Heater, manufacturing method therefor and use thereof

Abstract

The present invention relates to a heater, a manufacturing method therefor and the use thereof. The heater comprises a substrate, wherein a first protective layer, an ITO layer and a second protective layer are successively stacked on the substrate; an electrode layer partially covers the second protective layer; raw materials for manufacturing the electrode layer comprise a conductive metal and glass powder, the glass powder containing a compound selected from at least one of an acidic oxide, an alkaline oxide and a fluoride. The heater in the present invention can protect the ITO layer by means of the first protective layer and the second protective layer, such that the ITO layer can work stably at a high temperature and the resistance value changes slightly, thus achieving excellent environmental tolerance and low costs.

Description

A heater and a preparation method and application thereof

[0001] Cross-reference to related applications

[0002] The present application claims priority to Chinese Patent Application No. CN 202410799297.6, filed on June 20, 2024, entitled "A heater and a preparation method and application thereof", the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application belongs to the field of heating, and particularly relates to a heater and a preparation method and application thereof. BACKGROUND

[0004] Indium Tin Oxide (ITO) is a substitutional solid solution, which is a transparent brownish yellow film or yellowish gray block, and is formed by mixing 90% of In2O3 and 10% of SnO2. ITO is mainly used for manufacturing liquid crystal displays, flat panel displays, plasma displays, touch screens, electronic paper, organic light-emitting diodes, solar cells, anti-static plating films, transparent conductive plating for EMI shielding, various optical plating films, etc.

[0005] In recent years, many people have also used ITO in the field of electronic heating. However, the defects of ITO itself limit its application in the field of heating. When the temperature of ITO is greater than 200℃, the internal microstructure of ITO will change, and the activity of ITO to oxygen will increase, which will cause the resistance of ITO to change greatly and the reliability of ITO to decrease during long-term application. Specifically, the ITO layer is composed of many small crystal grains. The crystal grains will undergo fission during the heating process, and the particle size of the crystal grains will decrease, thereby increasing more grain boundaries. When electrons break through the grain boundaries, a certain amount of energy will be lost, which will cause the resistance of the ITO layer to increase with the increase of temperature below 600℃. At the same time, ITO will be very active at high temperatures, which will cause ITO to easily react with oxygen, absorb oxygen in the air, and make the film layer in an oxygen-rich state. At this time, the resistance of ITO will increase by several times, and ITO is less resistant to the environment than FTO. These factors all greatly affect the application of ITO in the field of high-temperature heating. Therefore, FTO is currently used in the field of high-temperature heating. However, the high cost and high sheet resistance of FTO limit its application. SUMMARY

[0006] In order to overcome at least one technical problem existing in the prior art, one of the purposes of the present application is to provide a heater.

[0007] The second purpose of the present application is to provide a preparation method of the heater.

[0008] The third purpose of the present application is to provide an electronic atomization device.

[0009] The fourth object of the present application is to provide a heater for household appliances, public transport or mechanical equipment.

[0010] To achieve the above object, the present application adopts the following technical solution:

[0011] The first aspect of the present application provides a heater, comprising a substrate, a first protective layer, an ITO layer and a second protective layer are sequentially stacked on the substrate; the second protective layer partially covers an electrode layer; the electrode layer is prepared from conductive metal and glass powder, and the glass powder contains at least one compound selected from acidic oxides, basic oxides and fluorides.

[0012] In some embodiments, the ITO layer and the electrode layer form an ohmic contact.

[0013] In some embodiments, the softening point of the glass powder is 350-800℃.

[0014] In some embodiments, when the substrate is a glass substrate, the materials of the first protective layer and the second protective layer are both silicon dioxide.

[0015] In some embodiments, when the substrate is a ceramic substrate, the materials of the first protective layer and the second protective layer are both aluminum oxide.

[0016] In some embodiments, when the substrate is a metal substrate with an insulating layer on the surface, the materials of the first protective layer and the second protective layer are both boron oxide.

[0017] In the present application, the materials of the first protective layer and the second protective layer need to be similar to or belong to the same group as the material of the substrate, which is beneficial to further reduce the resistance of the heater and improve the environmental stability of the heater, for example, a glass substrate can use silicon dioxide, and an aluminum oxide ceramic substrate can use aluminum oxide.

[0018] In some embodiments, the thickness of the first protective layer is 10-2.5μm; further, the thickness of the first protective layer is 10-1000nm; in some embodiments, the thickness of the first protective layer is 10-100nm.

[0019] In some embodiments, the thickness of the second protective layer is 10-2.5μm; further, the thickness of the second protective layer is 10-1000nm; in some embodiments, the thickness of the second protective layer is 10-100nm.

[0020] In some embodiments, the thickness of the electrode layer is 3-50μm; further, the thickness of the electrode layer is 5-30μm; in some embodiments, the thickness of the electrode layer is 5-20μm.

[0021] In some embodiments, the electrode layer comprises a conductive layer A and a conductive layer B, and the conductive layer A and the conductive layer B do not contact.

[0022] In some embodiments, the sheet resistance of the ITO layer is 1-20 ohm / sq; further, the sheet resistance of the ITO layer is 1-15 ohm / sq; in some embodiments, the sheet resistance of the ITO layer is 1-10 ohm / sq.

[0023] In some embodiments, the substrate is selected from borosilicate glass, quartz glass, sapphire, alumina or a metal tube coated with an insulating layer; further, the substrate is borosilicate glass or quartz glass.

[0024] In some embodiments, the shape of the substrate is planar, curved, tubular, needle-shaped or bowl-shaped; further, the shape of the substrate is planar, tubular or bowl-shaped. The substrate in the present application can adopt any shape of substrate, and the above is only exemplary.

[0025] In some embodiments, the acidic oxide is selected from at least one of silicon oxide, boron oxide, CrO3, Mn2O7.

[0026] In some embodiments, the basic oxide is selected from at least one of sodium oxide, calcium oxide, zinc oxide, potassium oxide, lithium oxide.

[0027] In some embodiments, the fluoride is selected from at least one of calcium fluoride, sodium fluoride, potassium fluoride, lithium fluoride.

[0028] In some embodiments, the conductive metal is selected from at least one of silver, silver palladium, silver platinum, gold, platinum, palladium.

[0029] In some embodiments, the mass percentage of the compound selected from at least one of the acidic oxide, the basic oxide, the fluoride in the glass powder is 1-20%.

[0030] In some embodiments, the preparation raw material of the electrode layer comprises the following mass percentage of components: conductive metal 60-80%, glass powder 1-10%, butyl carbitol 5-15%, dispersant 0.1-5%, resin 0.7-5%, thixotropic agent 0.1-5%.

[0031] In some embodiments, the dispersant is selected from at least one of sodium carboxymethyl cellulose, fatty acid ester.

[0032] In some embodiments, the resin is selected from ethyl cellulose.

[0033] In some embodiments, the thixotropic agent is selected from at least one of hydrogenated castor oil, polyamide wax.

[0034] A second aspect of the present application provides a method for preparing the heater provided by the first aspect of the present application, comprising the following steps:

[0035] S1: sequentially forming a first protective layer, an ITO layer, and a second protective layer on the surface of the substrate;

[0036] S2: forming a conductive paste including a conductive metal and glass powder on a partial area of the surface of the second protective layer, drying, degassing, and then sintering at a temperature of 500-900°C and a pressure of 1×10 -4 Pa to obtain the heater.

[0037] In some embodiments, the drying temperature is 120-180°C.

[0038] In some embodiments, the drying time is 0.5-4h.

[0039] In some embodiments, the degassing temperature is 350-550°C.

[0040] In some embodiments, the degassing time is 10min-24h; further, the degassing time is 30min-90min.

[0041] In some embodiments, the sintering temperature is 500-900°C.

[0042] In some embodiments, the sintering time is 10-30min.

[0043] The application sets the first protective layer and the second protective layer, so that the heater containing the ITO layer has excellent reliability and environmental resistance. The glass powder contains at least one compound selected from the group consisting of acidic oxides, basic oxides and fluorides. These compounds can make the glass powder have good corrosion and permeability. During the high-temperature sintering process, the second protective layer is etched to form cracks or voids. The molten glass powder penetrates downward and deposits on the surface of the ITO layer to form a good ohmic contact between the electrode layer and the ITO layer. In addition, the electrode layer needs to be dried at 120-180℃, degassed at 350-550℃, and then sintered at 500-900℃ under vacuum or low oxygen content. During the degassing process, the small grains in the ITO layer will fission and become smaller during heating, thereby increasing more grain boundaries. When the electrons break through the grain boundaries, a certain amount of energy will be lost. The resistance of the ITO layer will increase with the increase of temperature below 600℃. At the same time, the ITO layer will be very active at high temperature, which will easily absorb oxygen in the air, so that the ITO layer is in an oxygen-rich state, and the resistance of the ITO layer will increase by several times. During the sintering process, the application is sintered under vacuum or low oxygen content. The ITO layer will become active. Due to the extreme lack of oxygen in the sintering atmosphere, the ITO layer starts to lose oxygen, and the resistance of the ITO layer rapidly decreases to the initial state.

[0044] In some embodiments, the initial resistance of the heater is not more than 5Ω.

[0045] In some embodiments, after 10,000 aging cycles of heating from 25℃ to 350℃ and then cooling to 25℃, the resistance change rate of the heater is not more than 5%.

[0046] The third aspect of the application provides an electronic atomization device, comprising a shell and the heater of the first aspect of the application; the heater is installed in the shell.

[0047] The fourth aspect of the application provides the application of the heater of the first aspect of the application in household appliances, public transportation or mechanical equipment.

[0048] In some embodiments, the public transportation includes cars, trains and airplanes.

[0049] The beneficial effects of the application are that the heater in the application can protect the ITO layer through the first protective layer and the second protective layer, so that the ITO layer can work stably at high temperature with little change in resistance, has excellent environmental resistance and low cost.

[0050] In addition, the heater in the present application has a low initial resistance, can work stably at 200-350 DEG C, and has a small resistance change during long-term heating, specifically, the initial resistance of the heater is not more than 5 ohm, and after 10000 aging cycles of heating from 25 DEG C to 350 DEG C and then cooling to 25 DEG C, the resistance change rate is not more than 5%. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a structural schematic diagram of the heater in Example 1.

[0052] Fig. 2 is a structural schematic diagram of the heater in Example 5. DETAILED DESCRIPTION

[0053] The specific implementation of the present application is further described in detail below in combination with the drawings and examples, but the implementation and protection of the present application are not limited thereto. It should be noted that the following processes which are not specifically described in detail are realized or understood by those skilled in the art in reference to the prior art. The reagents or instruments used are not marked with the manufacturer, and are conventional products which can be purchased in the market.

[0054] The silver paste used in printing the electrode layer in Examples 1-6 and Comparative Examples 1-2 of the present application is composed of the following components in mass percentage: silver powder 78%, glass powder 2%, butyl carbitol 10%, dispersing agent 0.8%, resin 8.4%, and thixotropic agent 0.8%, wherein the glass powder is GF45A purchased from Anmi Micro-nano New Material (Guangzhou) Co., Ltd., and in the glass powder, the mass of the acidic oxide, the basic oxide and the fluoride is 1-20% of the total mass of the glass powder, the acidic oxide is CrO3, Mn2O7, silicon oxide, etc., the basic oxide is sodium oxide, calcium oxide, potassium oxide, zinc oxide, etc., the content of the basic oxide is not less than 1%, and the fluoride is calcium fluoride and sodium fluoride; the thixotropic agent is hydrogenated castor oil, the dispersing agent is fatty acid ester, and the resin is ethyl cellulose.

[0055] Example 1

[0056] Referring to the structural schematic diagram in Fig. 1, the present example provides a heater, which comprises a tubular substrate, and the outer surface of the tubular substrate is sequentially coated with a first protective layer, an ITO conductive layer and a second protective layer; the surface of the second protective layer is provided with an electrode layer, and the electrode layer is composed of a conductive layer A and a conductive layer B, and the conductive layer A and the conductive layer B are respectively located at the two end positions of the tubular substrate and have a gap between them. The material of the tubular substrate is high borosilicate glass, and the length is 14 mm, the outer diameter is 8.4 mm, and the wall thickness is 1.2 mm; the materials of the first protective layer and the second protective layer are both silicon dioxide, the thickness of the first protective layer is 50 nm, and the thickness of the second protective layer is 50 nm; and the square resistance of the ITO conductive layer is 7-10 ohm / sq.

[0057] The preparation method of the conductive layer A and the conductive layer B in this example is as follows: silver paste is printed circumferentially on both ends of the second protective layer, the printed silver paste is 2mm wide and 10μm thick, after printing the silver paste, drying is performed at 150℃ for 10min, then degassing is performed at 350℃ for 30min in air, and sintering is performed at 650℃ for 20min in vacuum, thereby obtaining the conductive layer A and the conductive layer B.

[0058] Example 2

[0059] The example provides a heater, which comprises a tubular substrate, and the outer surface of the tubular substrate is sequentially coated with a first protective layer, an ITO conductive layer and a second protective layer; an electrode layer is arranged on the surface of the second protective layer, the electrode layer is composed of a conductive layer A and a conductive layer B, the conductive layer A and the conductive layer B are respectively located at the two end positions of the tubular substrate, and there is a gap between the conductive layer A and the conductive layer B. The material of the tubular substrate is quartz glass, the length is 30mm, the outer diameter is 7.5mm, and the wall thickness is 1mm; the materials of the first protective layer and the second protective layer are both silicon dioxide, the thickness of the first protective layer is 40nm, the thickness of the second protective layer is 50nm, and the sheet resistance of the ITO conductive layer is 1-2ohm / sq.

[0060] The preparation method of the conductive layer A and the conductive layer B in this example is as follows: silver paste is printed circumferentially on both ends of the second protective layer, the printed silver paste is 2mm wide and 10μm thick, after printing the silver paste, drying is performed at 150℃ for 10min, then degassing is performed at 350℃ for 30min in air, and sintering is performed at 650℃ for 20min in vacuum, thereby obtaining the conductive layer A and the conductive layer B.

[0061] Example 3

[0062] The example provides a heater, which comprises a tubular substrate, and the outer surface of the tubular substrate is sequentially coated with a first protective layer, an ITO conductive layer and a second protective layer; an electrode layer is arranged on the surface of the second protective layer, the electrode layer is composed of a conductive layer A and a conductive layer B, the conductive layer A and the conductive layer B are respectively located at the two end positions of the tubular substrate, and there is a gap between the conductive layer A and the conductive layer B. The material of the tubular substrate is sapphire (alumina) material, the length is 12mm, the outer diameter is 8.4mm, and the wall thickness is 0.5mm; the materials of the first protective layer and the second protective layer are both Al2O3, the thickness of the first protective layer is 30nm, the thickness of the second protective layer is 40nm, and the sheet resistance of the ITO conductive layer is 3-4ohm / sq.

[0063] The preparation method of the conductive layer A and the conductive layer B in this example is as follows: silver paste is printed circumferentially on both ends of the second protective layer, the printed silver paste is 1.5mm wide and 8μm thick, after printing the silver paste, drying is performed at 150℃ for 10min, then degassing is performed at 350℃ for 90min in air, and sintering is performed at 700℃ for 20min in vacuum, thereby obtaining the conductive layer A and the conductive layer B.

[0064] Example 4

[0065] The present example provides a heater which differs from Example 3 in that:

[0066] (1) In the present example, a dielectric layer is further provided between the tubular substrate and the first protective layer, the material of the tubular substrate is metal material 430, the dielectric layer is a film layer formed by coating a dielectric paste (trade name: Saiya 07H) on the surface of the tubular substrate, and the materials of the first protective layer and the second protective layer are both boron oxide.

[0067] (2) In the present example, the sintering temperature in the preparation method of the conductive layer A and the conductive layer B is 600°C.

[0068] Example 5

[0069] Referring to the structural schematic diagram in FIG. 2, the present example provides a heater which includes a bowl-shaped substrate, the bottom region of the inner surface of the bowl-shaped substrate is coated with a first protective layer, an ITO conductive layer, and a second protective layer in sequence; an electrode layer is provided on the surface of the second protective layer, the electrode layer is composed of a conductive layer A and a conductive layer B, the conductive layer A is circular, the conductive layer B is circular annular, the conductive layer A and the conductive layer B share the same center and the diameter of the conductive layer B is greater than that of the conductive layer A, and the conductive layer A and the conductive layer B have a gap therebetween. The material of the bowl-shaped substrate is quartz, the maximum outer diameter is 16 mm, and the wall thickness and the bottom thickness are both 1 mm; the materials of the first protective layer and the second protective layer are both SiO2, the thickness of the first protective layer is 50 nm; the thickness of the second protective layer is 50 nm; and the square resistance of the ITO conductive layer is 3-4 ohm / sq.

[0070] The preparation method of the conductive layer A and the conductive layer B in the present example is as follows: a circular silver paste layer A is printed at the axial position on the surface of the second protective layer, the diameter of the circular silver paste layer A is 1.5 mm, and the thickness is 10 μm; then a circular annular silver paste layer B is printed, the silver paste layer B shares the same center with the circular silver paste layer A, the inner diameter of the silver paste layer B is 14 mm, the outer diameter is 16 mm, and the thickness is 10 μm; after printing, drying is performed at 150°C for 10 min, degassing is performed at 400°C for 60 min in air, and sintering is performed at 650°C for 20 min in vacuum, to respectively obtain the conductive layer A and the conductive layer B.

[0071] Example 6

[0072] The present example provides a heater which differs from Example 5 in that: a circular planar quartz plate is used instead of the bowl-shaped substrate in Example 5.

[0073] Comparative Example 1

[0074] The example provides a heater, which comprises a tubular substrate, and the outer surface of the tubular substrate is coated with a first protective layer and an ITO conductive layer in sequence; the surface of the ITO conductive layer is provided with an electrode layer, the electrode layer is composed of a conductive layer A and a conductive layer B, the conductive layer A and the conductive layer B are respectively located at the two end positions of the tubular substrate, and the conductive layer A and the conductive layer B have a gap therebetween. The material of the tubular substrate is high borosilicate glass, the length of the tubular substrate is 14 mm, the outer diameter is 8.4 mm, and the wall thickness is 1.2 mm; the material of the first protective layer is silicon dioxide, and the thickness of the first protective layer is 50 nm; the sheet resistance of the ITO conductive layer is 7-10 ohm / sq.

[0075] The preparation method of the conductive layer A and the conductive layer B in the example is as follows: silver paste is printed circumferentially at the two ends of the ITO conductive layer, the printed silver paste has a width of 2 mm and a thickness of 10 μm, the silver paste is dried at 150 ℃ for 10 min after printing, and then the ITO conductive layer is sintered at 650 ℃ for 20 min in air, so as to obtain the conductive layer A and the conductive layer B.

[0076] Comparative Example 2

[0077] The example provides a heater, which comprises a tubular substrate, and the outer surface of the tubular substrate is coated with a first protective layer and an ITO conductive layer in sequence; the surface of the ITO conductive layer is provided with an electrode layer, the electrode layer is composed of a conductive layer A and a conductive layer B, the conductive layer A and the conductive layer B are respectively located at the two end positions of the tubular substrate, and the conductive layer A and the conductive layer B have a gap therebetween. The material of the tubular substrate is high borosilicate glass, the length of the tubular substrate is 14 mm, the outer diameter is 8.4 mm, and the wall thickness is 1.2 mm; the material of the first protective layer is silicon dioxide, and the thickness of the first protective layer is 50 nm; the sheet resistance of the ITO conductive layer is 7-10 ohm / sq.

[0078] The preparation method of the conductive layer A and the conductive layer B in the example is as follows: silver paste is printed circumferentially at the two ends of the ITO conductive layer, the printed silver paste has a width of 2 mm and a thickness of 10 μm, the silver paste is dried at 150 ℃ for 10 min after printing, and then the ITO conductive layer is sintered at 650 ℃ for 20 min in air, so as to obtain the conductive layer A and the conductive layer B.

[0079] Performance test

[0080] The initial resistance of the heater in Examples 1-6 and Comparative Examples 1-2 is tested by using a resistance tester, which is recorded as R0, and then the heater is subjected to a temperature rising and falling cycle for 10,000 times, and then the resistance change rate is tested. The specific test method is as follows: the temperature is raised from 25 ℃ to 350 ℃, the temperature rising time is 10 s, and then the temperature is lowered to 25 ℃, which completes one aging cycle. According to the cycle mode, the temperature rising and falling process is cycled for 10,000 times, and then the resistance value of the heater after 10,000 aging cycles is tested, which is recorded as R 10000 , and the resistance change rate is =((R 10000(R0-R0) / R0)*100%, and then the calculation results are recorded in Table 1 below.

[0081] Table 1: Test results of initial resistance and resistance change rate

[0082] As can be seen from Table 1 above, compared with Comparative Example 1-2, the heater in Inventive Example 1-6 is protected by the first protective layer and the second protective layer to protect the ITO conductive layer, which can significantly reduce the initial resistance of the heater, and greatly improve the reliability and environmental resistance of the heater, so that the resistance change rate of the heater is less than 3.5% after 10000 times of aging cycle test.

[0083] The above embodiments of the present application are described in detail, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the spirit of the present application. In addition, the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

Claims

1. A heater, comprising a substrate, wherein a first protective layer, an ITO layer, and a second protective layer are sequentially stacked on the substrate; an electrode layer is partially covered on the second protective layer; the electrode layer is prepared from conductive metal and glass powder, wherein the glass powder contains a compound selected from at least one of acidic oxides, basic oxides, and fluorides.

2. The heater according to claim 1, wherein when the substrate is a glass substrate, the materials of the first protective layer and the second protective layer are both silicon dioxide; Alternatively, when the substrate is a ceramic substrate, the materials of both the first protective layer and the second protective layer are alumina; Alternatively, when the substrate is a metal substrate with an insulating layer on its surface, the materials of the first protective layer and the second protective layer are both boron oxide.

3. The heater according to claim 1, wherein the thickness of the first protective layer is 10 nm to 2.5 μm; And / or, the thickness of the second protective layer is 10nm-2.5μm; And / or, the thickness of the electrode layer is 3-50 μm; And / or, the sheet resistance of the ITO layer is 1-20 ohm / sq.

4. The heater according to claim 1, wherein the substrate is planar, curved, tubular, needle-shaped, or bowl-shaped.

5. The heater according to claim 1, wherein the acidic oxide is selected from at least one of silicon oxide, boron oxide, CrO3, and Mn2O7; And / or, the alkaline oxide is selected from at least one of sodium oxide, calcium oxide, zinc oxide, potassium oxide, and lithium oxide; And / or, the fluoride is selected from at least one of calcium fluoride, sodium fluoride, potassium fluoride, and lithium fluoride; And / or, the conductive metal is selected from at least one of silver, silver-palladium, silver-platinum, gold, platinum, and palladium; And / or, the glass powder contains 1-20% by mass of a compound selected from at least one of acidic oxides, basic oxides, and fluorides.

6. The heater according to any one of claims 1-5, wherein the initial resistance of the heater does not exceed 5Ω; And / or, after the heater undergoes 10,000 aging cycles of heating from 25°C to 350°C and then cooling back to 25°C, the resistance change rate does not exceed 5%.

7. A method for preparing the heater according to any one of claims 1-6, comprising the following steps: S1: A first protective layer, an ITO layer, and a second protective layer are sequentially formed on the surface of the substrate; S2: Form a conductive paste, including conductive metal and glass powder, into a film on a portion of the surface of the second protective layer, dry it, remove the adhesive, and then apply it under a vacuum degree not exceeding 1×10⁻⁶. -4 It was obtained by sintering under Pa.

8. The method for preparing the heater according to claim 7, wherein the drying temperature is 120℃-180℃; And / or, the glue discharge temperature is 350℃-550℃; And / or, the sintering temperature is 500℃-900℃; And / or, the sintering time is 10-30 min.

9. An electronic atomizing device, comprising a housing and a heater as described in any one of claims 1-6; the heater being installed within the housing.

10. The use of the heater according to any one of claims 1-6 in household appliances, public transportation vehicles or mechanical equipment.

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