Ceramic heating element for electronic cigarette

Abstract

The present invention provides a ceramic heating body for electronic cigarettes, comprising: a ceramic inner core and a ceramic substrate wound on the ceramic inner core, a heating circuit is arranged on the bonding surface of the ceramic substrate and the ceramic inner core, a heat-conducting layer is arranged outside the ceramic substrate, and the thermal conductivity of the heat-conducting layer is greater than the thermal conductivity of the ceramic substrate; the heat-conducting layer is a silver layer, a silver-palladium layer or a silver-platinum layer, so that the ceramic inner core and the ceramic substrate are made of low-temperature sintering materials. By bonding a heat-conducting layer with a thermal conductivity greater than the thermal conductivity of the ceramic substrate outside the ceramic substrate, the heat distribution on the surface of the ceramic heating body can be quickly balanced, so that the surface temperature of the ceramic heating body is uniform; at the same time, the presence of the heat-conducting layer reduces the requirements for the thermal conductivity of the ceramic substrate, so that it can use low thermal conductivity materials, thereby reducing the temperature of the welding line area.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic cigarettes, and in particular to a ceramic heating body for electronic cigarettes. Background Art

[0002] Due to the advantages of low-temperature baking electronic cigarettes, such as non-combustion and non-production of toxic substances such as carbon monoxide, they have been rapidly developed worldwide in recent years; and the ceramic heater, as its core component, determines the overall design and performance quality level of the electronic cigarette. At present, the electronic cigarette ceramic heaters on the market are divided into three categories according to their appearance: tubular, sheet, and needle. They are mainly made of alumina or zirconia ceramics, and are used with high-temperature fired tungsten slurry, platinum slurry, gold slurry, etc. as electrode materials.

[0003] Early products were mainly made of alumina, but due to the high thermal conductivity of alumina (thermal conductivity: 25-36W / mK), heat was quickly transferred to the non-heating area, resulting in defects such as slow heating speed, high power consumption, and excessive temperature at the bottom welding line. In order to solve the problem of excessive temperature at the bottom welding line, some products were equipped with structures such as thermal insulation flanges, which complicated the structure, made the appearance unsightly, and increased the cost.

[0004] Some existing technologies use zirconium oxide materials to make products. The thermal conductivity of the commonly used 3Y zirconium oxide is about 2.09W / mK, which is significantly lower than that of alumina. It can effectively solve the problems of slow heating, high power consumption and high temperature in the welding line area of ​​alumina material products; but it also brings about a very uneven temperature distribution on the surface of the heating body.

[0005] Moreover, alumina and zirconia materials need to be sintered at a high temperature of more than 1400°C. The high-temperature electrode slurries used with them mainly include tungsten slurry, gold slurry, platinum slurry, etc., but tungsten slurry needs to be sintered in an inert atmosphere or a reducing atmosphere, which has high requirements on the process; platinum slurry, gold slurry, etc. can be sintered in an oxidizing atmosphere, but the material itself is expensive.

[0006] At the same time, the heating needle made of alumina has the disadvantages of slow heating speed (8 to 10 seconds to reach 350°C), high welding zone temperature (higher than 100°C), high power consumption, and large temperature difference on the product surface (temperature difference of 20 to 40°C within 10 seconds); while the use of zirconia ceramics to make heating needles can increase the heating speed of the product (heating to 350°C in about 5 seconds) and reduce the temperature of the welding line area of ​​the product (less than 100°C), but the temperature difference of the product is increased (temperature difference of more than 50°C within 10 seconds); and the use of a mixture of alumina and zirconia has little effect on thermal conductivity and cannot solve the above problems.

[0007] In summary, the prior art lacks a needle-shaped heating body with a rapidly uniformly distributed surface temperature and a low temperature in the welding line area. Summary of the invention

[0008] In order to solve the problem in the prior art that there is a lack of a needle-shaped heating body with a rapidly evenly distributed surface temperature and a low temperature in the welding line area, the present invention provides a ceramic heating body for an electronic cigarette.

[0009] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0010] A ceramic heater for an electronic cigarette comprises: a ceramic inner core and a ceramic substrate wound on the ceramic inner core, a heating circuit is arranged on the bonding surface of the ceramic substrate and the ceramic inner core, a heat-conducting layer is arranged outside the ceramic substrate, and the thermal conductivity of the heat-conducting layer is greater than the thermal conductivity of the ceramic substrate; the heat-conducting layer is a silver layer, a silver-palladium layer or a silver-platinum layer, so that the ceramic inner core and the ceramic substrate are made of low-temperature sintering materials.

[0011] In some embodiments of the present invention, the following features are also provided:

[0012] The ceramic inner core and the ceramic substrate are LTCC materials with high bending strength and low thermal conductivity, wherein the bending strength is ≥250MPa and the thermal conductivity is ≤5.0W / mK.

[0013] An insulating layer is arranged outside the heat-conducting layer, and the material of the insulating layer is the same as that of the ceramic inner core and the ceramic substrate.

[0014] The heat-conducting layer is formed by printing a heat-conducting electrode paste on the insulating layer and then winding the paste around the outer side of the ceramic substrate and sintering the paste together.

[0015] The thermal conductive layer is a silver layer, a silver-palladium layer or a silver-platinum layer; the ceramic inner core and the ceramic substrate are co-fired at a first sintering temperature to obtain a green body; the thermal conductive layer is manufactured on the surface of the green body by dipping or spraying, and an oleophobic protective glaze layer is provided outside the thermal conductive layer; the thermal conductive layer and the protective glaze layer are sintered together at a second sintering temperature lower than the first sintering temperature, or are sintered in batches at a third sintering temperature and a fourth sintering temperature lower than the first sintering temperature.

[0016] The product of the thermal conductivity of the heat-conducting layer and the thickness of the heat-conducting layer is greater than 5500 mW / K.

[0017] When the heat conductive layer is a silver layer, the thickness of the silver layer is 10-15 μm.

[0018] The heat conducting layer has a hollow portion, so that the insulating layer and the ceramic substrate can contact and fuse at the hollow portion.

[0019] The heat-conducting layer is in a grid shape, and the product of the effective area ratio of the grid and the thickness of the grid is not less than the thickness of the heat-conducting layer without the grid.

[0020] It also includes a temperature measuring circuit, and the temperature measuring circuit and the heating circuit are arranged on the same layer of the ceramic substrate, or on different layers of the ceramic substrate.

[0021] The inner core is in the shape of a rod with a columnar body and a tip, and the ceramic substrate is attached to the upper part of the columnar body, so that the ceramic heater for the electronic cigarette is axially arranged in the shape of a tip, a heating part and an end part, and the cross-sectional shape of the columnar body is circular, elliptical or rounded rectangular.

[0022] The beneficial effects of the present invention are as follows: a ceramic heater for an electronic cigarette is provided, and by laminating a thermally conductive layer having a thermal conductivity greater than that of the ceramic substrate on the outside of the ceramic substrate, the heat distribution on the surface of the ceramic heater can be quickly balanced, so that the surface temperature of the ceramic heater is uniform; at the same time, the presence of the thermally conductive layer reduces the requirements for the thermal conductivity of the ceramic substrate, so that it can use low thermal conductivity materials, thereby reducing power consumption and lowering the temperature of the welding line area.

[0023] Furthermore, a silver layer, a silver-palladium layer or a silver-platinum layer is used as a thermal conductive layer, so that the ceramic core and the ceramic substrate can be made of low-temperature sintering materials. This not only has low cost and simple process, but also LTCC materials with low thermal conductivity are easy to obtain, which perfectly meets the requirement of using low thermal conductivity materials for the ceramic substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the planar unfolded structure of the first ceramic heater for electronic cigarette in an embodiment of the present invention.

[0025] Figure 2 Schematic diagram of the appearance of the second ceramic heater for electronic cigarette in an embodiment of the present invention.

[0026] Figure 3 It is a schematic diagram of the planar unfolded structure of the third ceramic heater for electronic cigarette in an embodiment of the present invention.

[0027] Figure 4 It is a schematic diagram of the planar unfolded structure of the fourth ceramic heater for electronic cigarette in an embodiment of the present invention.

[0028] Figure 5 It is a schematic cross-sectional view of the first ceramic heater for electronic cigarette in an embodiment of the present invention.

[0029] Figure 6 It is a schematic cross-sectional view of a second ceramic heater for electronic cigarettes in an embodiment of the present invention.

[0030] Figure 7It is a schematic diagram of the relationship between the temperature of the heat-conducting layer and the temperature difference on the surface of the electronic cigarette ceramic heating body in an embodiment of the present invention.

[0031] Figure 8 It is a schematic diagram of the relationship between the thermal conductivity of the heat-conducting layer and the temperature difference on the surface of the electronic cigarette ceramic heating body in an embodiment of the present invention.

[0032] Fig. 9 It is a schematic diagram of the relationship between the product of the temperature and thermal conductivity of the heat-conducting layer and the temperature difference on the surface of the electronic cigarette ceramic heating body in an embodiment of the present invention.

[0033] Among them, 1-ceramic inner core, 2-heating circuit, 3-temperature measuring circuit, 4-thermal conductive layer, 5-insulating layer printed with thermal conductive layer, 6-ceramic substrate, 7-reserved through hole, 8-insulating layer, 9-ceramic substrate. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the embodiments of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0035] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it can be directly on the other component or indirectly on the other component. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element. In addition, connection can be used for both fixing and circuit connection.

[0036] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", and "surface" are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0038] Example 1

[0039] Electronic cigarette ceramic heating bodies are mainly made of alumina or zirconia ceramics, and are used as electrode materials with high-temperature fired tungsten slurry, platinum slurry, gold slurry, etc. Most of them are made of alumina, and tungsten is used as the electrode material. The main problem is that alumina has high thermal conductivity. When heated, heat diffuses quickly through the ceramic body, causing the rear end temperature of the heating body to rise. Not only is the heat loss serious, but it will also cause other devices to heat up. Therefore, a low thermal conductivity flange ring is needed to block heat, which increases the cost. Using low thermal conductivity material zirconium oxide can solve the problems of slow heating, high power consumption, and high rear end temperature of alumina materials. The matching heating electrodes require high prices of platinum, palladium, and gold.

[0040] Furthermore, the ceramic heating body of the electronic cigarette is generally heated by a heating circuit. The setting of the heating circuit is uneven, and the low thermal conductivity of the ceramic body will hinder the diffusion of heat, so there is a problem of uneven temperature of the heating part of the ceramic heating body in a short period of time. Uneven temperature will cause some parts of the electronic cigarette to be insufficiently baked, resulting in a reduction in the amount of smoke; some parts are over-baked and produce a burnt smell, and produce many substances that are harmful to the body.

[0041] like Figure 1 As shown, the present invention provides a ceramic heater for an electronic cigarette, comprising: a ceramic inner core 1 and a ceramic substrate 6, a heating circuit 2 is printed on the bonding surface of the ceramic substrate 6 and the ceramic inner core 1, a thermal conductive layer 4 is bonded outside the ceramic substrate 6, and the thermal conductivity of the thermal conductive layer 4 is greater than the thermal conductivity of the ceramic substrate 6.

[0042] like Figure 2 The figure shows the appearance of a ceramic heater for an electronic cigarette.

[0043] Because the heating circuit 2 is a resistance heating circuit arranged in a U-shaped reciprocating or Z-shaped winding manner, the temperature is high where the heating circuit is located and low where the heating circuit is not located. There will be a large temperature difference on the surface of the ceramic substrate, and the temperature uniformity is poor. In response to the uneven temperature on the surface of the heating body, the present invention adds a thermal conductive layer made of high thermal conductivity material on the surface of the heating zone of the heating body. The thermal conductivity of the thermal conductive layer is greater than that of the ceramic substrate material, which can quickly balance the heat distribution on the surface of the heating body and make the surface temperature of the heating body uniform.

[0044] The thermal conductivity of the heat-conducting layer is higher than that of the ceramic substrate, which helps to quickly diffuse the heat generated by the heating circuit, so that the temperature of the surface of the heating body can be uniformed in a short time. Moreover, not limited to the above-mentioned needle-type heating body, a heat-conducting layer can also be added to a designated area on one or both sides of a sheet-type heating body or the inner surface of a tube-type heating body to improve the surface temperature distribution of the heating body.

[0045] In one embodiment of the present invention, the thermal conductive layer is a silver layer, a silver-palladium layer or a silver-platinum layer, that is, the same material as the heating layer. Like the heating layer, the use of this material can avoid the problem of high cost when using materials such as platinum and gold, but at this time the thermal conductive layer has the problem of both thermal conductivity and electrical conductivity. Therefore, in this embodiment, an insulating layer is arranged outside the thermal conductive layer, and the material of the insulating layer is the same as that of the ceramic inner core and the ceramic substrate, so that the shrinkage rate of each layer is similar, which effectively avoids the problem of stratification. During production, the thermal conductive electrode slurry of the thermal conductive layer is printed on the insulating layer and then wrapped around the outside of the ceramic substrate and sintered together to form. This requires that the sintering conditions of the thermal conductive layer and the ceramic substrate are the same, and the sintering conditions include the sintering temperature and the sintering atmosphere. In the present invention, the thermal conductive layer used is relatively cheap and low in cost. After the insulating layer is provided, the ceramic heating body can be easily cleaned and not prone to produce harmful substances.

[0046] In another embodiment of the present invention, the heat-conducting layer is also made of a silver layer, a silver-palladium layer or a silver-platinum layer; similarly, in order to avoid leakage, an insulating layer needs to be added outside the heat-conducting layer. However, the manufacturing method is different from the previous one. The ceramic inner core and the ceramic substrate are co-fired at a first sintering temperature to obtain a green body; the heat-conducting layer is manufactured on the surface of the green body by dip coating or spraying, and an oleophobic protective glaze layer is provided outside the heat-conducting layer. The heat-conducting layer and the protective glaze layer are sintered together or in batches at a sintering temperature lower than the first sintering temperature, generally at 700-900°C.

[0047] The above-mentioned configuration of the heat-conducting layer is only exemplary. The heat-conducting layer can be made of any high-thermal-conducting material, but it is best to use a high-thermal-conducting material that can be sintered at low temperature and does not require special atmosphere conditions. The thickness, thermal conductivity and structure of the heat-conducting layer will affect the effect of balancing the heat distribution. When the heat-conducting layer is a complete film structure, the product of the thickness and thermal conductivity of the heat-conducting layer is greater than 5500mW / K to better reflect the effect of improving the uniformity of temperature distribution.

[0048] In another embodiment of the present invention, the heat-conducting layer is a metal sleeve or a sleeve made of other high thermal conductivity materials, which is adhered to the outer surface of the product with high-temperature heat-conducting glue.

[0049] The thermal conductive layer is an integral film layer, which has the best thermal conductivity. In order to avoid the risk of delamination between the thermal conductive layer and the winding layer due to different shrinkage rates during the sintering process, or the risk of delamination due to thermal expansion and contraction during use, a hollow portion is provided on the thermal conductive layer so that the insulating layer and the ceramic substrate can contact and fuse in the hollow portion. In this way, since the same material is fused, delamination is not easy to occur. There are many ways to achieve the setting of the hollow portion. For example, the thermal conductive layer can be set to a grid shape, and the mesh portion is the hollow portion.

[0050] In the present invention, the ceramic core and the ceramic substrate adopt LTCC materials with low thermal conductivity, that is, materials with low thermal conductivity are used to solve the defects of slow heating speed, high power consumption, and excessive temperature at the bottom welding line position; at the same time, the use of a thermal conductive layer solves the problem of uneven temperature distribution in a short time. Considering the thermal conductivity and insulation materials of LTCC, the following can be selected: M63 (thermal conductivity 4.1W / mK, bending strength 400MPa) and M28 (thermal conductivity 1.9W / mK, bending strength 290MPa) of Japan N Company, X material (thermal conductivity 2.8W / mK, bending strength 280MPa) of Germany H Company, etc.

[0051] LTCC materials (low temperature co-fired ceramic materials) have high flexural strength and low thermal conductivity (flexural strength: ≥250MPa; thermal conductivity: ≤5.0W / mK). Using them to make heating elements has the following advantages:

[0052] (1) The sintering temperature is low (850-900°C), and it can be used with low-temperature sintering electrode pastes such as silver paste, silver-palladium paste, silver-platinum paste, etc., and no atmosphere protection is required.

[0053] (2) Due to the low thermal conductivity of the ceramic material, the heat diffusion through the ceramic body is reduced. At the same time, the density of the ceramic material is lower than that of the zirconia material, and its own heat capacity is also reduced accordingly, and the power consumption is reduced, so that the product has obvious advantages such as faster heating rate and lower temperature at the bottom solder point.

[0054] (3) The ceramic body has high bending strength, and the product is not easily damaged by external forces during use.

[0055] In one embodiment, a needle-shaped ceramic heating body is used, and the inner core is a rod with a columnar body and a tip. The ceramic substrate is attached to the upper part of the columnar body, so that the ceramic heating body for electronic cigarettes is axially composed of a tip, a heating part and an end part, and the cross-sectional shape of the ceramic inner core body is circular, elliptical or rounded rectangular. A welding pad is set at the end, and the lead can be welded by low-temperature soldering, which simplifies the process.

[0056] like Figure 3 and Figure 4As shown, in one embodiment of the present invention, the ceramic heating body also includes a temperature measuring circuit 3, and the temperature measuring circuit 3 and the heating circuit 2 are printed on the same layer of ceramic substrate or printed on different layers of ceramic substrates. The ceramic substrate 5 with the pre-printed heating circuit 2, the temperature measuring circuit 3, the heat conducting layer 4, and the connection through hole 7 reserved at a specific position is wound on the inner core 1 of the ceramic green body, and the wound green body is isostatically compacted to make the layers of the ceramic substrate and the green sheet and the green core rod tightly bonded, and then the organic components in the green body are removed by heating at high temperature, and then sintered at high temperature, and the internal electrode is led to the surface of the rod-shaped ceramic body through the pre-designed connection through hole and welded with a lead wire.

[0057] The inner core of the ceramic green body mentioned above is composed of an organic binder (such as thermoplastic resins such as acrylic resin, PVA, PVB, paraffin, etc.), ceramic powder, plasticizer, dispersant, release agent, etc., which is mixed into porcelain mud and then made by injection molding or molding.

[0058] The ceramic substrate mentioned above has the same ceramic material as the inner core, which is prepared into a slurry by an organic adhesive (such as acrylic resin, PVB, PVA, polyacrylamide and other thermoplastic resins), ceramic powder, dispersant, plasticizer, solvent, etc., and is formed into a film by cast film and cut into raw sheets as needed.

[0059] The sintering shrinkage rate of the ceramic substrate is not less than the sintering shrinkage rate of the ceramic inner core, so as to avoid excessive shrinkage of the inner core during sintering, which may lead to poor bonding between the substrate and the inner core.

[0060] In order to avoid the risk of delamination between the core rod and the ceramic substrate due to different shrinkage rates during the sintering process, or the risk of delamination due to thermal expansion and contraction during use, a hollow portion is provided on the core rod so that the core rod and the ceramic substrate can contact and fuse at the hollow portion. In this way, since the fusion is of the same material, delamination is not likely to occur. There are many ways to achieve the setting of the hollow portion. For example, the heat conductive layer can be set in a grid shape, and the mesh portion is the hollow portion.

[0061] In order to prevent the unevenness of the core rod surface from affecting the reliability of the wound layer electrode, it can be arranged that holes are only provided at the positions without electrodes on the core rod surface. In this way, the hollow parts do not contact the electrodes and will not affect the reliability of the electrodes.

[0062] In addition, the cavity may be changed into a protrusion; and the protrusion may be provided with barbs or hooks, so as to further increase the bonding force between the core rod and the ceramic substrate and reduce the risk of delamination.

[0063] like Figure 5 and Figure 6As shown, the printed pattern of the above-mentioned sheet includes a heating circuit, a temperature measuring circuit and a heat conducting layer. After winding, the heating layer, the temperature measuring layer and the heat conducting layer are formed respectively. The heating layer and the heat conducting layer should each form one layer on the heating body. The temperature measuring layer can be combined with the heating layer in one layer, or can be set as a whole layer separately. The heating circuit is a must, and the temperature measuring circuit and the heat conducting layer can be deleted according to different product requirements. The above-mentioned printed ceramic substrate, depending on the composition of its pattern, when winding on the inner core, the number of functional layers that can be wound is at least 1 layer and at most 3 layers.

[0064] like Figure 7 As shown in the figure, the vertical axis is the temperature difference on the surface of the heating body, in units of ℃, and the horizontal axis is the thickness of the thermal conductive layer, in units of μm. The thermal conductivity of the ceramic material used is 4.1W / mK. When there is no thermal conductive layer, the temperature difference on the surface of the heating body reaches 120℃; silver is used as the thermal conductive layer (thermal conductivity 429W / mK), and the thermal conductivity of the thermal conductive layer increases with its thickness. When the thickness of the thermal conductive layer reaches 5um, it can play a certain effect, and the temperature difference on the surface of the heating body is reduced to 53℃; after the thickness of the thermal conductive layer reaches 10um, the temperature difference on the surface of the heating body is reduced to 26℃; further increasing the thickness will still improve the thermal conductivity effect, but according to actual requirements, as well as comprehensive cost control and process difficulty, the thickness of the thermal conductive layer is preferably 10-15um.

[0065] like Figure 8 As shown in the figure, the ordinate is the temperature difference on the surface of the heating body, in degrees Celsius, and the abscissa is the thermal conductivity of the heat-conducting layer, in W / mK. The effect of the heat-conducting layer on the uniform distribution of heat on the surface of the product increases with the increase of its thermal conductivity. The thermal conductivity of the ceramic material used is 4.1W / mK. When the thickness of the heat-conducting layer is maintained at 15um and the thermal conductivity of the heat-conducting layer is below 200W / mK, the temperature difference on the surface of the product is greater than 50°C; and when the thermal conductivity of the heat-conducting layer reaches 300W / mK, the temperature difference on the surface of the product is reduced to 25°C.

[0066] like Fig. 9 As shown in Table 1, Fig. 9 The vertical axis is the temperature difference in °C, and the horizontal axis is the product of the thickness of the heat-conducting layer and the thermal conductivity of the heat-conducting layer. The effect of the heat-conducting layer on the uniform heat distribution on the surface of the product is related to the product of its thermal conductivity and thickness. The larger the product, the better the effect. To achieve a surface temperature difference of the ceramic heater of less than 20 degrees in a short time (power on for 5 seconds), the product must be greater than 5500mW / K.

[0067] Table 1 Test results of ceramic heater after 5S power on

[0068]

[0069]

[0070] The unit of the thickness of the thermal conductive layer is um; the unit of the thermal conductivity of the thermal conductive layer is W / mK.

[0071] The structure of the above-mentioned thermal conductive layer can adopt an integral film layer or a grid-like design. However, relative to the integral thermal conductive film layer, the product of the grid space ratio and the grid line thickness of the grid thermal conductive layer cannot be less than the film thickness of the integral thermal conductive layer, otherwise the thermal conductive effect will decrease.

[0072] The ceramic heating body of the present invention can be heated to a set temperature of 350°C within 3 to 5 seconds. When the temperature reaches 350 degrees, the temperature difference on the product surface does not exceed 20°C. After maintaining the temperature of 350°C for 30 seconds, the temperature of the product welding line area is less than 100°C. Moreover, compared with products made of zirconium oxide, the heating power required to maintain the product at 350°C is 1 / 3 less (the heating power maintained for 30 seconds after reaching the temperature of 350°C).

[0073] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art of the present invention, several equivalent substitutions or obvious variations can be made without departing from the concept of the present invention, and the performance or use is the same, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A ceramic heater for an electronic cigarette, characterized in that: include: A ceramic inner core and a ceramic substrate wound on the ceramic inner core, a heating circuit is arranged on the bonding surface of the ceramic substrate and the ceramic inner core, a heat-conducting layer is arranged outside the ceramic substrate, and the thermal conductivity of the heat-conducting layer is greater than the thermal conductivity of the ceramic substrate; the heat-conducting layer is a silver layer, a silver-palladium layer or a silver-platinum layer, so that the ceramic inner core and the ceramic substrate adopt low-temperature sintering materials, an insulating layer is arranged outside the heat-conducting layer, the insulating layer, the ceramic inner core and the ceramic substrate are made of the same material, there is a hollow part on the heat-conducting layer, the heat-conducting layer is in a grid shape, and the mesh part is the hollow part, so that the insulating layer and the ceramic substrate can contact and fuse at the hollow part, and the product of the effective area ratio of the grid and the thickness of the grid is not less than the thickness of the heat-conducting layer without the grid.

2. The ceramic heater for electronic cigarette according to claim 1, characterized in that: The ceramic inner core and the ceramic substrate are LTCC materials with high bending strength and low thermal conductivity, wherein the bending strength is ≥250MPa and the thermal conductivity is ≤5.0W / mK.

3. The ceramic heater for electronic cigarette according to claim 1, characterized in that: The heat-conducting layer is formed by printing a heat-conducting electrode paste on the insulating layer and then winding the paste around the outer side of the ceramic substrate and sintering the paste together.

4. The ceramic heater for electronic cigarette according to claim 1, characterized in that: The ceramic inner core and the ceramic substrate are co-fired at a first sintering temperature to obtain a green body; The thermal conductive layer is manufactured on the surface of the green body by dipping or spraying, and an oleophobic protective glaze layer is disposed outside the thermal conductive layer. The thermal conductive layer and the protective glaze layer are sintered together at a second sintering temperature lower than the first sintering temperature, or are sintered in stages at a third sintering temperature and a fourth sintering temperature lower than the first sintering temperature.

5. The ceramic heater for electronic cigarette according to claim 1, characterized in that: The product of the thermal conductivity of the heat-conducting layer and the thickness of the heat-conducting layer is greater than 5500 mW / K.

6. The ceramic heater for electronic cigarette according to claim 1, characterized in that: When the heat conductive layer is a silver layer, the thickness of the silver layer is 10-15 μm.

7. The ceramic heater for electronic cigarette according to any one of claims 1 to 6, characterized in that: It also includes a temperature measuring circuit, and the temperature measuring circuit and the heating circuit are arranged on the same layer of the ceramic substrate, or on different layers of the ceramic substrate.

8. The ceramic heater for electronic cigarette according to any one of claims 1 to 6, characterized in that: The ceramic inner core is in the shape of a rod with a columnar body and a tip, and the ceramic substrate is attached to the upper part of the columnar body, so that the ceramic heating body for electronic cigarettes is axially composed of a tip, a heating part and an end part, and the cross-sectional shape of the columnar body is circular, elliptical or rounded rectangular.

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