KR20060067858A - Heating apparatus of electic hot wind device - Google Patents

Abstract

The present invention relates to a heat generator of an electric hot air blower capable of shortening the surface temperature rise time of the metal plate or the non-metal plate and reducing the power consumption by using a thin film heater as the heat generating element. The heat generating device of the electric hot air blower according to the present invention includes a metal plate or a non-metal plate; An insulating film formed on one side of the metal plate for electrical insulation when a metal plate is used; A thin film heater mounted on one side of the insulating film or the non-metal plate to be supplied with power from the outside to instantaneously generate high temperature by its own electrical resistance; A conductor pattern formed on one side of the thin film heater to induce uniform heat generation of the entire surface of the thin film heater and reduce a temperature difference between the electrode introduction portion of the thin film heater and the central portion of the thin film heater in a faster time when power is supplied; A metal pad formed on at least one end of the thin film heater to supply power to the thin film heater; And a power connection terminal in contact with the metal pad.

Electricity, hot air, heater, heat generation, heating, thin film heater, insulation, metal plate, conductor pattern

Description

Heater of electric hot air fan {Heating Apparatus of Electic Hot Wind Device}

1 to 2 is a cross-sectional view for explaining an embodiment of a structure of a heat generator of the electric hot air blower according to the present invention using a metal plate.

3 to 4 is a cross-sectional view for explaining an embodiment of a structure of a heat generator of the electric hot air blower according to the present invention using a non-metal plate.

5 to 7 are exemplary views of a conductor pattern on which a conductor pattern is formed.

8 to 9 are exemplary views illustrating an embodiment of a metal pad in which a pattern is formed on a thin film heater.

10 to 12 is a graph of the heating device and the surface temperature measurement of the electric hot air fan applied invention.

* Explanation of symbols on the main parts of the drawing

11: metal plate 12: thin film heater

13: temperature sensor 14: insulating film

15 metal pad 16 power connector

17: fan 18: conductor pattern

19: protective layer 20: non-metallic plate

The present invention relates to a heating device for an electric hot air blower, and more particularly, to a heating device for an electric hot air blower, such as a hair dryer, a hand dryer, a drying hood, a fan heater, a hot air heater, a vehicle small hot air heater, a clothes dryer, a dish washer, a dish dryer, and a printer dryer. The present invention relates to a heat generating device of an electric hot air blower capable of shortening the temperature rise time and reducing the power consumption by using a thin film heater as the heat generating element.

Generally, a halogen lamp, a bulk heater, and a coil heater are used as a heating element used in an electric hot air fan such as a hair dryer, a drying hood, a fan heater, and a hot air fan. And, the electric hot air fan includes a sensor for sensing the temperature.

In the case of an electric hot air fan using a bulk heater, when power is supplied to the bulk heater through a power supply line, the bulk heater generates heat, and the temperature of the metal plate is increased by heat transfer. And the air heated by the metal plate is sent out by a fan.

Also in the case of a coil heater, when electric power is supplied, the temperature of the metal plate rises by the coil, and hot air is sent out by the fan. In the case of using a halogen lamp, heat generated by the halogen lamp is transferred by the reflector. Such a conventional electric hot air blower is a known technique, a detailed description thereof will be omitted.

However, such a conventional electric hot air heater uses a bulk heater, a halogen lamp, and a coil heater as a heating element, while the heating element has a large volume while the contact area with the metal plate is small.

Furthermore, there is a problem in that high power is consumed as the power required for heat generation of the heating element is 0.9 kW to several kW. In addition, in the case of a bulk heater or a coil heater, there is a problem that the temperature falling speed is slow even after turning off the power.

Therefore, the present invention has been proposed to solve the problems of the prior art as described above, and the present invention can shorten the surface temperature rise time of the metal plate by using a thin film heater as a heating element in the electric hot air, and heat generation of the electric hot air heater can be reduced in power. The purpose is to provide a device.

Heating device according to an embodiment of the present invention for achieving the above object, a metal plate; An insulating film formed on one side of the metal plate for electrical insulation; A thin film heater mounted on one side of the insulating film to receive power from the outside and instantaneously generate high temperature by its own electrical resistance; A metal pad formed at one end of the thin film heater to uniformly supply power supplied from the outside to the thin film heater; And a power connection terminal contacting the metal pad to supply power.

Heating device according to an embodiment of the present invention for achieving the above object, a non-metal plate; A thin film heater mounted on one side of the insulating film to receive power from the outside and instantaneously generate high temperature by its own electrical resistance; A metal pad formed at one end of the thin film heater to uniformly supply power supplied from the outside to the thin film heater; And a power connection terminal contacting the metal pad to supply power.

The thin film heater of the heating device has a conductor pattern for generating heat evenly on the entire surface of the thin film heater in a faster time at the initial power supply to one side and reducing the temperature difference between the electrode introduction portion of the thin film heater and the central portion of the thin film heater. The metal pad may form a pattern to form a plurality of heat generating thin film cells.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

1 is a view for explaining an embodiment of a heating device structure used in the electric hot air heater according to the present invention using a metal plate, 11 is a metal plate, 12 is a thin film heater, 13 is a temperature sensor, 14 is an insulating film, 15 Is a metal pad, 16 is a power connection terminal, and 17 is a fan.

2 is a view for explaining an embodiment of a heat generating device structure used in the electric hot air heater according to the present invention using a metal plate and a conductor pattern, and reference numeral 18 denotes a conductor pattern and 19 a protective layer, respectively.

3 is a view for explaining an embodiment of a heat generating device structure of an electric hot air heater according to the present invention using a non-metal plate with reference numeral 20 is a non-metal plate, 12 is a thin film heater, 13 is a temperature sensor, 14 is an insulating film, 15 is Metal pads, 16 denote power supply terminals, and 17 denote fans.

4 is a view for explaining another embodiment of the heat generator structure of the heat blower according to the present invention using a non-metal plate and a conductor pattern, and reference numeral 18 denotes a conductor pattern and 19 denotes a protective layer, respectively.

The heating device of the electric hot air blower according to the present invention includes a metal plate (11); An insulating film 14 formed on one side of the metal plate 11 to block electricity from being transferred to the metal plate; A thin film heater 12 formed on the insulating film 14 to generate heat by power supply; A metal pad 15 formed at one end of the thin film heater 12 to supply power to the thin film heater; And a power connection terminal 16 for supplying power in contact with the metal pad 15. In the figure, the temperature sensor 13 is for contacting a predetermined portion of the thin film heater 12 to sense the temperature and the fan 17 is for discharging the air warmed by the metal plate.

One side of the thin film heater 12 has a conductive pattern in order to generate heat evenly over the entire surface of the thin film heater in a faster time at the initial power supply and to reduce the temperature difference between the electrode introduction portion of the thin film heater and the thin film heater central portion. 18) can be formed.

In addition, the metal pad 15 may form a pattern to form a plurality of heat generating thin film cells.

On the other hand, it is preferable that the heater protection layer 19 for protecting the thin film heater 12 from external foreign matters is formed on the lower surface of the thin film heater 12. Herein, inorganic heater protective layers (SiNx, SiOx), organic heater protective layers (Polyimide, Polyamide, Teflon, PET, etc.) may be used as the material of the heater protective layer.

In the present invention, the metal plate 11 may be divided into several pieces and fixed by the support member. The metal plate 11 used in the present invention uses a metal having excellent thermal conductivity, such as aluminum and stainless steel. The thickness of the metal plate 11 is preferably in the range of 0.3 mm to 3 mm, in particular in the range of 0.3 mm to 2 mm.

In general, in the case of forming a thin film heater that generates heat by application of power on a plate-shaped substrate made of metal, a functional layer capable of performing an electrical insulation function between the thin film heater and the metal plate is required. .

The faster the thermal conductivity of the insulating film 14 is, the faster the heat generated from the thin film heater is transferred to the metal plate 11. Therefore, the thinner the insulating film is, the better the thickness of the insulating film should be designed to ensure the minimum electrical insulation between the thin film heater 12 and the metal plate 11. The thickness of the insulating layer 14 is preferably in the range of 0.5 μm to 500 μm, particularly in the range of 0.5 μm to 200 μm, and the thickness may vary depending on the material.

In order to achieve electrical isolation of the thin film heater 12, the insulating film 14 should not have insulation breakdown when a voltage of about 100 V is applied to the thin film heater, and the electrical leakage current should be 20 μA or less.

In addition, the thin film heater material should be excellent in contact with the thin film heater or the metal plate so that physical desorption from the metal plate does not occur when the thin film heater material is heated to high temperature. In addition, when the thin film heater material is heated to a high temperature, there should be no chemical reactivity between the insulating film and the thin film heater material or the metal plate.

If the surface roughness of the insulating film is poor, it affects the electrical resistivity of the thin film heater material, so the surface roughness should be good so as not to affect the electrical resistivity of the thin film heater material itself.

For example, the insulating film 14 may include an oxide insulating film which oxidizes a surface of aluminum or stainless steel using an arc, an insulating film obtained by coating ceramic, glass, porcelain glaze, or the like on a metal plate surface. One or two or more insulating films of a polymer insulating film having a polymer coated thereon may be formed on the surface of the metal plate.

For example, a polymer insulating film using a polymer-based material (Polyimide, Polyamide, Teflon, PET, etc.), and an oxide insulating film and a polymer insulating film may be simultaneously applied.

The oxide insulating layer is formed of metal atoms on the surface of the metal and oxygen from the outside by electrical energy such as an arc applied to the surface of the metal plate made of aluminum (Al), beryllium (Be), titanium (Ti), stainless steel, etc. contained in the alkaline electrolyte. It can be formed by causing an electrochemical reaction to convert the surface properties into an oxide film form.

Al ₂ O ₃ , ZrO ₃ , Y ₂ O _3, and the like are used as the oxide insulating film, and the oxide insulating film may be formed on a metal plate by using a plasma spray coating method. Hereinafter, an embodiment of a process of forming an oxide insulating film on a metal plate will be described.

Evaluate the concentration of the alkaline electrolyte solution filled in the bath, and the metal plate of the aluminum material in a state in which a conductor is connected to the metal plate 11 of the aluminum material so that external power can be supplied to the metal plate 11 of the aluminum material ( 11) is immersed in the alkaline electrolyte in the container, and then external power is supplied to the aluminum plate 11 made of aluminum to oxidize the surface of the metal plate 11 made of aluminum.

When a strong power source in the form of a high frequency alternating current (AC) is applied to the metal plate 11 made of aluminum material by an oxide insulating film forming process, an arc is generated on the surface of the metal plate 11 made of aluminum material. An oxide insulating film having a very small concentration of) is formed on the surface of the metal plate 11 made of aluminum.

Aluminum oxide may be formed on the surface of the metal plate 11 made of aluminum, or titanium oxide may be formed on the surface of the metal plate 11 made of titanium, or beryllium oxide may be formed on the surface of the metal plate 11 made of beryllium. This can be formed.

On the other hand, the electrical insulating film using a polymer material is formed with a uniform thickness of the polymer material to ensure electrical insulation between the metal substrate and the thin film heater that generates heat by a spin coating method or the like for electrical insulation between the two layers.

For example, an embodiment of a process of forming a polymer insulating film will be described below.

The polymer insulating film is formed using a liquid organic polymer material, and is coated with a uniform thickness on the metal plate 11 surface of the metal material.

Here, as the coating method, a spin coating method, a spray coating method, a dipping coating method, a screen printing method, or the like may be used.

In addition, the polymer material may be a polyimide-based material, a polyamide-based material, a teflon-based material, a paint-based material, silver-ston, Tefgel-S ( tefzel-s), epoxy, rubber, or the like, or a material that is sensitive to ultraviolet light (UV) may be used.

An embodiment of a process of forming a polyimide-based material on the metal plate 11 by spray coating is as follows.

The metal plate 11 is organically washed with acetone, isopropyl alcohol (IPA), and the like, and then the metal plate 11 is rotated at a high speed (for example, 2,000 rpm or more), and the polyimide-based material is transferred to the metal plate ( After spraying (spraying) 11), the polyimide-based material coated on the surface of the metal plate 11 is heat-treated.

A polymer insulating film having a high thermal stability and a glassy temperature (GT) of 300 ° C. or more is formed on the surface of the metal plate 11 by a spray coating method of forming a polymer insulating film.

In addition, by slowly cooling the polyimide-based material during the heat treatment of the polyimide-based material, the adhesion between the polymer insulating film and the metal plate 11 is excellent, and the uniformity of the thickness by coating the polymer-based material on the metal plate 11 during the spray coating process. Is excellent, the pinhole concentration of the polymer insulating film is very small, and no electrical leakage current is generated.

The double insulating film of the oxide insulating film and the polymer insulating film is formed by forming an oxide insulating film on the surface of the metal plate 21 of the metal material, and then coating a polymer-based material with a uniform thickness on the oxide insulating film or vice versa. Can be coated and an oxide insulating film formed thereon. When the oxide insulating film and the polymer insulating film are formed at the same time, the thickness of each insulating film can be reduced and the breakdown can be minimized as compared with the case where only one of the insulating films is applied.

The thickness of the insulating film 14 is in the range of 0.5 μm to 500 μm, in particular, 0.5 μm to 200 μm, which is preferable for thermal conductivity efficiency (the thickness varies depending on the material), and the dielectric breakdown voltage of the insulating film 14 ( The breakdown voltage is 1,000 V or more, the leakage current of the insulating film 14 is 20 μA or less when the voltage reaches 100 V, and the insulating film 14 when heat is generated in the thin film heater 12 (thermal cycle). ) So that desorption (peeling) does not occur from each of the metal plate 11 and the thin film heater 12.

The thin film heater 12 may generate heat by a resistive heating method, and a predetermined amount of current flows through the thin film heater by applying a direct current or an alternating voltage to the metal pad 15 connected to the thin film heater 12. Heat is generated.

The self-resistance heating temperature of the thin film heater may exceed 500 ° C., and unlike the bulk heater, a steep temperature rise may be possible. This is because the volume of the heater itself is very small in a thin film.

Since the thin film heater has a very large current flux in the form of a thin film, the electrical, thermal and chemical resistance characteristics of the thin film heater itself are required. Electrically, heater foils must have high Heater Strength, high resistance to continuously applied energy, and long life. When the thin film heater generates heat, physical peeling and cracking between the metal plate and the insulating layer should not occur.

In addition, the resistance change of the thin film heater due to the thermal shock should occur within the allowable value in the element subjected to continuous thermal shock, and because the chemical may be heated to a high temperature in the state immediately exposed to oxygen, No significant increase in resistance should occur.

As the material of the thin film heater 12, a single metal having a high melting point (for example, Ta, W, Pt, Ru, Hf, Mo, Zr, Ti, etc.) is used or a two-component metal alloy material combining these metals ( E.g., TaW, etc.) or two-component metal-nitride series combining metal-nitride (e.g., WN, MoN, ZrN, etc.) or metal-silicide combinations. Component type metal-silicide series (e.g., TaSi, WSi, etc.) are used, or thick film conductive pastes such as Ag / Pd are used.

The thin film heater 12 has a thickness of several tens of μm or less (eg, 0.05 μm to 30 μm, the thickness of which varies depending on the material).

The heat capacity of the thin film heater 12 itself may be made very small in order to increase the temperature of the thin film heater 12 instantaneously, that is, to minimize the time taken to heat itself.

That is, the heat capacity of the thin film heater 12 is expressed as a function using the thickness as a parameter, and as the thickness of the thin film heater 12 becomes thin, the value thereof becomes small. On the other hand, the life of the thin film heater 12 may be shorter as the thickness becomes thinner.

Therefore, in the present invention, the optimum thickness range of the thin film heater 12 could be derived through various simulations and experiments to satisfy two conditions for instantaneously raising the temperature of the thin film heater 12 and extending the service life. . There may be slight differences depending on the material of the thin film heater 12.

That is, the optimum thickness of the thin film heater 12 is derived based on the following formula.

(resistivity)는 박막 히터(12) 소재의 고유한 비저항 값이고, Rs(sheet resistance)는 박막 히터(12)의 면 저항값이고, t(thickness of film)는 박막 히터(12)의 두께이다. 한편, 두께와 고유 비저항 값은 비례 관계에 있음을 알 수 있다.here,

(resistivity) is a specific resistivity value of the thin film heater 12 material, Rs (sheet resistance) is the sheet resistance value of the thin film heater 12, t (thickness of film) is the thickness of the thin film heater 12. On the other hand, it can be seen that the thickness and the specific resistivity value have a proportional relationship.

In consideration of the specific resistance value range of the thin film heater 12 material, the above-described parameters are simulated as input data. Thus, the optimum thickness range of the thin film heater 12 suitable for the characteristics of each product depends on the material (for example, 0.05 μm). ~ 30 μm, etc.).

Methods of forming a thin film heater using vacuum deposition include thick film screen printing, PVD (Sputtering, Reactive Sputtering, Co-Sputtering, Evaporation, E-beam) and CVD (LPCVD, PECVD).

A protective layer for protecting the thin film heater is preferably formed on the upper side of the thin film heater. Herein, inorganic heater protective layers (SiNx, SiOx), organic heater protective layers (Polyimide, Polyamide, Teflon, PET, etc.) may be used as the material of the heater protective layer.

The protective layer may be formed on both the thin film heater in which the conductor pattern is formed and the thin film heater in the state in which the conductor pattern is not formed.

Meanwhile, as shown in FIGS. 5 to 7, a conductive pattern 18 having lower electrical resistance and higher thermal conductivity than a thin film heater having various shapes and shapes may be formed on one side of the thin film heater.

When using a thin film heater with no conductor pattern formed,

A temperature difference may occur between the electrode introduction portion and the center portion of the membrane heater to prevent uniform temperature distribution over the entire surface of the thin film heater, or overheating may occur at a portion of the thin film heater, thereby causing damage to the thin film heater or the insulating film. .

In order to prevent such a phenomenon and to uniformly generate heat on the entire surface of the thin film heater at the initial power supply, conductor patterns of various shapes and shapes may be formed on one side of the thin film heater as shown in FIGS. 5 to 7. .

In addition, by forming a conductor pattern in the thin film heater, it is possible to improve the production yield than a single thin film heater in which the conductor pattern is not formed in the production of the thin film heater. This is because a single thin film heater without a conductor pattern may have a deterioration in the quality of the entire resistor due to a slight thickness difference of a part of the entire thin film heater or damage to some thin films such as scratches, thereby lowering the yield of the thin film heater.

The metal pads 15 are formed at both ends of the thin film heater 12 to ensure uniform current density in the thin film heater 12, and are responsible for electrical connection between the thin film heater 12 and an external power source. The metal pad 15 may have various shapes and shapes, and the metal pad 15 may have a width equal to or greater than the width of the thin film heater 12 so that the current density is uniformly supplied to the thin film heater 12. It is good.

Meanwhile, the metal pad 15 of the present invention may form a pattern having various positions, shapes, sizes, and numbers such that a plurality of heat generating thin film cells are formed as shown in FIGS. 8 and 9.

In addition, there must be stability to temperature when heating the thin film heater, and there should be no increase in resistance or physical exfoliation due to oxidation. Metal pads usable in the present invention in consideration of the required properties include Al, Au, W, Pt, Ag, Ta, Mo, Ti and the like.

In addition, a protective layer for protecting the thin film heater 12 from moisture, foreign substances, etc. generated in a hair dryer, a hand dryer, a drying hood, a fan heater, a heater, a small car heater, a clothes dryer, a dishwasher, a dish dryer, a printer dryer, and the like. Is preferably formed on the upper side of the thin film heater 12. Here, as the material of the protective layer, inorganic heater protective layers (SiNx, SiOx), organic heater protective layers (Polyimide, Polyamide, Teflon, PET, etc.) may be used.

Another embodiment of the heat generator of the electric hot air according to the present invention, the non-metal plate 20; A thin film heater 12 formed at one side of the non-metal plate 20 to generate heat by power supply; A metal pad 15 formed at one end of the thin film heater 12 to supply power to the thin film heater; And a power connection terminal 16 for supplying power in contact with the metal pad 15.

3 and 4, when the non-metal plate 20 is used instead of the metal plate, it is not necessary to provide an insulating film between the non-metal plate and the thin film heater.

As in the case of using a metal plate on one side of the thin film heater 12, the heat generation is uniformly generated in the entire surface of the thin film heater in a faster time at the initial power supply, and the overheating phenomenon occurs at the electrode inlet of the thin film heater. The heater protection layer 19 may be formed to protect the conductor pattern 18 and the thin film heater 12 from external foreign matters.

In addition, as in the case of using a metal plate, the metal pad 15 may form a pattern to form a plurality of heat generating thin film cells.

As the material of the non-metal plate, heat-reinforced plastics, heat-resistant resins, ceramics, glass, ceramics, etc., which endure at least 250 ° C or more are used.

9 is a heat generating device of the electric hot air heater to which the present invention is applied, and FIG. 10 is a graph of measuring the surface temperature change with time when 50 watts are applied to the heat generating device of the electric hot air fan shown in FIG. 9. FIG. 11 is a graph measuring surface temperature change when power is changed for 10 seconds in the heat generator of the electric hot air fan shown in FIG. 9. On the other hand, the numerical values shown in Figures 9 to 11 are for the embodiment of the heat generating device of the electric hot air, different from the resistance value, thickness, material, etc. of each component, such as a thin film heater, insulating film, metal pad, metal plate, etc. Note that the results can be derived.

Referring to FIG. 10, it can be seen that when a predetermined time elapses when 50 watt power is applied, a saturation characteristic appears at 287 ° C. FIG.

Referring to FIG. 11, it can be seen that the surface temperature change that increases for 10 seconds according to the power change has a linearly increasing characteristic.

In addition, by reflecting the product requirements for the heating device of the electric hot air fan, the resistance value, thickness, material, and the like of each component such as a thin film heater, an insulating film, a metal pad, a metal plate, and the like are applied differently, so that the surface temperature arrival time The power consumption can be reduced to suit the characteristics of the product to produce an optimal product.

As mentioned above, although the present invention has been described by way of examples, the embodiments of the present invention are merely examples and should not be construed as limiting the scope of the present invention. Those skilled in the art to which the present invention pertains may modify or alter the present invention in various forms within the principles and scope described in the claims herein.

The present invention as described above can use the thin film heater attached to the metal plate as a heating element to shorten the time until the required temperature rise rapidly, the manufacturing process and parts are simplified, the production cost is low, and the temperature can be kept constant Overheating can be prevented and the power can be reduced.

Claims (13)

Metal plate 11; An insulating film 14 formed on one side of the metal plate for electrical insulation; A thin film heater 12 mounted on one side of the insulating film to receive power from the outside and instantaneously generate a high temperature by its own electrical resistance; A metal pad formed at one end of the thin film heater to uniformly supply power supplied from the outside to the thin film heater; And And a power connection terminal (16) contacting the metal pad and supplying power to the metal pad. The method of claim 1, In order to induce uniform heat generation of the entire surface of the thin film heater, a conductor pattern (18) is formed on one side of the thin film heater. The method of claim 1, The metal pad (15) is a heating device of the electric hot air, characterized in that to form a pattern to form a plurality of heat generating thin film cells. Non-metal plate 20; A thin film heater 12 mounted on one side of the insulating film to receive power from the outside and instantaneously generate a high temperature by its own electrical resistance; A metal pad formed at one end of the thin film heater to uniformly supply power supplied from the outside to the thin film heater; And And a power connection terminal (16) contacting the metal pad and supplying power to the metal pad. The method of claim 4, wherein In order to induce uniform heat generation of the entire surface of the thin film heater, a conductor pattern (18) is formed on one side of the thin film heater. The method of claim 4, wherein The metal pad (15) is a heating device of the electric hot air, characterized in that to form a pattern to form a plurality of heat generating thin film cells. The method according to any one of claims 1 to 6, One side of the thin film heater 12, the heat generating device of the electric hot air, characterized in that a protective layer for protecting the thin film heater from foreign matter is formed. The method according to any one of claims 1 to 6, The thin film heater 12 combines a single metal or a two-component metal alloy or a metal-nitride in which the metal is combined, or a two-component metal-nitride or a metal-silicide in combination. A heat generating device for an electric hot air blower, characterized by using any one of a component metal silicide or a thick film conductive paste. The method according to any one of claims 1 to 6, The metal pad 15 is set such that its width is greater than or equal to the width of the thin film heater so that current density can be uniformly supplied to the thin film heater, and is stable to temperature during heating and increases resistance due to oxidation and Heat generating device of an electric hot air blower characterized in that any one of Al or Au or W or Pt or Ag or Ta or Mo or Ti to prevent physical peeling. The method according to any one of claims 1 to 6, The insulating film 14 may be formed by coating an oxide insulating film formed by oxidizing the surface of the metal plate 11 with an arc or an insulating film formed by coating ceramic, glass, porcelain glaze, etc. on the surface of the metal plate, or by coating a polymer on the surface of the metal plate 11. And a polymer insulating film or at least one insulating film between the oxide insulating film and the polymer insulating film is formed on the surface of the metal plate (11). The method of claim 10, And said insulating film has an insulation breakdown voltage of 1000 V or more and a leakage current of 20 mA or less when 100 V voltage is applied. The method of claim 10, The oxide insulating film is any one of aluminum oxide or beryllium oxide or titanium oxide, and the polymer of the polymer insulating film is polyimide or polyamide or teflon or paint or silver-stone ( Heater of the electric hot air, characterized in that any one of silver-ston) or tefzel-s (epef) or epoxy (epoxy) or rubber (rubber). The method of claim 12, The polymer material is coated on the surface of the metal plate by any one of a spin coating method, a spray coating method, a dipping coating method or a screen printing method. Heating device for electric hot air fan.

Images