KR102017004B1 - Electric heating type smoking device using printed temperature sensor - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric heating smoking device using a printed temperature sensor, and to control the heating temperature of a film heater by a pulse width modulation (PWM) method through sensing a temperature of a film heater that generates heat at a high temperature. The film heater has a tubular shape in which one end of the solid cigarette is inserted, and includes a plurality of planar heating elements based on nano carbon particles that generate heat by receiving power. The temperature sensor is formed on the surface of the film heater by printing and is formed on the basis of carbon nanotubes for transmitting the temperature of the film heater. The controller controls the on / off of the film heater on a PWM basis based on the temperature received from the temperature sensor.

Description

Electric heating type smoking device using printed temperature sensor

The present invention relates to a solid-type electronic cigarette, and more particularly, an electric heating smoking device using a printed temperature sensor for sensing the temperature of the film heater for the pulse width modulation (PWM) control for the high heat generated from the film heater It is about.

A general combustion cigarette is a method of inhaling smoke by combustion through ignition such as a lighter and a match. Such combustion cigarettes inhale a large amount of harmful substances such as tar and heavy metals.

Recently, in order to solve this problem, a solid electronic cigarette of the type which smokes a cigarette (hereinafter referred to as a "solid cigarette") by electric heating has been introduced. It is possible to lower the inhalation of harmful substances and at the same time smoke through the steam without smoke.

In order to enjoy such a solid type electronic cigarette, an electrically heated smoking device that is a dedicated electronic device is required. The electrically heated smoking device includes a heater necessary to steam the solid cigarette.

As a heater of a conventional electrically heated smoking device, a heating blade or a metal etched film heater is used. However, there is a problem in that a large amount of time and power are consumed to heat the metal structure of the heating blade or the metal etched film heater to the temperature required to steam the solid cigarette. And since the power consumption of the heater is large, there is a problem that can not smoke two or more solid cigarettes continuously in the conventional electrically heated smoking device.

In the conventional electrically heated smoking device, in order to control the temperature of the heater, a temperature sensor for detecting the temperature of the heater is attached to the surface of the heater. As the temperature sensor, a positive temperature coefficient (PTC) type is used.

The constant temperature coefficient type temperature sensor exhibits PTC behavior below 200 ° C, but eventually changes to an electrically insulated state, and thus is not suitable for sensing a temperature above 200 ° C.

Since the temperature sensor is attached to the surface of the heater, a space for attaching the temperature sensor is required, and the size of the heater including the temperature sensor increases due to this space. This causes the temperature sensor to increase the size of the electrically heated smoking device.

Korean Registered Patent No. 10-1655716 (registered on September 1, 2016)

Accordingly, another object of the present invention is to provide an electric heating smoking device using a PWM control method for rapidly heating a solid cigarette with a high calorific value generated at low power.

Another object of the present invention to provide an electric heating smoking device using a printed temperature sensor for sensing the temperature of the heater for the PWM control of the high heat generated from the heater.

Still another object of the present invention is to provide an electrically heated smoking device using a printed temperature sensor that can minimize an increase in the attachment space and thickness of the temperature sensor.

Still another object of the present invention is to provide an electric heating smoking device using a printed temperature sensor having a flexibility to bend in a tube form together with a heater.

In order to achieve the above object, the present invention has a tubular shape in which one end of the solid cigarette is inserted, a film heater having a plurality of planar heating elements based on nano-carbon particles to generate heat by receiving power; And a temperature sensor based on carbon nanotubes formed by printing on the surface of the film heater and sensing and transferring the temperature of the film heater.

The film heater, the tube-shaped metal foil; An insulating layer covering one surface of the metal sheet; An electrode wiring pattern formed on the insulating layer; Is formed by printing a nano-carbon particle-based heating element composition to be connected to the electrode wiring pattern on the insulating layer, a plurality of heat connected to the electrode wiring pattern in a plurality of rows to generate heat by applying power from the electrode wiring pattern Planar heating element; And an inner cover layer covering the insulating layer on which the plurality of planar heating elements are formed.

The temperature sensor may include a temperature sensing unit formed by printing a temperature sensing composition containing the carbon nanotubes and a high heat resistant resin on the inner cover layer; And an outer cover layer covering the inner cover layer on which the temperature sensing unit is formed.

The temperature sensing unit is formed on the inner cover layer in which the plurality of planar heating elements are formed in a curved line shape.

The temperature sensing composition includes an epoxy resin or a phenol resin.

The temperature sensor exhibits a negative temperature coefficient (NTC) characteristic of linearly decreasing resistance from room temperature to 400 ° C.

The present invention also has a tubular shape in which one end of the solid cigarette is inserted, the film heater having a plurality of planar heating element based on the nano-carbon particles to generate heat by receiving power; A carbon nanotube-based temperature sensor formed by printing on the surface of the film heater and transmitting the sensing temperature of the film heater; And a controller configured to control on / off of the film heater in a pulse width modulation (PWM) manner based on the temperature received from the temperature sensor.

The controller controls the PWM to maintain the film heater temperature at 250 to 350 ° C. after initially heating the film heater to 350 to 400 ° C. based on the temperature received from the temperature sensor.

According to the present invention, it is possible to rapidly heat the solid cigarette inserted into the film heater through PWM control of the high heat generation generated at low power in the tube-type film heater based on the carbon nanoparticles.

That is, the film heater according to the present invention exhibits a heat density of 2 W / cm 2 or more per unit area while instantaneously generating a high calorific value of 500 ° C. or higher even at a low voltage of 3 to 4 V. Therefore, after peak heating at 350 to 400 ° C. for an initial few seconds using the rapid heating speed of the film heater, PWM control is performed to maintain the temperature at 250 to 350 ° C., thereby rapidly heating the solid cigarette inserted into the film heater. You can. In addition, it is possible to suppress degradation of the durability and life of the film heater due to the high heat generation amount of the film heater through PWM control.

Since the temperature sensor is formed on the surface of the film heater according to the present invention through printing, it is possible to minimize the increase in the attachment space and thickness of the temperature sensor. Because the temperature sensor is based on carbon nanotubes, it maintains the negative temperature coefficient (NTC) even at 400 ℃. Therefore, even for a high amount of heat generated in the film heater according to the present invention, the temperature sensor can accurately sense the temperature of the film heater for PWM control.

Since the temperature sensor is formed in the form of a film by printing a composition mixed with a high heat resistance resin based on carbon nanotubes on the surface of the film heater, the temperature sensor has the flexibility to be bent in the form of a tube together with the film heater.

In the film heater according to the present invention, since the insulating layer is directly formed by coating or casting on the metal thin plate, it is possible to exclude the use of the adhesive used between the existing metal thin plate (metal structure) and the insulating layer. This can solve the problems caused by the use of conventional adhesives. In particular, even though the film heater is initially heated to high temperature through PWM control, it is possible to maintain a stable bonding state between the metal sheet and the insulating layer.

Conventionally, in order to manufacture a metal structure directly in the form of a tube, a thickness of about 1.5 mm is required, which increases the heat capacity of the metal structure and consumes time and a lot of power to heat the metal structure. The problem of inconvenience may occur. However, since the present invention manufactures a plate-shaped film heater formed on the basis of a metal sheet of 1 mm or less in the form of a tube, the heat capacity of the metal sheet can be reduced, and the time for heating a solid cigarette is shortened and power is reduced. Reduce usage

Since the film heater according to the present invention is implemented in a tubular shape so that the solid cigarette can be inserted, there is no need to separately prepare a structure to mount the solid cigarette.

Since the film heater according to the present invention includes an electrode wiring pattern and a planar heating element that can be driven at a low voltage, the film heater can exhibit high heat generation characteristics at low power. Since the planar heating element is formed of a heating element composition in the form of a coating including nano-carbon particles and a mixed binder, it has a low specific resistance and excellent thermal conductivity, which is advantageous for low voltage driving and has a high temperature rising speed. This allows the film heater according to the present invention to quickly heat the solid cigarette.

Since the film heater according to the present invention includes a planar heating element formed to have a bend, it is possible to increase the contact area between the planar heating element and the metal sheet when rolled in the form of a tube. As a result, the film heater according to the present invention can reduce power consumption, heat transfer loss and manufacturing cost, and minimize the heat capacity of the metal sheet.

And by forming a heat insulation layer in the outer surface of the film heater which concerns on this invention, it can suppress that the heat generate | occur | produced in a planar heating element is discharged to the outside and is lost. In addition, the heat insulation layer allows heat to be transferred toward the solid cigarette to be inserted, thereby shortening the heating time of the solid cigarette and further reducing power consumption.

1 is a schematic view showing a solid-type electronic cigarette including the electrically heated smoking device according to the present invention.
2 is a perspective view showing a heater assembly for an electrically heated smoking device according to a first embodiment of the present invention.
3 and 4 are perspective views showing the heater assembly on the plate before drying in tubular form.
5 is a top view of the heater assembly of FIG. 3.
6 is a plan view illustrating the film heater of FIG. 2.
7 is a plan view illustrating the temperature sensor of FIG. 2.
8 to 21 are views showing each step according to the manufacturing method of the heater assembly according to the first embodiment of the present invention,
8 is a plan view showing a metal sheet,
FIG. 9 is a sectional view taken along line 9-9 of FIG. 8;
10 is a cross-sectional view showing a step of forming an insulating layer on the upper surface of the metal thin plate,
11 is a cross-sectional view showing a step of forming a metal layer on an insulating layer,
12 is a plan view illustrating a step of forming an electrode wiring pattern by patterning a metal layer;
13 is a plan view showing a step of forming a plurality of planar heating elements by printing the heating element composition;
14 is a cross-sectional view taken along line 13-13 of FIG. 13,
15 is a plan view illustrating a step of forming an inner cover layer on an insulating layer to cover an electrode wiring pattern and a plurality of planar heating elements;
16 is a cross-sectional view taken along line 16-16 of FIG. 15,
17 is a plan view illustrating a step of forming a temperature sensing unit by printing a temperature sensing composition on an inner cover layer having a plurality of planar heating elements formed thereon;
18 is a plan view illustrating a step of forming an outer cover layer covering a temperature sensing unit on an inner cover layer;
19 is a plan view showing a step of manufacturing a plate-shaped heater assembly by cutting away portions except the junction part and the electrode wiring pattern,
20 is a cross-sectional view taken along line 20-20 of FIG. 19,
21 is a cross-sectional view showing the step of rolling the heater assembly in the form of a tube so that the metal sheet faces the inner side.
22 is a plan view showing a unit heater assembly formed on a thin metal strip.
23 is a cross-sectional view showing a heater assembly according to a second embodiment of the present invention.
24 is a plan view illustrating a film heater of the heater assembly according to the third embodiment of the present invention.
FIG. 25 is a plan view illustrating a temperature sensor of the heater assembly of FIG. 24.
26 is a photograph showing film heaters of a heater assembly according to a third embodiment formed on a thin metal strip before punching.
27 is a photograph showing the lower surface of the film heater of Sample No. 5 after punching of FIG.
FIG. 28 is a photograph showing an upper surface of the film heater of Sample No. 5 in FIG. 27.
29 is a graph showing the exothermic behavior when DC 2V is applied to the film heater of Sample No. 5.
30 is a schematic diagram of PWM control of a sample heater 5.

In the following description, only parts necessary for understanding the embodiments of the present invention will be described, it should be noted that the description of other parts will be omitted in a range that does not distract from the gist of the present invention.

The terms or words used in the specification and claims described below should not be construed as being limited to the ordinary or dictionary meanings, and the inventors are appropriate to the concept of terms in order to explain their invention in the best way. It should be interpreted as meanings and concepts in accordance with the technical spirit of the present invention based on the principle that it can be defined. Therefore, the embodiments described in the present specification and the configuration shown in the drawings are only preferred embodiments of the present invention, and do not represent all of the technical idea of the present invention, and various equivalents may be substituted for them at the time of the present application. It should be understood that there may be variations and variations.

Hereinafter, with reference to the accompanying drawings will be described in detail an embodiment of the present invention.

1 is a schematic view showing a solid-type electronic cigarette including the electrically heated smoking device according to the present invention.

Referring to FIG. 1, a solid electronic cigarette 100 according to the present invention includes a solid cigarette 95 and an electrically heated smoking device 90. The solid-type electronic cigarette 100 is an electronic cigarette used by heating a stick-type solid cigarette 95 into an electric heating smoking device 90 and using electricity unlike the liquid electronic cigarette using a conventional liquid nicotine.

The solid cigarette 95 has a form similar to that of a general combustion cigarette. That is, the solid tobacco 95 is formed on one end of the tobacco section 95b, the tobacco section 95b to accommodate the tobacco, filter section for filtering harmful substances contained in the aerosol generated by steaming the tobacco section 95b. (95a). At this time, the tobacco of the tobacco part 95b is a tobacco which can be steamed by heat, and is distinguished from the general combustion type tobacco.

The electrically heated smoking device 90 according to the invention comprises a heater assembly 91 which steams the solid tobacco 95 by electric heating. The heater assembly 91 includes a tubular film heater 80 and a temperature sensor 60. The film heater 80 has a tubular shape in which one end of the solid cigarette 95 is inserted and includes a plurality of planar heating elements based on nano-carbon particles that generate heat by receiving power. The temperature sensor 60 is based on carbon nanotubes formed by printing on the surface of the film heater 80 to sense and transmit the temperature of the film heater 80.

In addition, the electrically heated smoking device 90 according to the present invention may further include a control unit 93 for performing temperature control of the film heater 80.

Here, the film heater 80 has a tubular shape in which openings 81 and 83 are opened at both sides, and one side of the openings 81 and 83 is an insertion hole 81 into which one end of the solid cigarette 95 is inserted. Is used. The other side of the openings 81, 89, ie, the opposite side of the insertion opening 81, allows the aerosol generated by the heating of the solid tobacco 95 to be sucked through the filter portion 95a of the solid tobacco 95. It is used as an inlet 83 through which air is introduced.

The film heater 80 is manufactured by rolling a plate-shaped film heater 80 having a metal thin plate as a base layer. The film heater 80 has a structure in which a plurality of planar heating elements based on nano carbon particles that generate heat by receiving power from one surface of a metal thin plate are formed.

The temperature sensor 60 detects the temperature of the film heater 80 and transmits the temperature to the controller 93. The temperature sensor 60 is based on carbon nanotubes, and has a NTC characteristic of linearly decreasing resistance up to 400 ° C. at room temperature. That is, when the resistance is constant at a specific temperature, the temperature of the film heater 80 may be controlled through current control. When the temperature sensor 60 detects a decrease in linear resistance according to an increase in temperature and transmits the linear resistance to the controller 95, the controller 95 controls the current supplied to the film heater 80 to control the current of the film heater 80. The temperature can be controlled to a temperature suitable for steaming the solid tobacco 95.

The controller 93 controls on / off of the film heater 80 based on the temperature received from the temperature sensor 60. That is, the control unit 93 turns on / off the film heater 80 based on the temperature received from the temperature sensor 60 so as to transfer heat of an appropriate temperature to the solid cigarette 95 inserted into the insertion hole 81. To control. The control unit 93 turns off the film heater 80 when it is separated from the solid cigarette 95 at the insertion hole 81.

In this case, the controller 91 may control the on / off of the film heater 80 in a pulse width modulation (PWM) manner. Here, the PWM method is one of pulse modulation methods and refers to a method of controlling by changing the duty ratio of the pulse according to the size of the modulation signal. In other words, the PWM control adjusts the control value by adjusting the duty ratio, and the average value of the pulse signal is changed by changing the duty ratio of the pulse signal, and the average value is used as the control signal value.

The control unit 91 turns on / off the film heater 80 so as to maintain an appropriate temperature at which the solid cigarette 95 can be struck among the temperature ranges that can be generated by the film heater 80 through the control of the PWM method. You can. That is, as shown in FIG. 30, the controller 91 maintains the temperature at 250 to 350 ° C. after peak heating at 350 to 400 ° C. for several seconds using the rapid heating speed of the film heater 80. PWM control is performed. As a result, the solid tobacco 95 inserted into the film heater 80 can be quickly heated. It is possible to stably drive the film heater 80 by suppressing deterioration in durability and lifespan of the film heater 80 due to the high heat generation amount of the film heater 80 through PWM control.

Meanwhile, although not shown, the electrically heated smoking device 90 according to the present invention further includes a power supply unit for supplying power to the film heater 80. As the power supply unit, a primary battery or a secondary battery may be used.

The heater assembly 91 used in the electrically heated smoking device 90 according to the present invention will be described with reference to FIGS. 2 to 26 as follows.

[First Embodiment]

2 is a perspective view showing a heater assembly 91 for an electrically heated smoking device according to a first embodiment of the present invention. 3 and 4 are perspective views showing the heater assembly 91 on the plate before drying in tubular form. 5 is a top view of the heater assembly 91 of FIG. FIG. 6 is a plan view illustrating the film heater 80 of FIG. 2. FIG. 7 is a plan view illustrating the temperature sensor 60 of FIG. 2.

2 to 7, the heater assembly 80 according to the first embodiment includes a tubular film heater 80 and a temperature sensor 60 formed by printing on the outer surface of the film heater 80. do.

The film heater 80 has a tube shape in which openings 81 and 83 into which one end of a solid cigarette is inserted are formed, and the metal thin plate 10, the insulating layer 20, the electrode wiring pattern 30, and a plurality of planes are formed. The heating element 40 and the inner cover layer 50 is included. Here, the thin metal plate 10 has a tubular shape. The insulating layer 20 covers one surface of the metal thin plate 10. The electrode wiring pattern 30 is formed on the insulating layer 20. The plurality of planar heating elements 40 are formed by printing a nano-carbon particle-based heating element composition on the insulating layer 20 so as to be connected to the electrode wiring pattern 30, and generate heat by receiving power from the electrode wiring pattern 30. The inner cover layer 50 covers the insulating layer 20 on which the plurality of planar heating elements 40 are formed.

The film heater 80 has a structure in which the metal thin plate 10 is located inside, and the cover layer 50 is located outside. The film heater 80 has a structure in which the insulating layer 20, the electrode wiring pattern 30, the plurality of planar heating elements 40, and the inner cover layer 50 are sequentially stacked on the outer surface of the metal thin plate 10. .

The metal thin plate 10 is a base layer on which the insulating layer 20, the electrode wiring pattern 30, the plurality of planar heating elements 40, and the inner cover layer 50 can be formed. The metal thin plate 10 has a lower surface 11 and an upper surface 13 opposite to the lower surface 11. As the material of the metal thin plate 10, aluminum, copper, nickel, stainless steel, brass or alloys thereof may be used. In this case, brass is a copper alloy containing copper and zinc, and may additionally include a small amount of As, P, Al, and Si. Brass may be a brass having a zinc content of 50% by weight or less.

The insulating layer 20 is formed by coating or casting on the upper surface 13 of the metal thin plate 10. As a material of the insulating layer 20, a plastic material may be used. For example, the material of the insulating layer 20 is polyimide, polyethersulphone (PES), polyacrylate (PAR), polyetherimide (PEI), polyethylene naphthalate (polyethyelenen napthalate; PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polyallylate, polycarbonate (PC), cellulose triacetate (CTA) or cellulose acetate propio Cellulose acetate propinonate (CAP) may be used, but is not limited to those listed.

An insulating ink composition may be used as the material of the insulating layer 20. For example, the insulating ink composition includes a mixed binder, inorganic nanoparticles, a dispersant, and an organic solvent. The insulating ink composition may further include an inorganic filler and a leveling agent.

The insulating ink composition may be implemented in the form of a paint or a solution by adjusting the amount of the organic solvent.

The insulating ink composition includes 8 to 10 parts by weight of the mixed binder, 0.001 to 0.5 parts by weight of the inorganic nanoparticles, 20 to 80 parts by weight of the organic solvent, and 0.5 to 5 parts by weight based on 100 parts by weight of the insulating ink composition.

Here, the same material as the mixed binder, the dispersant, the organic solvent, and the leveling agent may be used as the mixed binder, the dispersant, the organic solvent, and the leveling agent included in the heating element composition described below.

The inorganic nanoparticles include graphene oxide (GO) particles, partially reduced graphene oxide particles, or conductive carbon particles having a nano size in diameter. The inorganic nanoparticles enhance the heat resistance and insulation of the insulating ink composition.

The inorganic nanoparticles contain 0.001 to 0.5 parts by weight based on 100 parts by weight of the insulating ink composition. As a result, the conductive carbon particles may be distributed in an island form between the matrices formed by the mixed binder.

Graphene oxide particles are insulated within 120 layers and are partially graphitized particles.

Graphene oxide particles have a variety of functional groups. Using these various functional groups, the graphene oxide particles may induce direct chemical covalent bonds with the mixed binder which is an organic binder. For this reason, the insulating ink composition has stable heat resistance even at a temperature near 300 占 폚.

The graphene oxide particles have various chemically reactive functional groups such as carboxyl, amine, imine, hydroxyl, carbonyl, and lactone at the surface and the edge. The functional groups included in the graphene oxide particles may be chemically covalently bonded to the functional groups included in the diisocyanate, phenol, and epoxy. Therefore, the graphene oxide particles form chemical covalent bonds with epoxy acrylate, hexamethylene diisocyanate, and phenolic resin included in the mixed binder. Such chemical covalent bonds between the graphene oxide particles and the mixed binder form a three-dimensional network and have an effect of suppressing the movement of the polymer chain, which may cause an increase in glass transition and decomposition start temperature.

Since the graphene oxide particles have a large number of functional groups at the surface and the edge portion as described above, they exhibit good dispersibility in the mixed binder and the organic solvent.

The conductive carbon particles may comprise carbon black or graphite particles of 20 layers or less. Graphite particles may have a diameter of less than 2 μm. This is because when the diameter of the graphite particles exceeds 2 μm, a problem of lowering the impulse breaking strength may occur.

On the other hand, needle-like shapes such as carbon nanotubes and carbon fibers are not preferable as conductive carbon particles. The reason is that needle-shaped carbon nanotubes or carbon fibers are not suitable as components of the insulating ink composition for forming the insulating layer 20 because they can form an electrical network even with a small content.

The inorganic filler may be added for the purpose of improving reliability such as surface strength and moisture absorption resistance of the insulating layer 20 formed using the insulating ink composition. The inorganic filler may contain 10 to 70 parts by weight based on 100 parts by weight of the insulating ink composition. As the inorganic filler, fused silica particles or alumina particles having a particle size of 50 nm to 2 μm may be used. In order to increase the packing ratio, the fused silica particles may use particles having two or more particle sizes.

Thus, since the insulating layer 20 is formed by coating or casting on the metal thin plate 10, it is not necessary to use a separate adhesive to form the insulating layer 20 on the metal thin plate 10.

The insulating layer 20 is formed on both ends of the metal thin plate 10. Both ends of the metal thin plate 10 exposed outside the insulating layer 20 are used as the joint 17. The joining portion 17 is a portion to be joined when rolling both ends of the film heater made of a plate shape.

The electrode wiring pattern 30 is formed on the insulating layer 20, and supplies power applied from the outside to the planar heating element 40. The electrode wiring pattern 30 may be formed of a metal material to minimize a voltage drop. Silver, aluminum, copper, nickel, stainless steel, brass, or an alloy thereof may be used as the metal material for forming the electrode wiring pattern 30.

The electrode wiring pattern 30 can be formed by an etching method using a metal foil or a printing method using a metal paste. That is, the electrode wiring pattern 30 may be formed by laminating metal foil on the insulating layer 20 and patterning the same by an etching method. Alternatively, the electrode wiring pattern 30 may be formed by printing a metal paste on the insulating layer 20.

The planar heating element 40 is formed to be connected to the electrode wiring pattern 30. The planar heating element 40 may be formed by printing the heating element composition to be connected to the electrode wiring pattern 30 and then thermosetting and aging the same. As the printing method of the exothermic composition, screen printing, gravure printing (to roll to roll gravure printing), comma coating (to roll to roll comma coating), flexo, imprinting, offset printing and the like can be used. Thermal curing may be performed at 100 ° C to 180 ° C, and aging may be performed at 250 to 350 ° C. The reason for forming the planar heating element 40 by aging after thermosetting is to ensure high temperature stability of the planar heating element 40.

The planar heating element 40 is formed to be arranged in the horizontal direction on the insulating layer 20. That is, the planar heating element 40 may be formed on the insulating layer 20 in an n-row m-line (n, m is two or more natural numbers). In this case, the electrode wiring pattern 30 is formed to connect the plurality of planar heating elements 40 formed on the insulating layer 20 in parallel.

The heating element composition forming the planar heating element 40 includes a mixed binder and conductive particles based on nano carbon particles. In order to form the planar heating element 40, the heating element composition introduced into the printing process further includes an organic solvent and a dispersant in addition to the mixed binder and the conductive particles.

The heating element composition may include 5 to 30 parts by weight of the mixed binder, 0.7 to 60 parts by weight of the conductive particles, 29 to 80 parts by weight of the organic solvent, and 0.5 to 5 parts by weight of the dispersant based on 100 parts by weight of the heating element composition.

The conductive particles may include nano-sized carbon particles having conductivity, and may further include metal powder. As the carbon particles, carbon nanotube particles or graphite particles may be used. As the metal powder, a powder made of silver, copper or nickel may be used. For example, the conductive particles may include 0.1 to 5 parts by weight of carbon nanotube particles, 0.1 to 20 parts by weight of graphite particles, or 10 to 60 parts by weight of metal powder based on 100 parts by weight of the exothermic composition.

The carbon nanotube particles may be selected from single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, or mixtures thereof. For example, the carbon nanotube particles may be multi wall carbon nanotubes. When the carbon nanotube particles are multi-walled carbon nanotubes, the diameter may be 1 nm to 20 nm, and the length may be 1 μm to 100 μm.

Graphite particles may have a diameter of 1 μm to 25 μm and a thickness of 1 nm to 25 μm.

Metal powders include powders of silver, copper or nickel materials. In the case of silver powder, it may have the form of flakes, spherical shapes, polygonal plates, rods and the like. As the copper powder, silver coated copper powder, nickel coated copper powder, or the like may be used. And nickel powder may be used silver coated nickel (Ag coated Ni) powder.

When the planar heating element 40 is formed of a heating element composition including carbon particles and metal powder, the metal powder forms a main electric network, and carbon particles are filled in the space between the metal powders to form a three-dimensional random network structure.

As such, the heating element composition may include carbon particles and metal powder, thereby increasing the energy efficiency and the heating rate of the planar heating element 40. That is, the metal powder does not have a black body radiation function. However, by including the carbon particles in the heating element composition, it is possible to implement a blackbody radiation function. Due to the carbon particles, the heat resistance of the planar heating element 40 can be increased. And due to the carbon particles, the heat generation rate and energy efficiency of the planar heating element 40 can be increased.

The resistivity of the planar heating element 40 may be determined by the content of carbon particles or metal powder in the total solids. For example, the specific resistance can be controlled only by the carbon particles up to the 1 × 10 ⁻² Ωcm region, but the region below it requires additional introduction of metal powder. The planar heating element 40 may have a specific resistance of 9 × 10 ⁻² to 1.1 × 10 ⁻³ dBm.

The mixed binder includes at least two kinds of phenolic resins, acetal resins, isocyanate resins and epoxy resins so as to have heat resistance even at a temperature of about 300 ° C. For example, the mixed binder includes at least two of epoxy, epoxy acrylate, hexamethylene diisocyanate, polyvinyl acetal and phenolic resin.

For example, the mixed binder may include hexamethylene diisocyanate, polyvinyl acetal and phenolic resins or may include epoxy acrylate, polyvinyl acetal and phenolic resins. Here, the mixed binder may include 10 to 150 parts by weight of polyvinyl acetal resin and 100 to 500 parts by weight of phenolic resin based on 100 parts by weight of epoxy acrylate or hexamethylene diisocyanate. When the phenolic resin is 100 parts by weight or less with respect to 100 parts by weight of epoxy acrylate or hexamethylene diisocyanate, the heat resistance may be lowered, and when the phenolic resin is more than 500 parts by weight, the flexibility of the planar heating element 40 may be lowered, leading to brittleness.

By increasing the heat resistance of the mixed binder in this manner, even when the planar heating element 40 is generated at a high temperature of about 300 ° C., the resistance change and breakage of the planar heating element 40 can be suppressed.

Herein, the phenolic resin means a phenolic compound including phenol and a phenol derivative. For example, phenol derivatives include p-cresol, o-Guaiacol, Creosol, catechol, 3-methoxy-1,2-benzenediol (3- methoxy-1,2-Benzenediol), Homocatechol, Vinylguaiacol, Syringol, Iso-eugenol, Methoxyeugenol, o- O-Cresol, 3-methyl-1,2-benzenediol (3-methyl-1,2-Benzenediol), (z) -2-methoxy-4- (1-propenyl) -phenol (( z) -2-methoxy-4- (1-propenyl) -Phenol), 2,6-diethoxy-4- (2-propenyl) -phenol (2,6-dimethoxy-4- (2-propenyl)- Phenol), 3,4-dimethoxy-Phenol, 4-ethyl-1,3-benzenediol, 4-ethyl-1,3-Benzenediol, Resole phenol, 4-methyl-1,2-benzenediol (4-methyl-1,2-Benzenediol), 1,2,4-benzenetriol (1,2,4-Benzenetriol), 2-methoxy-6-methylphenol (2-Methoxy-6-methylphenol), 2-Methoxy-4-vinylphenol or 4-ethyl-2-methoxy-phenol (4-ethyl-2-methoxy-Phenol) Such as, but not limited to It is not.

The organic solvent is used to disperse the conductive particles and the mixed binder. Carbitol acetate, Butyl carbotol acetate, DBE (dibasic ester), ethyl carbitol, ethyl carbitol acetate, dipropylene glycol It may be a mixed solvent of two or more selected from methyl ether, cellosolve acetate, butyl cellosolve acetate, butanol (Butanol) and octanol (Octanol).

On the other hand, the dispersion process can be applied to a variety of commonly used methods, for example through the ultra-sonication (Roll mill), bead mill (Bead mill) or ball mill (Ball mill) process Can be done.

And the dispersing agent is to more smoothly disperse the conductive particles, it is possible to use a conventional dispersing agent used in the art, such as BYK, amphoteric surfactant such as Triton X-100, ionic surfactant such as SDS.

In addition, the heating element composition may further include 0.1 to 5 parts by weight of the silane coupling agent as an additive, based on 100 parts by weight of the heating element composition.

The silane coupling agent functions as an adhesion promoter to promote adhesion between the resins in the formulation of the heating element composition. The silane coupling agent may be an epoxy containing silane or a merceto containing silane. Examples of such silane coupling agents include epoxy and include 2- (3,4 epoxy cyclohexyl) -ethyltrimethoxysilane, 3-glycidoxytrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, containing amine groups, N-2 (aminoethyl) 3-amitopropylmethyldimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane , N-2 (aminoethyl) 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysil-N- (1,3-dimethyl Butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, containing merceto, 3-mercetopropylmethyldimethoxysilane, 3-mercetopropyltriethoxysilane, isocyanate 3-isocyanate propyl triethoxysilane contained, and the like is not limited thereto.

In addition, the heating element composition may further include 0.5 to 20 parts by weight of ceramic particles as an additive, based on 100 parts by weight of the heating element composition. The ceramic particles increase the heat capacity of the planar heating element 40. As such ceramic particles, glass particles or silicon particles may be used.

In addition, the heating element composition may further include 0.0001 to 1 part by weight of graphene oxide particles as an additive, based on 100 parts by weight of the heating element composition. Here, as graphene oxide particles, particles having an insulating property within 1 to 20 layers and partially graphitized particles are used.

Graphene oxide particles have a variety of functional groups. Using these various functional groups, the graphene oxide particles may induce direct chemical covalent bonds with the mixed binder which is an organic binder. For this reason, the exothermic composition according to the present invention has stable heat resistance even at a temperature near 300 ° C.

That is, the graphene oxide particles have various chemically reactive functional groups such as carboxyl, amine, imine, hydroxyl, carbonyl, and lactone on the surface and the edge thereof. The functional groups included in the graphene oxide particles may be chemically covalently bonded to the functional groups included in the diisocyanate, phenol, and epoxy. Therefore, the graphene oxide particles form chemical covalent bonds with epoxy acrylate, hexamethylene diisocyanate, and phenolic resin included in the mixed binder. Such chemical covalent bonds between the graphene oxide particles and the mixed binder form a three-dimensional three-dimensional network and have an effect of inhibiting the movement of the polymer chain, which may cause an increase in glass transition and decomposition start temperature.

Since the graphene oxide particles have a large number of functional groups at the surface and the edge portion as described above, they exhibit good dispersibility in the mixed binder and the organic solvent.

Meanwhile, in the first embodiment, an example in which the electrode wiring pattern 30 and the planar heating element 40 are sequentially formed on the insulating layer 20 is disclosed, but is not limited thereto. That is, after forming the planar heating element on the insulating layer, the electrode wiring pattern can be formed.

The inner cover layer 50 is formed to cover the insulating layer 20 on which the plurality of planar heating elements 40 are formed. The inner cover layer 50 protects the electrode wiring pattern 30 and the plurality of planar heating elements 40 formed on the insulating layer 20 from an external environment. As the material of the inner cover layer 50, an epoxy resin, a urethane resin, a silicone resin, an imide resin, or a metal foil having an insulating adhesive layer formed on a contact surface with the planar heating element 40 may be used. Urethane or epoxy resin may be used as a material of the insulating adhesive layer. For example, the inner cover layer 50 may be bonded to the insulating layer 20 by hot pressing or laminating.

Thus, since the film heater 80 according to the first embodiment includes a plurality of planar heating elements 40 which can be driven at low power, the film heater 80 exhibits high heat generation at low power.

Since the planar heating element 40 has a large heat generating area, heat loss in the heat transfer process may be minimized.

Since the planar heating element 40 can be variously designed through a printing process, the planar heating element 40 can be manufactured to be driven at various driving voltages that can be used in a device or environment in which the film heater 80 according to the first embodiment is used.

Since the planar heating element 40 is formed of a heating element composition in the form of a coating including conductive particles and a mixed binder, it has a low specific resistance and excellent thermal conductivity, which is advantageous for low voltage driving and has a high temperature rising speed. That is, since the heat generating composition includes a mixed binder containing hexamethylene diisocyanate or epoxy acrylate, polyvinyl acetal, and a phenolic resin together with the conductive particles, heat resistance can be maintained even at a temperature of 200 ° C or higher. For this reason, the film heater 80 according to the first embodiment may provide a heater having a planar heating element 40 having high heat generation behavior and high stability due to a small change in resistance according to temperature.

Since the planar heating element 40 formed of a heating element composition including carbon nanotube particles and graphite particles is a black body, the film heater 80 according to the first embodiment may provide additional energy efficiency due to black body radiation. You can get an improvement. Since the film heater 80 according to the first embodiment also emits far infrared rays due to black body radiation, it is possible to provide beneficial far infrared rays to the user.

The heating element composition may provide the film heater 80 according to the first embodiment having a low specific resistance and easy thickness control to enable high temperature heating with low voltage and low power.

And since the heating element composition is capable of screen printing, roll-to-roll gravure printing, roll-to-roll comma coating, flexographic printing, and offset printing, it is advantageous not only for mass production of the film heater 80 according to the first embodiment, but also for product length and area. Eliminate restrictions on

Thus, since the film heater 80 according to the first embodiment includes the electrode wiring pattern 30 and the planar heating element 40 capable of driving low voltage, the film heater 80 may exhibit high heat generation characteristics at low power. Since the planar heating element 40 is formed of a heating element composition in the form of a coating including carbon particles and a mixed binder, it has a low specific resistance and excellent thermal conductivity, which is advantageous for low voltage driving and has a high temperature rising speed. As a result, the film heater 80 according to the first embodiment can quickly heat the solid cigarette.

As described above, according to the first embodiment, the solid cigarette inserted into the film heater 80 is rapidly controlled through PWM control of the high heat generation generated at low power in the tube heater film heater 80 based on the carbon nanoparticles. Can be heated.

That is, the film heater 80 according to the first embodiment exhibits a heat density of 2 W / cm 2 or more per unit area while instantaneously generating a high calorific value of 500 ° C. or higher even at a low voltage of 3 to 4V. Therefore, after peak heating at 350 to 400 ° C. for an initial few seconds using the fast heating speed of the film heater 80, PWM control is performed to maintain the temperature at 250 to 350 ° C., thereby inserting the high temperature into the film heater 80. The body cigarette can be heated quickly. In addition, it is possible to suppress deterioration in durability and lifespan of the film heater 80 due to the high heat generation amount of the film heater 80 through PWM control.

Therefore, since the electrically heated smoking device including the film heater 80 according to the first embodiment can continuously smoke two or more solid cigarettes, the user's convenience can be increased.

Since the film heater 80 according to the first embodiment is implemented in a tubular shape so that the solid cigarette can be inserted, there is no need to separately prepare a structure for mounting the solid cigarette.

In the film heater 80 according to the first embodiment, since the insulating layer 20 is directly formed on the metal sheet 10 by coating or casting, the adhesive used between the existing metal sheet (metal structure) and the insulating layer is used. The use of can be excluded. This can solve the problems caused by the use of conventional adhesives.

The temperature sensor 60 includes a temperature sensing unit 61 and an outer cover layer 67. The temperature sensing unit 61 is formed by printing a temperature sensing composition containing carbon nanotubes and a high heat resistant resin on the inner cover layer 50. The outer cover layer 67 covers the inner cover layer 50 in which the temperature sensing unit 61 is formed. Since the temperature sensor 60 is formed on the surface of the film heater 80 through a printing process, it can be formed thinly on the surface of the film heater 80 with a thickness of 50 micrometers or less.

The reason why the temperature sensing unit 61 is formed based on the carbon nanotubes is to sense the temperature of the film heater 80 heated to 200 ° C. or more. That is, generally printable organic-based carbon materials exhibit positive temperature coefficient (PTC) characteristics with increasing temperature. This is because the resistance increases as the distance between the carbon particles increases with the volume expansion of the organic matrix with increasing temperature. Therefore, since the PTC behavior is lowered to 200 ° C or lower, and eventually changes to an electrically insulated state, it cannot be used as a temperature sensor for detecting a temperature higher than 200 ° C.

 However, the temperature sensor 60 according to the first embodiment shows NTC characteristics in which the resistance decreases linearly from room temperature to 400 ° C. This is because the carbon nanotubes have a needle-like shape, and thus the resistance of the organic nanoparticles is not affected by the volume expansion.

The temperature sensing composition includes a high heat resistant resin so that the temperature sensor 60 can have heat resistance over a temperature of 200 ° C. or higher. Here, as the high heat resistant resin, an epoxy resin, a phenol resin, or the like may be used, but is not limited thereto.

The temperature sensing unit 61 is formed on the inner cover layer 50 in which the plurality of planar heating elements 40 are formed in a curved line shape. The temperature sensing unit 61 includes a temperature sensing pattern 63 formed on the inner cover layer 50 on which the plurality of planar heating elements 40 are formed, and a temperature sensing pad 65 formed at both ends of the temperature sensing pattern 63. It includes. The temperature sensing pad 65 may be disposed on the side where the electrode pad 31 is formed.

The temperature sensing pattern 63 may be formed in a square wave shape that runs in a vertical direction. That is, the plurality of planar heating elements 40 are formed in a plurality of lines in the vertical direction. Therefore, the temperature sensing pattern 63 is formed in a direction orthogonal to the direction in which the plurality of planar heating elements 40 are formed to detect a change in resistance according to heat generated from the plurality of planar heating elements 40.

As such, since the temperature sensor 60 is formed on the surface of the film heater 80 through printing, the increase in the attachment space and the thickness of the temperature sensor 60 can be minimized. Since the temperature sensor 60 is based on carbon nanotubes, it maintains NTC characteristics even at 400 ° C. Therefore, even with a high amount of heat generated by the film heater 80, the temperature sensor 60 can accurately detect the temperature of the film heater 80 for PWM control.

And since the temperature sensor 60 is formed in the form of a film by printing a composition mixed with a high heat-resistant resin based on carbon nanotubes on the surface of the film heater 80, it can be bent in a tube form together with the film heater 80 Has the flexibility.

A method of manufacturing the heater assembly 91 according to the first embodiment will be described below with reference to FIGS. 2 to 21. 8 to 21 are views showing respective steps according to the manufacturing method of the heater assembly 91 according to the first embodiment of the present invention.

In the method of manufacturing the heater assembly 91 according to the first embodiment, the method may include manufacturing a plate-shaped film heater 80 based on the metal thin plate 10, and the temperature sensor 60 on the plate-shaped film heater 80. Manufacturing a, and rolling the plate-shaped film heater 80 and the temperature sensor 60 into a tubular shape to manufacture the heater assembly 91.

Referring to FIGS. 8 to 16, the steps of manufacturing the plate-shaped film heater 80 based on the metal thin plate 10 are as follows.

First, as shown in FIGS. 8 and 9, a plate-shaped metal thin plate 10 is prepared. At this time, the thickness of the metal thin plate 10 is 1mm or less.

The reason why the metal thin plate 10 of 1 mm or less can be used is to manufacture a film heater in the form of a plate using the metal thin plate 10 and roll it up to produce a tube-type film heater. In addition, when the metal thin plate is used in excess of 1mm, the heat capacity of the metal thin plate is increased, and since the time and a lot of power are consumed to heat the metal thin plate, a problem of inconvenience for the user may occur. Therefore, in the first embodiment, since the metal sheet 10 of 1 mm or less is rolled and manufactured in the form of a tube, the heat capacity of the metal sheet can be reduced, and the time for heating the solid cigarette can be shortened and the power consumption can be reduced. have.

Next, as shown in FIG. 10, the insulating layer 20 is formed on the upper surface 13 of the metal thin plate 10. The insulating layer 20 may be formed by a coating or casting method.

In this case, the insulating layer 20 is formed inside the junction 17 to be formed at both ends of the metal thin plate 10.

Next, as shown in FIG. 11, the metal layer 39 is formed on the insulating layer 20. That is, the metal layer 39 may be formed by bonding the metal foil on the insulating layer 20. Alternatively, the metal layer 39 may be formed by depositing a metal on the insulating layer 20.

Next, as shown in FIG. 12, the metal layer is patterned to form the electrode wiring pattern 30. In this case, photolithography may be used as the patterning method of the metal layer.

The electrode wiring pattern 30 includes a pair of electrode pads 31 and a pair of electrode terminals 35. The pair of electrode pads 31 are spaced at regular intervals and are portions to which power is applied. The pair of electrode terminals 35 are connected to the pair of electrode pads 31 and extend, respectively, and are a portion in which a plurality of planar heating elements are connected in parallel.

The electrode wiring pattern 30 has a structure in which a pair of electrode pads 31 are connected to one side of the pair of electrode terminals 35 in a vertical direction. That is, the electrode wiring pattern 30 may be formed in a tracer shape.

The pair of electrode pads 31 are connected to one end of the pair of electrode terminals 35, and a cable for supplying power is joined. The pair of electrode pads 31 protrude out of the cover film 50 of FIG. 15 to receive power through the cable. One of the pair of electrode pads 31 is connected with a cable for supplying a positive power, and the other with a cable for supplying a positive power.

The pair of electrode pads 31 are formed to be spaced apart from the plurality of planar heating elements. In the first embodiment, an example in which a pair of electrode pads 31 are formed at a position spaced apart from the planar heating element 50 positioned at the outermost in a direction in which a plurality of planar heating elements are arranged is disclosed, but is not limited thereto. no.

The pair of electrode terminals 35 includes a first electrode terminal 35a and a second electrode terminal 35b. The first electrode terminal 35a may be formed in a straight line, and the second electrode terminal 35b may be formed in a form of enclosing the first electrode terminal 35a in a recessed shape.

Meanwhile, the electrode wiring pattern 30 according to the first embodiment has disclosed an example in which a pair of electrode pads 31 are connected in a vertical direction to one side of a pair of electrode terminals 35 formed in a horizontal direction to form a transitory shape. It is not limited to this. For example, according to the position of the pair of electrode pads connected to the pair of electrode terminals can be implemented in the English letter "T" shape, of course.

Next, as shown in FIGS. 13 and 14, the heating element composition is printed on the insulating layer 20, and then thermoset and aged to form a plurality of planar heating elements 40. In this case, the plurality of planar heating elements 40 are formed on the insulating layer 20 between the pair of electrode terminals 35 and the pair of electrode terminals 35, and are formed to connect the pair of electrode terminals 35. do. The pair of electrode pads 31 of the electrode wiring pattern 30 are exposed out of the planar heating element 40.

As the printing method of the planar heating element 40, screen printing, gravure printing (to roll to roll gravure printing), comma coating (to roll to roll comma coating), flexo, imprinting, offset printing, and the like may be used. Thermal curing may be performed at 100 ° C to 180 ° C, and aging may be performed at 250 to 350 ° C.

The plurality of planar heating elements 40 connecting the pair of electrode terminals 33 are formed to have a curved portion in the middle portion rather than in a straight line shape. The bending of the planar heating element 40 may be formed in a curve such as a sine wave or a wave pattern. The planar heating element 40 is formed such that the radius of curvature of the curved portion is 2 cm or less. When the radius of curvature of the curved portion exceeds 2 cm, the length of the planar heating element becomes longer and the number of planar heating elements that can be formed between the pair of electrode terminals 33 is reduced, so that the heat generation is not performed quickly or the amount of heat generated is lowered. Problems may arise.

The reason why the planar heating element 40 is formed to have a bend is to increase the contact area between the planar heating element 40 and the metal thin plate 10 when the plate-shaped film heater is rolled in a tubular form. This is to allow the film heater to roll stably when rolling in the form of a tube. This is because the planar heating element 40 having the curved portion has a larger cross-sectional area than the planar planar heating element, so that the heat generating area can be increased.

Although one planar heating element 40 may be formed in the pair of electrode terminals 33, a plurality of planar heating elements 40 are formed in order to reduce the amount of power used to generate heat of the planar heating element 40.

As a result, power consumption, heat transfer loss, and manufacturing cost of the film heater 80 according to the first embodiment may be reduced, and heat capacity of the metal thin plate 10 may be minimized.

Next, as shown in FIGS. 15 and 16, the inner cover layer 50 is formed on the insulating layer 20 to cover the electrode wiring pattern 30 and the plurality of planar heating elements 40. As a method of forming the inner cover layer 50, a hot pressing or laminating method may be used.

In this case, the window 51 is formed on the inner cover layer 50 to correspond to the pair of electrode pads 31 so that the pair of electrode pads 31 of the electrode wiring pattern 30 are exposed. Therefore, when the inner cover layer 50 is formed on the insulating layer 20, the pair of electrode pads 31 are exposed to the outside through the window 51 of the inner cover layer 50. The junction 17 is also exposed out of the inner cover layer 50.

As described above, the electrode wiring pattern 30 includes a pair of electrode pads 31 and a pair of electrode terminals 35. The planar heating element 40 is formed to connect the pair of electrode terminals 35, and is sealed by the inner cover layer 50. The pair of electrode pads 31 are connected to the pair of electrode terminals 35, respectively, and protrude out of the inner cover layer 50 to receive power.

Next, as shown in FIGS. 17 and 18, the temperature sensor 60 is formed on the inner cover layer 50 by a printing method.

As shown in FIG. 17, the temperature sensing composition 61 is formed by printing a temperature sensing composition containing carbon nanotubes and a high heat resistant resin on the inner cover layer 50. As the printing method of the temperature sensing unit 61, screen printing, gravure printing (to roll to roll gravure printing), comma coating (to roll to roll comma coating), flexo, imprinting, offset printing, and the like may be used.

The temperature sensing unit 61 is formed on the inner cover layer 50 in which the plurality of planar heating elements are formed so as to sense the temperature generated by the plurality of planar heating elements. That is, the temperature sensing unit 61 includes a temperature sensing pattern 63 formed on the inner cover layer 50 on which a plurality of planar heating elements are formed, and a pair of temperature sensing pads 65 formed at both ends of the temperature sensing pattern 63. It includes.

A detection cable for detecting a change in resistance of the temperature sensing pattern 63 is connected to the pair of temperature sensing pads 65.

The pair of temperature sensing pads 65 may be disposed on the side where the pair of electrode pads 31 are formed. Therefore, the temperature sensing unit 61 may be formed on the electrode wiring pattern 30 in a form corresponding to the electrode wiring pattern 30. That is, since the electrode wiring pattern 30 is formed in a translator form, the on sensing unit 61 may also be formed in a translator form.

Next, as shown in FIG. 18, the outer cover layer 67 is formed on the inner cover layer 50 to cover the temperature sensing unit 61 to manufacture a temperature sensor. A hot pressing or laminating method may be used as a method of forming the outer cover layer 67.

In this case, the window 69 is formed on the outer cover layer 60 to correspond to the pair of temperature sensing pads 65 so that the pair of temperature sensing pads 65 of the temperature sensing unit 61 are exposed. Accordingly, when the outer cover layer 67 is formed on the inner cover layer 50, the pair of temperature sensing pads 65 are exposed to the outside through the window 69 of the outer cover layer 67. The junction 17 is also exposed out of the outer cover layer 67.

Next, as shown in FIG. 19 and FIG. 20, the plate-shaped film heater 80 and the temperature sensor (by cutting off portions except the junction 17, the electrode wiring pattern 30, and the temperature sensing unit 61). A heater assembly 91 having 60 can be obtained. That is, the plate-shaped heater assembly 91 may be obtained by leaving the junction 17 on both sides of the tracer-shaped electrode wiring pattern 30 and the temperature sensing unit 61. The heater assembly 91 has a tracer shape corresponding to the shape of the electrode wiring pattern 30 and the temperature sensing unit 61.

The junction portion 17 is located on both sides of the pair of electrode terminals 35 of the electrode wiring pattern 30. A pair of electrode pads 31 are positioned on one side in a direction perpendicular to an imaginary line connecting the pair of junctions 17. In the first embodiment, an example in which the pair of electrode pads 31 is formed on the side where the pair of junction portions 17 is located is disclosed, but the present invention is not limited thereto.

Next, as shown in FIG. 21, the heater assembly 91 is rolled in a tubular shape so that the metal thin plate 10 faces the inner surface thereof, and the joints 17 positioned at both ends are overlapped.

2 to 4, the heater assembly 91 according to the first embodiment may be obtained by bonding the overlapped joints 17 of the heater assembly 91 dried in a tubular shape. Ultrasonic or laser welding methods may be used as the bonding method. Yag laser, fiber laser, femto laser and the like can be used for the laser welding method.

Although not shown, a power supply cable is bonded to the electrode pad 31 exposed outside the inner cover layer 50, and a resistance sensing cable is bonded to the temperature sensing pad 65 exposed outside the outer cover layer 67. . Plating may be performed on the surfaces of the electrode pad 31 and the temperature sensing pad 65 in order to ensure stable bonding with cables and good electrical conductivity. Copper, nickel, gold and the like may be used as the plating material.

The film heater 80 according to the first embodiment having such a structure exhibits a heat density of 2 W / cm 2 or more per unit area while instantaneously generating a high calorific value of 500 ° C. or higher even at a low voltage of 3 to 4 V. FIG. For example, when DC 2 to 3.7V is applied to the electrode wiring pattern 30, the distance between the pair of electrode terminals 35 on which the planar heating element 40 is formed may be 4 mm to 6.5 mm.

Meanwhile, in the method of manufacturing the heater assembly 91 according to the first embodiment, an example of manufacturing one heater assembly 91 using the metal thin plate 10 is disclosed, but is not limited thereto. As shown in FIG. 22, a plurality of heater assemblies may be collectively manufactured using the metal thin strip 19.

Referring to FIG. 17, the metal thin strip 19 includes an array of unit metal thin plates 10 and a unit film heater 80 having electrode wiring patterns 30 formed on the unit metal thin plates 10, respectively. .

By forming the temperature sensors on the plurality of unit film heaters 80 through printing, the plurality of heater assemblies can be collectively manufactured. The plurality of heater assemblies manufactured collectively in the thin metal strip 19 may obtain a plate-shaped heater assembly through a process of separating them into individual heater assemblies. The obtained individual plate-shaped heater assembly can be rolled into a tubular shape to produce a tubular heater assembly according to the first embodiment.

In the method of manufacturing the heater assembly 91 according to the first embodiment, an example in which the electrode wiring pattern 30 is formed by using photolithography using metal foil is disclosed, but is not limited thereto. For example, the electrode wiring pattern 30 may be formed on the insulating layer 10 by a printing method using a metal paste.

Here, the metal paste includes a conductive binder including a mixed binder, silver powder, and carbon nanotube particles, an organic solvent, and a dispersant. Here, the metal paste may have a density of 2 g / cm 3 or less, and preferably 1.7 to 2 g / cm 3.

Carbon nanotube particles and graphite particles, organic solvents and dispersants included in the mixed binder, the conductive particles may be used as the material used in the heating element composition, and thus a detailed description thereof will be omitted.

The conductive particles may include silver powder and carbon nanotube particles, and may further include graphite particles.

The silver powder may have the form of flakes, spheres, polygonal plates, rods, and the like.

The silver powder may be 50 to 80 parts by weight based on 100 parts by weight of the metal paste. In the case where 50 parts by weight or less, the electrical network between the silver powder is not formed, the resistance is high, and if it exceeds 80 parts by weight, the durability against stress is lowered, the cost may increase.

In addition, by adding 50 parts by weight to 80 parts by weight of silver powder, a metal paste having a density of 2 g / cm 3 or less can be realized, and the electrical conductivity of the electrode wiring pattern to be manufactured can be increased. Here, the tap density of the silver powder may be 2.5 g / cm 3 or less.

Second Embodiment

23 is a view showing a heater assembly 191 according to a second embodiment of the present invention.

Referring to FIG. 23, the heater assembly 191 according to the second embodiment has a structure in which the temperature sensor 60 is disposed on the film heater 80 so that the metal thin plate 10 is located inward, and the temperature sensor 60 ), The insulating layer 70 is formed. That is, the heater assembly 191 according to the second embodiment has a structure in which the film heater 80, the temperature sensor 60, and the heat insulation layer 70 are sequentially stacked.

In this case, since the structure in which the temperature sensor 60 is formed on the film heater 80 is the same as the heater assembly according to the first embodiment, detailed description thereof will be omitted.

The heat insulation layer 70 suppresses heat generated in the planar heating element from being discharged to the outside through the film heater 80 and is lost. As the material of the heat insulation layer 70, a plastic material or porous silicon having heat resistance and electrical insulation may be used. For example, a material of the heat insulation layer 70 may be a silicon tube having an air layer therein, porous silicon, perfluoroalkoxy (PFA), aramid fibers, or the like, but is not limited thereto.

As described above, the heater assembly 191 according to the second embodiment may suppress heat loss generated by the planar heating element from being discharged to the outside by forming the heat insulation layer 70 on the outer surface. In addition, the heat insulation layer 70 allows heat to be transferred toward the metal thin plate 10 into which the solid cigarette is inserted, thereby further shortening the heating time of the solid cigarette and further reducing the power consumption.

Third Embodiment

24 is a plan view showing a film heater 280 of the heater assembly according to the third embodiment of the present invention. FIG. 25 is a top view illustrating the temperature sensor 260 of the heater assembly of FIG. 24.

24 and 25, the heater assembly according to the third embodiment includes a film heater 280 and a temperature sensor 260 formed on the outer surface of the film heater 280.

The film heater 380 includes a metal thin plate 10, an insulating layer 20, an electrode wiring pattern 30, a plurality of planar heating elements 40, and a cover layer 50.

The electrode wiring pattern 30 is formed on the insulating layer 20 so that the plurality of planar heating elements 40 may be electrically connected and arranged in parallel. The electrode wiring pattern 30 includes a pair of electrode pads 31, a pair of connection wirings 33, and a plurality of electrode terminals 35.

The pair of electrode pads 31 are formed spaced apart from each other at regular intervals. The pair of connection wires 33 are respectively connected to the pair of electrode pads 31 and extend in one direction. The plurality of electrode terminals 35 are connected to the pair of connection wires 33, respectively, and extend toward the opposite connection wires 33. A plurality of planar heating elements 40 are connected to the pair of electrode terminals 35 connected to the pair of connection wires 33. In the fourth embodiment, an example in which four planar heating elements 40 are formed in a pair of electrode terminals 35 is disclosed, but the present invention is not limited thereto.

Here, the pair of electrode pads 31 are connected to one end of the pair of connection wires 33, and a cable for supplying power is joined. The pair of electrode pads 33 includes a first electrode pad and a second electrode pad. The pair of electrode pads 33 protrude out of the cover film 50 to receive power through the cable. One of the pair of electrode pads 31 is connected with a cable for supplying a positive power, and the other with a cable for supplying a positive power.

The pair of electrode pads 31 are formed to be spaced apart from the plurality of planar heating elements 40. In the first embodiment, an example in which a pair of electrode pads 31 are formed at a position spaced apart from the outermost surface heating element 40 in the direction in which the plurality of surface heating elements 40 are arranged is described. It is not limited.

The pair of connection wires 33 are connected to the corresponding electrode pads 31, respectively, and are formed outside the plurality of planar heating elements 40 in a direction in which the plurality of planar heating elements 40 are arranged. The pair of connection wires 33 includes a first connection wire 33a connected to the first electrode pad and a second connection wire 33b connected to the second electrode pad, and the first and second connection wires. A plurality of planar heating elements 40 are positioned between the 33a and 33b. The first and second connection wires 33a and 33b may be formed in a straight line parallel to each other.

The plurality of electrode terminals 35 are connected to a pair of connection wires 33, respectively. The plurality of electrode terminals 35 includes a plurality of first electrode terminals 35a connected to the first connection line 33a and a plurality of second electrode terminals 35b connected to the second connection line 33b. do. The plurality of first electrode terminals 35a are formed to face the second connection wire 33b and are spaced apart from the second connection wire 33b. The plurality of second electrode terminals 35b are formed to face the first connection line 33a and are spaced apart from the first connection line 33a.

The planar heating element 40 is formed to connect the first and second electrode terminals 35a and 35b in pairs with the first electrode terminal 35a and the second electrode terminal 35b. The first and second electrode terminals 35a and 35b may be formed to be parallel to each other, and may be formed to be perpendicular to the connected first and second connection wires 33a and 33b.

When the first and second connection wires 33a and 33b are formed in a straight line in parallel with each other, the plurality of planar heating elements 40 connected to the plurality of first electrode terminals 35a and the plurality of second electrode terminals 35b. ) May be formed in a line. The plurality of planar heating elements 40 generate heat by receiving power through the first and second electrode terminals 35a and 35b.

The plurality of planar heating elements 40 are arranged in a line, and are electrically connected in parallel to the electrode wiring pattern 30. The reason for connecting in parallel is to suppress occurrence of voltage drop in the process of applying power to the plurality of planar heating elements 40 via the electrode wiring pattern 30.

The plurality of planar heating elements 40 are elongated in the direction in which the film heater 280 is rolled in a tube shape. That is, the plurality of planar heating elements 40 are formed in the direction in which the first and second connection wirings 33a and 33b are formed. By forming the plurality of planar heating elements 40 in this way, when the plate-shaped film heater 280 is rolled in a tubular shape, the contact area between the planar heating element 40 and the metal thin plate 10 can be increased, and the film heater ( 280) to be able to reliably bend when rolling in the form of a tube.

Of course, the plurality of planar heating elements 40 may be formed to have a curved portion in the middle portion rather than in a straight shape.

The temperature sensor 260 includes a temperature sensing unit 61 and an outer cover layer 67. The temperature sensing unit 61 is formed by printing a temperature sensing composition containing carbon nanotubes and a high heat resistant resin on the inner cover layer 50. The outer cover layer 67 covers the inner cover layer 50 in which the temperature sensing unit 61 is formed. Since the temperature sensor 260 is formed on the surface of the film heater 280 through a printing process, the temperature sensor 260 may be thinly formed on the surface of the film heater 280 with a thickness of 50 μm or less.

In this case, the temperature sensing unit 61 is formed on the inner cover layer 50 in which the plurality of planar heating elements 40 are formed in a curved line shape. The temperature sensing unit 61 includes a temperature sensing pattern 63 formed on the inner cover layer 50 on which the plurality of planar heating elements 40 are formed, and a temperature sensing pad 65 formed at both ends of the temperature sensing pattern 63. It includes. The temperature sensing pad 65 may be disposed on the side where the electrode pad 31 is formed.

The temperature sensing pattern 63 according to the third embodiment has been described in the form of a square wave form running in the horizontal direction. That is, the plurality of planar heating elements 40 are formed in a plurality of lines in the horizontal direction. Therefore, the temperature sensing pattern 63 is formed in a direction orthogonal to the direction in which the plurality of planar heating elements 40 are formed to detect a change in resistance according to heat generated from the plurality of planar heating elements 40.

Experimental Example

In order to confirm the characteristics of the heater assembly according to the present embodiment as described above, the experiment was performed by manufacturing the film heater 380 as follows.

First, the heating element composition was prepared as follows. Carbon nanotubes and graphite particles were added to a carbitol acetate solvent and a dispersant was added to prepare a carbon nanotube / graphite dispersion (Solution A) through ultrasonication for 60 minutes. Epoxyacrylates, phenolic resins and polyvinyl acetal resins are mixed and added to a carbitol acetate solvent to produce a master batch (M / B) through mechanical kneading, which allows mechanical stirring or autorotation. It was. And after mixing the solution A and M / B through physical stirring, and completely kneaded using a 3-roll mill to produce a heating element composition.

Using the heating element composition prepared by the above-described manufacturing method, a sample film heater was prepared as shown in FIGS. 26 to 28. FIG. 26 is a photograph showing film heaters 280 according to a third embodiment formed on the thin metal strip 19 before punching. FIG. 27 is a photograph showing the upper surface of the sample No. 5 film heater 280 after punching of FIG. 26. 28 is a photograph showing the lower surface of the sample No. 5 film heater 280 of FIG.

26 to 28, the film heaters 280 of Samples 1 to 9 according to the third embodiment may be collectively manufactured using the metal thin strip 19.

That is, first, the polyimide or high heat-resistant insulating ink is cast on the metal thin strip 19 of SUS material having a thickness of 0.025 to 0.03 mm, and then dried and thermally cured to form the insulating layer 20. Next, a metal layer of brass material is formed on the insulating layer 20. Next, the metal layer is patterned by a photolithography process to form an electrode wiring pattern 30. Next, after screen-printing the heating element composition prepared by the above-described manufacturing method using a 250 mesh screen mask according to the electrode wiring pattern 30, and after heat-curing the printed heating composition at 100 ℃ to 180 ℃, 250 to Aging was performed at 350 ° C. to form a plurality of planar heating elements 40. Then, the inner cover layer 50 is hot pressed on the insulating layer 20 having the electrode wiring pattern 30 and the planar heating element 40 formed thereon, and the plurality of film heaters 280 are collectively disposed on the metal thin strip 19. Prepared.

Then, by punching the plurality of film heaters 280 in the thin metal strip 19, as shown in Figs. 27 and 28, it is possible to obtain a separate film heater 280. Here, the individual film heater 280 illustrated in FIGS. 27 and 28 is the film heater 280 of Sample No. 5. FIG.

Subsequently, the individual film heaters 280 are rolled up in a tubular shape so that the metal thin plates 10 face the inner surface thereof, and the joints 17 positioned at both ends are overlapped.

And the overlapping junction part 17 of the film heater 280 dried in the form of a tube was bonded by the fiber laser, and the film heaters of samples 1-9 were manufactured. At this time, butt welding is performed by using a fiber laser at a feed rate of 20 mm / s to 30 mm / s at a power of 40 to 60 W, thereby joining the overlapped joints 17 of the film heater 280 dried in a tubular shape. do.

29 is a graph showing the exothermic behavior when DC 2V is applied to the film heater of Sample No. 5.

Referring to FIG. 29, the heating behavior of the metal sheet when the driving voltage DC 2V is applied to the film heater of Sample No. 5 and the cooling behavior when the driving voltage is off is shown. When applying DC 2V it can be seen that the metal sheet is heated to 300 ℃ at a rate of about 25 seconds.

Therefore, when applying the driving voltage DC 2V or more to the film heater of the sample 5, it can be expected that the metal sheet will be heated to 300 ℃ or more in less than 25 seconds.

Table 1 shows the results of measuring and calculating the heat generation characteristics and the electrical characteristics when the driving voltages DC 2V and 3.7V were applied to the film heaters of Samples 1-9.

Referring to Table 1, when DC 3.7V is applied, the film heaters of Samples 1 to 9 are expected to generate heat at a high temperature of 500 ° C or higher. However, at a high temperature of 500 ° C. or higher, the film heaters of samples 1 to 9 are difficult to maintain durability and lifespan, and power consumption is also high as 8W or more.

As such, a heater having a heat density of 2 W / cm 2 or more per unit area and capable of generating heat of 500 ° C. or higher at a driving voltage of DC 3.7 V and having an output of 8 W or higher cannot be driven without control.

Therefore, in the case where DC 3.7V is applied to the film heaters according to samples 1 to 9, as shown in FIG. 30, temperature control through PWM control is required. Here, FIG. 30 is a schematic diagram of PWM control of Sample No. 5 film heater.

Referring to FIG. 30, a is a heating behavior profile when a driving voltage of less than 3.7 V is applied to the film No. 5 film heater, and a1 is a PWM while a driving voltage of less than 3.7 V is applied to the film No. 5 film heater. The exothermic behavior profile that performed the control.

b is an actual exothermic behavior profile when DC 3.7V is applied to the sample # 5 film heater, and b1 is an exothermic behavior profile where PWM control is performed while applying DC 3.7V to the sample # 5 film heater.

Comparing the a profile and the b profile, it can be seen that the heating rate increases as the driving voltage applied increases.

After peak heating to 350 to 400 ° C. using the rapid heating rate of the film heater No. 5, the PWM is controlled to maintain the temperature at 250 to 350 ° C., thereby obtaining 150 to 150 solid cigarettes inserted into the film heater. Can be heated to 160 ° C.

When DC 3.7V is applied as the driving voltage, it takes less than 3 seconds to peak heat to 350 to 400 ° C. And by PWM control, by maintaining a film heater at 250-350 degreeC, the solid tobacco inserted into a film heater can be heated quickly to 150-160 degreeC within 10 second. Through such PWM control, the durability and life of the film heater may be suppressed from being lowered due to the high calorific value of the sample heater 5.

The sample Nos. 1 to 9 have a power ratio of 3.4 to 4.8 when a driving voltage of DC 2V and DC 3.7V is applied. Heaters of samples 1 to 9 have a thermal density of 2 W / cm 2 or more when a driving voltage of DC 3.7V is applied.

On the other hand, the embodiments disclosed in the specification and drawings are merely presented specific examples to aid understanding, and are not intended to limit the scope of the present invention. It is apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

10: metal thin plate
11: lower surface
13: upper surface
17: junction
19: thin metal strip
20: insulation layer
30: electrode wiring pattern
31: electrode pad
33: connection wiring
35: electrode terminal
39: metal layer
40: plane heating element
50: inner cover layer
51: Windows
60, 260: temperature sensor
61: temperature sensing unit
63: temperature sensing pattern
65: temperature sensing pad
67: outer cover layer
69: Windows
70: heat insulation layer
80, 280: film heater
81: insertion hole
83 inlet
90: electric heating smoking device
91, 191: heater assembly
93: control unit
95: solid cigarette
100: solid state electronic cigarette

Claims (5)

A film heater having a planar heating element based on nano carbon particles that generate heat by receiving power; And
A temperature sensor based on carbon nanotubes formed by printing on the surface of the film heater in which the planar heating element is formed and sensing and transferring the temperature of the film heater and exhibiting a negative temperature coefficient (NTC) characteristic. ;
An electrical heated heater assembly comprising a. The method of claim 1,
The film heater is an electric heating heater assembly, which is a flexible material that can be bent in the form of a plate based on a thin metal plate. The method of claim 1,
And the planar heating element is comprised of one or more. A carbon nanotube-based temperature sensor formed by printing on the surface of an electrically heated film heater, sensing and transferring a temperature of the film heater, and exhibiting a negative temperature coefficient (NTC) characteristic; And
A controller configured to control on and off of the film heater based on temperature information received from the temperature sensor;
Containing, electrically heated smoking device. The method of claim 4, wherein
The temperature sensor is formed on the surface of the film heater thin through a printing process to a thickness of less than 50um, electrically heated smoking device.

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