forming substrate is heated to release volatile flavor compounds without burning the aerosol-forming substrate. The released volatile compounds are carried to the user in the aerosol.

[0003] Any aerosol-generating device that operates by heating an aerosol-forming substrate must include a heating assembly. Many different types of heating assemblies have been proposed for different types of aerosol-forming substrates.

[0004] One type of heating assembly that has been proposed for heated smoking devices operates by incorporating a heater into a solid aerosol-forming substrate, such as a tobacco plug. This configuration allows for direct and efficient heating of the substrate. However, this type of heating assembly presents many technical challenges, including meeting the requirements for compactness, robustness, low manufacturing costs, sufficient operating temperature, and efficient localization of the generated heat.

[0005] WO2014 / 102092 discloses a heating assembly for an aerosol generating device. The heating assembly includes a heater having a ceramic substrate and an electrically resistive track, and a heater mount formed on a holder for the heater. The heater is designed to be inserted into and removed from a solid aerosol-forming substrate.

[0006] During use, it has been observed that the tobacco plug (aerosol-forming substrate) of a smoking article often "sticks" or "adheres" to the heater of the device disclosed in WO 2014 / 102092. Pulling on the smoking article to remove the article from the device exerts a force on the heater. Repeated use means that the adhesion between the heater and the tobacco plug causes repeated pulling on the heater. This weakens the bond between the heater mount and the heater, causing the heater to loosen. It is important that the heater does not loosen within the heater mount.

[0007] Attempts have been made to improve the "anchoring" provided by overmolded heater mounts. One of these attempts involved adding friction powder to the heater to improve the anchoring built into the heater mount. However, this is not a preferred technique because heater vanes are manufactured in a clean room environment and the use of powder is generally not welcome under these conditions. Summary of the Invention

[0008] The present disclosure provides an electrically heated aerosol generating device comprising a heating assembly for heating an aerosol-forming substrate to generate an inhalable aerosol. The heating assembly includes a heater and a heater mount.

[0009] The heater is substantially blade-shaped for insertion into the aerosol-forming substrate and has a length of 10 mm to 60 mm, a width of 2 mm to 10 mm, and a thickness of 0.2 mm to 1 mm. The length is preferably 15 mm to 50 mm, and may be, for example, 18 mm to 30 mm. The length is preferably about 19 mm or about 20 mm. The width is preferably 3 mm to 7 mm, and may be, for example, 4 mm to 6 mm. The width is preferably about 5 mm. The thickness is preferably 0.25 mm to 0.5 mm. The thickness is preferably about 0.4 mm. The heater includes an electrically insulating heater substrate and an electrically resistive heating element supported by the heater substrate. A through-hole is defined through the thickness of the heater. A heater mount provides structural support for the heater and allows it to be positioned within the aerosol-generating device. The heater mount is formed from a moldable material that is molded around a portion of the heater, and the through-hole connects the heater to the heater mount. The heater may have a tapered or pointed end to facilitate insertion into the aerosol-forming substrate.

[0010] The heater mount is preferably formed in a portion of the heater that does not significantly increase in temperature during operation. This portion can be referred to as a support portion, and the resistivity of this portion can be reduced so that the heating element does not heat up significantly in the path of the operating current. The through-hole is located in the support portion.

[0011] Without the through-holes, the heater would be secured to the heater mount by a joint formed between the heater and the overmolded mount. Repeated use of the device would weaken this joint, leading to the heater loosening. The presence of the through-holes allows for the formation of a mechanical bond. The moldable material flows through the through-holes and bonds. This connection or bond resists movement of the heater even if the bond between the moldable material and the heater breaks. Additionally, the moldable material flowing through the through-holes adds an anchoring effect, preventing excessive movement of the heater within the heater mount and helping to prevent failure of the joint between the heater and heater mount.

[0012] The holes preferably have a maximum diameter of 0.8 mm to 3 mm, for example, 1 mm to 2.5 mm, e.g., 2 mm. The holes do not have to be circular. The term diameter is used to indicate the maximum diameter across the mouth of the hole. For example, the holes may be rectangular holes, and the maximum diameter may be the dimension extending from one corner of the square to the opposite corner along the diagonal.

[0013] There may be two or more through-holes defined through the thickness of the heater, with the moldable material of the heater mount extending through each of the two or more through-holes. For example, the heater retainer may have two, three, or four through-holes. The holes may be arranged in a specific pattern to provide optimal anchoring.

[0014] The heater can further include one or more outwardly extending protrusions to enhance coupling of the heater mount to the heater. The heater is substantially blade-shaped, thus having two substantially parallel ridges and two substantially parallel faces. The protrusions can extend or protrude outward from the faces or edges and further provide mechanical anchoring for the heater.

[0015] Alternatively, or in addition, the heater may further include one or more inwardly extending notches or grooves to enhance coupling of the heater mount to the heater.

[0016] Advantageously, the heater mount's moldable material may be a polymeric material, for example, polyetheretherketone (PEEK), and the heater substrate may be formed from a ceramic material, for example, zirconium or alumina.

[0017] The through holes can be formed in the heater before or after the electrically resistive heating element is formed on the heater substrate. The device can be formed by fastening or bonding the heating assembly to or within a housing.

[0018] One method of manufacturing an aerosol generating device includes the steps of providing a heater substrate having a length of 10 mm to 60 mm, a width of 2 mm to 10 mm, and a thickness of 0.2 mm to 1 mm, the heater substrate being formed of an electrically insulating material and having through holes defined through its thickness, disposing one or more electrically resistive heating elements on the heater substrate to form a heater, coupling a heater mount to the heater to form a heater assembly, the heater mount being formed from a moldable material that is molded around a portion of the heater such that the moldable material passes through the through holes, and disposing the heater assembly within a housing.

[0019] If the heater substrate is ceramic, the through holes can be formed before firing the ceramic. The through holes can be formed by machining, for example, by laser machining or drilling, after firing. The housing can include a power source, and the method can include connecting the electrical resistive heating element to the power source.

[0020] One method of manufacturing an aerosol generating device includes the steps of providing a heater substrate having a length of 10 mm to 60 mm, a width of 2 mm to 10 mm, and a thickness of 0.2 mm to 1 mm, the heater substrate being formed from an electrically insulating material; disposing one or more electrically resistive heating elements on the heater substrate to form a heater and forming through-holes through the thickness of the heater; coupling a heater mount to the heater to form a heater assembly, the heater mount being formed from a moldable material that is molded around a portion of the heater such that the moldable material passes through the through-holes; and disposing the heater assembly within a housing.

[0021] The through holes can be formed by machining, for example by laser machining or drilling. The housing can include a power source and the method can include connecting an electrically resistive heating element to the power source.

[0022] As used herein, the term "electrically heated aerosol-generating device" is used to describe a device that interacts with the aerosol-forming substrate of an aerosol-generating article to generate an aerosol. Preferably, the aerosol-generating device is a smoking device that interacts with the aerosol-forming substrate of a heated aerosol-generating article to generate an aerosol that is inhalable directly through the user's mouth into the user's lungs. Preferably, the aerosol-generating device interacts with the aerosol-generating article to cause air to flow through the aerosol-forming substrate.

[0023] The term "aerosol-forming substrate", as used herein, relates to a substrate capable of releasing volatile compounds capable of forming an aerosol. Such volatile compounds can be released by heating the aerosol-forming substrate. The aerosol-forming substrate can conveniently be part of an aerosol-generating article or a smoking article.

[0024] The terms "aerosol-generating article" and "smoking article," as used herein, refer to an article comprising an aerosol-forming substrate capable of emitting a volatile compound capable of forming an aerosol. For example, an aerosol-generating article may be a smoking article that produces an aerosol that can be inhaled directly through a user's mouth into the user's lungs. The aerosol-generating article may be disposable. A smoking article with an aerosol-forming substrate containing tobacco is called a tobacco stick.

[0025] The heater mount provides structural support for the heater and ensures that the heater mount is securely fixed within the aerosol generating device. The use of a moldable material, such as a moldable polymer, allows the heater mount to be molded around the heater, thereby holding the heater securely in place, and also allows the heater mount to be manufactured in an inexpensive manner with the desired external shape and dimensions.

[0026] The use of a polymer to hold the heater means that the temperature of the heater near the heater mount must be controlled below the temperature at which the polymer melts or degrades. At the same time, the temperature of the portion of the heater inserted into the aerosol-forming substrate must be sufficient to generate an aerosol with the desired properties during use. Therefore, it is desirable to ensure that the holding portion of the heating element, at least the portion of the heater in contact with the heater mount, remains below the maximum allowable temperature during use.

[0027] In an electrical resistance heater, the heat generated by the heater depends on the resistance of the heating element. For a given current, the higher the resistance of the heating element, the more heat is generated. It is desirable that most of the heat generated is generated by the portion of the heating element inserted into the aerosol-forming substrate, that is, the portion of the heating element supported by the heater insert or heating portion. Therefore, it may be desirable for the heater insert to support a portion of the heating element that has a higher electrical resistance per unit length than the portion of the heating element supported by the heater support portion.

[0028] Advantageously, the heating element can be made of different materials. The first portion or heating section of the heating element (i.e., the portion supported by the heater insert or heating section) can be made of a first material, and the heating element holder (i.e., the portion supported by the heater holder) can be made of a second material, the first material having a higher electrical resistance coefficient than the second material. For example, the first material can be Ni-Cr (nickel-chromium), platinum, tungsten, or alloy wire, and the second material can be gold, silver, or copper. The dimensions of the first and second portions of the heating element can also be different to lower the electrical resistance per unit length of the second portion.

[0029] The heater substrate is formed from an electrically insulating material, which may be a ceramic material such as zirconium or alumina. The heater substrate can provide mechanically stable support for the heating element over a wide temperature range and can provide a rigid structure suitable for insertion into the aerosol-forming substrate. The heater substrate can have a flat surface on which the heating element is positioned and a tapered end configured to allow insertion into the aerosol-forming substrate. The heater substrate advantageously has a thermal conductivity of 2 watts per meter per degree Kelvin or less.

[0030] Heaters with different configurations of heater element material and heater substrate material are presented in WO2014 / 102092.

[0031] The aerosol generating device preferably includes a housing defining a cavity surrounding a heater insert, the cavity being configured to receive an aerosol-forming article containing an aerosol-forming substrate, and the heater mount may form a surface closing one end of the cavity.

[0032] The device is preferably a portable or handheld device that is comfortable to hold between the fingers of one hand. The device may be substantially cylindrical in shape and have a length of 70-120 mm. The maximum diameter of the device is preferably 10-20 mm. In one embodiment, the device has a polygonal cross-section and a protruding button formed on one side. In this embodiment, the diameter of the device is 12.7-13.65 mm from one flat surface to the opposite flat surface, 13.4-14.2 mm from one edge to the opposite edge (i.e., from the intersection of two surfaces on one side of the device to the corresponding intersection on the other side), and 14.2-15 mm from the top of the button to the flat surface of the opposite button.

[0033] The device may include other heaters in addition to the heater assembly according to the first embodiment. For example, the device may include an external heater located near the periphery of the cavity. The external heater may take any suitable form. For example, the external heater may take the form of one or more flexible heating foils on a dielectric substrate such as polyimide. The flexible heating foil may be shaped to fit the periphery of the cavity. Alternatively, the external heater may take the form of a metal grid(s), a flexible printed circuit board, a molded interconnect device (MID), a ceramic heater, a flexible carbon fiber heater, or may be formed using a coating technique such as plasma deposition on a substrate of appropriate shape. The external heater may also be formed using a metal having a well-defined relationship between temperature and resistivity. In such an exemplary device, the metal may be formed as a track between two layers of suitable insulating material. The external heater thus formed may be used both to heat the external heater and to monitor its temperature during operation.

[0034] The power supply of the device may be any suitable power supply, for example, a DC voltage supply such as a battery. In one embodiment, the power supply is a lithium-ion battery. Alternatively, the power supply may be a nickel-metal hydride battery, a nickel-cadmium battery, or a lithium-based battery, such as a lithium-cobalt, lithium-iron-phosphate, lithium-titanium-oxide, or lithium-polymer battery.

[0035] The device preferably includes a control element, which may be a simple switch, or alternatively, the control element may be an electrical circuit and may include one or more microprocessors or microcontrollers.

[0036] The present disclosure provides an aerosol generation system comprising an aerosol generation device and one or more aerosol-forming articles configured to be received in a cavity of the aerosol generation device, as described above.

[0037] The aerosol-forming article may be a smoking article. In operation, the smoking article comprising the aerosol-forming substrate may be partially contained within the aerosol-generating device.

[0038] The smoking article may be substantially cylindrical in shape. The smoking article may be substantially elongated. The smoking article may also have a length and a circumference substantially perpendicular to the length. The aerosol-forming substrate may be substantially cylindrical in shape. The aerosol-forming substrate may be substantially elongated. The aerosol-forming substrate may also have a length and a circumference substantially perpendicular to the length.

[0039] The smoking article may have a total length of about 30 mm to about 100 mm. The smoking article may have an outer diameter of about 5 mm to about 12 mm. The smoking article may include a filter plug. The filter plug may be located at the downstream end of the smoking article. The filter plug may be a cellulose acetate filter plug. The filter plug may be about 7 mm long in one embodiment, but may have a length of about 5 mm to about 10 mm.

[0040] In one embodiment, the smoking article has a total length of approximately 45 mm. The smoking article may have an outer diameter of approximately 7.2 mm. Furthermore, the length of the aerosol-forming substrate may be approximately 10 mm. Alternatively, the length of the aerosol-forming substrate may be approximately 12 mm. Furthermore, the diameter of the aerosol-forming substrate may be between approximately 5 mm and approximately 12 mm. The smoking article may include an outer paper wrapper. Furthermore, the smoking article may include a separation between the aerosol-forming substrate and the filter plug. The separation may be approximately 18 mm, but may range from approximately 5 mm to approximately 25 mm.

[0041] The aerosol-forming substrate may be a solid aerosol-forming substrate. Alternatively, the aerosol-forming substrate may include both solid and liquid components. The aerosol-forming substrate may include a tobacco-containing material that includes volatile tobacco flavor compounds that are released from the substrate upon heating. Alternatively, the aerosol-forming substrate may include a non-tobacco material. The aerosol-forming substrate may further include an aerosol former that promotes the formation of a dense, stable aerosol. Examples of suitable aerosol formers are glycerin and propylene glycol.

[0042] When the aerosol-forming substrate is a solid aerosol-forming substrate, the solid aerosol-forming substrate may comprise, for example, one or more of powder, granules, pellets, shreds, spaghetti, strips, or sheets, including one or more of herb leaves, tobacco leaves, tobacco stem fragments, reconstituted tobacco, homogenized tobacco, extruded tobacco, cast leaf tobacco, and expanded tobacco. The solid aerosol-forming substrate may be in loose form or may be provided in a suitable container or cartridge. Optionally, the solid aerosol-forming substrate may contain additional tobacco or non-tobacco volatile flavor compounds that are released upon heating of the substrate. The solid aerosol-forming substrate may also include, for example, capsules containing additional tobacco or non-tobacco volatile flavor compounds, which dissolve during heating of the solid aerosol-forming substrate.

[0043] As used herein, "homogenized tobacco" refers to a material formed by agglomerating particulate tobacco. The homogenized tobacco may be in the form of a sheet. The homogenized tobacco material may have an aerosol former content of greater than 5% by dry weight. Alternatively, the homogenized tobacco material may have an aerosol former content of about 5 to about 30 weight percent by dry weight. The homogenized tobacco material sheet may be formed by agglomerating particulate tobacco obtained by grinding or otherwise combining one or both of tobacco lamina and tobacco stem. Alternatively, or additionally, the homogenized tobacco material sheet may include one or more of tobacco dust, tobacco fines, and other particulate tobacco by-products formed, for example, during tobacco processing, handling, and transportation. The homogenized tobacco material sheet may include one or more inherent binders (i.e., tobacco intrinsic binders), one or more extrinsic binders (i.e., tobacco extrinsic binders), or a combination thereof to aid in the cohesion of the particulate tobacco, although alternatively or additionally, the homogenized tobacco material sheet may include other additives, including but not limited to tobacco and non-tobacco fibers, aerosol formers, humectants, plasticizers, flavorants, fillers, aqueous and non-aqueous solvents, and combinations thereof.

[0044] Optionally, the solid aerosol-forming substrate may be provided on or embedded in a thermally stable carrier. The carrier may be in the form of a powder, granules, pellets, pieces, spaghetti, strips, or sheets. Alternatively, the carrier may be a tubular carrier having a thin layer of solid substrate disposed on its interior surface, its exterior surface, or both its interior and exterior surfaces. Such a tubular carrier may be formed, for example, from paper or paper-like material, nonwoven carbon fiber mat, a thin, open-mesh metal screen, or a perforated metal foil or any other thermally stable polymeric matrix.

[0045] In a particularly preferred embodiment, the aerosol-forming substrate comprises an assembly of crimped sheets of homogenized tobacco material. As used herein, the term "crimped sheet" refers to a sheet having a plurality of substantially parallel ridges or corrugations. Preferably, the substantially parallel ridges or corrugations extend along or parallel to the longitudinal axis of the aerosol-generating article when the aerosol-generating article is assembled. This conveniently facilitates assembly of the crimped sheets of homogenized tobacco material to form the aerosol-forming substrate. However, it is recognized that a crimped sheet of homogenized tobacco material for inclusion in an aerosol-generating article may alternatively or additionally have a plurality of substantially parallel ridges or corrugations that are disposed at an acute or obtuse angle to the longitudinal axis of the aerosol-generating article when the aerosol-generating article is assembled. In certain embodiments, the aerosol-forming substrate may comprise an assembly of sheets of homogenized tobacco material that are substantially uniformly textured over substantially its entire surface. For example, the aerosol-forming substrate may comprise an assemblage of a crimped sheet of homogenized tobacco material containing a plurality of substantially parallel ridges or corrugations that are substantially uniformly spaced across the width of the sheet.

[0046] The solid aerosol-forming substrate may be disposed on the surface of the carrier in the form of, for example, a sheet, foam, gel or slurry. The solid aerosol-forming substrate may be deposited on the entire surface of the carrier, or alternatively, may be deposited in a pattern to provide a non-uniform flavor delivery during use.

[0047] An aerosol generating system is a combination of an aerosol generating device and one or more aerosol generating articles for use with the device, although an aerosol generating system may include additional components, such as a charging unit for recharging an on-board power supply in an electrically operated or electric aerosol generating device.

[0048] Although the disclosure has been described with reference to different embodiments, it will be apparent that features described in relation to one embodiment of the disclosure may be applied to other embodiments of the disclosure.

[0049] Embodiments of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings in which: [Brief explanation of the drawings]

[0050] [Figure 1] FIG. 1 is a schematic diagram of an aerosol generating device. [Figure 2] 2 is a schematic cross-sectional view of the front end of an aerosol generating device of the type shown in FIG. 1, with a heater inserted into a smoking article. [Figure 3] 1 is a schematic diagram of a heating assembly according to the present invention; [Figure 4] FIG. 4 is a cross-sectional view of a portion of the heating assembly of FIG. 3. [Figure 5] FIG. 1 is a schematic diagram of an alternative heating assembly according to the present invention. [Figure 6] FIG. 1 is a schematic diagram of an alternative heating assembly according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0051] 1 illustrates in a simplified manner the components of an embodiment of an electrically heated aerosol generating system 100. In particular, the elements of the electrically heated aerosol generating system 100 are not drawn to scale in FIG. 1. Elements that are not relevant to an understanding of this embodiment have been omitted from the simplified FIG.

[0052] The electrically heated aerosol generating system 100 comprises an aerosol generating device having a housing 10 and an aerosol-forming article 12 (e.g., a tobacco stick). The aerosol-forming article 12 comprises an aerosol-forming substrate that is forced within the housing 10 into thermal proximity with a portion of a heater 14. The aerosol-forming substrate emits a variety of volatile compounds at different temperatures.

[0053] Within housing 10 is an electrical energy source 16, such as a rechargeable lithium-ion battery. A controller 18 is connected to heater 14, electrical energy source 16, and a user interface 20 (e.g., buttons or a display). Controller 18 controls the power supplied to heater 14 to regulate its temperature. Typically, the aerosol-forming substrate is heated to a temperature of 250-450°C.

[0054] Figure 2 is a schematic cross-sectional view of the front end of an aerosol-generating device of the type shown in Figure 1, with a heater 14 inserted within an aerosol-forming article 12, which in this embodiment is a smoking article. The aerosol-generating device is shown engaged with the aerosol-generating article 12 for consumption of the aerosol-generating article 12 by a user.

[0055] The aerosol generating device housing 10 defines an open cavity at its proximal (or mouth) end for receiving the aerosol-generating article 12 for consumption. A heating assembly 24, including a heater 14 and a heater mount 26, is mounted at the distal end of the cavity. The heater 14 is held by the heater mount 26 so that the heater's effective heating area (heating portion) is located within the cavity. The heater's effective heating area is located within the distal end of the aerosol-generating article 12 when the aerosol-generating article 12 is fully received within the cavity. The heater mount is formed from polyetheretherketone and is molded around the heater's holding portion. A first end of the heater, including the heating portion, extends from one side of the heater mount. A second end of the heater, including the connection portion, extends from the other side of the heater mount.

[0056] The heater 14 is shaped in the form of a blade terminating in a tip. That is, the length dimension of the heater is greater than its width dimension, which is greater than its thickness dimension. The first and second sides of the heater are defined by the width and length of the heater.

[0057] The exemplary aerosol-forming article shown in Figure 2 can be described as follows: The aerosol-generating article 12 includes four elements: an aerosol-forming substrate 30, a support element (such as a hollow tube 40), a transfer section 50, and a mouthpiece filter 60. These four elements are, in turn, aligned in a coaxial arrangement and assembled by cigarette paper 70 to form a rod. When assembled, the aerosol-forming article is 45 millimeters long and 7 millimeters in diameter.

[0058] The aerosol-forming substrate comprises a bundle of crimped cast leaf tobacco wrapped in filter paper (not shown) to form a plug. The cast leaf tobacco contains one or more aerosol formers, such as glycerin.

[0059] The hollow tube 40 is located immediately adjacent to the aerosol-forming substrate 30 and is formed from cellulose acetate tubing. The tube 40 defines an opening that is 3 millimeters in diameter. One function of the hollow tube 40 is to position the aerosol-forming substrate 30 toward the distal end 23 of the rod 21 so that it can come into contact with the heater. The hollow tube 40 serves to prevent the aerosol-generating substrate 30 from being forced along the rod toward the mouthpiece when the heater is inserted into the aerosol-forming substrate 30.

[0060] The transfer section 50 comprises a thin-walled tube having a length of 18 millimeters. The transfer section 50 allows the volatile material to be released from the aerosol-forming substrate 30 and pass along the article towards the mouthpiece filter 60. The volatile material may also be cooled within the transfer section to form an aerosol.

[0061] Mouthpiece filter 60 is a conventional mouthpiece filter formed from cellulose acetate and having a length of approximately 7.5 millimeters.

[0062] The four elements identified above are assembled by being tightly wrapped within cigarette paper 70. The paper in this particular embodiment is standard cigarette paper having standard attributes or classifications. The paper in this particular embodiment is conventional cigarette paper. The joints between the paper and each element position the elements and define the aerosol-forming article 12.

[0063] When the aerosol-generating article 12 is pressed into the cavity, the tapered tip of the heater engages with the aerosol-forming substrate 30. Applying force to the aerosol-forming article causes the heater to penetrate into the aerosol-forming substrate 30. Once the aerosol-forming article 12 is properly engaged with the aerosol-generating device, the heater 14 is inserted into the aerosol-forming substrate 30. When the heater is activated, the aerosol-forming substrate 30 is heated and volatile substances are generated or released. When a user inhales on the mouthpiece filter 60, air is drawn into the aerosol-forming article, and the volatile substances condense to form an inhalable aerosol. This aerosol passes through the mouthpiece filter 60 of the aerosol-forming article and into the user's mouth.

[0064] FIG. 3 illustrates in more detail a heating assembly 1000 of the type that can be attached to the apparatus shown in FIG. 2. The heating assembly includes a heater 1010 and a heater mount 1020. The heater mount is molded around the heater with a heater holder. The heater mount is shown in dotted lines so that the entire heater is visible. The heater 1010 includes an electrically insulating heater substrate 1080 that defines the shape of the heater 1010. The heater substrate 1080 is formed from an electrically insulating material, such as alumina (Al2O3) or zirconium (ZrO2). The electrically insulating material may be any suitable electrically insulating material, and those skilled in the art will recognize that many ceramic materials are suitable for use as the electrically insulating material. The heater substrate 1080 is substantially blade-shaped. That is, the heater substrate has a length extending along the length of the aerosol-forming article that engages the heater during use, a width, and a thickness. The width is greater than the thickness. In a particular embodiment, the heater substrate has a length of 19.2 mm, a width of 4.9 mm, and a thickness of 0.38 mm. The heater substrate 1080 terminates in a tip or spike 1090 for penetrating the aerosol-forming substrate 30.

[0065] A heating element 1082, formed from a conductive material, is deposited on the flat surface of the heater substrate 1080 using evaporation or any other suitable technique. The heating element is formed with three distinct sections. The first section 1084 is formed from platinum. This section is located in the heating section 1091 of the heater. This is the region of the heater that reaches its maximum temperature during use and provides heat to the aerosol-forming substrate. The first section 1084 of the heating element is substantially U-shaped or hairpin-shaped. The second section 1086 is formed from gold. This second section includes two parallel tracks, each connecting to an end of the first section 1084. The second section 1086 spans the heater's holding section 1093 and is the region of the heater that contacts the heater mount 1020. The third section 1088 is formed from silver. This third section is located in the connection section 1095 and provides a bonding pad to which external wires can be attached using solder paste or other adhesive techniques. The third portion includes two parallel pads, each connected to the end of one of the parallel tracks of the second portion 1086 opposite the first portion 1084. The third portion 1088 is positioned on the opposite side of the heater mount from the first portion.

[0066] The shape, thickness, and width of the first, second, and third sections can be selected to provide the desired resistance and temperature distribution during use. However, the first section has significantly greater electrical resistance per unit length than the second and third sections, resulting in the first section generating the most heat and reaching the highest temperature when current passes through the heating element 1082. The second and third sections are configured to have very low electrical resistance, resulting in negligible Joule heating. The total electrical resistance of the heating element is approximately 0.80 ohms at 0°C, rising to approximately 2 ohms as the active heating section 1091 reaches 400°C. The battery voltage of a lithium-ion battery is approximately 3.7 volts, resulting in a typical peak current provided by a power supply (at 0°C) of approximately 4.6 A.

[0067] Platinum has a positive temperature coefficient of resistance, so the electrical resistance of first portion 1084 increases with increasing temperature. Gold and silver have a lower temperature coefficient of resistance, so the second and third portions do not increase in temperature as much as the first portion.

[0068] Through holes 1200 are defined through the thickness of the heater substrate between the parallel conductive tracks of the heater carrier.

[0069] Heater mount 1020 is formed from polyetheretherketone (PEEK) and is injection molded around the heater at retainer 1093. As can be seen in Figure 4, the PEEK flows through through-holes 1200, thereby securing the heater to the heater mount.

[0070] In this embodiment, the heater mount 1020 has a circular cross section to mate with the circular housing 10 of the aerosol generation device. However, the heater mount can be shaped to have any desired shape and any desired mating characteristics for mating with other components of the aerosol generation device.

[0071] The heater assembly can be mounted within the housing of the aerosol generating device with contacts that are coupled to a power supply, as shown in Figure 3. The heater can then be inserted into the aerosol-forming substrate, which becomes heated when the heater is activated.

[0072] Figure 5 shows an alternative embodiment of a heating assembly. The heating assembly 2000 differs from that described above in connection with Figure 3 in that it defines three through-holes 2200 through the thickness of the heater in the holder. As described above, the material of the heater mount 2020 flows through the through-holes to mechanically secure the heater mount to the heater. The use of three through-holes can increase the anchoring effect compared to a single through-hole.

[0073] Figure 6 shows an alternative embodiment of a heating assembly. Heating assembly 3000 has the difference that the heater of the holder defines an outwardly extending protrusion 3400 and an inwardly extending notch 3500, as described above in connection with Figure 3. The use of the notch and protrusion can increase the anchoring effect compared to the use of through-holes alone.

[0074] The above-described exemplary embodiments are illustrative and not limiting. In light of the exemplary embodiments discussed above, other embodiments consistent with the above exemplary embodiments will now be apparent to those skilled in the art.

Claims

1. 1. An electrically heated aerosol generating device comprising a heating assembly for heating an aerosol-forming substrate to generate an inhalable aerosol, the heating assembly comprising a heater and a heater mount; the heater is substantially blade-shaped for insertion into the aerosol-forming substrate and has a length of 10 mm to 60 mm, a width of 2 mm to 10 mm, and a thickness of 0.2 mm to 1 mm, the heater comprising an electrically insulating heater substrate and an electrically resistive heating element supported by the heater substrate, and two or more through holes defined through the thickness of the heater; the heater mount provides structural support to the heater and allows the heater to be positioned within the aerosol generating device, the heater mount being formed from a moldable material that is molded around a portion of the heater, the moldable material extending through each of the two or more through-holes to couple the heater to the heater mount; the heater has two substantially parallel edges and two substantially parallel faces; the heater includes an outwardly extending protrusion to enhance coupling of the heater mount to the heater, the protrusion extending outwardly from a first edge of the two substantially parallel edges of the heater; An electrically heated aerosol generating device, wherein the heater includes an inwardly extending notch to strengthen the coupling of the heater mount to the heater, the notch extending inward from a second of the two substantially parallel edges of the heater.

2. The electrically heated aerosol generating device according to claim 1 , wherein the two or more through-holes are non-circular.

3. An electrically heated aerosol generator as described in claim 1 or 2, wherein the heater mount is formed in a holding portion of the heater where the temperature does not rise significantly during operation, and the two or more through holes are arranged in the holding portion.

4. The electrically heated aerosol generating device according to claim 3 , wherein the protrusion and the notch are disposed in the holding portion.

5. An electrically heated aerosol generating device as described in claim 3 or 4, wherein the electrically resistive heating element includes a conductive track within the holding portion of the heater, and the two or more through holes are defined between the conductive tracks within the holding portion of the heater.

6. The electrically heated aerosol generating device according to any one of claims 1 to 5, wherein the two or more through holes have a maximum diameter of 1 mm to 3 mm.

7. the two or more through holes are non-circular; the heater mount is formed in a holding portion of the heater where the temperature does not rise significantly during operation, and the protrusion, the notch, or the two or more through holes are disposed in the holding portion; 2. The electrically heated aerosol generating device according to claim 1, wherein each of the two or more through holes has a maximum diameter of 1 mm to 3 mm.

8. The heater mount is formed in a holding portion of the heater that does not significantly increase in temperature during operation; the protrusion and the notch are disposed on the retaining portion; the electrically resistive heating element includes conductive tracks within the retaining portion of the heater, and the two or more through holes are defined between the conductive tracks within the retaining portion of the heater; 2. The electrically heated aerosol generating device according to claim 1, wherein the two or more through holes have a maximum diameter of 1 mm to 3 mm.

9. An electrically heated aerosol generator according to any one of claims 1 to 8, wherein the moldable material of the heater mount is a polymeric material, for example polyetheretherketone (PEEK).

10. The electrically heated aerosol generating device according to any one of claims 1 to 9, wherein the heater substrate is formed from a ceramic material such as zirconium or alumina.

11. providing a heater substrate having a length of 10 mm to 60 mm, a width of 2 mm to 10 mm, and a thickness of 0.2 mm to 1 mm, said heater substrate being formed from an electrically insulating material and having two or more through holes defined through its thickness; disposing one or more electrically resistive heating elements on the heater substrate to form a heater; coupling a heater mount to the heater to form a heater assembly, the heater mount being formed from a moldable material molded around a portion of the heater such that the moldable material passes through the two or more through holes; and placing the heater assembly in a housing.

12. providing a heater substrate having a length of 10 mm to 60 mm, a width of 2 mm to 10 mm, and a thickness of 0.2 mm to 1 mm, said heater substrate being formed from an electrically insulating material; disposing one or more electrically resistive heating elements on the heater substrate to form a heater; forming two or more through holes through a thickness of the heater; coupling a heater mount to the heater to form a heater assembly, the heater mount being formed from a moldable material molded around a portion of the heater such that the moldable material passes through the two or more through holes; and placing the heater assembly in a housing.

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