KR20140120400A - Planar heating apparatus using ceramic thin film heating material and manufacturing method of the same - Google Patents

Abstract

The present invention relates to a planar heat emission device and a manufacturing method thereof. The planar heat emission device includes: a ceramic substrate; a ceramic thin-film heat emission body formed on the ceramic substrate; a metal electrode which is formed on the ceramic thin-film heat emission body; and an electricity insulating protection film arranged on the upper part of the ceramic thin-film heat emission body apart from a region where the metal electrode is formed. The ceramic thin-film heat emission body is made of a transparent fluorine-containing tin oxide conductive film. And the molar ratio of tin (Sn) and flourine (F) of the transparent fluorine-containing tin oxide conductive film is in the range of 1:0.01-2.0. A crystal plane primarily arranged. The present invention can be applied to a household utensil, a heating susceptor for a semiconductor device, a hot water heater for a boiler, an air heater and the like using characteristics of heating when electricity is applied to transparent FTO conductive film with excellent heat resistance, chemical resistance, wear resistance, low resistance and high transmission ratio.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar heating apparatus using a ceramic thin film heating element and a manufacturing method thereof,

More particularly, the present invention relates to a heat generating apparatus and a method of manufacturing the same, and more particularly, to a heat generating apparatus and a method of manufacturing the same using a heat generating property when electricity is applied to an FTO transparent conductive film having excellent heat resistance, chemical resistance and abrasion resistance, A heat generating susceptor for a semiconductor, a hot water heater for a boiler, a hot air system, etc., and a manufacturing method thereof.

In general, household heaters using heat-resistant glass use low-heat-expansion heat-resistant glass as a substrate, and as a heating element for heating, a coil, which is a metal heating element such as a conventional nichrome wire, is used. Such a heating system has the effect of reducing the generation of toxic and flammable gas compared to the existing gas range, is more popular because it is safer and more energy efficient, and is being used in commercial restaurants. In addition, although cooking utensils such as induction heating are also used, there is a disadvantage in that cooking is possible only in a special kitchen container.

Electrode materials having high transparency to visible light, such as heat generating resistors and displays for preventing fogging or freezing of window glass such as automobiles, airplanes, and buildings, have been used. As the transparent conductive material, antimony tin oxide (ATO) containing indium and indium tin oxide (ITO) containing indium are known. Among them, low specific resistance ITO is widely used as a reason. However, when the ITO transparent conductive film is molded by heating at 500 ° C, there is a problem that the electrical properties of ITO are changed and deteriorated, and heat resistance, chemical resistance and abrasion resistance are weak.

Therefore, studies have been made on fluorine-doped tin oxide (FTO) having high stability against high temperature and high voltage and having low resistance and high transmittance.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide a transparent conductive film of FTO (Fluorine doped Tin Oxide) having excellent heat resistance, chemical resistance and abrasion resistance and having low resistance and high transmittance, A heat generating susceptor for a semiconductor, a hot water heater for a boiler, a hot air system, etc., and a manufacturing method thereof.

The present invention provides a ceramic thin film heating element comprising a ceramic substrate, a ceramic thin film heating element formed on the ceramic substrate, a metal electrode formed on the ceramic thin film heating element, and an electrically insulating protective film provided on an upper portion of the ceramic thin film heating element, Wherein the ceramic thin film heating element comprises a fluorine-containing tin oxide transparent conductive film, wherein the fluorine-containing tin oxide transparent conductive film has a molar ratio of tin (Sn) to fluorine (F) of 1: 0.01 to 2.0, Wherein the layer is composed of a preferentially oriented layer.

The surface heating device may further include a heat insulating layer provided under the ceramic substrate, and the heat insulating layer may be formed of at least one material selected from the group consisting of ceramic fibers, ceramic fiber blanket, and airgel blanket, It is preferable to have a thickness.

The ceramic thin film heating element preferably has a thickness of 0.01 to 2 탆 and has a resistance in the range of 1 to 200 Ω, a transmittance in the range of 70 to 85%, a temperature in the application of 220 V AC voltage, .

The electrically insulating protective film may be made of a SiO ₂ film or a composite film of at least one oxide selected from TiO ₂ , ZrO ₂ and Al ₂ O ₃ and SiO ₂ , and preferably has a thickness of 0.05 to 100 μm .

The ceramic substrate may be made of glass, heat-resistant glass or alumina (Al ₂ O ₃ ).

Forming a ceramic thin film heating element on the ceramic substrate; forming a metal electrode on the ceramic thin film heating element; and forming an electrically insulating protective film on the ceramic thin film heating element other than the region where the metal electrode is formed Forming a precursor aqueous solution by mixing a tin precursor, a fluorine precursor, and deionized water to form a ceramic thin film heating element; and spraying the precursor aqueous solution onto the ceramic substrate at 350 to 550 占 폚 Forming a fluorine-containing tin oxide transparent conductive film comprising a layer in which the molar ratio of tin (Sn) to fluorine (F) is in the range of 1: 0.01 to 2.0 and the crystal plane is preferentially oriented A method of manufacturing an area heating device is provided.

The method for manufacturing an area heating device may further include forming a heat insulating layer below the ceramic substrate, and the heat insulating layer may be formed of at least one material selected from the group consisting of ceramic fibers, ceramic fiber blanket, and airgel blanket And it is preferable to form it so as to have a thickness of 0.1 to 20 mm.

Preferably, the ceramic thin film heating element is formed to have a thickness of 0.01 to 2 m, and the ceramic thin film heating element has a resistance in the range of 1 to 200 OMEGA, a transmittance in the range of 70 to 85% And can be heated to 550 to 640 캜.

The ceramic substrate may be glass, heat-resistant glass, or a substrate made of alumina (Al ₂ O ₃ ).

The tin precursor may be at least one selected from SnCl ₄ .5H ₂ O, SnCl ₂ and SnCl ₂ .2H ₂ O, and the fluorine precursor may be selected from NH ₄ F, HF and acetyl fluoride One or more materials may be used.

The electrically insulating protective film may be formed of a SiO ₂ film or a composite film of SiO ₂ and at least one oxide selected from TiO ₂ , ZrO ₂ and Al ₂ O ₃ , and is preferably formed to have a thickness of 0.05 to 100 μm Do.

The step of forming the electrically insulating protective film comprises dissolving the silicate-based alkoxide in the alcohol in the range of ₁ to 20 M, adding distilled water to the solution in a molar ratio of H ₂ O / Si in the range of 0.5 to 10 for the hydrolysis reaction, Preparing a coating solution by adding at least one acid selected from nitric acid, hydrochloric acid and acetic acid so as to have a concentration of 1 × 10 ^{-5 to} 0.1 M and performing a catalytic reaction; And heating the resultant coated with the coating solution at 150 to 300 캜 to form an electrically insulating protective layer having a thickness of 0.05 to 100 탆.

The step of forming the electrically insulating protective film may be performed by mixing 10 to 50 parts by weight of polysilazane with 100 parts by weight of at least one material selected from xylene, polydimethyl ethyl acetate and n-butyl ether (nBE) Spraying the coating solution onto the ceramic thin film heating element other than the region where the metal electrode is formed, and heat treating the resultant coated with the coating solution at a temperature ranging from 150 to 300 캜 to a thickness of 0.05 to 100 탆 And forming an electrically insulating protective film having an insulating film.

The step of forming the electrically insulating protective film may include screen printing the paste including the glass frit on the ceramic thin film heating element other than the region where the metal electrode is formed and drying the screen printed product to a temperature higher than the softening point of the glass frit Treated at a high temperature of 400 to 650 占 폚 to form an electrically insulating protective film having a thickness of 0.05 to 100 占 퐉.

According to the present invention, a transparent conductive film of FTO (Fluorine doped Tin Oxide) is formed by a spray coating method with a ceramic thin film heating element, which is advantageous in manufacturing cost and simple in manufacturing process and excellent in heat resistance, chemical resistance and abrasion resistance And has a low resistance and a high transmittance.

The surface heating apparatus using the FTO transparent conductive film of the present invention can be applied to a kitchen cooking apparatus, a hot water system for a boiler, a hot air system, a heating window, a heating susceptor for a semiconductor, .

1 is a conceptual view showing a structure of a planar heating device using a ceramic thin film heating element according to a preferred embodiment of the present invention.
FIG. 2 is a plan view of a 500 nm FTO transparent conductive film formed on a lithium aluminum silicate (LAS) heat-resistant glass according to Example 1, a silver (Ag) electrode formed on the FTO transparent conductive film, It is a photograph of a heating device.
3 is a field emission scanning electron microscope (FE-SEM) image showing the surface microstructure of the FTO transparent conductive film formed by coating the upper part of LAS heat-resistant glass at 400 ° C. for 40 minutes according to Example 1 .
FIG. 4 is a field emission scanning electron microscope (FE-SEM) image showing a cross section of an FTO transparent conductive film formed by coating the upper part of LAS heat-resistant glass at 400 ° C. for 40 minutes according to Example 1.
5 is a graph showing the thickness and resistance change of the FTO transparent conductive film depending on the deposition temperature and the deposition time.
FIG. 6 is a graph showing a change in temperature due to a heat generation characteristic when a voltage is applied to an FTO transparent conductive film having sheet resistances of 10, 20, and 200 OMEGA.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not. Wherein like reference numerals refer to like elements throughout.

1 is a conceptual view showing a structure of a planar heating device using a ceramic thin film heating element according to a preferred embodiment of the present invention.

Referring to FIG. 1, a surface heating apparatus using a ceramic thin film heating element according to a preferred embodiment of the present invention includes a ceramic substrate 10, a ceramic thin film heating element 20 formed on the ceramic substrate 10, The ceramic thin film heating element 20 includes a metal electrode 30 formed on the substrate 20 and an electrically insulating protective film 40 provided on the ceramic thin film heating element 20 other than the region where the metal electrode 30 is formed, Wherein the fluorine-containing tin oxide transparent conductive film is composed of a fluorine-doped tin oxide (FTO) transparent conductive film, wherein the molar ratio of tin (Sn) to fluorine (F) is 1: 0.01 to 2.0, Are preferentially oriented layers.

The surface heating device may further include a heat insulating layer 50 provided below the ceramic substrate 10. The heat insulating layer 50 may be formed of one or more materials selected from ceramic fibers, ceramic fiber blanket and airgel blanket And preferably has a thickness of 0.1 to 20 mm.

The electrically insulating protective film 40 may be made of a SiO ₂ film or a composite film of at least one oxide selected from TiO ₂ , ZrO _2, and Al ₂ O ₃ and SiO ₂ , and may have a thickness of 0.05 to 100 μm .

The ceramic substrate 10 may be made of glass, heat-resistant glass, or alumina (Al ₂ O ₃ ).

The ceramic thin film heating element 20 preferably has a thickness of 0.01 to 2 탆 and has a resistance in the range of 1 to 200 Ω, a transmittance in the range of 70 to 85%, a temperature in the range of 550 to 640 ° C. .

The transparent conductive film of fluorine-doped tin oxide (hereinafter referred to as 'FTO') is excellent in heat resistance, chemical resistance and abrasion resistance, has low resistance and high transmittance and generates heat when electricity is applied, The surface heating apparatus of the present invention can be used for domestic cooking utensils, heat sinks for semiconductors, hot water heaters for boilers, hot air systems, and the like.

The FTO transparent conductive film has a specific molar ratio of Sn relative to Sn for a low resistance and has a (200) crystal plane preferentially oriented layer. By coating the FTO transparent conductive film at a temperature of the lowest resistance of the FTO transparent conductive film, The ceramic thin film heating element of Fig.

A method of manufacturing an area heating apparatus using a ceramic thin film heating element according to a preferred embodiment of the present invention includes the steps of forming a ceramic thin film heating element on a ceramic substrate, forming a metal electrode on the ceramic thin film heating element, And forming an electrically insulating protective film on the ceramic thin film heating element other than the formed region, wherein the step of forming the ceramic thin film heating element comprises the steps of: forming a precursor aqueous solution by mixing a tin precursor, a fluorine precursor and deionized water; The precursor aqueous solution is spray-coated on the ceramic substrate at a temperature of 350 to 550 DEG C to form a molten ratio of tin (Sn) to fluorine (F) in the range of 1: 0.01 to 2.0, And forming a tin oxide transparent conductive film.

The method for manufacturing an area heating device may further include forming a heat insulating layer below the ceramic substrate, and the heat insulating layer may be formed of at least one material selected from the group consisting of ceramic fibers, ceramic fiber blanket, and airgel blanket And it is preferable to form it so as to have a thickness of 0.1 to 20 mm.

Hereinafter, a method of manufacturing a planar heating apparatus using a ceramic thin film heating element according to a preferred embodiment of the present invention will be described in detail.

First, a ceramic substrate is prepared. The ceramic substrate may be glass, heat-resistant glass, or a substrate made of alumina (Al ₂ O ₃ ). The glass may be a borosilicate glass, a lithium aluminum silicate (LAS) heat-resistant glass, or the like. The ceramic substrate uses a substrate which can prevent the ceramic thin film heating element from being broken by thermal shock even if it generates heat at a high temperature.

The heat insulating layer may be formed of at least one material selected from the group consisting of ceramic fiber, ceramic fiber blanket, and airgel blanket, and is preferably formed to have a thickness of 0.1 to 20 mm . When the ceramic thin film heating element is heated, the heat is also transferred to the lower portion of the ceramic heating element. Since the efficiency of heat dissipation is lowered, a heat insulating layer for insulating the lower portion of the ceramic substrate is formed. The heat insulating layer is preferably thin in terms of the configuration of the surface heating device, but it is preferable that the heat insulating layer is formed in the range of 0.1 to 20 mm.

A ceramic thin film heating element is formed on the ceramic substrate.

More specifically, the method of forming the ceramic thin film heating element includes mixing a tin precursor, a fluorine precursor, and deionized water to form a precursor aqueous solution. The tin precursor may be at least one selected from SnCl ₄ .5H ₂ O, SnCl ₂ and SnCl ₂ .2H ₂ O. The fluorine precursor may be at least one selected from the group consisting of NH ₄ F, HF, and acetyl fluoride, which does not contain an alkyl group.

There is an advantage that a lower resistance can be achieved by adding an alcohol such as ethanol to the aqueous solution of the precursor for spray coating together with the deionized water. Alcohol enables the crystal growth of the FTO transparent conductive film to grow well on the (200) plane, thereby enabling formation of a ceramic film heating element with lower resistance.

Wherein the precursor aqueous solution is spray-coated on the ceramic substrate at a temperature of 350 to 550 DEG C to form a fluorine-containing oxide having a molar ratio of tin (Sn) to fluorine (F) in the range of 1: 0.01 to 2.0, Thereby forming a tin transparent conductive film. The spray coating can be carried out under atmospheric or oxygen atmosphere conditions. The fluorine-containing tin oxide transparent conductive film formed by the coating has a main crystal growth direction of (200) crystal plane. Considering that a large amount of electric current is flowed when the same voltage is applied to the ceramic thin film heating element, it is preferable to keep the (200) crystal face preferentially oriented. The manufacturing process is simple by using the spray coating method as described above.

In the present invention, the fluorine content of the FTO transparent conductive film is a very important factor greatly affecting the conductivity and transmittance characteristics of the FTO transparent conductive film, and the molar ratio of Sn to F of the FTO transparent conductive film is maintained in the range of 0.01 to 2.0. In order to control the fluorine content, the precursor aqueous solution is prepared by using deionized water as a solvent and mixing the tin precursor and the fluorine precursor so that the molar ratio of Sn to F is in the range of 0.01 to 2.0.

At this time, if the content of fluorine is too high, many carrier electrons (or free electrons) are formed and scattered inside the FTO transparent conductive film, which may act as resistance to each other, resulting in a problem of deterioration of electrical conductivity. When the number of carrier electrons increases, If the content of fluorine is too low, the synergistic effect of the electric conductivity is insignificant and the crystal orientation plane may grow arbitrarily. If the number of carrier electrons (conduction electrons) in the FTO transparent conductive film is small Therefore, it is preferable to maintain the above range because a problem may occur that the transmittance is high but the electrical resistivity is high.

Spray coating is advantageous in manufacturing cost compared with conventional sputtering and chemical vapor deposition (CVD) methods and has a simple manufacturing process. The spray coating method is not particularly limited, and for example, an ultrasonic spray coating method using an air nozzle or an ultrasonic spray nozzle may be used.

Preferably, the ceramic thin film heating element is formed to have a thickness of 0.01 to 2 m, and the ceramic thin film heating element has a resistance in the range of 1 to 200 OMEGA, a transmittance in the range of 70 to 85% And can be heated to 550 to 640 캜.

The ceramic thin film heating element preferably has a thickness of 0.01 to 2 占 퐉. Normally, the thickness of the ceramic thin film heating element may exceed 1 占 퐉 in which the transmittance is lowered, but it is preferable to maintain the thickness of 1 占 퐉 or less for application as a heat generating window for maintaining the transmittance. If the thickness of the ceramic thin film heating element is less than 0.01 占 퐉, there is a problem that the heating efficiency is too low for use as a heating element because the specific resistance is high.

A metal electrode is formed on the ceramic thin film heating element. It is possible to form electrodes by screen printing using high-temperature silver (Ag) paste, or to form metal electrodes by ink jet or electrohydrodynamic jet using nano ink or the like. In the case of the metal electrode, metals such as gold, platinum, nickel, and copper may be used.

An electrically insulating protective film is formed on the upper portion of the ceramic thin film heating element other than the region where the metal electrode is formed. Since the ceramic thin film heating element generates heat when electricity flows, it is necessary to protect the ceramic thin film heating element by electrical insulation. In addition, since the surface of the ceramic thin film heating element has irregularities, it has an effect of coating the electrical insulation protective film to smooth the surface. The ceramic thin film heating element is protected from mechanical scratches to maintain a more stable and durable ceramic thin film heating element. . In addition, a metal electrode is formed to apply electricity to the ceramic thin film heating element, which also protects the metal electrode.

The electrically insulating protective film may be formed of a SiO ₂ film or a composite film of SiO ₂ and at least one oxide selected from TiO ₂ , ZrO ₂ and Al ₂ O ₃ , and is preferably formed to have a thickness of 0.05 to 100 μm Do.

The step of forming the electrically insulating protective film comprises dissolving the silicate-based alkoxide in the alcohol in the range of ₁ to 20 M, adding distilled water in the range of 0.5 to 10 in the molar ratio of H ₂ O / Si for the hydrolysis reaction, Adding at least one acid selected from hydrochloric acid and acetic acid so as to have a concentration of 1 × 10 ^{-5 to} 0.1 M and carrying out a catalytic reaction to prepare a coating solution (silicate sol) Coating the upper surface of the ceramic thin-film heating element other than the formed region with the coating solution, and heat-treating the resultant coated with the coating solution at 150 to 300 캜 to form an electrically insulating protective layer having a thickness of 0.05 to 100 탆 .

The coating may be dip coating, spray coating, bar coating, spin coating, brush, or the like. At this time, the thickness of the electrically insulating protective film is set in the range of 0.05 to 100 mu m. When the thickness of the electrically insulating protective film is less than 0.05 탆, the electrical insulating performance is deteriorated. When the thickness exceeds 100 탆, the electrically insulating protective film may be broken by the residual stress.

It is also possible to form an electrically insulating protective film by using a sol, alumina sol, TiO ₂ sol, ZrO ₂ sol, or a mixture thereof using colloidal silica in addition to the silicate sol. When an alumina sol is used, it is also possible to form an electrically insulating protective film by coating the alumina powder dispersed in ethanol. When a TiO ₂ sol is used, colloidal sol in which TiO ₂ nanoparticles are dispersed or an alkoxide such as titanium isopropoxide is dissolved in ethanol and then coated with a sol which is stabilized with an acid or a base It is possible.

The step of forming the electrically insulating protective film may be performed by mixing 10 to 50 parts by weight of polysilazane with 100 parts by weight of at least one material selected from xylene, polydimethyl ethyl acetate, and n-butyl ether (nBE) Spraying the coating solution onto an upper portion of the ceramic thin-film heating element other than the region where the metal electrode is formed, and heat-treating the resultant coated with the coating solution at a temperature of 150 to 300 캜, And forming an electrically insulating protective film.

The step of forming the electrically insulating protective film may include screen printing a paste containing glass frit on the ceramic thin film heating element other than the region where the metal electrode is formed, To a temperature of 400 to 650 占 폚 higher than the softening point of the insulating layer to form an electrically insulating protective film having a thickness of 0.05 to 100 占 퐉. The viscosity of the paste containing the glass frit may be about 10,000 to 150,000 cP, and the solid content of the paste containing the glass frit is preferably about 40 to 80%.

The ceramic thin film heating element manufactured as described above includes the FTO ceramic thin film heating element having excellent heat resistance, chemical resistance, and abrasion resistance and having low resistance. The resistance is in the range of 1 to 200 Ω, the transmittance is in the range of 70 to 85% Can generate heat up to 550 ~ 640 ℃ when 220V AC voltage is applied.

It is expected to be usefully used in cooking apparatus, semiconductor susceptor heating element, experimental hot plate, hot water system for boiler, hot air system, etc., by using the surface heating apparatus of the present invention using the characteristic of generating heat when electricity is applied.

Hereinafter, embodiments according to the present invention will be specifically shown, and the present invention is not limited to the following embodiments.

≪ Example 1 >

A heat insulating layer for heat insulation was formed on the lower part of the ceramic substrate, and the heat insulating layer was formed of a ceramic fiber blanket. The heat insulating layer was formed to a thickness of about 10 mm. The ceramic substrate is made of lithium aluminum silicate (LAS) heat-resistant glass to prevent the ceramic thin film heating element from being broken by thermal shock even if it generates heat at a high temperature.

An FTO transparent conductive film was formed on the ceramic substrate as a ceramic thin film heating element. The FTO transparent conductive film had a molar ratio of F to Sn of 0 (in the case of 'no F' in Table 2, , 1.5 (in the case of Table 1), and the influence of the molar ratio of Sn relative to Sn was examined.

The FTO transparent conductive film was formed by spray coating an aqueous precursor solution. The precursor aqueous solution was prepared by mixing SnCl ₄ .5H ₂ O, which is a Sn precursor, and NH ₄ F, which is a fluorine (F) precursor, And mixing 5 g of ethanol with 95 g of water. The precursor aqueous solution was spray-coated on the ceramic substrate at a deposition temperature of 350 to 550 ° C for 20 to 50 minutes (deposition time), and the FTO transparent conductive film was formed to a thickness of about 500 nm.

A metal electrode was formed on the ceramic thin film heating element, and the metal electrode was formed by screen-printing a commercially available high-temperature silver (Ag) paste at 500 ° C. for 30 minutes.

An electrothermal protection film was formed on the ceramic thin film heating element except for the region where the metal electrode was formed. The electrically insulating protective film was prepared by dissolving tetraethylorthosilicate in 95% ethanol to give a concentration of about 1M, The molar ratio of H ₂ O / Si was about 4, and then nitric acid was added at a concentration of about 1 × 10 ^-4 M to form a silicate-based sol. The silicate-based sol was coated by ordinary dip coating and heat-treated at a temperature of about 200 캜 to prepare an electrically insulating protective film having a thickness of about 100 nm.

≪ Example 2 >

A heat insulating layer for heat insulation was formed on the lower part of the ceramic substrate, and the heat insulating layer was formed of a ceramic fiber blanket. The heat insulating layer was formed to a thickness of about 10 mm. The ceramic substrate is made of lithium aluminum silicate (LAS) heat-resistant glass to prevent the ceramic thin film heating element from being broken by thermal shock even if it generates heat at a high temperature.

An FTO transparent conductive film was formed as a ceramic thin film heating element on the ceramic substrate. In the FTO transparent conductive film, the molar ratio of Sn to F was determined by changing the molar ratio of Sn to F to 0 and 1.5.

The FTO transparent conductive film was formed by spray coating an aqueous precursor solution. The precursor aqueous solution was prepared by mixing SnCl ₄ .5H ₂ O, which is a Sn precursor, and NH ₄ F, which is a fluorine (F) precursor, And mixing 5 g of ethanol with 95 g of water. The precursor aqueous solution was spray-coated on the ceramic substrate at a deposition temperature of 350 to 550 ° C for 20 to 50 minutes (deposition time), and the FTO transparent conductive film was formed to a thickness of about 500 nm.

A metal electrode was formed on the ceramic thin film heating element, and the metal electrode was formed by screen-printing a commercially available high-temperature silver (Ag) paste at 500 ° C. for 30 minutes.

The electrically insulating protective layer was formed by mixing 20 parts by weight of polysilazane (HTT1800) with 100 parts by weight of polydimethyl ethyl acetate (PDMEA) and spraying Followed by heat treatment at a temperature of about 300 < 0 > C.

[Measurement of physical properties]

1. Sheet resistance

The electrical resistivity was measured by a 4-probe method to evaluate the electrical characteristics of the FTO transparent conductive film. The results are shown in Table 1.

2. Transmittance

The transmittance of the visible light region of the FTO transparent conductive film shows a tendency to decrease with increasing thickness. The transmittance was measured at a wavelength of 200 to 2500 nm using a UV / VIS / NIR photospectrometer (UV / VIS / NIR photospectrophotometer, JASCO, V570) The transmittance measurement results are shown in Table 1.

3. Thermal characteristics due to voltage

FTO Transparency The film can be evaluated by measuring the increase in temperature due to the heat generated when the voltage is applied. The change in temperature was measured when a constant voltage was applied using a potentiostat and a K-type thermometer. The measured results are shown in Table 3 and FIG. 6.

FIG. 2 is a photograph of a surface heat generating device in which a 500 nm FTO transparent conductive film is formed on a lithium aluminum silicate (LAS) heat-resistant glass according to Example 1, and a silver electrode and an electrically insulating protective film are formed on the FTO transparent conductive film.

3 is a field emission scanning electron microscope (FE-SEM) image showing the surface microstructure of the FTO transparent conductive film formed by coating the upper part of LAS heat-resistant glass at 400 ° C. for 40 minutes according to Example 1 . As shown in FIG. 3, the FTO transparent conductive film mainly has a triangular microstructure having a (200) crystal plane. Considering that the ceramic thin film heating element has a high heat generation efficiency to flow a large amount of current when the same voltage is applied, it is preferable to keep the (200) crystal plane in the preferential orientation.

FIG. 4 is a field emission scanning electron microscope (FE-SEM) image showing a cross section of an FTO transparent conductive film formed by coating the upper part of LAS heat-resistant glass at 400 ° C. for 40 minutes according to Example 1.

5 is a graph showing the thickness and resistance change of the FTO transparent conductive film depending on the deposition temperature and the deposition time.

Table 1 below shows the thickness, specific resistance, and transmittance at 550 nm for the FTO transparent conductive film prepared according to Example 1, depending on the deposition temperature and the deposition time.

Deposition temperature (° C) Deposition Time (min) shape
(shape) thickness
(nm) Resistivity
(Ω / □) Transmittance (550 nm) (%)
350 30 Thin Film (Film) 750 17 71.2 40 Thin Film (Film) 1050 11 71.8 50 Thin Film (Film) 1150 12 67.6
400 30 Thin Film (Film) 850 6.5 74.7 40 Thin Film (Film) 950 5 69.4 50 Thin Film (Film) 1100 3.5 61.9
450 30 Thin Film (Film) 700 4.5 73.0 40 Thin Film (Film) 900 4.3 70.7 50 Thin Film (Film) 1100 3.3 56.4
500 30 Thin Film (Film) 350 45 85.7 40 Thin Film (Film) 450 40 75.6 50 Thin Film (Film) 650 25 73.8
550 30 Thin Film (Film) 200 9K 83.0 40 Thin Film (Film) 400 700 74.6 50 Thin Film (Film) 400 1K 57.0

Table 2 below shows the line resistance before and after the formation of the metal electrode for the FTO transparent conductive film formed by deposition at a deposition temperature of 400 ° C for 20 to 40 minutes (deposition time) according to Example 1. In Table 2 below, 'no F' means the composition without fluorine (when the molar ratio of F / Sn is 0).

Deposition temperature
(° C) Deposition time
(min) resistance
(Ω) Line resistance after metal electrode formation
(Ω / □) Line resistance before metal electrode formation
(Ω / □) Electrode gap (cm)
400 40 10 5.5 20 3.8 20 20 10.5 36 3.8 30 No F 200 110 560 3.9

Referring to Table 2, after forming the metal electrode, the line resistance was found to decrease as compared with before forming the metal electrode.

Table 3 below shows the heat generation temperature depending on the resistance of the planar heating device manufactured according to the embodiment 1. Fig.

Resistance (Ω) Voltage (V) Current (mA) Temperature (℃)

Heat generation characteristics Example 1

10 0 0 25 10 56.1 20 36.5 252 30 37.7 285 40 40.8 400

Heat generation characteristics Example 2

20 0 0 25 10 21.3 52.5 20 32.8 218 30 37.5 270.4 40 38.7 310

Exothermic characteristic example 3

40 0 0 25 10 20.9 20 50 177 100 400 150 644

Heat generation characteristics Example 4

200 0 0 25 20 34.5 29.7 30 37.4 63 40 39.0 87 50 37.3 126 60 37.9 164

FIG. 6 is a graph showing a change in temperature due to a heat generation characteristic when a voltage is applied to an FTO transparent conductive film having sheet resistances of 10, 20, and 200 OMEGA.

Referring to Table 3 and FIG. 6, as the applied voltage increases for each resistance, the exothermic temperature increases. As the resistance increases to 10, 20, and 200Ω, the exothermic temperature decreases.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, This is possible.

10: Ceramic substrate
20: Ceramic thin film heating element
30: metal electrode
40: electrically insulating protective film
50: insulating layer

Claims (14)

A ceramic substrate;
A ceramic thin film heating element formed on the ceramic substrate;
A metal electrode formed on the ceramic thin film heating element; And
And an electrically insulating protective film provided on an upper portion of the ceramic thin film heating element other than the region where the metal electrode is formed,
Wherein the ceramic thin film heating element comprises a fluorine-containing tin oxide transparent conductive film,
Wherein the fluorine-containing tin oxide transparent conductive film is composed of a layer in which the molar ratio of tin (Sn) to fluorine (F) is in the range of 1: 0.01 to 2.0, and the (200) crystal face is preferentially oriented.
The ceramic substrate according to claim 1, further comprising a heat insulating layer provided under the ceramic substrate, wherein the heat insulating layer is made of at least one material selected from the group consisting of ceramic fibers, ceramic fiber blanket and airgel blanket, Wherein the heating device is a heating device.
The ceramic thin film heating element according to claim 1, wherein the ceramic thin film heating element has a thickness of 0.01 to 2 占 퐉, a resistance of 1 to 200?, A transmittance of 70 to 85%, a temperature of 550 to 640 占 폚 And the heat generated by the heat generating device is generated.
[2] The method according to claim 1, wherein the electrically insulating protective film is made of a SiO ₂ film or a composite film of at least one oxide selected from TiO ₂ , ZrO ₂ and Al ₂ O ₃ and SiO ₂ , And a second heat exchanger.
The apparatus according to claim 1, wherein the ceramic substrate is made of glass, heat-resistant glass, or alumina (Al ₂ O ₃ ).
Forming a ceramic thin film heating element on a ceramic substrate;
Forming a metal electrode on the ceramic thin film heating element; And
And forming an electrically insulating protective film on the ceramic thin film heating element other than the region where the metal electrode is formed,
The step of forming the ceramic thin film heating element may include:
Mixing a tin precursor, a fluorine precursor, and deionized water to form a precursor aqueous solution; And
The precursor aqueous solution is spray-coated on the ceramic substrate at a temperature of 350 to 550 DEG C to form a molten ratio of tin (Sn) to fluorine (F) in the range of 1: 0.01 to 2.0, And forming a transparent conductive film of tin oxide on the surface of the substrate.
7. The method of claim 6, further comprising forming a heat insulating layer below the ceramic substrate, wherein the heat insulating layer is formed of at least one material selected from the group consisting of ceramic fibers, ceramic fiber blanket, and airgel blanket, Is formed so as to have a predetermined thickness.
The ceramic thin film heating element according to claim 6, wherein the ceramic thin film heating element is formed to have a thickness of 0.01 to 2 탆, the resistance of the ceramic thin film heating element is in the range of 1 to 200 Ω, the transmittance is in the range of 70 to 85% And the heat is generated to 550 to 650 占 폚.
The method according to claim 6, wherein the ceramic substrate is made of glass, heat-resistant glass, or alumina (Al ₂ O ₃ ).
The method of claim 6, wherein the tin precursor is at least one selected from the group consisting of SnCl ₄ .5H ₂ O, SnCl _2, and SnCl ₂ .2H ₂ O,
Wherein the fluorine precursor is at least one selected from the group consisting of NH ₄ F, HF, and acetyl fluoride.
7. The method of claim 6 wherein the electrically insulating protective layer is SiO ₂ film or, TiO _2, ZrO ₂ and Al ₂ O ₃ and one or more kinds of oxides formed in the composite film of SiO ₂ selected from, so as to have a thickness of 0.05~100㎛ Wherein the heat sink is made of a metal.
7. The method of claim 6, wherein forming the electrically insulating protective film comprises:
A silicate-based alkoxide is dissolved in an alcohol in a range of 1 to 20 M, distilled water is added in a molar ratio of H ₂ O / Si within a range of 0.5 to 10 for the hydrolysis reaction, and at least one selected from nitric acid, hydrochloric acid and acetic acid Adding an acid at a concentration of 1 x 10 < ^-5 > to 0.1 M to cause a catalytic reaction to prepare a coating solution;
Coating the coating solution on an upper portion of the ceramic thin film heating element other than the region where the metal electrode is formed; And
And heat treating the resultant coated with the coating solution at 150 to 300 캜 to form an electrically insulating protective film having a thickness of 0.05 to 100 탆.
7. The method of claim 6, wherein forming the electrically insulating protective film comprises:
Mixing 10 to 50 parts by weight of polysilazane with 100 parts by weight of at least one material selected from xylene, polydimethyl ethyl acetate and n-butyl ether (nBE) to prepare a coating solution;
Spray coating the coating solution on the upper portion of the ceramic thin film heating element other than the region where the metal electrode is formed; And
And heat treating the resultant coated with the coating solution at 150 to 300 캜 to form an electrically insulating protective film having a thickness of 0.05 to 100 탆.
7. The method of claim 6, wherein forming the electrically insulating protective film comprises:
Screen printing the paste including the glass frit on the upper portion of the ceramic thin film heating element other than the region where the metal electrode is formed; And
And then heat-treating the resultant screen-printed product at a temperature of 400 to 650 占 폚 higher than the softening point of the glass frit to form an electrically insulating protective film having a thickness of 0.05 to 100 占 퐉 .

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