WO2006065058A1

WO2006065058A1 - Heating apparatus of electronic pot device

Info

Publication number: WO2006065058A1
Application number: PCT/KR2005/004272
Authority: WO
Inventors: Hyung Woo Kim
Original assignee: Hyung Woo Kim
Priority date: 2004-12-14
Filing date: 2005-12-13
Publication date: 2006-06-22
Also published as: KR20060067857A

Abstract

The present invention relates to a heating apparatus of an electronic hot wind device, wherein a thin film heater is used as a heating element to shorten temperature rise time of a surface of a metal or nonmetal plate and to lower electric power consumption. A heating apparatus of an electronic hot wind device according to the present invention comprises a metal plate or nonmetal plate; in case of use of the metal plate, an insulation film for electrical insulation formed on one side of the metal plate; a thin film heater mounted as a thin film on one side of the insulation film or nonmetal plate to instantaneously generate heat at a high temperature by means of its own electrical resistance of the thin film heater by receiving external electric power; a conductive pattern formed on one side of the thin film heater to induce uniform heat generation of an entire surface of the thin film heater and to reduce a difference in temperature between an electrode lead-in portion of the thin film heater and a central portion of the thin film heater within a shorter period of time during supply of electric power; metal pads formed at end portions of at least one side of the thin film heater to supply electric power to the thin film heater; and power connection terminals that are in contact with the metal pads.

Description

HEATINGAPPARATUSOFELECTRONICPOTDEVICE

Technical Field

[1] The present invention relates to a heating apparatus of an electronic pot device, and more particularly, to a heating apparatus of an electronic pot device, wherein a thin film heater is used as a heating element to shorten temperature rise time and to lower electric power consumption. Background Art

[2] Generally, a bulk heater or a coil heater is used as a heating element in an electronic pot device for heating a liquid. A typical electronic pot device comprises a metal plate placed below a container capable of containing a liquid, and a heating element such as a bulk heater or a coil heater provided below the metal plate. Electric power is supplied to the bulk heater or the coil heater through a power connection terminal, and a temperature sensor is in contact with the bulk heater or the coil heater. The bulk heater or the coil heater is fixedly supported by a support or attached to the metal plate.

[3] In such a conventional electronic pot device, the bulk heater or the coil heater generates heat by receiving electric power, and the generated heat is transferred to the metal plate so as to boil the liquid.

[4] Since the bulk heater or the coil heater is used as a heating element in the conventional electronic pot device, the area of contact of the heating element with the metal plate is small. Therefore, it takes a great deal of time to reach a liquid-boiling temperature since a heating rate of the heating element is very low.

[5] Furthermore, there is a problem in that high power of 1.5kW to 2.OkW is consumed for heat generation of the heating element. Further, in case of the bulk heater or the coil heater, there are problems in that a temperature descent rate is slow even when power supply is cut off after use of the electronic pot device, and it is difficult to make a transparent electronic pot device since the heater is bulky and shabby and has heavy weight. Disclosure of Invention

Technical Problem

[6] The present invention is conceived to solve the problems in the prior art. An object of the present invention is to provide a heating apparatus of an electronic pot device, wherein a thin film heater is used as a heating element of the electronic pot device, thereby shortening temperature rise time of a surface of a metal or nonmetal plate and lowering electric power consumption. Technical Solution [7] A heating apparatus according to one embodiment of the present invention comprises a metal plate; an insulation film for electrical insulation formed on one side of the metal plate; a thin film heater mounted as a thin film on one side of the insulation film to instantaneously generate heat at a high temperature by means of its own electrical resistance of the thin film heater by receiving external electric power; metal pads formed at end portions of one side of the thin film heater to uniformly supply the external electric power to the thin film heater; and power connection terminals that are in contact with the metal pads to supply the electric power to the metal pads.

[8] A heating apparatus according to another embodiment of the present invention comprises a nonmetal plate; a thin film heater mounted as a thin film on one side of the nonmetal plate to instantaneously generate heat at a high temperature by means of its own electrical resistance of the thin film heater by receiving external electric power; metal pads formed at end portions of one side of the thin film heater to uniformly supply the external electric power to the thin film heater; and power connection terminals that are in contact with the metal pads to supply the electric power to the metal pads.

[9] A conductive pattern may be formed on one side of the thin film heater of the heating apparatus to induce uniform heat generation of an entire surface of the thin film heater and to reduce a difference in temperature between an electrode lead-in portion of the thin film heater and a central portion of the thin film heater within a shorter period of time at an early stage of supply of electric power, and the metal pads may define a pattern such that a plurality of heating thin film cells are formed.

Advantageous Effects

[10] By using the thin film heater attached to the metal plate as a heat generating member in the present invention, there are advantages in that it is possible to remarkably reduce temperature rise time of water, to simplify a manufacturing process and reduce the number of parts, resulting in lowered production costs, to consistently maintain temperature so as to prevent overheating, and to lower power consumption. Brief Description of the Drawings

[11] Figs. 1 and 2 are sectional views illustrating embodiments of the structure of a heating apparatus of an electronic pot device using a metal plate, according to the present invention.

[12] Figs. 3 and 4 are sectional views illustrating embodiments of the structure of a heating apparatus of an electronic pot device using a nonmetal plate, according to the present invention.

[13] Figs. 5 to 7 are views showing embodiments of a thin film heater with a conductive pattern formed thereon.

[14] Figs. 8 and 9 are views showing embodiments of a metal pad defining a pattern on a thin film heater.

[15] Figs. 10 to 12 are a view showing a heating apparatus of an electronic pot device to which the present invention is applied, and graphs showing measured surface temperature values of the heating apparatus, respectively.

[16] *Explanation of Reference Numerals for Main Portions in the Drawings*

[17] 11: Metal plate 12: Thin film heater

[18] 13: Temperature sensor 14: Insulation film

[19] 15: Metal pad 16: Power connection terminal

[20] 17: Support 18: Conductive pattern

[21] 19: protecting layer 20: Nonmetal plate

Best Mode for Carrying Out the Invention

[22] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, details on well- known functions or constitutions relevant to the present invention will be omitted if they would make the gist of the present invention unnecessarily obscure. The terms used in the description are defined considering the functions of the present invention and may vary depending on the intention or usual practice of a user or operator. Therefore, the definitions should be made based on the entire contents of the description.

[23] Fig. 1 is a view illustrating an embodiment of the structure of a heating apparatus of an electronic pot device using a metal plate, according to the present invention. Reference numerals 11, 12, 13, 14, 15, 16 and 17 designate a metal plate, a thin film heater, a temperature sensor, an insulation film, a metal pad, a power connection terminal and a support, respectively.

[24] Fig. 2 is a view illustrating another embodiment of the structure of a heating apparatus of an electronic pot device using a metal plate, according to the present invention. Reference numerals 18 and 19 designate a conductive pattern and a protecting layer, respectively.

[25] Fig. 3 is a view illustrating an embodiment of the structure of a heating apparatus of an electronic pot device using a nonmetal plate, according to the present invention. Reference numerals 20, 12, 13, 14, 15, 16 and 17 designate a nonmetal plate, a thin film heater, a temperature sensor, an insulation film, a metal pad, a power connection terminal and a support, respectively.

[26] Fig. 4 is a view illustrating another embodiment of the structure of a heating apparatus of an electronic pot device using a nonmetal plate, according to the present invention. Reference numerals 18 and 19 designate an conductive pattern and a protecting layer, respectively.

[27] A heating apparatus of an electronic pot device according to an embodiment of the present invention comprises a metal plate 11; an insulation film 14 formed on a bottom surface of the metal plate 11 to shield transfer of electricity to the metal plate; a thin film heater 12 formed on a bottom surface of the insulation film 14 to generate heat by receiving electric power; metal pads 15 formed at end portions of one side of the thin film heater 12 to supply electric power to the thin film heater; and power connection terminals 16 that are in contact with the metal pads 15 to supply electric power to the metal pads. In these figures, a temperature sensor 13 is in contact with a certain portion of the thin film heater 12 to sense temperature, and a support 17 supports the heating apparatus.

[28] A conductive pattern 18 is formed on the one side of the thin film heater 12 to induce uniform heat generation of an entire surface of the thin film heater within a short period of time at an early stage of supply of electric power and to prevent an overheating phenomenon from occurring at an electrode lead-in portion of the thin film heater.

[29] Furthermore, the metal pads 15 can define a pattern such that a plurality of heating thin-film cells are formed.

[30] Meanwhile, a heater protecting layer 19 is preferably formed on the one side of the thin film heater 12 to protect the thin film heater 12 from external foreign substances and the like. Here, the heater protecting layer may be formed of inorganic heater protecting layer materials (SiNx, SiOx), organic heater protecting layer materials (polyimide, polyamide, Teflon, PET, etc.), and the like.

[31] The metal plate 11 in the present invention is fixed by a support. The metal plate 11 used in the present invention is formed of a metal with superior thermal conductivity, such as aluminum or stainless steel and preferably has a thickness ranging from 0.3mm to 3mm.

[32] Generally, in a case where a thin film heater for generating heat through application of electric power thereto is formed on a plate made of a metal, an insulation film is required as a functional layer capable of performing the function of electrically insulating the thin film heater and the metal plate.

[33] When the thermal conductivity of the insulation film 14 is higher, heat generated by the thin film heater 12 is transferred at a higher rate to the metal plate 11. Therefore, it is preferred that the insulation film have a smaller thickness. That is, the insulation film should be designed to have a smallest thickness capable of securing electrical insulation between the thin film heater 12 and the metal plate 11. The thickness of the insulation film 14 preferably ranges from 0.5D to 500D, preferably 0.5D to 150D. The thickness of the insulation film may vary according to the material of the insulation film.

[34] For electrical isolation of the thin film heater 12, the insulation film 14 should not produce dielectric breakdown and should maintain a leakage current below 2OD when a voltage of about 100V is applied to the thin film heater.

[35] Additionally, the insulation film should have a superior contact property with the thin film heater or the metal plate such that the insulation film is not physically de- laminated from the metal plate when the material of the thin film heater generates heat at a high temperature. Furthermore, when the material of the thin film heater generates heat at a high temperature, a chemical reaction between the insulation film and the material of the thin film heater or the metal plate should not occur. Since bad surface roughness of the insulation film affects electrical resistivity of the material of the thin film heater, the insulation film should have good surface roughness such that the surface roughness thereof does not affect the electrical resistivity of the material of the thin film heater.

[36] For example, the insulation film 14 may be an oxidized insulation film formed by oxidizing the surface of aluminum or stainless steel using an arc, a polymer insulation film formed of polymer-based materials such as polyimide, polyamide, Teflon and PET, or a film to which the oxidized insulation film and the polymer insulation film are simultaneously applied.

[37] The oxidized insulation film can be formed using electrical energy such as an arc applied from the outside to the metallic surface of a metal plate, which is made of aluminum (Al), beryllium (Be), titanium (Ti) or stainless steel and dipped in an alkaline electrolyte, so that an electrochemical reaction occurs between metal atoms of the metal surface and external oxygen to convert properties of the metallic surface into an oxidized film.

[38] Al O , ZrO , Y O or the like is used for the oxidized insulation film, and the oxidized insulation film may be formed on the metal plate by means of plasma spray coating and the like. Hereinafter, one embodiment of a process of forming the oxidized insulation film on the metal plate will be described below.

[39] The concentration of an alkaline electrolyte filled in a bath is evaluated, a metal plate 11 made of aluminum is dipped into the alkaline electrolyte filled in the bath in a state where a lead wire is connected to the metal plate 11 made of aluminum so that external power can be supplied to the metal plate 11 made of aluminum, and the external power is supplied to the metal plate 11 made of aluminum so as to oxidize the surface of the metal plate 11 made of aluminum.

[40] As radio frequency AC power is strongly applied to the metal plate 11 made of aluminum through the process of forming an oxidized insulation film, an arc is instan- taneously generated on the surface of the metal plate 11 made of aluminum. Thus, an oxidized insulation film that is a dense oxidized film having a very low pinhole concentration is formed on the surface of the metal plate 11 made of aluminum.

[41] Through such a process of forming an oxidized insulation film, an aluminum oxide can be formed on the surface of a metal plate 11 made of aluminum, a titanium oxide can be formed on the surface of a metal plate 11 made of titanium, and a beryllium oxide can be formed on the surface of a metal plate 11 made of beryllium.

[42] In the meantime, an electrical insulation film using a polymer material is formed to have a uniform thickness between a metal substrate and a thin film heater for generating heat by means of a spin coating method using the polymer material capable of securing an electrical insulation property for electrical insulation between the two layers.

[43] One embodiment of a process of forming a polymer insulation film will be described below.

[44] A polymer insulation film is formed using a liquid organic polymer material that is to be uniformly coated on the surface of the metal plate 11 made of a metal.

[45] Here, coating methods include a spin coating method, a spray coating method, a dipping coating method, and a screen printing method.

[46] Furthermore, polymer materials include polyimide-based materials, polyamide- based materials, Teflon-based materials, paint-based materials, silver-ston, Tefzel-s, epoxy, rubber, and UV-sensitive materials.

[47] For example, a process of coating a polyimide-based material on the metal plate 11 by means of the spray coating method is as follows.

[48] The metal plate 11 is cleaned with acetone, IPA (isopropyl alcohol) or the like, the polyimide-based material is sprayed onto the metal plate 11 while the cleaned metal plate 11 is rotated at a high speed (e.g., 2,000rpm or more), and the polyimide-based material coated on the surface of the metal plate 11 is subjected to heat treatment.

[49] Through the process of forming a polymer insulation film by means of the spray coating method, a polymer insulation film having superior thermal stability and a glassy temperature (GT) of 300⁰C or more is formed on the surface of the metal plate 11.

[50] Furthermore, by slowly cooling the polyimide-based material during the process of heat treatment of the polyimide-based material, adhesiveness of the polymer insulation film to the metal plate 11 is improved. By coating the polymer-based material on the surface of the metal plate 11 during the spray coating process, thickness uniformity of the polymer insulation film is enhanced and the polymer insulation film has a very low pinhole concentration, thereby preventing the occurrence of current leakage.

[51] A double insulation film comprising an oxidized insulation film and a polymer insulation film can be formed by forming the oxidized insulation film on the surface of a metal plate 21 made of a metal and uniformly coating a polymer-based material on the oxidized insulation film, or by coating the polymer-based material on the surface of the metal plate made of a metal and forming the oxidized insulation film on the coated polymer-based material. The case where the oxidized insulation film and the polymer insulation film are simultaneously formed can reduce the thickness of each of the insulation films and minimize dielectric breakdown of the insulation films as compared with a case where only one insulation film of the oxidized insulation film and the polymer insulation film is formed.

[52] The thickness of the insulation film 14 preferably ranges from 0.5D to 500D, more preferably 0.5D to 150D (the thickness of the insulation film varies according to the material of the insulation film). The insulation film 14 has a dielectric breakdown voltage of 1,000V or more, and a leakage current of 2OD or less upon application of a voltage of 100V. The insulation film 14 should be formed such that it is not de- laminated respectively from the metal plate 11 and the thin film heater 12 when the thin film heater 12 generates heat (in a thermal cycle).

[53] The thin film heater 12 generates heat in a resistive heat generation manner by means of application of a DC or AC voltage to the metal pads 15 connected to the thin film heater 12 so that a predetermined amount of current can flow through the thin film heater.

[54] Temperature obtained through heat generation due to the its own resistance of the thin film heater may exceed 800⁰C and may rapidly rise contrary to a bulk heater. This is because the thin film heater has a very small volume as a thin film.

[55] Since the thin film heater in the form of a thin film has a very large current flux, the thin film heater is required to have electrically, thermally and chemically resistant properties. The thin film heater should electrically have high heater strength, have high resistance to continuously applied energy and maintain a long life span. Physical de- lamination between and cracking in the metal plate and the insulation film should not occur when the thin film heater generates heat.

[56] Furthermore, as for electrical properties, in the thin film heater that is a device subjected to continuous thermal shocks, changes in a resistance value of the thin film heater due to the thermal shocks should occur within an allowable numerical value range. As for chemical properties, since the thin film heater may be exposed directly to oxygen or undergoes high temperature, substantial increases in the resistance value of the thin film heater due to oxidation should be prevented.

[57] The thin film heater 12 may be made of a single metal (e.g., Ta, W, Pt, Ru, Hf, Mo,

Zr, Ti, etc.) with a high melting point, a binary metal alloy (e.g., TaW, etc.) with a combination of the above metals, a binary metal-nitride (e.g., WN, MoN, ZrN, etc.) combined with a metal-nitride, a binary metal- suicide (e.g., TaSi, WSi, etc.) combined with a metal-silicide, or a thick conductive paste such as Ag/Pd.

[58] The thin film heater 12 has a thickness of several tens D or less (e.g., 0.05D to 30D, wherein the thickness of the thin film heater varies according to the material of the thin film heater).

[59] To ensure that the temperature of the thin film heater 12 rises instantaneously, i.e., to minimize time taken until the thin film heater itself is heated to a high temperature, it is necessary to make the heat capacity of the thin film heater 12 itself very low.

[60] That is, the heat capacity of the thin film heater 12 is expressed as a function with a parameter of thickness. The thinner the thin film heater 12 is, the smaller the heat capacity thereof is. On the other hand, the thinner the thin film heater 12 is, the shorter the lifespan of the thin film heater 12 may be.

[61] Therefore, the present invention can deduce an optimum thickness range of the thin film heater 12 through various simulations and experiments to satisfy two requirements for the instantaneous rise of the temperature of the thin film heater 12 and the extension of the lifespan of the thin film heater 12. On the other hand, although there is a slight difference in thickness according to the material of the thin film heater 12, the difference is merely a minute difference.

[62] That is, the optimum thickness of the thin film heater 12 is deduced based on the following formula.

[63] [Formula 1]

[64] p=Rsxt

[65] where p (resistivity) is a specific resistivity value of the material of the thin film heater 12, Rs (sheet resistance) is a surface resistance value of the thin film heater 12, and t (thickness of film) is the thickness of the thin film heater 12. Meanwhile, it can be seen that the thickness and specific resistivity value have a proportional relationship therebetween.

[66] Therefore, the optimum thickness range of the thin film heater 12 (e.g., 0.05D to 30D) is deduced according to the material of the thin film heater 12 corresponding to characteristics of each product by performing simulation with the aforementioned parameters as input data considering the resistivity value range of the material of the thin film heater 12.

[67] Methods for forming a thin film heater using vacuum evaporation include a thick film screen printing method, physical vapor deposition (sputtering, reactive sputtering, co-sputtering, evaporation and E-beam) methods, and chemical vapor deposition (low pressure chemical vapor deposition (LPCVD) and plasma enhanced chemical vapor deposition (PECVD)) methods.

[68] A protecting layer is preferably formed on one side of the thin film heater to protect the thin film heater. Here, the heater protecting layer is formed of inorganic heater protecting layer materials such as SiNx and SiOx and organic heater protecting layer materials such as polyimide, polyamide, Teflon and PET.

[69] The protecting layer may be formed on a thin film heater with a conductive pattern formed thereon as well as a thin film heater with no conductive pattern formed thereon.

[70] Meanwhile, as illustrated in Figs. 5 to 7, a conductive pattern 18 having lower electric resistance and higher thermal conductivity than thin film heaters with various shapes and configurations can be formed on one side of the thin film heater.

[71] In a case where a thin film heater on which a conductive pattern is not formed is used, uniform temperature distribution may not be achieved on the entire surface of the thin film heater or the thin film or the insulation film may be damaged by means of an overheating phenomenon occurring at a portion of the thin film heater, due to a temperature difference generated between an electrode lead-in portion of the thin film heater and a central portion of the thin film heater at an early stage of supply of electric power.

[72] In order to prevent the overheating phenomenon and induce uniform heat generation on the entire surface of the thin film heater within a shorter period of time at the early stage of supply of electric power, it is possible to form conductive patterns with various shapes and configurations on one side of the thin film heater, as illustrated in Figs. 5 to 7.

[73] Furthermore, the formation of the conductive pattern on the thin film heater can improve a production yield over a single thin film heater on which a conductive pattern is not formed upon production of the thin film heater. This is because the single thin film heater on which a conductive pattern is not formed may suffer from degradation in the quality of the entire resistor even due to a minute thickness difference in or damage such as a scratch to a portion of the entire thin film heater, resulting in drop in the production yield of the thin film heater.

[74] The metal pads 15 are formed on both ends of the thin film heater 12 to secure a uniform current density in the thin film heater 12, so that the metal pads 15 can be responsible for electrical connection between the thin film heater 12 and an external power supply. The metal pads 15 may have various shapes and configurations. It is preferred that the width of the metal pads 15 be identical with or larger than that of the thin film heater 12 to provide a constant current density to the thin film heater 12.

[75] Meanwhile, the metal pads 15 in the present invention can define patterns at different positions with a variety of configurations, sizes and numbers such that a plurality of heating thin film cells are formed as illustrated in Figs. 8 and 9.

[76] Additionally, the metal pads should have temperature stability during heat generation of the thin film heater and should not produce resistance increase or physical delamination due to oxidation of the metal pads. Considering the required properties of the metal pads, the metal pads in the present invention can be made of Al, Au, W, Pt, Ag, Ta, Mo, Ti or the like.

[77] A heating apparatus of an electronic pot device according to another embodiment of the present invention comprises a nonmetal plate 20; a thin film heater 12 formed on one side of the nonmetal plate 20 to generate heat by receiving electric power; metal pads 15 formed at end portions of one side of the thin film heater 12 to supply electric power to the thin film heater; and power connection terminals 16 that are in contact with the metal pads 15 to supply electric power to the metal pads.

[78] As illustrated in Figs. 3 and 4, in the case where the nonmetal plate 20 is used instead of the metal plate, it is not necessary to provide an insulation film between the nonmetal plate and the thin film heater.

[79] Similarly to the case where the metal plate is used, the one side of the thin film heater 12 may be formed with a conductive pattern 18 for ensuring uniform heat generation on the entire surface of the thin film heater within a shorter period of time at an early stage of supply of electric power and for preventing the occurrence of an overheating phenomenon at an electrode lead-in portion of the thin film heater as well as a heater protecting layer 19 for protecting the thin film heater 12 from external foreign substances.

[80] Furthermore, the metal pads 15 can define a pattern such that a plurality of heating thin film cells are formed in the same manner as the case where the metal plate is used.

[81] A nonmetal plate is made of thermally enhanced plastics, heat resistant resins, ceramics, glass and earthenware capable of resisting to a temperature of at least 25O⁰C.

[82] Fig. 10 shows a heating apparatus of an electronic pot device to which the present invention is applied, Fig. 11 illustrates a graph showing measured changes in the surface temperature of the heating apparatus with time when an electric power of 50 watts is applied to the heating apparatus of the electronic pot device shown in Fig. 10, and Fig. 12 illustrates a graph showing measured changes in the surface temperature when varying power is applied for 10 seconds to the heating apparatus of the electronic pot device shown in Fig. 10.

[83] Meanwhile, it should be noted that numerical values illustrated in Figs. 10 to 12 are numerical values obtained in one embodiment of a heating apparatus of an electronic pot device, and the numerical values may be deduced as different results according to resistance values, thicknesses and materials of respective components such as the thin film heater, the insulation film, the metal pads and the metal plate.

[84] As illustrated in Fig. 11, it can be seen that a saturation characteristic is represented at 287⁰C after passage of a predetermined period of time when an electric power of 50 watts is applied. [85] As illustrated in Fig. 12, it can be seen that the surface temperature linearly increases for 10 seconds with varying electric power.

[86] Additionally, an optimum product can be produced by differently applying resistance values, thicknesses, materials and the like of respective components such as the thin film heater, the insulation film, the metal pads and the metal plate in consideration of product requirements for a heating apparatus of an electronic pot device so as to reduce time required to reach a surface temperature and power consumption corresponding to product characteristics.

[87] Although the present invention has been described in connection with the preferred embodiments, the embodiments of the present invention are only for illustrative purposes and should not be construed as limiting the scope of the present invention. It will be understood by those skilled in the art that various changes and modifications can be made thereto within the technical spirit and scope defined by the appended claims.

Claims

[1] A heating apparatus of an electronic pot device, comprising: a metal plate (11); an insulation film (14) for electrical insulation formed on one side of the metal plate; a thin film heater (12) mounted as a thin film on one side of the insulation film to instantaneously generate heat at a high temperature by means of its own electrical resistance of the thin film heater by receiving external electric power; metal pads (15) formed at end portions of one side of the thin film heater to uniformly supply the external electric power to the thin film heater; and power connection terminals (16) that are in contact with the metal pads to supply the electric power to the metal pads.

[2] The heating apparatus as claimed in claim 1, wherein a conductive pattern (18) is formed on the one side of the thin film heater to induce uniform heat generation throughout an entire surface of the thin film heater.

[3] The heating apparatus as claimed in claim 1, wherein the metal pads (15) define a pattern such that a plurality of heating thin film cells are formed.

[4] A heating apparatus of an electronic pot device, comprising: a nonmetal plate (20); a thin film heater (12) mounted as a thin film on one side of the nonmetal plate to instantaneously generate heat at a high temperature by means of its own electrical resistance of the thin film heater by receiving external electric power; metal pads (15) formed at end portions of one side of the thin film heater to uniformly supply the external electric power to the thin film heater; and power connection terminals (16) that are in contact with the metal pads to supply the electric power to the metal pads.

[5] The heating apparatus as claimed in claim 4, wherein a conductive pattern (18) is formed on the one side of the thin film heater to induce uniform heat generation throughout an entire surface of the thin film heater.

[6] The heating apparatus as claimed in claim 4, wherein the metal pads (15) define a pattern such that a plurality of heating thin film cells are formed.

[7] The heating apparatus as claimed in any one of claims 1 to 6, wherein a heater protecting layer (19) is formed at a lower portion of the thin film heater (12) to protect the thin film heater from foreign substances.

[8] The heating apparatus as claimed in any one of claims 1 to 6, wherein the thin film heater (12) is made of any one of a single metal, a binary metal alloy combined with the single metal, a binary metal-nitride combined with a metal- nitride, a binary metal- suicide combined with a metal-silicide, and a thick c onductive paste.

[9] The heating apparatus as claimed in any one of claims 1 to 6, wherein the metal pads (15) are configured such that the width of the metal pads is identical with or larger than that of the thin film heater to supply electric power of a uniform current density to the thin film heater, and the metal pads are made of any one of Al, Au, W, Pt, Ag, Ta, Mo and Ti that have temperature stability during heat generation and avoid resistance increase and physical delamination due to oxidation.

[10] The heating apparatus as claimed in any one of claims 1 to 6, wherein the insulation film (14) is formed on the surface of the metal plate (11) by forming at least one insulation film selected among an oxidized insulation film formed by oxidizing the surface of the metal plate (11) using an arc, an insulation film formed by coating ceramic, glass, ceramic glaze or the like on the surface of the metal plate (11), and a polymer insulation film formed by coating a polymer on the surface of the metal plate (11).

[11] The heating apparatus as claimed in claim 10, wherein the insulation film has a dielectric breakdown voltage of 1,000V or more and has a leakage current of 2OD or less when a voltage of 100V is applied thereto.

[12] The heating apparatus as claimed in claim 10, wherein the oxidized insulation film is formed of any one of an aluminum oxide, a beryllium oxide or a titanium oxide, and the polymer of the polymer insulation film is any one of polyimide, polyamide, Teflon, paint, silver-ston, tefzel-s, epoxy and rubber.

[13] The heating apparatus as claimed in claim 12, wherein the polymer is coated on the surface of the metal plate by means of any one of a spin coating method, a spray coating method, a dipping coating method and a screen printing method.