Aerosol generating device and heating chamber thereof

Abstract

An aerosol generating device (100) has a heating chamber (108) for receiving a substrate carrier (114) containing an aerosol substrate (128). The heating chamber (108) includes a tubular sidewall (126) having a first open end (110), the tubular sidewall (126) defining an interior volume of the heating chamber (108). A metal layer (144) is provided, the metal layer being in direct contact with the heating chamber (108) and covering a portion of an outer surface of the sidewall (126).

Description

Technical Field

[0001] The present disclosure relates to an aerosol generating device and a heating chamber thereof. The present disclosure is particularly applicable to a portable aerosol generating device, which may be self-contained and cryogenic. Such a device may heat tobacco or other suitable materials by conduction, convection and / or radiation rather than burning them to generate an aerosol for inhalation. Background Art

[0002] Over the past several years, there has been a rapid growth in the popularity and use of reduced risk or modified risk devices (also known as vaporizers) to help habitual smokers who wish to quit traditional tobacco products such as cigarettes, cigars, cigarillos and roll-ons. Rather than burning the tobacco in traditional tobacco products, various devices and systems are available that heat or warm an aerosolizable substance.

[0003] A commonly available risk-reduced or risk-modified device is a heated substrate aerosol generating device or a heat-but-not-burn device. This type of device generates an aerosol or vapor by heating an aerosol substrate to a temperature typically in the range of 150°C to 300°C, the aerosol substrate typically comprising moist tobacco leaves or other suitable aerosolizable material. Heating but not burning or burning the aerosol substrate releases an aerosol that includes the components sought by the user but does not include the toxic and carcinogenic byproducts of burning and burning. In addition, the aerosol generated by heating tobacco or other aerosolizable materials typically does not include a burnt or bitter taste that may be unpleasant to the user due to burning and burning, and therefore, the substrate does not require sugars and other additives that are typically added to such materials to make the smoke and / or vapor more palatable to the user.

[0004] In a general sense, it is desirable to quickly heat the aerosol substrate to a temperature at which the aerosol can be released, and to maintain the aerosol substrate at that temperature. Obviously, the aerosol will only be released from the aerosol substrate and delivered to the user when there is airflow through the aerosol substrate.

[0005] Aerosol generating devices of this type are portable devices and therefore energy consumption is an important design consideration.The present invention aims to solve the problems of existing devices and to provide an improved aerosol generating device and a heating chamber thereof. Summary of the invention

[0006] According to a first aspect of the present disclosure, a heating chamber for an aerosol generating device is provided, the heating chamber comprising: a tubular side wall having a first open end, the tubular side wall defining an internal volume of the heating chamber; and a metal layer, the metal layer being in direct contact with the heating chamber and covering a portion of an outer surface of the side wall.

[0007] Optionally, the metal layer is an electroplated layer.

[0008] Optionally, the tubular sidewall has a first thickness and the metal layer has a second thickness less than the first thickness.

[0009] Optionally, the metal layer has a thickness between 10 μm and 50 μm, preferably between 10 μm and 30 μm, preferably about 20 μm.

[0010] Optionally, the metal layer comprises a metal having a thermal conductivity of at least 150 W / mK, preferably, wherein the metal layer is copper.

[0011] Optionally, the tubular side wall comprises a metal having a thermal conductivity of 50 W / mK or less, preferably, wherein the tubular side wall is stainless steel.

[0012] Optionally, the tubular sidewall has a thickness of 90 μm or less.

[0013] Optionally, a portion of the outer surface of the tubular sidewall adjacent to the first open end is not covered by the metal layer.

[0014] Optionally, the tubular sidewall further comprises a second end opposite the first open end, and wherein the portion of the outer surface of the sidewall adjacent to the second end is not covered by the metal layer.

[0015] Optionally, the tubular sidewall further comprises a base coupled to a second end of the tubular wall opposite the first open end.

[0016] Optionally, the tubular sidewall further comprises at least one protrusion extending inwardly from an inner surface of the tubular sidewall.

[0017] Optionally, the portion of the outer surface of the tubular side wall corresponding to the (or each) protrusion on the inner surface is covered by the metal layer.

[0018] Optionally, the heating chamber further comprises a heater positioned at least partially on the metal layer.

[0019] Optionally, the heater is positioned entirely on the metal layer.

[0020] According to a second aspect of the present disclosure, an aerosol generating device is provided, which includes: a power supply; a heating cavity fixed in the device as described above; a heater arranged to provide heat to the heating cavity, the heater being positioned on a metal layer on a surface of the tubular side wall facing in a direction opposite to the internal volume; and a control circuit system arranged to control the supply of electrical power from the power supply to the heater.

[0021] Optionally, the heating chamber is removable from the aerosol generating device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic perspective view of an aerosol-generating device according to a first embodiment of the present disclosure.

[0023] Figure 2 yes Figure 1 Schematic cross-sectional view of an aerosol generating device from the side.

[0024] Figure 2 (a) Yes Figure 1 The top of the aerosol generating device is along Figure 2 A schematic cross-sectional view taken along line XX is shown.

[0025] Figure 3 yes Figure 1 Schematic perspective view of an aerosol generating device, in which a substrate carrier of an aerosol substrate is shown being loaded into the aerosol generating device.

[0026] Figure 4 yes Figure 1 Schematic cross-sectional view of an aerosol generating device from the side, showing a substrate carrier of an aerosol substrate being loaded into the aerosol generating device.

[0027] Figure 5 yes Figure 1 Schematic perspective view of an aerosol generating device, in which a substrate carrier of an aerosol substrate is shown to have been loaded into the aerosol generating device.

[0028] Figure 6 yes Figure 1 Schematic cross-sectional view of an aerosol generating device from the side, showing that a substrate carrier of an aerosol substrate has been loaded into the aerosol generating device.

[0029] Figure 6 (a) Yes Figure 6 Detailed cross-sectional view of a portion of FIG, highlighting the interaction between the substrate carrier and the protrusions in the heating chamber and the corresponding impact on the airflow path.

[0030] Figure 7 is a plan view of the heater separated from the heating chamber.

[0031] Figure 8 is a schematic cross-sectional view from the side of an aerosol generating device with an alternative airflow arrangement according to a second embodiment of the present disclosure.

[0032] Fig. 9 is a schematic perspective view of a heating chamber according to a third embodiment of the present disclosure.

[0033] Fig.10 is a schematic perspective view of a heating chamber according to a fourth embodiment of the present disclosure.

[0034] Fig.11 is a schematic cross-sectional view of a heating chamber as part of a masking and plating step according to a fifth embodiment.

[0035] Fig.12 is a schematic perspective view of a heating chamber as part of a masking and plating step according to a fifth embodiment. DETAILED DESCRIPTION

[0036] First embodiment

[0037] See also Figure 1 and Figure 2 According to a first embodiment of the present disclosure, an aerosol generating device 100 includes a housing 102 that houses a plurality of different components of the aerosol generating device 100. In the first embodiment, the housing 102 is tubular. More specifically, the housing is cylindrical. It should be noted that the housing 102 does not have to have a tubular or cylindrical shape, but can be any shape as long as its size is adapted to the components described in the different embodiments set forth herein. The housing 102 can be formed of any suitable material or even material layer. For example, a metal inner layer can be surrounded by a plastic outer layer. This makes the housing 102 pleasant for the user to hold. Any heat leaking from the aerosol generating device 100 is distributed around the housing 102 by the metal layer, thereby preventing the formation of hot spots, while the plastic layer softens the feel of the housing 102. In addition, the plastic layer can help protect the metal layer from rust or scratches, thereby improving the long-term appearance of the aerosol generating device 100.

[0038] For convenience, the first end 104 of the aerosol generating device 100 (shown as facing toward Figures 1 to 6 The second end 106 of the aerosol generating device 100 (shown as facing toward the Figures 1 to 6 The first end 104 and the second end 106 are described as the top or upper end of the aerosol-generating device 100. In the first embodiment, the first end 104 is the lower end of the housing 102. In use, the user typically orients the aerosol-generating device 100 with the first end 104 facing downward and / or in a distal position relative to the user's mouth, and the second end 106 facing upward and / or in a proximal position relative to the user's mouth.

[0039] As shown, the aerosol generating device 100 is held in place at the second end 106 by a pair of gaskets 107a, 107b via an interference fit with the interior portion of the housing 102 (in Figure 1 , Figure 3 and Figure 5 , only the upper gasket 107a is visible). In some embodiments, the housing 102 is curled or bent around the upper gasket 107a of the gaskets at the second end 106 of the aerosol generating device 100 to hold the gaskets 107a, 107b in place. The other gasket 107b (i.e., the gasket farthest from the second end 106 of the aerosol generating device 100) is supported on a shoulder or annular ridge 109 of the housing 102, thereby preventing the lower gasket 107b from sitting more than a predetermined distance from the second end 106 of the aerosol generating device 100. The gaskets 107a, 107b are formed of an insulating material. In the present embodiment, the insulating material is suitable for use in medical devices, for example, polyetheretherketone (PEEK).

[0040] The aerosol generating device 100 has a heating chamber 108 positioned towards the second end 106 of the aerosol generating device 100. The heating chamber 108 is open towards the second end 106 of the aerosol generating device 100. In other words, the heating chamber 108 has a first open end 110 towards the second end 106 of the aerosol generating device 100. The heating chamber 108 is maintained spaced from the inner surface of the housing 102 by fitting through a central aperture of the gaskets 107a, 107b. This arrangement maintains the heating chamber 108 in a substantially coaxial arrangement with the housing 102. The heating chamber 108 is suspended by a flange 138 of the heating chamber 108, which is located at the open end 110 of the heating chamber 108 and sandwiched between the pair of gaskets 107a, 107b. This means that heat conduction from the heating cavity 108 to the housing 102 generally passes through the gaskets 107a, 107b and is thereby limited by the insulating properties of the gaskets 107a, 107b. Heat transfer from the heating cavity 108 to the housing 102 other than via the gaskets 107a, 107b is also reduced due to the presence of air gaps elsewhere around the heating cavity 108. In the illustrated embodiment, the flange 138 extends outwardly away from the side wall 126 of the heating cavity 108 by a distance of approximately 1 mm, forming an annular structure.

[0041] In order to further improve the insulation of the heating chamber 108, the heating chamber 108 is also surrounded by insulation. In some embodiments, the insulation is a fibrous material or a foam material, such as cotton wool. In the embodiment shown, the insulation includes an insulating member 152 in the form of an insulating cup, which includes a double-walled tube 154 and a base 156. In some embodiments, the insulating member 152 may include a pair of nested cups with an inner cavity enclosed therebetween. The inner cavity 158 defined between the walls of the double-walled tube 154 may be filled with an insulating material, such as fiber, foam, gel or gas (e.g., under low pressure). In some cases, the inner cavity 158 may include a vacuum. Advantageously, the vacuum requires a very small thickness to achieve high insulation, and the wall of the double-walled tube 154 enclosing the inner cavity 158 can be as small as 100 μm thick, and the total thickness (two walls and the inner cavity 158 between them) can be as low as 1 mm. The base 156 is an insulating material, such as silicone. Because silicone is flexible, the electrical connection 150 of the heater 124 can pass through the base 156 , while forming a seal around the electrical connection 150 .

[0042] like Figures 1 to 6 As shown, the aerosol generating device 100 may include a housing 102, a heating chamber 108, and a thermal insulation member 152, as described above. Figures 1 to 6 A resiliently deformable member 160 is shown positioned between the outwardly facing surface of the insulating sidewall 154 and the inner surface of the housing 102 to hold the insulating member 152 in place. The resiliently deformable member 160 can provide sufficient friction to create an interference fit to hold the insulating member 152 in place. The resiliently deformable member 160 can be a gasket or an O-ring, or other closed loop of material that conforms to the outwardly facing surface of the insulating sidewall 154 and the inner surface of the housing 102. The resiliently deformable member 160 can be formed of a thermally insulating material, such as silicone. This can provide further insulation between the insulating member 152 and the housing 102. Therefore, this can reduce the amount of heat transferred to the housing 102, allowing the user to comfortably hold the housing 102 during use. The resiliently deformable material is capable of being compressed and deformed, but springs back to its original shape, such as an elastomeric material or a rubber material.

[0043] As an alternative to this arrangement, the insulation 152 may be supported by struts extending between the insulation 152 and the housing 102. The struts may ensure added rigidity, centrally locate the heating chamber 108 within the housing 102, or locate the heating chamber at a set location. This may be designed so that heat is evenly distributed throughout the housing 102 so that hot spots do not form.

[0044] As yet another alternative, the heating chamber 108 may be secured in the aerosol generating device 100 by engagement portions on the housing 102 for engaging the side wall 126 at the open end 110 of the heating chamber 108. As the open end 110 is exposed to the greatest cold airflow and therefore cools fastest, attaching the heating chamber 108 to the housing 102 near the open end 110 allows heat to be quickly dissipated into the environment and ensures a secure fit.

[0045] It should be noted that in some embodiments, the heating chamber 108 is removable from the aerosol generating device 100. Thus, the heating chamber 108 can be easily cleaned or replaced. In such embodiments, the heater 124 and the electrical connection 150 may not be removable and may remain in place within the thermal insulation member 152.

[0046] In a first embodiment, the base 112 of the heating chamber 108 is closed. That is, the heating chamber 108 is cup-shaped. In other embodiments, the base 112 of the heating chamber 108 has one or more holes or is perforated, and the heating chamber 108 remains roughly cup-shaped but is not closed at the base 112. In yet other embodiments, the base 112 is closed, but the side wall 126 has one or more holes or is perforated in the area near the base 112, for example, between the heater 124 (or metal layer 144) and the base 112. The heating chamber 108 also has a side wall 126 between the base 112 and the open end 110. The side wall 126 and the base 112 are connected to each other. In a first embodiment, the side wall 126 is tubular. More specifically, the shell is cylindrical. However, in other embodiments, the side wall 126 has other suitable shapes, such as a tube with an elliptical or polygonal cross-section. Typically, the cross-section is generally uniform over the length of the heating chamber 108 (not accounting for the protrusions 140), but in other embodiments the cross-section may vary, for example the cross-section may taper toward one end such that the tubular shape tapers or is frusto-conical.

[0047] In the illustrated embodiment, the heating chamber 108 is unitary, that is, the sidewall 126 and the base 112 are formed from a single piece of material, for example, by a deep drawing process. This can produce a more robust overall heating chamber 108. Other examples can form the base 112 and / or the flange 138 as separate parts and then attach them to the sidewall 126. This in turn can make the flange 138 and / or the base 112 made of a material different from the material from which the sidewall 126 is made. The sidewall 126 itself is arranged as a thin wall. Typically, the sidewall 126 is less than 100 μm thick, for example, about 90 μm thick, or even about 80 μm thick. In some cases, the sidewall 126 can be about 50 μm thick, but as the thickness decreases, the failure rate during the manufacturing process increases. In general, a range of 50 μm to 100 μm is generally suitable, and a range of 70 μm to 90 μm is optimal. Manufacturing tolerance is approximately ±10 μm, but the parameters provided are intended to be accurate to approximately ±5 μm.

[0048] When the sidewall 126 is thin as defined above, the thermal characteristics of the heating chamber 108 change significantly. The resistance to heat transfer through the sidewall 126 is negligible because the sidewall 126 is so thin, however, heat transfer along the sidewall 126 (i.e., parallel to the central axis of the sidewall 126 or around the circumference of the sidewall) has a small path along which conduction can occur, and thus the heat generated by the heater 124 located on the outer surface of the heating chamber 108 remains concentrated near the heater 124 in a direction radially outward from the sidewall 126 at the open end, but quickly causes heating of the inner surface of the heating chamber 108. In addition, the thin sidewall 126 helps to reduce the thermal mass of the heating chamber 108, thereby improving the overall efficiency of the aerosol generating device 100 because less energy is used to heat the sidewall 126.

[0049] The heating chamber 108, and in particular the sidewalls 126 of the heating chamber 108, comprise a material having a thermal conductivity of 50 W / mK or less. In a first embodiment, the heating chamber 108 is a metal, preferably stainless steel. The thermal conductivity of stainless steel is between about 15 W / mK and 40 W / mK, the exact value depending on the specific alloy. As another example, a 300 series stainless steel suitable for this purpose has a thermal conductivity of about 16 W / mK. Suitable examples include 304, 316, and 321 stainless steels, which have been approved for medical use, are strong, and have sufficiently low thermal conductivity to allow the heat concentration described herein.

[0050] Materials having the above levels of thermal conductivity reduce the ability of heat to be conducted away from the area to which heat is applied, compared to materials having higher thermal conductivity. For example, heat remains concentrated near the heater 124. Since heat is inhibited from moving to other parts of the aerosol-generating device 100, heating efficiency is improved by ensuring that only those parts of the aerosol-generating device 100 that are intended to be heated are actually heated, while those parts that are not intended to be heated are not heated.

[0051] Metals are suitable materials because they are strong, ductile, and easily shaped. In addition, the thermal properties of metals vary greatly from metal to metal and can be adjusted by careful alloying if necessary. In this application, "metal" refers to elemental (i.e., pure) metals as well as alloys of several metals or other elements (e.g., carbon).

[0052] Thus, configuring the heating chamber 108 with a thin sidewall 126, and selecting a material for forming the sidewall 126 having desired thermal properties, ensures that heat can be effectively conducted through the sidewall 126 and into the aerosol substrate 128. Advantageously, this also reduces the time it takes to raise the temperature from ambient temperature to a temperature at which aerosol can be released from the aerosol substrate 128 following initial activation of the heater.

[0053] The heating cavity 108 is formed by deep drawing. This is an effective method for forming the heating cavity 108, and can be used to provide a very thin side wall 126. The deep drawing process involves pressing a metal sheet blank with a punching tool to force it into a forming die. By using a series of gradually smaller punching tools and dies, a tubular structure is formed, which has a base at one end and forms a tube deeper than the distance across the tube (this means that the length of the tube is relatively greater than its width, which leads to the term "deep drawing"). Since it is formed in this way, the side wall of the tube formed in this way is the same thickness as the original metal sheet. Similarly, the base formed in this way is the same thickness as the initial metal sheet blank. A flange can be formed at the end of the tube by leaving an outwardly extending edge of the original metal sheet blank at the end of the tubular wall opposite to the base (that is, starting with more material than required to form the tube and the base in the blank). Alternatively, the flange can be formed by a separate step afterwards, and this separate step involves one or more of cutting, bending, rolling, die forging, etc.

[0054] As previously mentioned, the tubular sidewall 126 of the first embodiment is thinner than the base 112. This can be achieved by first deep drawing the tubular sidewall 126 and then ironing the wall. Ironing refers to heating and stretching the tubular sidewall 126, making it thinner in the process. In this way, the tubular sidewall 126 can be made into the dimensions described herein.

[0055] The thin sidewall 126 may be fragile. This can be alleviated by providing additional structural support to the sidewall 126 and by forming the sidewall 126 into a tubular (preferably cylindrical) shape. In some cases, additional structural support is provided as a separate feature, but it should be noted that the flange 138 and the base 112 also provide a certain degree of structural support. Considering the base 112 first, it should be noted that a tube with open ends is generally easy to break, and providing a base 112 for the heating chamber 108 of the present disclosure increases support. It should be noted that in the embodiment shown, the base 112 is thicker than the sidewall 126, for example, 2 to 10 times the thickness of the sidewall 126. In some cases, this may result in a base 112 with a thickness between 200 μm and 500 μm, for example, a thickness of about 400 μm. The base 112 also has another purpose, which is to prevent the substrate carrier 114 from being inserted too far into the aerosol generating device 100. In the event that the user accidentally uses too much force when inserting the substrate carrier 114, the increased thickness of the base 112 helps prevent damage to the heating chamber 108. Similarly, when the user cleans the heating chamber 108, the user may typically insert an object such as an elongated brush through the open end 110 of the heating chamber 108. This means that when the elongated object is against the base 112 instead of against the sidewall 126, the user may apply more force to the base 112 of the heating chamber 108. Therefore, the thickness of the base 112 relative to the sidewall 126 can help prevent damage to the heating chamber 108 during the cleaning process. In other embodiments, the thickness of the base 112 and the sidewall 126 are the same, which provides some of the advantageous effects set forth above.

[0056] The flange 138 extends outwardly from the side wall 126 and has an annular shape extending all the way around the edge of the side wall 126 at the open end 110 of the heating chamber 108. The flange 138 resists bending and shear forces on the side wall 126. For example, lateral deformation of the tube defined by the side wall 126 may require the flange 138 to bend. It should be noted that although the flange 138 is shown as extending generally vertically from the side wall 126, the flange 138 can extend obliquely from the side wall 126, such as forming a funnel shape with the side wall 126, while still retaining the above-mentioned advantageous features. In some embodiments, the flange 138 is only positioned around a portion of the edge of the side wall 126, rather than being annular. In the illustrated embodiment, the flange 138 is the same thickness as the side wall 126, but in other embodiments, the flange 138 is thicker than the side wall 126 to improve the ability to resist deformation. Any added thickness of specific parts for strength is weighed against the increased thermal mass introduced so that the aerosol-generating device 100 as a whole remains robust and efficient.

[0057] A plurality of protrusions 140 are formed on the inner surface of the side wall 126. The width of the protrusion 140 (around the perimeter of the side wall 126) is relatively small relative to its length (parallel to the central axis of the side wall 126, or generally along the direction from the base 112 of the heating chamber 108 to the open end 110). In this example, there are four protrusions 140. Four is generally a suitable number of protrusions 140 for fixing the substrate carrier 114 in a central position within the heating chamber 108, as will become clear from the following discussion. In some embodiments, three protrusions may be sufficient, for example spaced (evenly) at intervals of approximately 120 degrees around the circumference of the side wall 126. The protrusions 140 have a number of different purposes, and the exact form of the protrusions 140 (and the corresponding indentations on the outer surface of the side wall 126) is selected based on the desired effect. In any case, the protrusions 140 extend toward the substrate carrier 114 and engage the substrate carrier, and are therefore sometimes referred to as engaging elements. Indeed, the terms "protrusion" and "engagement element" may be used interchangeably herein. Similarly, when the protrusion 140 is provided by extruding the sidewall 126 from the outside, such as by hydroforming or pressing, etc., the term "indentation" may also be used interchangeably with the terms "protrusion" and "engagement element". Forming the protrusions 140 by indenting the sidewall 126 has the advantage that these protrusions are integral with the sidewall 126 and therefore have minimal impact on the flow of heat. In addition, the protrusions 140 do not add any thermal mass, which would be added if additional elements were added to the inner surface of the sidewall 126 of the heating chamber 108. Indeed, since the protrusions 140 are formed by indenting the sidewall 126, the thickness of the sidewall 126 remains substantially constant in the circumferential direction and / or in the axial direction, even where the protrusions are provided. Finally, indenting the sidewall as described increases the strength of the sidewall 126 by introducing a portion extending transversely to the sidewall 126, thereby providing resistance to bending of the sidewall 126.

[0058] The heating chamber 108 is arranged to receive a substrate carrier 114. Typically, the substrate carrier includes an aerosol substrate 128, such as tobacco or another suitable aerosolizable material that can be heated to produce an aerosol for inhalation. In a first embodiment, the heating chamber 108 is sized to receive a single serving of an aerosol substrate 128 (also referred to as a "consumable") in the form of a substrate carrier 114, such as Figures 3 to 6 However, this is not required, and in other embodiments, the heating chamber 108 is arranged to receive other forms of aerosol substrate 128, such as loose tobacco or otherwise packaged tobacco.

[0059] The aerosol-generating device 100 works by conducting surface heat from the protrusions 140 that engage the outer layer 132 of the substrate carrier 114, and heating the air in the air gap between the inner surface of the sidewall 126 and the outer surface of the substrate carrier 114. That is, when a user sucks on the aerosol-generating device 100, there is convective heating of the aerosol substrate 128 (as described in more detail below) as the heated air is drawn through the aerosol substrate 128. The width and height (i.e., the distance each protrusion 140 extends into the heating cavity 128) increase the surface area of ​​the sidewall 126 that transfers heat to the air, thereby allowing the aerosol-generating device 100 to reach an effective temperature more quickly.

[0060] The protrusions 140 on the inner surface of the side wall 126 extend toward the substrate carrier 114 and actually contact the substrate carrier when the substrate carrier is inserted into the heating chamber 108 (see, for example, Figure 6 ). This results in the aerosol substrate 128 also being heated conductively through the outer layer 132 of the substrate carrier 114.

[0061] Obviously, in order to conduct heat into the aerosol substrate 128, the surface 145 of the projection 140 must be mutually engaged with the outer layer 132 of the substrate carrier 114. However, manufacturing tolerances may cause the diameter of the substrate carrier 114 to have a slight variation. In addition, due to the relatively soft and compressible outer layer 132 of the substrate carrier 114 and the aerosol substrate 128 that is maintained therein, any damage to the substrate carrier 114 or rough handling may cause the diameter to be reduced or changed into an oval or elliptical cross section in the region where the outer layer 132 is intended to be mutually engaged with the surface 145 of the projection 140. Therefore, any variation in the diameter of the substrate carrier 114 may cause the thermal engagement between the outer layer 132 of the substrate carrier 114 and the surface 145 of the projection 140 to be reduced, which adversely affects the conduction of heat from the surface 145 of the projection 140 through the outer layer 132 of the substrate carrier 114 into the aerosol substrate 128. To mitigate the effects of any diameter variations of the substrate carrier 114 due to manufacturing tolerances or damage, the protrusions 140 are preferably sized to extend far enough into the heating chamber 108 to cause compression of the substrate carrier 114 and thereby ensure an interference fit between the surface 145 of the protrusions 140 and the outer layer 132 of the substrate carrier 114. Such compression of the outer layer 132 of the substrate carrier 114 may also cause longitudinal marking of the outer layer 132 of the substrate carrier 114 and provide a visual indication that the substrate carrier 114 has been used.

[0062] Figure 6(a) shows an enlarged view of the heating chamber 108 and the substrate carrier 114. It can be seen that arrow B illustrates the airflow path that provides the above-mentioned convective heating. As described above, the heating chamber 108 can be cup-shaped with a sealed, airtight base 112, which means that air must flow downward from the side of the substrate carrier 114 to enter the first end 134 of the substrate carrier because airflow through the sealed, airtight base 112 is not possible. As described above, the protrusion 140 extends into the heating chamber 108 a sufficient distance to at least contact the outer surface of the substrate carrier 114 and generally cause at least a certain degree of compression to the substrate carrier. Therefore, due to Figure 6 The cross-sectional view of (a) cuts through the protrusion 140 on the left and right sides of the figure, so there are no air gaps all along the heating chamber 108 in the plane of the figure. Instead, the airflow path (arrow B) is shown in dashed lines in the area of ​​the protrusion 140, indicating that the airflow path is located in front of and behind the protrusion 140. In fact, Figure 2 Comparison of (a) shows that the airflow path occupies four equally spaced interstitial regions between four protrusions 140. Of course in some cases there will be more or less than four protrusions 140, in which case the general idea that the airflow path exists in the interstitial spaces between the protrusions remains correct.

[0063] Also in Figure 6 What is emphasized in (a) is that when substrate carrier 114 is just inserted into heating chamber 108, it is forced to pass through the deformation of the outer surface of substrate carrier 114 caused by projection 140. As mentioned above, the distance that projection 140 extends into heating chamber can be advantageously selected as far enough away and any substrate carrier 114 produces compression. This (permanent) deformation during heating can help provide the stability of substrate carrier 114 in the following sense: the deformation of the outer layer 132 of substrate carrier 114 creates the denser region of aerosol substrate 128 near the first end 134 of substrate carrier 114. In addition, the outer surface of the band profile of the resulting substrate carrier 114 provides a clamping effect on the edge of the denser region of aerosol substrate 128 near the first end 134 of substrate carrier 114. Generally speaking, this reduces the possibility that any loose aerosol substrate will fall from the first end 134 of substrate carrier 114, which can cause heating chamber 108 to become dirty. This is a useful effect because, as described above, heating the aerosol substrate 128 may cause it to shrink, thereby increasing the likelihood that the loose aerosol substrate 128 will fall from the first end 134 of the substrate carrier 114. This undesirable effect is mitigated by the deformation effect described.

[0064] To ensure that the protrusions 140 contact the substrate carrier 114 (contact is necessary to cause conductive heating, compression and deformation of the aerosol substrate), the manufacturing tolerances of each of the following are taken into account: the protrusions 140; the heating chamber 108; and the substrate carrier 114. For example, the inner diameter of the heating chamber 108 can be 7.6±0.1 mm, the substrate 114 carrier can have an outer diameter of 7.0±0.1 mm, and the protrusions 140 can have a manufacturing tolerance of ±0.1 mm. In this example, assuming that the substrate carrier 114 is centered in the heating chamber 108 (i.e., leaving a uniform gap around the outside of the substrate carrier 114), the gap that each protrusion 140 must cross in order to contact the substrate carrier 114 ranges from 0.2 mm to 0.4 mm. In other words, because each protrusion 140 spans a radial distance, the lowest possible value for this example is half the difference between the smallest possible heating cavity 108 diameter and the largest possible substrate carrier 114 diameter, or [(7.6-0.1)-(7.0+0.1)] / 2 = 0.2 mm. The upper end of the range for this example is (for similar reasons) half the difference between the largest possible heating cavity 108 diameter and the smallest possible substrate carrier 114 diameter, or [(7.6+0.1)-(7.0-0.1)] / 2 = 0.4 mm. To ensure that the protrusions 140 are in contact with the substrate carrier, it is clear that in this example the protrusions must each extend at least 0.4 mm into the heating cavity. However, this does not take into account manufacturing tolerances for the protrusions 140. When a 0.4 mm protrusion is desired, the actual range produced is 0.4±0.1 mm, or varies between 0.3 mm and 0.5 mm. Some of these protrusions will not span the maximum possible gap between the heating chamber 108 and the substrate carrier 114. Therefore, the protrusions 140 of the present example should be produced with a nominal protrusion distance of 0.5 mm, which results in a range of values ​​between 0.4 mm and 0.6 mm. This is sufficient to ensure that the protrusions 140 will always be in contact with the substrate carrier.

[0065] Typically, the inner diameter of the heating chamber 108 is written as D±δ D , the outer diameter of the matrix carrier 114 is written as d±δ d , and the distance that the protrusion 140 extends into the heating chamber 108 is written as L±δ L , then the distance that the protrusion 140 is intended to extend into the heating chamber should be selected as:

[0066]

[0067] Among them, |δ D | refers to the manufacturing tolerance of the inner diameter of the heating chamber 108, |δ d | refers to the size of the manufacturing tolerance of the outer diameter of the substrate carrier 114, and |δ L| refers to the manufacturing tolerance of the distance that the protrusion 140 extends into the heating chamber 108. For the avoidance of doubt, when the inner diameter of the heating chamber 108 is D±δ D =7.6±0.1mm, then |δ D |=0.1mm.

[0068] In addition, manufacturing tolerances may cause aerosol substrate 128 to have a slight change in density in substrate carrier 114. This change in the density of aerosol substrate 128 may exist in both axial and radial directions in a single substrate carrier 114, or between different substrate carriers 114 manufactured in the same batch. Therefore, it is also obvious that in order to ensure that the heat conduction in the aerosol substrate 128 in a specific substrate carrier 114 is relatively uniform, it is important that the density of aerosol substrate 128 is relatively consistent. In order to alleviate the influence of any inconsistency of the density of aerosol substrate 128, the size of protrusion 140 can be determined to extend far enough in heating chamber 108 so that the aerosol substrate 128 in substrate carrier 114 is compressed, which can improve the heat conduction through aerosol substrate 128 by eliminating air gaps. In the embodiment shown, it is suitable for protrusion 140 to extend about 0.4mm in heating chamber 108. In other examples, the distance that protrusion 140 extends in heating chamber 108 can be defined as the percentage of the distance across heating chamber 108. For example, the protrusions 140 may extend between 3% and 7%, such as approximately 5%, of the distance across the heating cavity 108. In another embodiment, the limited diameter circumscribed by the protrusions 140 in the heating cavity 108 is between 6.0 mm and 6.8 mm, more preferably between 6.2 mm and 6.5 mm, and especially 6.2 mm (± 0.5 mm). Each of the plurality of protrusions 140 spans a radial distance between 0.2 mm and 0.8 mm, most preferably between 0.2 mm and 0.4 mm.

[0069] About protrusion / dent 140, width corresponds to the distance around the perimeter of sidewall 126.Similarly, its length direction extends transversely to this, generally extends from the base 112 of heating chamber 108 to the open end or extends to flange 138, and its height corresponds to the distance that protrusion extends from sidewall 126.It should be noted that the space between adjacent protrusion 140, sidewall 126 and outer layer 132 matrix carrier 114 defines the area that can be used for air flow.As a result, the distance between adjacent protrusions 140 and / or the height of protrusion 140 (that is, the distance that protrusion 140 extends into heating chamber 108) is smaller, and the difficulty that user sucks to draw air through aerosol generating device 100 is greater (called increased resistance to suction).Obviously, (assuming that protrusion 140 is contacting outer layer 132 of matrix carrier 114), it is the width of protrusion 140 that defines the reduction of airflow channel between sidewall 126 and matrix carrier 114. On the contrary, (assuming that projection 140 is contacting the outer layer 132 of substrate carrier 114 as well), increasing the height of projection 140 leads to more compression of aerosol substrate, which eliminates the air gap in aerosol substrate 128 and also increases the draw resistance. These two parameters can be adjusted to provide satisfactory draw resistance, neither too low nor too high. Heating chamber 108 can also be made larger, to increase the air flow channel between sidewall 126 and substrate carrier 114, but there is a practical limit before heater 124 begins to lose effectiveness due to too large gap. Typically, the gap of 0.2mm to 0.4mm or 0.2mm to 0.3mm around the outer surface of substrate carrier 114 is a kind of good compromise, which allows fine-tuning the draw resistance within an acceptable value by changing the size of projection 140. The air gap around the outside of substrate carrier 114 can also be changed by changing the quantity of projection 140. Any number of protrusions 140 (from one upward) provides at least some of the advantages described herein (increasing the heating area, providing compression, providing conductive heating of the aerosol substrate 128, adjusting the air gap, etc.). Four is the minimum number that reliably maintains the substrate carrier 114 in alignment with the heating chamber 108 centered (i.e., coaxial). In another possible design, there are only three protrusions distributed at a distance of 120 degrees from each other. Designs with less than four protrusions 140 tend to allow the following situation: the substrate carrier 114 is pressed against a portion of the side wall 126 between two protrusions 140. Obviously, for limited space, providing a very large number of protrusions (e.g., thirty or more) tends to allow the following situation: there is very little or no gap between them, which can completely close the airflow path between the outer surface of the substrate carrier 114 and the inner surface of the side wall 126, thereby greatly reducing the ability of the aerosol generating device to provide convective heating. However, in combination with the possibility of providing a hole in the center of the base 112 to define the airflow channel, this design can still be used.Typically, the protrusions 140 are evenly spaced around the perimeter of the sidewall 126, which can help provide uniform compression and heating, but some variations may have asymmetrical placement, depending on the exact effect desired.

[0070] Obviously, the size and number of protrusions 140 also allow the balance between conductive heating and convective heating to be adjusted. By increasing the width of the protrusions 140 that contact the substrate carrier 114 (the distance that the protrusions 140 extend around the perimeter of the sidewall 126), the sidewall 126 that acts as an airflow channel ( Figure 6 and Figure 6 (a) arrow B) available perimeter is reduced, therefore reduced the convection heating that aerosol generating device 100 provides.Yet, because wider projection 140 contacts with substrate carrier 114 on the larger part of perimeter, therefore increased the conduction heating that aerosol generating device 100 provides.If add more projection 140, similar effect will be seen, because the available perimeter for convection of sidewall 126 reduces, and by increasing the total contact surface area between projection 140 and substrate carrier 114, increase conduction channel simultaneously.It should be noted that increasing the length of projection 140 also can reduce the air volume heated by heater 124 in heating chamber 108 and reduce convection heating, increase the contact surface area between projection 140 and substrate carrier simultaneously and increase conduction heating.Increasing the distance that each projection 140 extends in heating chamber 108 can improve conduction heating when not significantly reducing convection heating.Therefore, aerosol generating device 100 can be designed to balance conduction heating type and convection heating type by changing the quantity and size of projection 140, as mentioned above. The heat concentration effect resulting from the relatively thin sidewalls 126 and the use of a relatively low thermal conductivity material (e.g., stainless steel) ensures that conductive heating is an appropriate means of transferring heat to the substrate carrier 114 and subsequently to the aerosol substrate 128, because the portion of the sidewalls 126 that is heated can generally correspond to the location of the protrusions 140, which means that the heat generated is conducted by the protrusions 140 to the substrate carrier 114, rather than away from it. The heating of the sidewalls 126 at locations that are heated but not corresponding to the protrusions 140 produces the above-mentioned convective heating.

[0071] like Figures 1 to 6As shown, the projection 140 is elongated, that is to say, the length of the projection extension is greater than its width. In some cases, the length of the projection 140 can be five times, ten times or even twenty-five times its width. For example, as described above, the projection 140 can extend 0.4mm into the heating chamber 108, and can further be 0.5mm wide and 12mm long in an example. These dimensions are applicable to the heating chamber 108 with a length between 30mm and 40mm. In this example, the projection 140 does not extend the full length of the heating chamber 108, because in the example given, the projection is shorter than the heating chamber 108. Therefore, the projection 140 has a top edge 142a and a bottom edge 142b respectively. The top edge 142a is the part of the projection 140 that is closest to the open end 110 of the heating chamber 108 and also closest to the flange 138. The bottom edge 142b is the end of the projection 140 that is closest to the base 112. Above the top edge 142a (closer to the open end than the top edge 142a) and below the bottom edge 142b (closer to the base 112 than the bottom edge 142b), it can be seen that the side wall 126 is free of protrusions 140, that is, the side wall 126 has no deformations or indentations in these portions. In some examples, the protrusions 140 are longer and extend all the way to the top and / or bottom of the side wall 126, so that one or both of the following are true: the top edge 142a is aligned with the open end 110 (or flange 138) of the heating chamber 108; and, the bottom edge 142b is aligned with the base 112. In fact, in such cases, the top edge 142a and / or the bottom edge 142b may not even exist.

[0072] It may be advantageous that the protrusion 140 does not extend all the way along the length of the heating chamber 108 (e.g., from the base 112 to the flange 138). At the upper end, as will be described below, the top edge 142a of the protrusion 140 can be used as an indicator to let the user ensure that they do not insert the substrate carrier 114 too much into the aerosol generating device 100. However, it can be used not only to heat the area of ​​the substrate carrier 114 containing the aerosol substrate 128, but also in other areas. This is because once the aerosol is generated, it is advantageous to keep its temperature high (higher than room temperature, but not so high as to burn the user) to prevent re-condensation, which in turn will reduce the user experience. Therefore, the effective heating area of ​​the heating chamber 108 extends past (i.e., above the heating chamber 108, closer to the open end) the expected position of the aerosol substrate 128. This means that the heating chamber 108 extends to a higher position than the upper edge 142a of the protrusion 140, or equivalently means that the protrusion 140 does not extend all the way up to the open end of the heating chamber 108. Similarly, compression of the aerosol substrate 128 at the end 134 of the substrate carrier 114 that is inserted into the heating chamber 108 may cause some of the aerosol substrate 128 to fall out of the substrate carrier 114 and soil the heating chamber 108. Therefore, it may be advantageous to place the lower edge 142b of the protrusion 140 further from the base 112 than the expected position of the end 134 of the substrate carrier 114.

[0073] In some embodiments, the projection 140 is not elongated and has a width that is approximately the same as its length. For example, the width of the projection can be the same as the height (e.g., having a square or circular profile in the radial direction), or the length of the projection can be two to five times the width. It should be noted that even when the projection 140 is not elongated, the centering effect provided by the projection 140 is also achievable. In some instances, there may be multiple groups of projections 140, for example, one group of projections above is close to the open end of the heating chamber 108, and one group of projections below is spaced apart from the one group of projections above and is positioned close to the base 112. This can help ensure that the matrix carrier 114 remains in a coaxial arrangement while reducing the suction resistance introduced by a single group of projections 140 at the same distance. The two groups of projections 140 can be substantially the same, or their length or width or the number or position of projections 140 arranged around the sidewall 126 can vary.

[0074] In the side view, the protrusion 140 is shown as having a trapezoidal profile. What is meant here is that the profile along the length of each protrusion 140 (e.g., the longitudinal central cross-section of the protrusion 140) is generally trapezoidal. That is, the upper edge 142a is generally planar and tapers to merge with the side wall 126 near the open end 110 of the heating chamber 108. In other words, the profile of the upper edge 142a is a beveled shape. Similarly, the protrusion 140 has a lower portion 142b, which is generally planar and tapers to merge with the side wall 126 near the base 112 of the heating chamber 108. That is, the profile of the lower edge 142b is a beveled shape. In other embodiments, the upper edge 142a and / or the lower edge 142b do not taper toward the side wall 126, but extend from the side wall 126 at an angle of approximately 90 degrees. In yet other embodiments, the upper edge 142a and / or the lower edge 142b have a curved or rounded shape. Bridging the upper edge 142a and the lower edge 142b is a generally planar region that contacts and / or compresses the substrate carrier 114. The planar contact portion can help provide uniform compression and conductive heating. In other examples, the planar portion can alternatively be a curved portion that bends outward to contact the substrate carrier 128, such as having a polygonal or curved profile (e.g., a portion of a circle).

[0075] In the case where the protrusion 140 has an upper edge 142a, the protrusion 140 also serves to prevent the substrate carrier 114 from being over-inserted. Figure 4 and Figure 6 As most clearly shown, the substrate carrier 114 has a lower portion containing an aerosol substrate 128, which ends halfway along the substrate carrier 114 at the boundary of the aerosol substrate 128. The aerosol substrate 128 is generally more compressible than other regions 130 of the substrate carrier 114. Therefore, due to the reduced compressibility of other regions 130 of the substrate carrier 114, a user inserting the substrate carrier 114 feels an increase in resistance when the upper edge 142a of the projection 140 is aligned with the boundary of the aerosol substrate 128. To achieve this, the portion of the base 112 that the substrate carrier 114 contacts and the top edge 142a of the projection 140 should be spaced apart by the same length of the substrate carrier 114 occupied by the aerosol substrate 128. In some examples, the aerosol substrate 128 occupies about 20 mm of the substrate carrier 114 so that when the substrate carrier 114 is inserted into the heating chamber 108, the spacing between the top edge 142a of the protrusion 140 and the portion of the base that the substrate carrier contacts is also about 20 mm.

[0076] As shown, the base 112 also includes a platform 148. The platform 148 is formed by a single step of pressing the base 112 from below (e.g., by hydroforming, mechanical pressure, as part of the formation of the heating cavity 108) to leave an indentation on the outer surface (lower face) of the base 112 and a platform 148 on the inner surface (upper face, inside the heating cavity 108) of the base 112. When the platform 148 is formed in this manner, such as by corresponding indentations, these terms may be used interchangeably. In other cases, the platform 148 may be formed by a separate part attached to the base 112 separately, or by milling away a portion of the base 112 to leave the platform 148; in either case, there need not be a corresponding indentation. The latter case may provide more achievable variety in the shape of the platform 148, because it does not rely on deformation of the base 112, which (although a convenient way) limits the complexity of the shape that can be selected. Although the shape shown is generally circular, there are of course a wide variety of shapes that will achieve the desired effects detailed herein, including but not limited to: polygonal shapes, curvilinear shapes, multiple shapes including one or more of these types. In fact, although shown as a centrally located platform 148, in some cases there may be one or more platform elements spaced from the center, such as at the edge of the heating chamber 108. Typically, the platform 148 has a generally flat top, but hemispherical platforms or platforms with a rounded dome shape on top are also contemplated.

[0077] As described above, the distance between the top edge 142a of the protrusion 140 and the portion of the base 112 that the substrate carrier 114 contacts can be carefully selected to match the length of the aerosol substrate 128 to indicate to the user that they have inserted the substrate carrier 114 as far into the aerosol generating device 100 as they should. In the case where there is no platform 148 on the base 112, this simply means that the distance from the base 112 to the top edge 142a of the protrusion 140 should match the length of the aerosol substrate 128. When the platform 148 is present, then the length of the aerosol substrate 128 should correspond to the distance between the top edge 142a of the protrusion 140 and the uppermost portion of the platform 148 (i.e., in some examples, the portion closest to the open end 110 of the heating chamber 108). In yet another example, the distance between the top edge 142a of the protrusion 140 and the uppermost portion of the platform 148 is slightly less than the length of the aerosol substrate 128. 148, and the aerosol substrate 128 of the end 134 of substrate carrier 114 is compressed.In fact, even when there is not protrusion 140 on the inner surface of sidewall 126, this compression effect can also take place.This compression can help to prevent the aerosol substrate 128 of the end 134 of substrate carrier 114 from falling out and falling in heating chamber 108, has reduced the needs of cleaning heating chamber 108 thus, and cleaning may be a complicated and difficult task.In addition, this compression helps to compress the end 134 of substrate carrier 114, when using the protrusion 140 extending from sidewall 126 to compress this zone, it is inappropriate to alleviate the above-mentioned influence, because the protrusion tends to increase the possibility that aerosol substrate 128 falls out from substrate carrier 114.

[0078] The platform 148 also provides an area that can collect any aerosol substrate 128 that falls out of the substrate carrier 114 without obstructing the airflow path of the tip 134 entering the substrate carrier 114. For example, the platform 148 divides the lower end of the heating chamber 108 (i.e., the portion closest to the base 112) into a raised portion that forms the platform 148 and a lower portion that forms the rest of the base 112. The lower portion can accommodate loose, small amounts of aerosol substrate 128 that fall out of the substrate carrier 114, while air can still flow through these loose, small amounts of aerosol substrate 128 and enter this end of the substrate carrier 114. To achieve this effect, the platform 148 can be about 1 mm higher than the rest of the base 112. The diameter that the platform 148 has can be smaller than the diameter of the substrate carrier 114, so that the platform does not prevent air from flowing through the aerosol substrate 128. Preferably, the platform 148 has a diameter between 0.5 mm and 0.2 mm, most preferably between 0.45 mm and 0.35 mm, for example 0.4 mm (± 0.03 mm).

[0079] The aerosol generating device 100 has a user operable button 116. In a first embodiment, the user operable button 116 is located on a side wall 118 of the housing 102. The user operable button 116 is arranged so that once the user operable button 116 is actuated, for example by pressing the user operable button 116, the aerosol generating device 100 is activated to heat the aerosol substrate 128 to generate an aerosol for inhalation. In some embodiments, the user operable button 116 is also arranged to allow the user to activate other functions of the aerosol generating device 100, and / or illuminate to indicate the status of the aerosol generating device 100. In other examples, a single light or multiple lights (e.g., one or more LEDs or other suitable light sources) may be provided to indicate the status of the aerosol generating device 100. In this context, the status can refer to one or more of the following: remaining battery power, heater status (e.g., on, off, fault, etc.), device status (e.g., ready to suck or not suck), or other status indications, such as an error mode, an indication of the number of sucks used or remaining before the power runs out or the entire matrix carrier 114, and the like.

[0080] In a first embodiment, the aerosol generating device 100 is electric. That is, the aerosol generating device is arranged to use electric power to heat the aerosol substrate 128. For this purpose, the aerosol generating device 100 has a power source 120, such as a battery. The power source 120 is connected to a control circuit system 122. The control circuit system 122 is further connected to a heater 124. A user-operable button 116 is arranged to connect and disconnect the power source 120 to the heater 124 via the control circuit system 122. In this embodiment, the power source 120 is positioned toward the first end 104 of the aerosol generating device 100. This allows the power source 120 to be spaced apart from the heater 124, which is positioned toward the second end 106 of the aerosol generating device 100. In other embodiments, the heating chamber 108 is heated in other ways, such as by burning a combustible gas.

[0081] The heater 124 is attached to the outer surface of the heating chamber 108. The heater 124 is disposed on a metal layer 144, which itself is in contact with the outer surface of the sidewall 126. The metal layer 144 forms a band around the heating chamber 108, thereby conforming to the shape of the outer surface of the sidewall 126. The heater 124 is shown as being centrally mounted on the metal layer 144, wherein the metal layer 144 extends an equal distance upward and downward beyond the heater 124. As shown, the heater 124 is completely located on the metal layer 144, so that the area covered by the metal layer 144 is larger than the area covered by the heater 124. Figures 1 to 6The heater 124 is shown attached to the middle portion of the heating cavity 108, between the base 112 and the open end 110, and to the area of ​​the outer surface covered by the metal layer 114. It should be noted that in other embodiments, the heater 124 can be attached to other parts of the heating cavity 108, or can be contained within the sidewall 126 of the heating cavity 108, and it is not necessary for the outside of the heating cavity 108 to include the metal layer 144.

[0082] The heater 124 includes a heating element 164, an electrical connection track 150, and a backing film 166, such as Figure 7 As shown. The heating element 164 is configured so that when an electric current passes through the heating element 164, the heating element 164 becomes hot and the temperature increases. The heating element 164 is shaped to not contain sharp corners. Sharp corners can cause hot spots in the heater 124, or create melting points. The width of the heating element 164 is also uniform, and the portions of the element 164 that are close to each other remain approximately equidistantly spaced. Figure 7 The heating element 164 of FIG. 1 shows two resistive paths 164a, 164b, each of which takes a serpentine path over the area of ​​the heater 124, thereby covering as much area as possible while meeting the above criteria. These paths 164a, 164b are Figure 7 164a, 164b do not cross each other as this would create a short circuit. The heating element 164 is configured to have a resistance in order to create the correct power density for the desired heating level. In some examples, the heating element 164 has a resistance between 0.4Ω and 2.0Ω, particularly advantageously between 0.5Ω and 1.5Ω, and more particularly between 0.6Ω and 0.7Ω.

[0083] The electrical connection track 150 is shown as part of the heater 124, but may be replaced with wires or other connection elements in some embodiments. The electrical connection 150 is used to provide power to the heating element 164 and complete an electrical circuit with the power source 120. The electrical connection track 150 is shown extending vertically downward from the heating element 164. After the heater 124 is in place, the electrical connection 150 extends through the base 112 of the heating cavity 108 and through the base 156 of the insulation member 152 to connect with the control circuit system 122.

[0084] The backing film 166 can be a single sheet with the heating element 164 attached, or can form an envelope that sandwiches the heating element between two sheets 166a, 166b. In some embodiments, the backing film 166 is formed of polyimide. In some embodiments, the thickness of the backing film 166 is minimized to reduce the thermal mass of the heater 124. For example, the thickness of the backing film 166 can be 50 μm, or 40 μm, or 25 μm.

[0085] A heating element 164 is attached to the side wall 108. Figure 7 In the embodiment of the present invention, by carefully selecting the size of the heater 124, the heating element 164 is configured to wrap around the heating cavity 108. This ensures that the heat generated by the heater 124 is substantially evenly distributed around the surface covered by the heater 124. It should be noted that in some examples, the heater 124 can wrap around the heating cavity 108 an integer number of times, rather than a full circle.

[0086] It should also be noted that the height of the heater 124 is approximately 14 mm to 15 mm. The circumference (or length before being applied to the heating chamber 108) of the heater 124 is approximately 24 mm to 25 mm. The height of the heating element 164 can be less than 14 mm. This allows the heating element 164 to be completely positioned within the backing film 166 of the heater 124, which has a border around the heating element 164. Therefore, in some embodiments, the area covered by the heater 124 can be approximately 3.75 cm 2 .

[0087] The power used by the heater 124 is provided by a power supply 120, which is in the form of a battery cell (or battery) in the present embodiment. The voltage provided by the power supply 120 is a regulated voltage or a boost voltage. For example, the power supply 120 can be configured to generate a voltage within the range of 2.8V to 4.2V. In an example, the power supply 120 is configured to generate a voltage of 3.7V. Taking the exemplary resistance of the heating element 164 in one embodiment as 0.6Ω and the exemplary voltage as 3.7V as an example, this will generate a power output of about 30W in the heating element 164. It should be noted that based on the exemplary resistance and voltage, the power output can be between 15W and 50W. The battery cell forming the power supply 120 can be a rechargeable battery cell, or alternatively can be a disposable battery cell 120. The power supply is generally configured to provide power for 20 or more thermal cycles. This enables the user to use a complete pack of 20 substrate carriers 114 to a single charge of the aerosol generating device 100. The battery cell may be a lithium ion battery cell, or any other type of commercially available battery cell. For example, it may be a 18650 battery cell or a 18350 battery cell. If the battery cell is a 18350 battery cell, then the aerosol generating device 100 may be configured to store enough power for 12 thermal cycles or indeed 20 thermal cycles to allow the user to consume 12 or even 20 substrate carriers 114.

[0088] An important value for the heater 124 is the power per unit area it produces. This is a measure of how much heat the heater 124 can provide to the area it is in contact with (in this case, the heating chamber 108). For the example described, this ranges from 4W / cm 2 Up to 13.5W / cm 2 Heaters are usually rated at 2W / cm 2 With 10W / cm 2 Therefore, for some of these embodiments, a copper or other conductive metal layer 144 may be disposed on the heating cavity 108 to effectively conduct heat from the heater 124 and reduce the possibility of damaging the heater 124.

[0089] The power delivered by the heater 124 may be constant in some embodiments, but may not be constant in other embodiments. For example, the heater 124 may provide variable power through a duty cycle, or more specifically, a pulse width modulated cycle. This allows the power to be delivered in pulses, and the time-averaged power output of the heater 124 to be easily controlled by simply selecting the ratio of the "on" time to the "off" time. The power level output by the heater 124 may also be controlled by additional control means, such as current or voltage manipulation.

[0090] like Figure 7 As shown, the aerosol generating device 100 has a temperature sensor 170, which is used to detect the temperature of the heater 124 or the temperature of the environment around the heater 124. The temperature sensor 170 can be, for example, a thermistor, a thermocouple, or any other thermometer. For example, the thermistor can be formed by a glass bead that encapsulates a resistive material connected to a voltmeter and has a known current flowing through the material. Therefore, when the temperature of the glass changes, the resistance of the resistive material changes in a predictable manner, and such a temperature can be determined by the voltage drop across the resistive material under a constant current (constant voltage mode is also possible). In some embodiments, the temperature sensor 170 is positioned on the surface of the heating cavity 108, such as in a dent formed in the outer surface of the heating cavity 108. The dent can be one of those described elsewhere herein, such as as part of the protrusion 140, or the dent can be a dent specifically provided for accommodating the temperature sensor 170. In the embodiment shown, the temperature sensor 170 is provided on the backing layer 166 of the heater 124. In other embodiments, the temperature sensor 170 is integral to the heating element 164 of the heater 124 in the sense that the temperature is detected by monitoring changes in the resistance of the heating element 164 .

[0091] In the aerosol generating device 100 of the first embodiment, the time when the first puff is taken after the aerosol generating device 100 is activated is an important parameter. The user of the aerosol generating device 100 will find it best to start inhaling the aerosol from the substrate carrier 128 as soon as possible, wherein the lag time between activating the aerosol generating device 100 and inhaling the aerosol from the substrate carrier 128 is minimized. Therefore, during the first stage of heating, the power supply 120 provides 100% of the available power to the heater 124, for example by setting the duty cycle to normally on or by manipulating the product of voltage and current to the maximum possible value. This can be used for a period of 30 seconds, or more preferably for a period of 20 seconds, or for any period until the temperature sensor 170 gives a reading corresponding to 240°C. Typically, the substrate carrier 114 can operate optimally at 180°C, but it may be advantageous to heat the temperature sensor 170 to a temperature above this so that the user can extract the aerosol from the substrate carrier 114 as quickly as possible. This is done because the temperature of the aerosol substrate 128 typically lags (i.e., is lower than) the temperature detected by the temperature sensor 170, since the aerosol substrate 128 is heated by convection of warm hot air passing through the aerosol substrate 128 and, to some extent, by conduction between the protrusions 140 and the outer surface of the substrate carrier 114. In contrast, the temperature sensor 170 maintains good thermal contact with the heater 124, and thus measures a temperature closer to the temperature of the heater 124 than to the temperature of the aerosol substrate 128. In practice, it can be difficult to accurately measure the temperature of the aerosol substrate 128, so the heating cycle is typically determined empirically, where different heating curves and heater temperatures are tried and the aerosol generated by the aerosol substrate 128 is monitored for different aerosol components formed at that temperature. The optimal cycle provides the aerosol as quickly as possible, but avoids the generation of combustion products due to overheating of the aerosol substrate 128.

[0092] The temperature detected by the temperature sensor 170 can be used to set the power level delivered by the battery cell 120, for example by forming a feedback loop in which the temperature detected by the temperature sensor 170 is used to control the heater power cycle. The heating cycle described below can be used when the user wants to consume a single substrate carrier 114.

[0093] In a first embodiment, the heater 124 extends around the heating cavity 108. That is, the heater 124 surrounds the heating cavity 108. In more detail, the heater 124 extends around the sidewall 126 of the heating cavity 108, but does not extend around the base 112 of the heating cavity 108. The heater 124 does not extend over the entire sidewall 126 of the heating cavity 108. Rather, the heater extends all the way around the sidewall 126, but only extends for a portion of the length of the sidewall 126, in this context, from the base 112 of the heating cavity 108 to the open end 110. In other embodiments, the heater 124 extends over the entire length of the sidewall 126. In still other embodiments, the heater 124 includes two heating portions separated by a gap, leaving a central portion of the heating cavity 108 uncovered, for example, a portion of the sidewall 126 midway between the base 112 and the open end 110 of the heating cavity 108. In other embodiments, since the heating cavity 108 is cup-shaped, the heater 110 is similarly cup-shaped, for example, the heater extends completely around the base 112 of the heating cavity 108. In yet other embodiments, the heater 124 includes a plurality of heating elements 164 distributed about the heating cavity 108. In some embodiments, there are spaces between the heating elements 164; in other embodiments, the heating elements overlap each other. In some embodiments, the heating elements 164 can be spaced apart (e.g., laterally) around the circumference of the heating cavity 108 or the sidewall 126, and in other embodiments, the heating elements 164 can be spaced apart (e.g., longitudinally) along the length of the heating cavity 108 or the sidewall 126. It should be understood that the heater 124 of the first embodiment is disposed on the outer surface of the heating cavity 108, on the outside of the heating cavity 108. The heater 124 is disposed in good thermal contact with the heating cavity 108 to allow good heat transfer between the heater 124 and the heating cavity 108.

[0094] The metal layer 144 can be formed of copper or any other material (e.g., metal or alloy) with high thermal conductivity, such as gold or silver. In this context, high thermal conductivity can refer to a metal or alloy with a thermal conductivity of 150W / mK or higher. The metal layer 144 can be applied by any suitable method (e.g., electroplating). Other methods of applying the layer 144 include attaching a metal tape to the heating chamber 108, chemical vapor deposition, physical vapor deposition, and the like. Although electroplating is a convenient method for applying the layer 144, the portion of the layer 144 that needs to be plated is conductive. Other deposition methods are not like this, and these other methods provide the possibility that the heating chamber 108 is formed of a non-conductive material (e.g., ceramic), which may have useful thermal properties. Similarly, when the layer is described as metallic, although this should generally be understood as "formed of a metal or alloy", in this context it refers to a relatively high thermal conductivity material (>150W / mK). When the metal layer 144 is electroplated on the sidewall 126, it may be necessary to first form a "pre-plating layer" to ensure that the electroplated layer adheres to the outer surface. For example, when the metal layer 144 is copper and the sidewall 126 is stainless steel, a nickel pre-plating layer is often used to ensure good adhesion. Electroplated and deposited layers have the advantage that there is direct contact between the metal layer 144 and the material of the sidewall 126, thereby improving heat conduction between the two components.

[0095] Regardless of the method used to form the metal layer 144, the thickness of the layer 144 is typically slightly thinner than the thickness of the sidewalls 126. For example, the thickness of the metal layer may range between 10 μm and 50 μm, or between 10 μm and 30 μm, such as about 20 μm. When a pre-plating layer is used, the pre-plating layer is even thinner than the metal layer 144, such as 10 μm or even 5 μm. As described in more detail below, the purpose of the metal layer 144 is to distribute the heat generated by the heater 124 over a larger area than the area occupied by the heater 124. Once this effect is satisfactorily achieved, there is little benefit in making the metal layer 144 thicker, as this simply increases the thermal mass and reduces the efficiency of the aerosol generating device 100.

[0096] from Figures 1 to 6It is apparent that the metal layer 144 extends over only a portion of the outer surface of the side wall 126. This not only reduces the thermal mass of the heating chamber 108, but also allows the heating area to be defined. In general, the metal layer 144 has a higher thermal conductivity than the side wall 126, so the heat generated by the heater 124 is quickly spread over the area covered by the metal layer 144, but because the side wall 126 is thinner than the metal layer 144 and has a relatively lower thermal conductivity, the heat is still relatively concentrated in the area of ​​the side wall 126 covered by the metal layer 144. Selective electroplating is achieved by masking multiple portions of the heating chamber 108 with a suitable tape (e.g., polyester or polyimide) or silicone rubber mold. Other plating methods may use different tapes or masking methods as appropriate.

[0097] like Figures 1 to 6 As shown, the metal layer 144 overlaps the entire length of the heating cavity 108 along which the protrusion / indentation 140 extends. This means that the protrusion 140 is heated by the thermal conductivity effect of the metal layer 144, which in turn allows the protrusion 140 to provide the above-mentioned conductive heating. The extent of the metal layer 144 generally corresponds to the extent of the heating area, and therefore, it is generally not necessary to extend the metal layer to the top and bottom of the heating cavity 108 (i.e., closest to the open end and the base 112). As described above, the area of ​​the substrate carrier 114 to be heated begins not far above the boundary of the aerosol substrate 128 and extends toward the end 134 of the substrate carrier 114, but in many cases does not include the end 134 of the substrate carrier 114. As described above, the role of the metal layer 144 is to spread the heat generated by the heater 124 over an area larger than the area occupied by the heater 124 itself. This means that the heater 124 can be provided with more than the rated power W / cm based on the heater 124. 2 The effective area of ​​heater 124 is greater than the surface area actually occupied by heater 124 because the heat generated is spread over a larger area.

[0098] Since the heating zone can be defined by multiple portions of the sidewall 126 covered by the metal layer 144, the exact placement of the heater 124 on the outside of the heating chamber 108 is less important. For example, the heater 124 does not need to be aligned at a specific distance from the top or bottom of the sidewall 126, instead the metal layer 144 can be formed in a very specific area and the heater 124 can be placed on top of the metal layer 144 to spread the heat over the metal layer 144 area or heating zone, as described above. It is usually easier to standardize the masking process for electroplating or deposition than to accurately align the heater 124.

[0099] Similarly, when there are protrusions 140 formed by making indentations in the sidewall 126, these indentations represent portions of the sidewall 126 that are not in contact with the heater 124 wrapped around the heating cavity 108; instead, the heater 124 tends to bridge over the indentations leaving gaps. The metal layer 144 can help mitigate this effect because even portions of the sidewall 126 that are not directly in contact with the heater 124 receive heat from the heater 124 by conduction via the metal layer 144. In some cases, the heater element 164 can be arranged to minimize the overlap between the heater element 164 and the indentations on the outer surface of the sidewall 126, such as by arranging the heater element 164 to span the indentations rather than extending along the indentations. In other cases, the heater 124 is positioned on the outer surface of the sidewall 126 so that the portion of the heater 124 that covers the indentations is the gap between the heater elements 164. Regardless of which method is chosen to mitigate the effect of the heater 124 covering the indentations, the metal layer 144 mitigates this effect by conducting heat into the indentations. Additionally, metal layer 144 provides additional thickness to the indented areas of sidewalls 126, thereby providing additional structural support to these areas. In fact, the additional thickness provided by metal layer 126 strengthens thin sidewalls 126 in all portions covered by metal layer 144.

[0100] The metal layer 144 may be formed before or after the step of forming the indentation in the outer surface sidewall 126 to provide the protrusion 140 extending into the heating cavity 108. It is preferred to form the indentation before the metal layer because once the metal layer 144 is formed, steps such as annealing tend to damage the metal layer 144, and stamping the sidewall 126 to form the protrusion 140 becomes more difficult due to the added thickness of the sidewall 126 in combination with the metal layer 144. However, where the indentation is formed before the metal layer 144 is formed on the sidewall 126, it is easier to form the metal layer 144 so that it extends beyond the indentation (i.e., above and below) because it is difficult to mask the outer surface of the sidewall 126 so that it extends into the indentation. Any gap between the mask and the sidewall 126 may allow the metal layer 144 to be deposited below the mask.

[0101] An insulating layer 146 is wrapped around the heater 124. This layer 146 is under tension, thus providing a compressive force on the heater 124, pressing the heater 124 tightly against the outer surface of the side wall 126. Advantageously, this insulating layer 146 is a heat shrink material. This allows the insulating layer 146 to be tightly wrapped around the heating cavity (above the heater 124, the metal layer 144, etc.) and then heated. Once heated, the insulating layer 146 shrinks and presses the heater 124 tightly against the outer surface of the side wall 126 of the heating cavity 108. This eliminates any air gap between the heater 124 and the side wall 126, and keeps the heater 124 in very good thermal contact with the side wall. This in turn ensures good efficiency, because the heat generated by the heater 124 causes the side wall (and subsequently the aerosol substrate 128) to heat up, and is not wasted to heat the air or leak in other ways.

[0102] Preferred embodiments use heat shrinkable materials that shrink only in one dimension, such as treated polyimide tapes. For example, in the example of polyimide tapes, the tape can be configured to shrink only in the length direction. This means that the tape can be wrapped around the heating chamber 108 and the heater 124, and when heated, it will shrink and press the heater 124 against the sidewall 126. Because the insulation layer 146 shrinks in the length direction, the force generated in this way is consistent and directed inward. If the tape shrinks in the transverse (width) direction, this may cause the heater 124 or the tape itself to wrinkle. This in turn introduces gaps and reduces the efficiency of the aerosol generating device 100.

[0103] See also Figures 3 to 6 , the substrate carrier 114 includes a prepackaged amount of aerosol substrate 128 and an aerosol collection area 130 wrapped in an outer layer 132. The aerosol substrate 128 is positioned toward a first end 134 of the substrate carrier 114. The aerosol substrate 128 extends across the entire width of the substrate carrier 114 within the outer layer 132. They also partially abut each other along the substrate carrier 114 and meet at the boundary. In general, the substrate carrier 114 is generally cylindrical. The aerosol generating device 100 is Figure 1 and Figure 2 is shown without the matrix carrier 114. Figure 3 and Figure 4 , the substrate carrier 114 is shown above the aerosol generating device 100, but not loaded in the aerosol generating device 100. Figure 5 and Figure 6 , the substrate carrier 114 is shown to be loaded in the aerosol generating device 100.

[0104] When a user wishes to use the aerosol generating device 100, the user first loads the aerosol generating device 100 with the substrate carrier 114. This involves inserting the substrate carrier 114 into the heating cavity 108. The insertion of the substrate carrier 114 into the heating cavity 108 is oriented so that the first end 134 of the substrate carrier 114 (the aerosol substrate 128 is positioned toward this end) enters the heating cavity 108. The substrate carrier 114 is inserted into the heating cavity 108 until the first end 134 of the substrate carrier 114 rests on a platform 148 extending inwardly from the base 112 of the heating cavity 108, that is, until the substrate carrier 114 can no longer be inserted further into the heating cavity 108. In the illustrated embodiment, as described above, the interaction between the upper edge 142a of the protrusion 140 and the boundary of the aerosol substrate 128 and the adjacent less compressible region of the substrate carrier 114 has the additional effect of alerting the user that the substrate carrier 114 has been inserted far enough into the aerosol generating device 100. From Figure 3 and Figure 4 108, only a portion of the length of the substrate carrier 114 is within the heating cavity 108. The remaining length of the substrate carrier 114 protrudes from the heating cavity 108. At least a portion of the remaining length of the substrate carrier 114 also protrudes from the second end 106 of the aerosol generating device 100. In a first embodiment, all of the remaining length of the substrate carrier 114 protrudes from the second end 106 of the aerosol generating device 100. That is, the open end 110 of the heating cavity 108 coincides with the second end 106 of the aerosol generating device 100. In other embodiments, the entire or substantially the entire substrate carrier 114 may be received in the aerosol generating device 100 such that none or substantially none of the substrate carrier 114 protrudes from the aerosol generating device 100.

[0105] With the substrate carrier 114 inserted into the heating cavity 108, the aerosol substrate 128 within the substrate carrier 114 is at least partially disposed within the heating cavity 108. In a first embodiment, the aerosol substrate 128 is completely within the heating cavity 108. In fact, the prepackaged amount of the aerosol substrate 128 in the substrate carrier 114 is disposed along the substrate carrier 114 extending from the first end 134 of the substrate carrier 114 a distance that is approximately (or even exactly) equal to the interior height of the heating cavity 108 from the base 112 of the heating cavity 108 to the open end 110. This is effectively the same as the length of the side wall 126 of the heating cavity 108 within the interior of the heating cavity 108.

[0106] When substrate carrier 114 is loaded in aerosol generating device 100, user uses user-operable button 116 to open aerosol generating device 100. This makes the electric power from power supply 120 be provided to heater 124 via control circuit system 122 (and under its control). Heater 124 conducts heat to aerosol substrate 128 via projection 140, thus aerosol substrate 128 is heated to a temperature at which it can begin to release steam. Once heated to a temperature at which steam can begin to be released, user can inhale steam by sucking steam through second end 136 of substrate carrier 114. That is, steam is produced from aerosol substrate 128 at first end 134 of substrate carrier 114 in heating chamber 108, and is sucked to second end 136 of substrate carrier along the length of substrate carrier 114, through steam collection area 130 in substrate carrier 114, where steam enters user's mouth. Figure 6 Arrow A in FIG. 3 shows this flow of vapor.

[0107] It should be understood that when the user follows Figure 6 When the vapor is sucked in the direction of arrow A, the vapor flows out from the vicinity of the aerosol matrix 128 in the heating chamber 108. This action draws ambient air from the environment surrounding the aerosol generating device 100 (via Figure 6 Indicated by arrow B, and Figure 6 (a) in more detail shown in the flow path) is drawn into the heating chamber 108. Then, the ambient air is heated by the heater 124, which in turn heats the aerosol substrate 128 to generate an aerosol. More specifically, in the first embodiment, the air enters the heating chamber 108 through the space between the sidewall 126 and the outer layer 132 of the substrate carrier 114 disposed in the heating chamber 108. For this purpose, the outer diameter of the substrate carrier 114 is smaller than the inner diameter of the heating chamber 108. More specifically, in the first embodiment, the inner diameter of the heating chamber 108 (when no protrusions are provided, for example, when there is no protrusion 140 or between the protrusions) is 10mm or less, preferably 8mm or less, and most preferably about 7.6mm. This allows the diameter of the substrate carrier 114 to be about 7.0mm (±0.1mm) (when not compressed by the protrusion 140). This corresponds to an outer circumference of 21mm to 22mm, or more preferably 21.75mm. In other words, the space between the substrate carrier 114 and the sidewall 126 of the heating chamber 108 is most preferably about 0.1 mm. In other variations, the space is at least 0.2 mm, and in some instances up to 0.3 mm. Figure 6 Arrow B in FIG. 1 shows the direction in which air is drawn into the heating chamber 108 .

[0108] When the user activates the aerosol generating device 100 by actuating the user-operable button 116, the aerosol generating device 100 heats the aerosol substrate 128 to a temperature sufficient to vaporize a portion of the aerosol substrate 128. In more detail, the control circuit system 122 provides electrical power from the power supply 120 to the heater 124 to heat the aerosol substrate 128 to a first temperature. When the aerosol substrate 128 reaches the first temperature, the components 128 of the aerosol substrate begin to vaporize, that is, the aerosol substrate produces steam. Once the steam is produced, the user can inhale the steam through the second end 136 of the substrate carrier 114. In some scenarios, the user may know that the aerosol generating device 100 needs a certain time to heat the aerosol substrate 128 to the first temperature and to start the aerosol substrate 128 to produce steam. This means that the user can judge when to start inhaling the steam. In other scenarios, the aerosol generating device 100 is arranged to send an indication that the steam is available for inhalation to the user. Indeed, in a first embodiment, the control circuit system 122 illuminates the user-operable button 116 when the aerosol substrate 128 has been at the first temperature for an initial period of time. In other embodiments, the indication is provided by another indicator, such as by producing an audio sound or by vibrating a vibrator. Similarly, in other embodiments, the indication is provided after a fixed time after the aerosol generating device 100 is activated, once the heater 124 reaches the operating temperature, or after some other event occurs.

[0109] The user can continue to inhale the vapor for the entire time that the aerosol matrix 128 can continue to generate vapor, for example, for the entire time that the aerosol matrix 128 has vaporized the remaining vaporizable components into suitable vapor. The control circuit system 122 adjusts the electric power provided to the heater 124 to ensure that the temperature of the aerosol matrix 128 does not exceed the threshold level. Specifically, at a specific temperature depending on the composition of the aerosol matrix 128, the aerosol matrix 128 will begin to burn. This is not a desired effect, and temperatures above and at this temperature are avoided. To help this, the aerosol generating device 100 is provided with a temperature sensor (not shown). The control circuit system 122 is arranged to receive an indication of the temperature of the aerosol matrix 128 from the temperature sensor, and use the indication to control the electric power provided to the heater 124. For example, in one scenario, the control circuit system 122 provides the maximum electric power to the heater 124 during the initial time period until the heater or cavity reaches a first temperature. Subsequently, once the aerosol substrate 128 reaches the first temperature, the control circuit system 122 stops providing electrical power to the heater 124 for a second period of time until the aerosol substrate 128 reaches a second temperature lower than the first temperature. Subsequently, once the heater 124 reaches the second temperature, the control circuit system 122 starts providing electrical power to the heater 124 for a third period of time until the heater 124 reaches the first temperature again. This can continue until the aerosol substrate 128 is exhausted (i.e., all aerosol that can be generated by heating has been generated) or the user stops using the aerosol generating device 100. In another scenario, once the first temperature is reached, the control circuit system 122 reduces the electrical power provided to the heater 124 to maintain the aerosol substrate 128 at the first temperature without increasing the temperature of the aerosol substrate 128.

[0110] A single inhalation by a user is often referred to as a “puff.” In some scenarios, it is desirable to simulate the smoking experience, which means that the aerosol-generating device 100 is typically able to contain enough aerosol substrate 128 to provide ten to fifteen puffs.

[0111] In some embodiments, the control circuit system 122 is configured to count the sucks and turn off the heater 124 after the user has taken ten to fifteen sucks. The suck counting is performed in one of a variety of different ways. In some embodiments, the control circuit system 122 determines when the temperature drops during the sucking process when fresh cold air flows through the temperature sensor 170, causing the cooling detected by the temperature sensor. In other embodiments, the airflow is directly detected using a flow detector. Other suitable methods are clear to the technician. In other embodiments, the control circuit system additionally or alternatively turns off the heater 124 after a predetermined amount of time has passed since the first suck. This can help reduce power consumption and provide backup for turning off in the event that the suck counter fails to correctly record the predetermined number of sucks that have been taken.

[0112] In some instances, the control circuit system 122 is configured to power the heater 124 so that it follows a predetermined heating cycle that requires a predetermined amount of time to complete. Once the cycle is complete, the heater 124 is completely turned off. In some cases, this cycle can utilize a feedback loop between the heater 124 and a temperature sensor (not shown). For example, the heating cycle can be parameterized with a series of temperatures to which the heater 124 (or more accurately, the temperature sensor) is heated or allowed to cool. The temperature and duration of such a heating cycle can be determined empirically to optimize the temperature of the aerosol substrate 128. This may be necessary because it may be impractical or misleading to directly measure the temperature of the aerosol substrate, for example, when the outer layer of the aerosol substrate 128 has a different temperature from the core.

[0113] In the following examples, the time to the first sucking is 20 seconds. After this point, the power level provided to the heater 124 is reduced from 100%, so that the temperature is kept constant at about 240 ℃ in the time of about 20 seconds. Then, the power provided to the heater 124 can be further reduced, so that the temperature reading recorded by the temperature sensor 170 is about 200 ℃. This temperature can be kept for about 60 seconds. The power level can be further reduced then, so that the temperature measured by the temperature sensor 170 drops to the operating temperature of the substrate carrier 114, which is about 180 ℃ in this example. This temperature can be kept for 140 seconds. This time interval can be determined by the time length that the substrate carrier 114 can be used. For example, the substrate carrier 114 can stop producing aerosol after the time period set, and therefore the heating cycle can be allowed to continue this duration in the time period when the temperature is set to 180 ℃. After this point, the power provided to the heater 124 can be reduced to zero. Even when the heater 124 is turned off, the aerosol or vapor generated when the heater 124 is turned on can still be sucked out of the aerosol generating device 100 by the user. Therefore, even when the heater 124 is turned off, the user can be alerted to this situation by the visual indicator remaining on, but the heater 124 has been turned off to prepare for the end of the aerosol inhalation process. In some embodiments, this set period can be 20 seconds. In some embodiments, the total duration of the heating cycle can be about 4 minutes.

[0114] Above-mentioned exemplary thermal cycle can be changed by user using substrate carrier 114.When user draws aerosol from substrate carrier 114, user's breathing encourages cold air to flow to the base 112 of heating chamber 108 through the open end of heating chamber 108, thereby flows through heater 124 downwards.Then, air can enter substrate carrier 114 through the tip 134 of substrate carrier 114.Cold air enters the inner chamber of heating chamber 108 and reduces the temperature measured by temperature sensor 170, because cold air replaces pre-existing hot air.When temperature sensor 170 senses that temperature has reduced, this can be used to increase the power that battery cell provides to heater, so that temperature sensor 170 is heated back to the operating temperature of substrate carrier 114.This can be realized by providing maximum power amount to heater 124 or alternatively by providing than the larger power amount needed in order to keep temperature sensor 170 reading stable temperature.

[0115] The power source 120 is at least sufficient to bring the aerosol substrate 128 in the single substrate carrier 114 to the first temperature and maintain it at the first temperature to provide sufficient vapor for at least ten to fifteen puffs. More generally, consistent with the experience of simulating smoking, the power source 120 is generally sufficient to repeat this cycle (bringing the aerosol substrate 128 to the first temperature, maintaining the first temperature, and vapor generation for ten to fifteen puffs) ten or even twenty times before the power source 120 needs to be replaced or recharged, thereby simulating the user experience of smoking a pack of cigarettes.

[0116] In general, the efficiency of the aerosol generating device 100 is improved when the heat generated by the heater 124 causes as much as possible the heating of the aerosol substrate 128. To this end, the aerosol generating device 100 is generally configured to provide heat to the aerosol substrate 128 in a controlled manner while reducing the flow of heat to other parts of the aerosol generating device 100. In particular, heat flow to parts of the aerosol generating device 100 that are operated by the user is kept to a minimum, thereby keeping these parts cool and comfortable to hold, for example by means of insulation, as described in more detail herein.

[0117] from Figures 1 to 6 As can be understood from the accompanying description, according to the first embodiment, a heating chamber 108 for an aerosol generating device 100 is provided, the heating chamber 108 comprising an open end 110, a base 112, and a sidewall 126 between the open end 110 and the base 112, wherein the sidewall 126 has a first thickness and the base 112 has a second thickness greater than the first thickness. The reduced thickness of the sidewall 126 can help reduce the power consumption of the aerosol generating device 100 because less energy is required to heat the heating chamber 108 to a desired temperature.

[0118] Second embodiment

[0119] See now Figure 8 The second embodiment is described. Except for the following explanation, the aerosol generating device 100 of the second embodiment is the same as that of the embodiment of FIG. Figures 1 to 6 The aerosol-generating device 100 of the first embodiment described is identical and like reference numerals are used to indicate similar features.The aerosol-generating device 100 of the second embodiment has a different arrangement to that of the first embodiment for allowing air to be drawn into the heating chamber 108 during use.

[0120] For more details, see Figure 8, a channel 113 is provided in the base 112 of the heating chamber 108. The channel 113 is located in the middle of the base 112. The channel extends through the base 112 so as to be in fluid communication with the environment outside the housing 102 of the aerosol generating device 100. More specifically, the channel 113 is in fluid communication with an inlet 137 in the housing 102.

[0121] The inlet 137 extends through the housing 102. The inlet is positioned along a portion of the length of the housing 102 between the first end 104 and the second end 106 of the aerosol generating device 100. In the second embodiment, the housing defines a gap 139 adjacent the control circuit system 122 and between the inlet 137 in the housing 102 and the channel 113 in the base 112 of the heating chamber 108. The gap 139 provides fluid communication between the inlet 137 and the channel 113 so that air can enter the heating chamber 108 from the environment outside the housing 102 via the inlet 137, the gap 139 and the channel 113.

[0122] In use, when a user inhales vapor at the second end 136 of the substrate carrier 114, air is drawn from the environment surrounding the aerosol generating device 100 into the heating chamber 108. More specifically, air passes through the inlet 137 in the direction of arrow C into the void 139. Air passes through the passage 113 from the void 139 in the direction of arrow D into the heating chamber 108. This allows first vapor, then vapor mixed with air, to be drawn through the substrate carrier 114 in the direction of arrow D for inhalation by the user at the second end 136 of the substrate carrier 114. The air is typically heated when it enters the heating chamber 108, so that the air helps transfer heat to the aerosol substrate 128 by convection.

[0123] It should be appreciated that in the second embodiment, the airflow path through the heating chamber 108 is generally linear, that is, the path extends in a generally straight line from the base 112 of the heating chamber 108 to the open end 110 of the heating chamber 108. The arrangement of the second embodiment also allows for a reduced gap between the sidewall 126 of the heating chamber 108 and the substrate carrier. In fact, in the second embodiment, the diameter of the heating chamber 108 is less than 7.6 mm, and the space between the 7.0 mm diameter substrate carrier 114 and the sidewall 126 of the heating chamber 108 is less than 1 mm.

[0124] In variations of the second embodiment, the inlet 137 is located in different locations. In one particular embodiment, the inlet 137 is located at the first end 104 of the aerosol-generating device 100. This allows the air path through the entire aerosol-generating device 100 to be generally linear, for example, air enters the aerosol-generating device 100 at the first end 104, which is generally distal to the user during use, thereby flowing through (or over, through, etc.) the aerosol substrate 128 within the aerosol-generating device 100, and flows out at the second end 136 of the substrate carrier 114 and into the user's mouth, which is generally proximal to the user during use, such as in the user's mouth.

[0125] Third embodiment

[0126] See now Fig. 9 The third embodiment is described. Except for the following explanation, the heating chamber 108 of the third embodiment is similar to that of FIG. Figures 1 to 6 The heating chamber 108 of the first embodiment described is the same, and the same reference numerals are used to indicate similar features. Except as described below, the heating chamber 108 of the third embodiment can also correspond to the heating chamber 108 of the second embodiment, for example, the channel 113 is provided in the base 112 of the heating chamber 108, and this forms another embodiment of the present disclosure.

[0127] The heating chamber 108 has a set of indentations on the outer surface of the tubular wall 126 that correspond to a set of protrusions or engagement elements 140 in the interior volume of the heating chamber 108. Each indentation on the outer surface of the side wall 126 corresponding to the engagement elements 140 of the third embodiment has a heater 124 wrapped around the side wall so that the heating element 164 barely overlaps the indentation.

[0128] Heater 124 and Figure 7 The similarity shown is that there is a heating element 164 that snakes around the heating cavity 108 in a serpentine manner. The vertical gaps between the multiple portions of the heating element 164 are aligned with the indentations on the outer surface of the tubular wall 126. By aligning the vertical gaps with the indentations, the overlap of the heating element 164 with the indentations is minimized. For example, Figure 2 As shown, there is an air gap where the heater 124 overlaps the indentation, which means that the heat generated by this part of the heater 124 is not directly conducted to the heating chamber 108, so that this part of the heater 124 is at risk of overheating. Since it is necessary to provide gaps between the resistive paths 164a, 164b, it is advantageous to have these gaps overlap the indentation to mitigate this effect. Fig. 9 The heating chamber 108 shown has four-fold rotational symmetry, so the heating element 164 should have a four-fold repeating property. Fig. 9The rear portion of the heater 124 is not visible in the figure, but it should be understood that the pattern continues so that the horizontal portion of the heating element 164 overlaps the indents and the vertical portion is located between the indents. Of course, other designs of the heater 124 can be provided so as to align with different numbers of indents using the above method.

[0129] Although arranging the heating element 164 in this manner is beneficial for avoiding overheating, it is also possible to provide a metal layer ( Fig. 9 The metal layer 144 has a relatively high thermal conductivity and thus spreads the heat rather than causing it to be localized directly under the heating element 164. Generally, the heating element 164 is slightly misaligned with the indentation and overlaps the indentation to a greater extent than the indentation. Fig. 9 As shown more, the metal layer 144 mitigates this effect by effectively spreading the heat away from the heater 124, thereby preventing any given area from overheating. In addition, the metal layer 144 tends to reduce the size of the area of ​​the heater 124 that is not in contact with the heating cavity 108 because the metal layer partially fills in the indentation.

[0130] Fig. 9 The temperature sensor is not shown in the figure, and the temperature sensor can be used as described above. Figure 7 The described mode is assembled in the indent.When the side of the indent contacts with the side of temperature sensor 170, compared with other situations, this makes temperature sensor 170 have close contact with the larger part of sidewall 126 outer surfaces.In addition, temperature sensor 170 is positioned in the indent and can help prevent temperature sensor 170 from protruding outwards from heating chamber 108, protect temperature sensor 170 thus.In order to make temperature sensor 170 be closely installed in the indent, in some instances, indent at least expands or forms different shapes in a certain area.In other instances, can form the customized indent separated with the indent for contacting substrate carrier 114.Provide independent indent to allow to select the shape and position of indent to meet temperature sensor 170.In some instances, temperature sensor 170 does not need a certain area of ​​heater 124 to be surrounded by resistive track 164a, 164b.On the contrary, temperature sensor 170 can be positioned outside the heater 124 area of ​​rectangle generally.

[0131] Fourth embodiment

[0132] See now Fig.10 The fourth embodiment is described. Except for the following explanation, the heating chamber 108 of the fourth embodiment is similar to that of FIG. Fig. 9The heating chamber 108 of the described eighth embodiment is the same, and the same reference numerals are used to indicate similar features. Except as described below, the heating chamber 108 of the fourth embodiment may also correspond to the heating chamber 108 of the second embodiment, for example the channel 113 is provided in the base 112 of the heating chamber 108, and this forms another embodiment of the present disclosure.

[0133] The heating chamber 108 has a set of indentations on the outer surface of the tubular wall 126 that correspond to a set of protrusions or engagement elements 140 in the interior volume of the heating chamber 108. Each indentation on the outer surface of the side wall 126 that corresponds to the engagement elements 140 of the fourth embodiment has a heater 124 wrapped around the side wall 126 so that the heating element 164 barely overlaps the indentation. A metal layer 144 is located between the heater 124 and the side wall 126.

[0134] As described above, metal layer 144 helps to spread the heat generated by heater 124 to the area where metal layer 144 contacts the outer surface of sidewall 126. Fig.10 In the fourth embodiment, the protrusion 140 extends along a greater length of the heating cavity 108 than the heater 124. Given the relatively low thermal conductivity of the sidewall 126, this means that (in the absence of the metal layer 144) the heat remains concentrated in the area of ​​the heater 124 and does not quickly spread to the upper and lower extents of the protrusion 140. In the fourth embodiment, the metal layer 144 extends a greater length of the heating cavity 108 than the length of the protrusion 140, thereby covering at least the entire length of the portion of the heating cavity 108 corresponding to the protrusion 140. Although the rear portion of the heating cavity 108 is not shown, the metal layer 144 also extends around the entire perimeter of the sidewall 126. It should be understood that the metal layer 144 defines a "heating zone" that quickly heats to approximately the temperature of the heater 124. Due to the low thermal conductivity of the sidewalls 126, portions of the heating cavity 108 that are not within the "heating zone" receive very little heat from the heater 124, which means that the extent of the metal layer 144 can be selected to direct heat to specific portions of the heating cavity 108, while other portions are not heated. This provides a very effective way to limit heating power to those portions of the device that are actually intended to receive heat, thereby improving efficiency.

[0135] Fifth embodiment

[0136] See now Fig.11 and Fig.12 A fifth embodiment is described. Fig.11 is a schematic cross-sectional view of a heating chamber as part of a masking and plating step according to a fifth embodiment, and Fig.121 is a schematic perspective view of a heating chamber as part of a masking and plating step according to a fifth embodiment. In addition to the following, the heating chamber 108 of the fifth embodiment may also correspond to the heating chamber 108 of the second embodiment, for example, the channel 113 is provided in the base 112 of the heating chamber 108, and this forms another embodiment of the present disclosure.

[0137] Broadly, the fifth (and further) embodiments involve creating a metal layer on only a portion of the tubular wall 126 (e.g., Fig.10 The selective plating is achieved by masking a portion of the heating chamber 108 to ensure that the plating step does not plate portions that are not intended to be plated. Although this embodiment is dedicated to electroplating, it should be noted that deposition methods can also utilize masking to achieve a selective plating effect.

[0138] like Fig.11 and Fig.12 As shown, an upper masking mold 174a and a lower masking mold 174b are provided and assembled on the heating cavity 108. The molds 174 can be flexible or pliable so that they can deform, for example, on the flange 138 (in the example where the flange is present), or elastic so that they always form a tight seal around the heating cavity 108. The molds 174 can be designed to provide the following metal layer 144: starting at a constant distance from the base 112 and ending at a constant distance from the upper end (e.g., where the flange 138 or open end 110 of the heating cavity 108 is located) by ensuring that the base 112 contacts the inner surface of the lower masking mold 174b, and the flange 138 (or the upper edge of the heating cavity 108) contacts the inner surface of the upper masking mold 174a.

[0139] The upper masking mold 174a has guide holes for the resilient electrodes 176. This allows the heating cavity 108 to be connected to a current source, which is necessary if the metal layer is deposited by electroplating. The electrodes 176 are biased to spring back outward so that once they are fed into the interior of the heating cavity 108, they press against the sidewalls 126 and provide an electrical connection between the resilient electrodes 176 and the sidewalls 126.

[0140] In the electroplating example, Fig.11 and 12As shown, the masking mold 174 is assembled to the outside of the heating chamber 108. The entire arrangement is then placed in a suitable electrolyte solution, and a sacrificial electrode of the metal to be plated is used as one electrode, and the heating chamber 108 is used as another electrode (via the elastic electrode 176) to make the current flow through the solution. Broadly, the time spent in the electrolyte at a given current determines the thickness of the deposited layer. After the appropriate time has passed, the heating chamber 108 is removed and rinsed, etc., and then the mold 174 is removed, leaving the selectively plated layer. The plating step can be performed as a batch process, wherein one or more heating chambers 108 are equipped with a masking mold 174 and are immersed in the electrolyte for a predetermined period of time while power is supplied to the elastic electrode 176. When the predetermined time has passed, each of the one or more heating chambers 108 is removed from the electrolyte, wherein the metal layer 144 deposited in the unmasked area of ​​the outer surface of the heating chamber 108 has a desired thickness. In other examples, the process is continuous, where a series of heating chambers 108 are fitted with a masking mold 174 and are dragged through a reservoir of electrolyte while power is supplied to the elastic electrodes 176. The dragging step is arranged so that each heating chamber 108 takes a predetermined time from one end of the reservoir to the other, at which point the heating chamber 108 rises out of the electrolyte with the metal layer 144 deposited in the unmasked areas of the outer surface of the heating chamber 108 having a desired thickness.

[0141] In some cases, such as electroplating copper onto stainless steel, a nickel pre-plating layer is first deposited to improve adhesion. This can be done using the same masking mold 174 used later in the copper plating step.

[0142] Definitions and Alternative Embodiments

[0143] It can be understood from the above description that many features of these different embodiments are interchangeable with each other. The present disclosure extends to other embodiments that include features from different embodiments combined in a manner not specifically mentioned. For example, the third to fifth embodiments do not include the following: Figures 1 to 6 The platform 148 shown. This platform 148 may be included in the third to fifth embodiments, thereby bringing the benefits of the platform 148 described with respect to these figures.

[0144] Fig. 9 and Fig.10The heating chamber 108 is shown separated from the aerosol generating device 100. This is to emphasize that the advantageous features described for the design of the heating chamber 108 are independent of the other features of the aerosol inhalation device 100. Specifically, the heating chamber 108 has many uses, but not all of them are relevant to the vapor inhalation device 100 described herein. Such designs may benefit from the heat generated by the heater 124 being transmitted away from the heater 124 and spread over a larger area. Such uses are advantageously provided by the heating chamber described herein.

[0145] The term "heater" should be understood to refer to any device for outputting heat energy sufficient to form an aerosol from the aerosol substrate 128. The transfer of heat energy from the heater 124 to the aerosol substrate 128 can be conductive, convective, radiative, or any combination of these. As non-limiting examples, conductive heaters can directly contact and press against the aerosol substrate 128, or these heaters can contact a separate component that itself causes the aerosol substrate 128 to heat up by conduction, convection, and / or radiation. Convective heating can include heating a liquid or gas that thereby transfers heat energy (directly or indirectly) to the aerosol substrate.

[0146] Radiative heating includes, but is not limited to, transferring energy to the aerosol substrate 128 by emitting electromagnetic radiation within the ultraviolet, visible, infrared, microwave, or radio wave portions of the electromagnetic spectrum. Radiation emitted in this manner can be absorbed directly by the aerosol substrate 128 to cause heating, or the radiation can be absorbed by another material (such as a susceptor or fluorescent material) that causes the radiation to be re-emitted at a different wavelength or spectral weighting. In some cases, radiation can be absorbed by a material that then transfers heat to the aerosol substrate 128 by any combination of conduction, convection, and / or radiation.

[0147] The heater may be electrically powered, combustion driven, or driven in any other suitable manner. The electrically powered heater may include a resistive tracking element (optionally including an insulating package), an induction heating system (e.g., including an electromagnet and a high frequency oscillator), etc. The heater 128 may be arranged around the outside of the aerosol substrate 128, the heater may partially or fully penetrate the aerosol substrate 128, or any combination of these.

[0148] The term "temperature sensor" is used to describe an element that is capable of determining the absolute or relative temperature of a part of the aerosol generating device 100. This may include a thermocouple, a thermopile, a thermistor, etc. The temperature sensor may be provided as part of another component, or may be a separate component. In some examples, more than one temperature sensor may be provided, for example for monitoring heating of different parts of the aerosol generating device 100 in order to determine a thermal profile, for example.

[0149] The control circuit system 122 is always shown as having a single user-operable button 116 to trigger the aerosol generating device 100 to turn on. This keeps the control simple and reduces the chance of a user misusing the aerosol generating device 100 or failing to properly control the aerosol generating device 100. In some cases, however, the input controls available to the user may be more complex than this, such as for controlling the temperature within, for example, pre-set limits, for changing the taste balance of the vapour, or for example for switching between an energy saving mode or a rapid heating mode.

[0150] With reference to the above-mentioned embodiment, aerosol substrate 128 comprises tobacco in a dried or smoked form, for example, with additional ingredients for flavoring or for producing a smoother or otherwise more pleasant experience in some cases. In some instances, aerosol substrates 128 such as tobacco can be processed with vaporizers. Vaporizers can improve the steam generation from aerosol substrates. For example, vaporizers can include polyols such as glycerol, or ethylene glycols such as propylene glycol. In some cases, aerosol substrates may not contain tobacco or even nicotine, but may contain natural or artificially extracted ingredients for flavoring, volatilization, improving smoothness and / or providing other pleasant effects. Aerosol substrates 128 can be provided as solid or paste-type materials in pulverized, granulated, powdered, granular, strip-shaped or sheet-shaped forms, optionally in combination with these forms. Similarly, aerosol substrates 128 can be liquid or gel. In fact, some instances can include both solid parts and liquid / gel parts.

[0151] Thus, the aerosol generating device 100 may also be referred to as a "heated tobacco device", "heating but not burning tobacco device", "device for vaporizing tobacco products", etc., and this is interpreted as a device suitable for achieving these effects. The features disclosed herein are also applicable to devices designed to vaporize any aerosol substrate.

[0152] The embodiment of the aerosol generating device 100 is described as being arranged to receive an aerosol substrate 128 in a pre-packaged substrate carrier 114. The substrate carrier 114 can be substantially similar to a cigarette, having a tubular region with an aerosol substrate arranged in a suitable manner. In some designs, filters, vapor collection regions, cooling regions, and other structures may also be included. An outer layer of paper or other flexible planar material (such as foil) may also be provided, for example, to hold the aerosol substrate in place, so as to make it more like a cigarette, etc.

[0153] As used herein, the term "fluid" should be understood to refer generally to non-solid materials that are capable of flowing, including but not limited to liquids, pastes, gels, powders, etc. "Fluidized material" should be interpreted accordingly as a material that is essentially fluid, or a material that has been modified to behave like a fluid. Fluidization may include but is not limited to: powderization, dissolution in a solvent, gelation, thickening, dilution, etc.

[0154] As used herein, the term "volatile" refers to a substance that can easily change from a solid or liquid state to a gaseous state. As a non-limiting example, a volatile substance may be a substance that boils or sublimates at a temperature close to room temperature at ambient pressure. Thus, "volatilize" or "volatilise" should be interpreted as meaning to volatilize (a material) and / or to cause it to evaporate or disperse in a vapor.

[0155] As used herein, the term "vapour" or "vapor" means: (i) the form to which a liquid naturally transforms when sufficient heat is applied; or (ii) liquid / moisture particles suspended in the atmosphere and visible as a vapor / smoke cloud; or (iii) a fluid that fills space like a gas but liquefies under pressure alone below its critical temperature.

[0156] Consistent with this definition, the terms "vaporise" or "vaporize" mean: (i) to change or cause to change into a vapor; and (ii) when a particle changes physical state (ie, from a liquid or solid to a gas).

[0157] As used herein, the term "atomize" or "atomize" shall mean: (i) to reduce (a substance, especially a liquid) into very small particles or droplets; and (ii) to keep the particles in the same physical state (liquid or solid) as before atomization.

[0158] As used herein, the term "aerosol" shall refer to a system of particles dispersed in air or gas (such as mist, fog or smoke). Therefore, the term "aerosolization" refers to making an aerosol and / or dispersing into an aerosol. It should be noted that the meaning of aerosol / aerosolization is consistent with each of the above-defined volatilization, atomization and vaporization. For the avoidance of doubt, aerosol is used to consistently describe a mist or droplets consisting of atomized, volatilized or vaporized particles. Aerosols also include mists or droplets containing any combination of atomized, volatilized or vaporized particles.

Claims

1. A heating chamber (108) for an aerosol generating device (100), the heating chamber (108) comprising: a tubular sidewall (126) having a first open end (110), the tubular sidewall (126) defining an interior volume of the heating chamber (108); a metal layer (144) in direct contact with the tubular sidewall (126) and covering a portion of the outer surface of the tubular sidewall (126); and a heater (124) positioned on the metal layer (144); wherein the tubular sidewall (126) has a first thickness and the metal layer (144) has a second thickness less than the first thickness; wherein the metal layer (144) comprises a metal having a thermal conductivity of at least 150 W / mK and the tubular sidewall (126) comprises a metal having a thermal conductivity of 50 W / mK or less; and A portion of the outer surface of the tubular side wall (126) adjacent to the first open end (110) is not covered by the metal layer (144).

2. The heating chamber (108) according to claim 1, wherein: The metal layer (144) is an electroplated layer.

3. The heating chamber (108) according to claim 1, wherein: The metal layer (144) has a thickness between 10 μm and 50 μm.

4. The heating chamber according to claim 3, wherein: The metal layer (144) has a thickness between 10 μm and 30 μm.

5. The heating chamber according to claim 3, wherein: The metal layer (144) has a thickness of 20 μm.

6. The heating chamber (108) according to claim 1, wherein: The metal layer (144) is copper.

7. The heating chamber (108) according to claim 1, wherein: The tubular side wall (126) is stainless steel.

8. The heating chamber (108) according to claim 1, wherein: The tubular sidewall (126) has a thickness of 90 μm or less.

9. The heating chamber (108) according to claim 1, wherein: The tubular sidewall (126) further includes a second end opposite the first open end (110), and wherein a portion of the outer surface of the tubular sidewall (126) adjacent to the second end is not covered by the metal layer (144).

10. The heating chamber (108) according to claim 1, wherein: The tubular sidewall (126) further includes a base coupled to a second end of the tubular sidewall (126) opposite the first open end (110).

11. The heating chamber (108) according to claim 1, wherein: The tubular sidewall (126) further includes a plurality of protrusions (140) extending radially inwardly from an inner surface of the tubular sidewall (126).

12. The heating chamber (108) according to claim 11, wherein: A portion of the outer surface of the tubular sidewall (126) corresponding to at least one of the plurality of protrusions (140) on the inner surface is covered by the metal layer (144).

13. An aerosol generating device (100), comprising: Power supply (120); A heating chamber (108) according to claim 1 fixed in the device; The heater (124) is positioned on a metal layer (144) on a surface of the tubular sidewall (126) facing in a direction opposite to the interior volume; and Control circuitry (122) is arranged to control the supply of electrical power from the power source (120) to the heater (124).

14. The aerosol generating device (100) according to claim 13, wherein: The heating chamber (108) is removable from the device (100).

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