JP7748065B2 - Zirconium carbide film, zirconium carbide substrate, zirconium carbide powder, resistor, heat generating member, and method for producing zirconium carbide film - Google Patents

Description

The present invention relates to a zirconium carbide film suitable for semiconductor devices used in high-temperature environments and for photothermal conversion, a zirconium carbide substrate, a zirconium carbide powder suitable for forming the zirconium carbide film of the present invention, a resistor, a heat-generating component, and a method for producing a zirconium carbide film.

Zirconium is inexpensive and is used as a resistor material and a light-to-heat conversion material.

As a resistor using zirconium, Patent Document 1 discloses a thin-film resistor formed by sputtering using a mixed target of SiC and TiC or ZrC. Patent Document 2 discloses a thermal head having a substrate, a heating resistor formed on the substrate, and an electric conductor for supplying power to _the heating resistor, characterized in that the heating resistor uses a mixture of any one of Hf, Nb, or Ta and any one of _B4C , BN, BeO, _CeO2 , _HfO2 , _{La2O3 , Ti2O3 ,} VC, VN, _Y2O3 , _and ZrC. Patent Document 3 also discloses a heating resistor manufactured by a resistor manufacturing method characterized by forming a thin film of titanium carbide and silicon carbide, or zirconium carbide and silicon carbide, by chemical vapor deposition or physical vapor deposition, and then performing a laser heating treatment.

As an example of a photothermal conversion material that uses zirconium as the photothermal conversion material, Patent Document 4 discloses a low-heat generating film that is adhered to a specific location on a textile product. The low-heat generating film uses a flexible resin substrate in which at least one type of ceramic fine powder with heat storage function is uniformly dispersed. This flexible resin substrate is laminated with a hot melt layer or adhesive layer, and the hot melt layer or adhesive layer is used to attach the film to the textile product or its fiber material.

Japanese Unexamined Patent Publication No. 62-95801 Japanese Patent Application Publication No. 02-050847 Japanese Patent Application Publication No. 2-234402 Utility Model Registration No. 3190772

When resistors are used in automotive power transistors, which have become increasingly popular in recent years, temperatures can reach 250°C or higher depending on the operating environment. Therefore, resistors are required to suppress changes in resistance value within a certain range even in high-temperature environments of 250°C or higher. The resistors disclosed in Patent Documents 1 and 2 are formed in a temperature range of 200°C to 700°C, and therefore have an amorphous structure. Therefore, there is a problem in that they cannot suppress fluctuations in resistance value at high temperatures of 250°C or higher.

When used in automotive power transistors, the large temperature change from low to high temperatures poses a challenge, posing a problem of stress due to differences in the linear thermal expansion coefficients of materials. This necessitates the use of flexible resistors formed on flexible substrates. However, the manufacturing methods described in Patent Documents 1 and 2 use high-temperature processes, making them difficult to fabricate on non-heat-resistant substrates, metals, resins, or glass, and are therefore unable to address the stress caused by differences in linear thermal expansion coefficients. Furthermore, the manufacturing method described in Patent Document 3 uses a carbon dioxide laser with an output of 100 W and a beam diameter of 0.05 watts (mmφ) to scan the heating element pattern at a speed of 8.5 cm/sec to perform the crystallization process. This essentially involves a high-temperature heating process, making it difficult to fabricate on non-heat-resistant substrates, metals, resins, or glass, as with Patent Documents 1 and 2.

The low-temperature exothermic film disclosed in Patent Document 4 has the problem of poor weather resistance because it is kneaded with polyurethane resin. Furthermore, the low-temperature exothermic film disclosed in Patent Document 4 also has the problem of low temperature rise when exposed to light.

The present invention was made in consideration of the above-mentioned problems, and provides zirconium carbide films, zirconium carbide substrates, zirconium carbide powder, resistors, heat-generating components, and methods for manufacturing the same, which are inexpensive, have little change in resistance over a wide temperature range from low to high, are highly weather-resistant, and have excellent light-to-heat conversion performance.

In order to solve the above problems, the present invention proposes the following means.
<1> A zirconium carbide film according to one aspect of the present invention contains zirconium carbide as a main component and at least one of a metal oxide, a metal, and carbon.
<2> In the zirconium carbide film according to the above item <1>, zirconium oxide may be present on the surface or inside of the zirconium carbide film.
<3> In the zirconium carbide film according to the above item <1> or <2>, the metal oxide may be present on the surface and inside of the zirconium carbide film.
<4> In the zirconium carbide film according to any one of the above items <1> to <3>, the metal oxide may be at least one selected from the group consisting of tin oxide, indium oxide, ruthenium oxide, zinc oxide, titanium oxide, and perovskite oxide.
<5> In the zirconium carbide film according to <4> above, the perovskite oxide _may be represented by A1 _{- xDxEOy} , in which A is any one of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, D is any one of Sr, Ca, and Ba, and E is any one of Mn, Fe, and Ni, and x satisfies the following formula (1), and y satisfies the following formula (2):
0≦x≦1 (1)
2.65<y<3.05...(2)
<6> In the zirconium carbide film according to any one of the above items <1> to <5>, the metal may be one or more selected from the group consisting of Ni, Ag, Cu, Pd, Sn, In, Ru, Ti, and Cr.
<7> The zirconium carbide film according to any one of <1> to <6> above may have a sheet resistance of 1000 Ω/□ or less at room temperature and an average temperature coefficient of resistance of 500 ppm/K or less in a temperature range of 25°C to 250°C.
<8> The zirconium carbide film according to any one of the above items <1> to <6> may have a sheet resistance of more than 1000 Ω/□ at room temperature and an average temperature coefficient of resistance of 500 ppm/K or less in a temperature range of 25°C to 250°C.
<9> A zirconium carbide substrate according to one aspect of the present invention includes a substrate and the zirconium carbide film according to any one of <1> to <8> above, formed on the substrate.
<10> In the zirconium carbide substrate according to the above item <9>, the substrate may be any one of alumina, zirconia, a low-temperature fired multilayer ceramic substrate, a liquid crystal polymer, and polyethylene naphthalate.
<11> The zirconium carbide substrate according to the above item <9> or <10> may have a heat-resistant temperature of 150° C. or less.
<12> A resistor according to one aspect of the present invention includes the zirconium carbide substrate according to any one of <9> to <11> above.
<13> A heat generating member according to one aspect of the present invention includes the zirconium carbide substrate according to any one of <9> to <11> above.
<14> In the heat-generating member according to the above item <13>, the temperature of the zirconium carbide film may be increased by 20°C or more compared to the temperature of the substrate when irradiated with light of 1800 W/ ^m2 or more.
<15> A method for producing a zirconium carbide film according to one aspect of the present invention includes: a slurry preparation step of mixing zirconium carbide, at least one of a carbon material and a metal organic compound, and a solvent to prepare a slurry; a coating film formation step of applying the slurry obtained in the slurry preparation step to a substrate and drying the substrate to form a coating film; and a zirconium carbide film formation step of performing a photoreaction or a thermal reaction on the coating film obtained in the coating film formation step to form a zirconium carbide film.
<16> In the method for producing a zirconium carbide film according to the above item <15>, a flash lamp or an ultraviolet laser may be used for the photoreaction.
<17> In the method for producing a zirconium carbide film according to the above item <15> or <16>, the zirconium carbide may be zirconium carbide powder made of zirconium carbide represented by the general formula ZrC _x1 (wherein x1 is 0.5 or more and 2.0 or less), and the zirconium carbide powder may have an average particle size of 0.2 μm to 15 μm and a specific surface area of 0.5 m ² /g to 20 m ² /g.
<18> In the method for producing a zirconium carbide film according to the above item <17>, the x1 may be 0.6 or more and 1.8 or less, the average particle size may be 1 μm to 10 μm, and the specific surface area may be 2 m ² /g to 15 m ² /g.
<19> A zirconium carbide powder according to one aspect of the present invention is a zirconium carbide powder made of zirconium carbide represented by the general formula ZrC _x1 (wherein x1 is 0.5 or more and 2.0 or less), and the zirconium carbide powder may have an average particle size of 0.2 μm to 15 μm and a specific surface area of 0.5 m ² /g to 20 m ² /g.
<20> In the zirconium carbide powder according to the above item <19>, the x1 may be 0.6 or more and 1.8 or less, the average particle size may be 1 μm to 10 μm, and the specific surface area may be 2 m ² /g to 15 m ² /g.

The above aspects of the present disclosure make it possible to provide zirconium carbide films, zirconium carbide substrates, zirconium carbide powders, resistors, heat-generating components, and methods for manufacturing the same that are inexpensive, exhibit little change in resistance over a wide temperature range from low to high, have excellent weather resistance, and have excellent photothermal conversion performance.

FIG. 2 is a diagram showing the results of XRD measurement of the zirconium carbide film of Example 1. FIG. 10 is a diagram showing the results of XRD measurement of the zirconium carbide film of Example 3. FIG. 2 is a view showing a SEM photograph of the surface of the zirconium carbide film of Example 1. FIG. 10 is a view showing a surface SEM photograph of the zirconium carbide film of Example 3. FIG. 1 is a diagram showing the resistance value of the zirconium carbide film of Example 1 normalized at room temperature.

<Zirconium carbide substrate>
The zirconium carbide substrate according to this embodiment includes a substrate and a zirconium carbide film formed on the substrate. The phrase "formed on the substrate" refers not only to a case where a zirconium carbide film is formed on the substrate so as to be in direct contact with the substrate, but also to a case where an intermediate layer such as a plating layer is provided on the substrate and the zirconium carbide film is formed on the intermediate layer. In this specification, numerical ranges expressed using "to" refer to a range that includes the numerical values before and after "to" as the lower and upper limits. Numerical values indicated as "less than" and "more than" do not include the value in the numerical range.

(substrate)
The substrate is not particularly limited as long as it can form the zirconium carbide film according to this embodiment. Materials for the substrate include, but are not limited to, alumina, zirconia, quartz glass, low-temperature fired multilayer ceramic substrates, borosilicate glass, polyimide, polyacrylonitrile, polystyrene, liquid crystal polymer (LCP), polyetherimide (PEI), and the like. Furthermore, from the viewpoint of cost and application, polyethylene, polypropylene, ABS resin, polyvinyl chloride, vinyl chloride resin, acrylic resin, methacrylic resin, PVA resin, polyvinyl alcohol, polyvinylidene fluoride, nylon 6 (polyamide), engineering plastics, acetal resin, polyacetal, polyamide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyethylene naphthalate, phenolic resin, urea resin, melamine resin, unsaturated polyester, polyurethane, urethane resin, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, fluorinated resin copolymer, and the like, which can be formed at low temperatures, are preferred. Resin substrates are particularly preferred as substrates in order to alleviate stress caused by temperature changes from low to high. Polyimide is particularly preferred as a resin substrate. The substrate is preferably one of alumina, zirconia, low-temperature fired multilayer ceramic substrates, liquid crystal polymers, and polyethylene naphthalate. Plating, electrodes, or an insulating layer may be provided on the substrate surface depending on the purpose. The heat-resistant temperature of the substrate is preferably 150°C or lower. The heat-resistant temperature refers to the lowest temperature at which the resin substrate undergoes deterioration or state change, such as the melting point, glass transition point, or decomposition temperature. Furthermore, it is also preferred to use a substrate directly on a metal substrate or with an insulating protective film formed thereon. The metal substrate is not particularly limited, but metals including Ti, Al, Cu, Fe, Cr, Ni, W, and Zr are preferred.

The thickness of the substrate is not particularly limited. For example, the thickness of the substrate is 50 μm to 100 mm. For stress relief, the thickness is more preferably 50 μm to 500 μm. The thickness of the substrate can be adjusted appropriately depending on the application.

(Zirconium carbide film)
The zirconium carbide film according to the present embodiment is primarily composed of zirconium carbide and contains at least one of a metal oxide, a metal, and carbon. Here, "mainly composed of zirconium carbide" means that the zirconium carbide content in the zirconium carbide film is 60% by mass or more. By incorporating zirconium carbide, a carbide with metallic conductivity that increases resistance with increasing temperature, and a metal oxide or carbon with semiconducting conductivity that decreases resistance with increasing temperature, the temperature change in resistance can be reduced over a wide temperature range. Furthermore, the zirconium carbide film according to the present embodiment does not contain large amounts of glass materials and adjusters, which are typically added to adjust the temperature coefficient of resistance, allowing for the fabrication of low-resistance resistors. Furthermore, the absence of large amounts of glass materials and adjusters prevents reactions with the metal oxide or carbon in the zirconium carbide film, thereby suppressing fluctuations in resistance at high temperatures. A small amount of glass material may be included in the film as long as it is within the acceptable range of resistance fluctuation and resistance.

Furthermore, the zirconium carbide film according to this embodiment is primarily composed of zirconium carbide and contains at least one of a metal oxide, a metal, and carbon, and therefore has high weather resistance. Additionally, when a zirconium carbide film is formed on a substrate, the primary component is zirconium carbide, so that the temperature of the zirconium carbide film can be increased by 20°C or more compared to the substrate when irradiated with light at 1800 W/m² or ^more . This makes it possible to control light-induced heat generation in devices and components where heat generation due to electrical current is a problem, and to control heat generation due to sunlight both indoors and outdoors.

"Zirconium carbide"
The main component of the zirconium carbide film according to this embodiment is zirconium carbide, represented by ZrC _x0 . Here, x0 in the general formula ZrC _x0 satisfies 0.5≦x0≦2.0. By using ZrC _x0 as the main component, the balance between the decrease in resistance due to temperature rise in metal oxide or carbon and the increase in resistance due to temperature rise in zirconium carbide can be well adjusted, thereby suppressing fluctuations in resistance. Furthermore, compared to oxides, zirconium carbide has the characteristic of suppressing surface adsorption and oxidation reactions. The zirconium carbide film according to this embodiment may contain zirconium oxide (ZrO ₂ ). Zirconium oxide may be present on the surface or inside the zirconium carbide film.

The zirconium carbide content in the zirconium carbide film according to this embodiment is preferably 60% to 98% by mass. A more preferred content is 75% to 90% by mass.

"Metal oxides"
The metal oxide may be a conductive oxide that exhibits metallic electrical conductivity to semiconducting conductivity. By using a conductive oxide that exhibits metallic electrical conductivity to semiconducting conductivity, fluctuations in resistance value can be suppressed. The metal oxide is preferably one or more selected from the group consisting of tin oxide, indium oxide, ruthenium oxide, zinc oxide, titanium oxide, and perovskite oxide. Tin oxide, indium oxide, ruthenium oxide, zinc oxide, titanium oxide, and perovskite oxide are stable to oxidation over a wide temperature range, and are therefore preferred from the perspective of long-term stability.

When the metal oxide is a perovskite oxide, it is preferably an oxide represented by A _1-x D _x EO _y . Here, A is any one of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; D is any one of Sr, Ca, and Ba; E is any one of Mn, Fe, and Ni; x satisfies the following formula (3); and y satisfies the following formula (4). A may have a deficiency compared to the stoichiometric composition. When the metal oxide is represented by A _1-x D _x EO _y , it is preferable because it has excellent high-temperature stability.
0≦x≦1 (3)
2.65<y<3.05...(4)

When using the zirconium carbide film according to this embodiment as a photothermal conversion material, zirconium carbide doped with Ti, B, or the like can also be used. It is particularly preferable to mix or laminate it with a material with low thermal conductivity, specifically a material with a thermal conductivity of 3 (W/mK) or less. It is even more preferable to use a material with a thermal conductivity of 1 (W/mK) or less. Specifically, a metal oxide with low thermal conductivity and high light absorption can be used. Examples of such oxides include zirconium oxide.

It is also preferable to form a zirconium carbide film on a resin with low thermal conductivity. From the perspective of outdoor applications, film formation on a fluorine-containing resin is preferred, such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, and fluorinated resin copolymers. When coating a metal material, the zirconium carbide film of this embodiment can be formed after coating glass or resin, thereby improving light-to-heat conversion efficiency. It is also possible to coat wood with low thermal conductivity. Examples of wood include cypress, cedar, and Japanese pine. It is effective to layer these materials with low thermal conductivity, but small amounts may also be included in the zirconium carbide film.

The metal oxide is preferably present on the surface and inside of the zirconium carbide film. More preferably, in addition to the presence of a metal oxide inside the zirconium carbide film of this embodiment, a metal oxide layer made of the metal oxide is preferably formed on the surface. The presence of a metal oxide on the surface and inside of the zirconium carbide film can suppress fluctuations in resistance value and also prevent oxidation of the zirconium carbide film.

The thickness of the metal oxide layer is preferably 1 nm to 100 μm. The more preferred thickness of the metal oxide film is 1 nm to 1 μm. The even more preferred thickness of the metal oxide layer is 10 nm to 500 nm.

In order to precisely control the conductivity of the film, the metal oxide present inside the zirconium carbide film is preferably present in the form of fine particles. When the metal oxide is in the form of fine particles, the average particle size of the metal oxide is preferably 5 nm to 1 μm. The more preferred average particle size of the metal oxide is 5 nm to 0.2 μm. The even more preferred average particle size of the metal oxide is 5 nm to 50 nm.

The metal oxide content in the zirconium carbide film according to this embodiment is preferably 1% to 35% by mass. A more preferred content is 8% to 25% by mass.

"carbon"
The carbon contained in the zirconium carbide film according to this embodiment is conductive carbon. By using conductive carbon, it is possible to suppress changes in resistance value due to temperature rise. The conductive carbon is not particularly limited, but it is possible to control the resistance value using carbon with different conductivity, such as Ketjen Black, acetylene black, graphite, and carbon nanotubes.

The carbon content in the zirconium carbide film according to this embodiment is preferably 1% to 10% by mass. A more preferred content is 2% to 5% by mass.

"metal"
The zirconium carbide film according to this embodiment may further contain a metal such as Ni, Ag, Cu, Pd, Sn, In, Ru, Ti, or Cr. The metal contained in the zirconium carbide according to this embodiment is preferably one or more selected from the group consisting of Ni, Ag, Cu, Pd, Sn, In, Ru, Ti, and Cr. The resistance value can be adjusted by containing a metal such as Ni, Ag, Cu, Pd, Sn, In, Ru, Ti, or Cr.

The metal in the zirconium carbide film according to this embodiment is preferably in the form of fine particles to prevent metal particles from coming into contact with each other and exhibiting metallic conductivity as conductive paths in the film. The particle size of these fine particles is 5 nm to 1 μm. The average particle size of the metal fine particles is more preferably 5 nm to 0.2 μm. The average particle size is even more preferably 5 nm to 50 nm. Furthermore, from the standpoint of flexibility, nanowires are preferred. The average particle size in the zirconium carbide film can be confirmed by observation using a scanning electron microscope (SEM).

The zirconium carbide, metal oxide, and carbon in the zirconium carbide film according to this embodiment can be measured, for example, by transmission electron microscopy (TEM) or energy dispersive X-ray spectroscopy (EDX) in a cross section of the zirconium carbide film. The zirconium carbide film according to this embodiment is characterized by a gradient structure in which the crystal grains change from large to small from the film surface toward the substrate.

"Thickness of zirconium carbide film"
The thickness of the zirconium carbide film according to this embodiment is preferably 0.05 μm to 10 μm, and more preferably 0.5 μm to 5 μm.

"Sheet resistance"
The sheet resistance of the zirconium carbide film according to this embodiment is not particularly limited. For high-resistance applications, the sheet resistance of the zirconium carbide film may be greater than 1000 Ω/□ at room temperature (20°C to 30°C). For low-resistance applications, the sheet resistance of the zirconium carbide film according to this embodiment may be 1000 Ω/□ or less at room temperature (20°C to 30°C).

The sheet resistance of the zirconium carbide film according to this embodiment can be measured, for example, by the following method. A silver paste is applied to the zirconium carbide film, which is then dried at 100°C for 20 minutes to create a four-terminal electrode. After the electrode is created, the sheet resistance is measured at each temperature using the DC four-terminal method (for example, a DC current of 3 mA). The measurement temperature range is, for example, between 25°C and 250°C. The measurement temperature interval can be adjusted to a range that confirms that the sheet resistance is within the specified range within the temperature range of 25°C to 250°C.

"Average temperature coefficient of resistance"
The zirconium carbide film according to this embodiment preferably has an average temperature coefficient of resistance of 500 ppm/K or less in the temperature range of 25°C to 250°C.

The average temperature coefficient of resistance of the zirconium carbide film according to this embodiment can be measured by the following method. For example, a silver paste is applied to the zirconium carbide film, which is then dried at 100°C for 20 minutes to create a four-terminal electrode. After the electrode is created, the sheet resistance at each temperature is measured using a DC four-terminal method (for example, a DC current of 3 mA). The average temperature coefficient of resistance can be calculated from the obtained sheet resistance. The measurement temperature range is, for example, 25°C to 250°C. The measurement temperature interval can be adjusted within a range that confirms that the average temperature coefficient of resistance is 500 ppm/K or less within the temperature range of 25°C to 250°C.

<Method of manufacturing zirconium carbide film>
A method for producing a zirconium carbide film according to this embodiment will be described. Note that the following production method is an example of a method for producing a zirconium carbide film according to this embodiment, and is not limited to this production method. The production method according to this embodiment includes a slurry preparation step of mixing zirconium carbide, at least one carbon material and metal organic compound, and a solvent to prepare a slurry; a coating film formation step of applying the slurry obtained in the slurry preparation step to a substrate and drying it to form a coating film; and a zirconium carbide film formation step of forming a zirconium carbide film by subjecting the coating film obtained in the coating film formation step to a photoreaction or thermal reaction. The metal organic compound in the coating film becomes carbon and an oxide through the photoreaction or thermal reaction, and forms covalent bonds with powdered ZrC, the metal oxide, and carbon to form a zirconium carbide film.

(Slurry preparation process)
In the slurry preparation step, zirconium carbide, at least one carbon material and at least one metal organic compound, and a solvent are mixed together to prepare a slurry.

"Zirconium carbide"
The zirconium carbide is preferably zirconium carbide represented by the general formula ZrC _x1 . Here, x1 in ZrC _x1 satisfies 0.5≦x1≦2.0. That is, x1 in the formula is 0.5 or more and 2.0 or less. x1 is preferably 0.6 or more. x1 is more preferably 0.7 or more. Furthermore, it is even more preferably 0.8 or more. Particularly preferably, x1 is 0.9 or more. Furthermore, it is especially preferably 1.0 or more. x1 is preferably 1.8 or less, more preferably 1.6 or less, even more preferably 1.5 or less, particularly preferably 1.4 or less, especially preferably 1.3 or less, and especially preferably 1.2 or less.

It is preferable to carry out a reduction treatment to reduce the oxides on the surface of the zirconium carbide. The reduction treatment is preferably carried out for 1 hour at 1000° C. in an atmosphere of 1% H ₂ and 99% Ar. By carrying out the reduction treatment, the amount of zirconium oxide in the zirconium carbide film can be reduced.

Zirconium carbide may contain hafnium as an inevitable impurity. The molar ratio of hafnium to zirconium (Hf/Zr) is, for example, 0.01 to 0.05.

The zirconium carbide is preferably in powder form. When the zirconium carbide is in powder form (hereinafter sometimes referred to as zirconium carbide powder), the average particle size of the zirconium carbide powder is preferably 0.2 μm or more and 15 μm or less. The lower limit of the average particle size of the zirconium carbide powder is preferably 0.2 μm or more, more preferably 0.5 μm or more, even more preferably 1 μm or more, and particularly preferably 2 μm or more. The upper limit of the average particle size of the zirconium carbide powder is preferably 12 μm or less, more preferably 10 μm or less, even more preferably 8 μm or less, and particularly preferably 6 μm or less. When the average particle size of the zirconium carbide powder is 0.2 μm or more and 15 μm or less, it is easy to form a zirconium carbide film having the desired properties. The average particle size of the zirconium carbide powder can be measured on a volume basis by laser diffraction. The average particle size is the particle size _D50 corresponding to a cumulative 50% value from the minimum particle size value.

The specific surface area of the zirconium carbide powder is preferably 0.5 m ² /g or more and 20 m ² /g or less. The specific surface area of the zirconium carbide powder is preferably 1 m ² /g or more, more preferably 1.5 m ² /g or more, even more preferably 2 m ² /g or more, and particularly preferably 2.3 m ² /g or more. The specific surface area of the zirconium carbide powder is preferably 18 m ² /g or less, more preferably 15 m ² /g or less, even more preferably 13 m ² /g or less, and particularly preferably 12 m ² /g or less. When the specific surface area is 0.5 ^{m 2} /g or more and 20 m ² /g or less, the zirconium carbide powder is likely to form a zirconium carbide film having the desired properties. The specific surface area of the zirconium carbide powder can be measured by the BET method using a specific surface area meter.

To form the zirconium carbide film of the present invention, it is preferable that the zirconium carbide powder satisfy both the average particle size and specific surface area requirements.

The zirconium carbide content in the slurry is preferably 50% to 95% by mass. The more preferred zirconium carbide content is 75% to 90% by mass.

The zirconium carbide powder according to this embodiment can preferably be obtained by obtaining an ingot by a melting method (electrofusion method) and then finely pulverizing the ingot. Specifically, the zirconium carbide ingot and powder can preferably be produced by the method for producing zirconium carbide ingot and powder disclosed in Japanese Patent No. 5,896,968. A more detailed method for fine pulverization is to disperse the zirconium carbide in a dispersion medium such as pure water to form a slurry, which is then wet-pulverized. After wet pulverization, the resulting mixture can be dried and passed through a sieve to remove coarse particles, thereby obtaining zirconium carbide powder.

"Organometallic compound"
Examples of the metal organic compound include metal organic acid salts, β-diketonates, metal alkoxides, metal acetates, metal 2-ethylhexanoates, metal acetylacetonates, metal naphthenates, and silane coupling agents. Any metal organic compound that dissolves in a solvent can be used without any particular limitation.

The metal in the metal organic compound is preferably one that produces a substance that provides conductivity through a photoreaction or thermal reaction. Examples of metals in metal organic compounds that are preferred include Cu, Ni, Fe, Ag, Pd, Ru, Sn, In, Ti, Cr, V, Mn, Sn, and Zn. From the standpoints of film adhesion, electrical resistance, temperature coefficient of resistance, and photothermal conversion performance, metals in metal organic compounds are preferably Ti, Cr, V, Mn, Sn, and Zn.

The metal oxide content in the slurry is preferably 4% to 44% by mass. A more preferred metal oxide content is 10% to 25% by mass.

"Carbon material"
Examples of the carbon material in the slurry include carbon black, carbon nanotubes, etc. Examples of carbon black include acetylene black, furnace black, ketjen black, etc. By adding the carbon material to the slurry, carbon can be introduced into the zirconium carbide film.

The average particle size of the carbon material is preferably 0.2 μm to 5 μm. The average particle size of the metal microparticles is preferably 0.2 μm to 2 μm. The average particle size of the carbon material is measured by laser diffraction.

The carbon material content in the slurry is preferably 1% to 5% by mass. A more preferred carbon material content is 2% to 5% by mass.

"solvent"
The solvent in the slurry is not particularly limited as long as it dissolves the metal organic compound, but methanol, ethanol, propanol, butanol, hexanol, heptanol, ethyl acetate, butyl acetate, toluene, xylene, benzene, acetylacetonate, ethylene glycol, water, etc. are preferred.

"Other ingredients"
The slurry may contain other components such as metals, such as Ni, Ag, Cu, Pd, Sn, In, Ru, Ti, and Cr. The other components are preferably at least one selected from the group consisting of Ni, Ag, Cu, Pd, Sn, In, Ru, Ti, and Cr. The resistance of the zirconium carbide film can be adjusted by adding metals, such as Ni, Ag, Cu, Pd, Sn, In, Ru, Ti, and Cr, to the slurry. The shape of the metal is not particularly limited, but granular is preferred. Compounds containing metals that are insoluble in solvents, such as solid materials such as metal oleates and metal stearates, can also be used.

When the metal is in the form of particles, the average particle size of the metal particles is preferably 0.2 μm to 5 μm. The preferred average particle size of the metal particles is 0.2 μm to 2 μm. The average particle size of the metal particles is measured by laser diffraction.

The metal content in the slurry is preferably 0% to 50% by mass. A more preferred metal content is 0% to 30% by mass.

The method for mixing these raw materials is not particularly limited. Examples of mixing methods include mixing in a mortar, or using a planetary ball mill, bead mill, hammer mill, jet mill, or roller mill. From the perspective of achieving high crystallization, it is preferable to uniformly micronize the raw materials (to nanosize) when preparing the slurry.

(Coating film forming process)
In the coating film forming step, the slurry obtained in the slurry preparation step is applied to a substrate and dried to form a coating film.

(substrate)
The substrate is not particularly limited as long as it can form the zirconium carbide film according to this embodiment. Materials for the substrate include, but are not limited to, alumina, zirconia, quartz glass, low-temperature fired multilayer ceramic substrates, borosilicate glass, polyimide, polyacrylonitrile, polystyrene, liquid crystal polymer (LCP), polyetherimide (PEI), and the like. From the standpoint of cost and application, materials that allow low-temperature film formation, such as polyethylene, polypropylene, ABS resin, polyvinyl chloride, vinyl chloride resin, acrylic resin, methacrylic resin, PVA resin, polyvinyl alcohol, polyvinylidene fluoride, nylon 6 (polyamide), engineering plastics, acetal resin, polyacetal, polyamide, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, polyethylene naphthalate, phenolic resin, urea resin, melamine resin, unsaturated polyester, polyurethane, and urethane resin, are preferred. Resin substrates are particularly preferred for their ability to mitigate stress caused by temperature changes from low to high temperatures. Polyimide is particularly preferred as a resin substrate. For applications requiring heat dissipation, the substrate is preferably made of ceramics or metal with high heat dissipation properties. The substrate is preferably one of alumina, zirconia, low-temperature fired multilayer ceramic substrate, liquid crystal polymer, and polyethylene naphthalate. Depending on the purpose, an electrode or an insulating layer formed by plating, printing, inkjet, or the like may be provided on the substrate surface. Furthermore, it is also preferable to use a substrate formed directly on a metal substrate or on which an insulating protective film is formed. The metal substrate is not particularly limited, but metals including Ti, Al, Cu, Fe, Cr, Ni, W, and Zr are preferred.

The method for applying the slurry is not particularly limited. Examples of methods for applying the slurry include an applicator method, a blade coating method, a gravure coating method, a spray coating method, a spin coating method, and a brush coating method.

The thickness of the slurry applied is preferably 0.2 μm to 5 μm. If the thickness of the slurry applied exceeds 5 μm, cracks may occur when the slurry dries. If the thickness of the slurry applied is less than 0.2 μm, the coating film may not be formed uniformly over the entire substrate.

There are no particular limitations on the drying conditions, as long as they allow the solvent in the slurry to evaporate. For example, drying can be performed at 100°C for 10 minutes.

In the coating film formation process, the slurry application and drying may be repeated multiple times to build up the coating film.

(Zirconium carbide film forming process)
In the zirconium carbide film forming step, a zirconium carbide film is formed by subjecting the coating film obtained in the coating film forming step to a photoreaction or thermal reaction. When forming the zirconium carbide film by a photoreaction, it is preferable to use a flash lamp or ultraviolet laser. When forming the zirconium carbide film by a thermal reaction, it is preferable to perform firing at a temperature range of 300°C to 1100°C. In order to control the resistance value of the zirconium carbide film, a firing step in an inert gas atmosphere is effective. When forming a zirconium carbide film on a resin substrate, it is particularly preferable to use a photoreaction. Due to the characteristics of the manufacturing method, the molten and solidified product may contain a small amount of semi-molten and solidified product.

When forming a zirconium carbide film by photoreaction, the coating film is irradiated with light (e.g., ultraviolet light). A laser light source or a lamp light source can be used as the light source for the photoreaction. Zirconium carbide films formed by photoreaction are characterized by a gradient structure in which the crystal grains change from large to small from the film surface toward the substrate. Light irradiation can form a gradient structure film in which the crystal grains change from large to small from the substrate side toward the film surface. The laser light source can be an excimer laser or a higher harmonic of a semiconductor laser selected from ArF, KrF, XeCl, XeF, or _F2 . Effective lamp light sources include a xenon flash lamp, a mercury lamp, a metal halide lamp, and an excimer lamp. Furthermore, light irradiation is preferably performed in the atmosphere at room temperature (20°C to 30°C). Laser irradiation can densify and crystallize the zirconium carbide film, and a wide range of substrates, such as glass and film, can be used. When flash lamp irradiation is used, zirconium oxide contained in the raw material can be converted to zirconium carbide through a photoreaction, which is effective in controlling the resistance value and density of the film. UV irradiation can also be performed after or while baking the substrate at a temperature that does not cause thermal deformation of the substrate. If necessary, UV irradiation in a vacuum chamber is also effective in terms of controlling the resistance value.

The zirconium carbide film, zirconium carbide substrate, and method for manufacturing a zirconium carbide film according to this embodiment have been described in detail above. Furthermore, within the spirit of the present invention, the components in the above embodiment may be replaced with known components as appropriate, and the above-described modifications may also be combined as appropriate. The zirconium carbide film and zirconium carbide substrate according to this embodiment can be used in resistors. Furthermore, the zirconium carbide film and zirconium carbide substrate according to this embodiment can be used in heat-generating components. Heat-generating components using the zirconium carbide film according to this embodiment can use both solar heating and electric current heating.

Next, an example of the present invention will be described. However, the conditions in the example are merely an example of conditions adopted to confirm the feasibility and effectiveness of the present invention, and the present invention is not limited to these examples. Various conditions may be adopted in the present invention as long as they do not deviate from the gist of the present invention and achieve the objectives of the present invention.

Example 1
Zirconium carbide powder (ZrC _x ) (x = 1.1, particle size 2.5 μm, specific surface area 11.2 m ² /g, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was reduced at 1000 ° C (H ₂ : 1%, Ar: 99%). 0.3 g of the reduced zirconium carbide powder, 1 ml of Ru organic compound solution (Ru 6%, isobutanol, Daiken Chemical), and 1 ml of toluene (special grade, manufactured by Wako Pure Chemical Industries) were placed in a planetary mill container, and a planetary mill (Nagao System Planet) was used to prepare a slurry at 600 rpm for 15 minutes. The prepared slurry was applied to a polyimide substrate (thickness 125 μm), dried at 100 ° C for 10 minutes, and then coated with another slurry, dried at 100 ° C for 10 minutes, and laminated to a two-layer structure (thickness 1.8 μm). The laminated film was irradiated with light from a flash lamp (manufactured by NovaCentrix) at a pulse width of 1000 μsec and irradiation energy of 6.34 J/cm ² to obtain the zirconium carbide film of Example 1.

Example 2
The same operation as in Example 1 was carried out except that the irradiation energy was changed to 8.29 J/cm ² to obtain a zirconium carbide film of Example 2.

Example 3
Zirconium carbide powder (ZrC _x ) (x = 1.1, particle size 2.5 μm, specific surface area 11.2 m ² /g, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was reduced at 1000 ° C (H ₂ : 1%, Ar: 99%). 0.3 g of the reduced zirconium carbide powder, 1 ml of Ru organic compound solution (Ru 6%, isobutanol, Daiken Chemical), and 1 ml of toluene (special grade, manufactured by Wako Pure Chemical Industries) were placed in a planetary mill container, and a planetary mill (Nagao System Planet) was used to prepare a slurry at 600 rpm for 15 minutes. The prepared slurry was applied to a polyimide substrate (thickness 125 μm), dried at 100 ° C for 10 minutes, and then coated with another slurry, dried at 100 ° C for 10 minutes, and laminated to a two-layer structure (thickness 1.8 μm). The laminated film was irradiated with light from a flash lamp (manufactured by NovaCentrix) at a pulse width of 1000 μsec and irradiation energy of 2.31 J/cm ² to obtain a zirconium carbide film of Example 3.

Example 4
Zirconium carbide powder (ZrC _x ) (x = 1.1, particle size 2.5 μm, specific surface area 11.2 m ² /g, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was reduced (H ₂ : 1%, Ar: 99%) at 1000°C. 0.3 g of the reduced zirconium carbide powder, 0.015 g of carbon black (manufactured by Alfa Alsar), 1 ml of Ru organic compound solution (Ru 6%, isobutanol) (Daiken Chemical Co., Ltd.), and 1 ml of toluene (special grade, manufactured by Wako Pure Chemical Industries Co., Ltd.) were placed in a planetary mill container and milled at 600 rpm for 15 minutes using a planetary mill (Nagao Systems Planet) to produce a slurry. The resulting slurry was applied to a polyimide substrate (125 μm thick) and dried at 100° C. for 10 minutes. The slurry was then applied again and dried at 100° C. for 10 minutes to form a two-layer laminate (1.8 μm thick). The laminated film was irradiated with a flash lamp (manufactured by NovaCentrix) at a pulse width of 1000 μs and an irradiation energy of 2.31 J/ ^cm2 , yielding the zirconium carbide film of Example 4.

Example 5
The same procedure as in Example 4 was carried out except that the irradiation energy was changed to 8.29 J/cm ² to obtain a zirconium carbide film of Example 5.

Example 6
The same operation as in Example 4 was carried out except that the irradiation energy was changed to 10.93 J/cm ² to obtain a zirconium carbide film of Example 6.

Example 7
The same operation as in Example 4 was carried out except that the irradiation energy was changed to 4.71 J/cm ² to obtain a zirconium carbide film of Example 7.

(Example 8)
The same procedure as in Example 4 was carried out except that the irradiation energy was changed to 6.34 J/cm ² to obtain a zirconium carbide film of Example 8.

Example 9
The same operation as in Example 3 was carried out except that the irradiation energy was changed to 4.71 J/cm ² to obtain a zirconium carbide film of Example 9.

Example 10
Zirconium carbide powder (ZrC _x ) (x = 1.1, particle size 2.5 μm, specific surface area 11.2 m ² /g, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was reduced at 1000°C (H ₂ : 1%, Ar: 99%). 0.3 g of the reduced zirconium carbide powder, 0.015 g of carbon black (manufactured by Alfa Alsar), 1 ml of Ru organic compound solution (Ru 6%, isobutanol, Daiken Chemical), 0.093 g of Ag, and 1 ml of toluene (special grade, manufactured by Wako Pure Chemical Industries) were placed in a planetary mill container and milled at 600 rpm for 15 minutes using a planetary mill (Nagao Systems Planet). The resulting slurry was applied to a polyimide substrate (thickness 75 μm) and dried at 100°C for 10 minutes. The thickness of one layer was 0.9 μm. The film was then irradiated with KrF laser light (COMPEX110 manufactured by COHERENT) at room temperature, 50 Hz, and 50 mJ/ ^cm² to decompose the organic components. The slurry was applied to the laminated film after laser irradiation under the same conditions and dried at 100°C for 10 minutes. The dried laminated film was irradiated with KrF laser light (COMPEX110 manufactured by COHERENT) at room temperature, 50 Hz, and 50 mJ/ ^cm² , and then irradiated with 50 Hz and 70 mJ/ ^cm² to obtain the zirconium carbide film of Example 10.

Example 11
0.3 g of zirconium carbide powder (ZrC _x ) (x = 1.1, particle size 2.5 μm, specific surface area 11.2 m ² /g, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), 0.03 g of carbon black (manufactured by Alfa Alsar), and 2 ml of isopropyl alcohol (special grade, manufactured by Wako Pure Chemical Industries Co., Ltd.) were placed in a planetary mill container, and a planetary mill (Nagao Systems Planet) was used to prepare a slurry at 600 rpm for 15 minutes. The prepared slurry was applied to a Si ₃ N ₄ substrate (thickness 0.32 mm) and dried at 100 ° C for 10 minutes. The slurry application and drying were repeated under the same conditions, resulting in a total of two layers (thickness 1.8 μm). The obtained laminated film was fired at 300 ° C for 10 minutes to obtain the zirconium carbide film of Example 11.

Example 12
The same treatment as in Example 11 was carried out except that the firing temperature was set to 400° C., to obtain a zirconium carbide film of Example 12.

Example 13
Zirconium carbide powder (ZrC _x ) (x = 1.1, particle size 2.5 μm, specific surface area 11.2 m ² /g, manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.) was reduced at 1000°C (H ₂ : 1%, Ar: 99%). 0.3 g of the reduced zirconium carbide powder, 0.015 g of carbon black (manufactured by Alfa Alsar), 1 ml of Ru organic compound solution (Ru 6%, isobutanol, Daiken Chemical), and 1 ml of toluene (special grade, manufactured by Wako Pure Chemical Industries) were placed in a planetary mill container and milled at 600 rpm for 15 minutes using a planetary mill (Nagao Systems Planet). The resulting slurry was applied to a polyimide substrate (75 μm thick) and dried at 100°C for 10 minutes. The slurry application and drying were repeated under the same conditions, resulting in a total of two layers (1.8 μm thick). The laminated film was irradiated with KrF laser light (COMPEX110 manufactured by COHERENT) at room temperature, 50 Hz, and 70 mJ/cm ² to obtain a zirconium carbide film of Example 13.

Example 14
A zirconium carbide film of Example 14 was obtained by carrying out the same treatment as in Example 10, except that the substrate was changed from polyimide to Si ₃ N ₄ and baking was carried out at 300° C. for 10 minutes instead of laser irradiation.

Example 15
The zirconium carbide powder (ZrC _x ) was changed to one with x = 1.2, particle size 5.0 μm, and specific surface area 2.3 m ² /g (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), and the same treatment as in Example 1 was carried out. During the formation of the laminated film, the laminated film was irradiated with a flash lamp (manufactured by NovaCentrix) at a pulse width of 1000 μsec and irradiation energy of 7.11 J/cm ² to obtain the zirconium carbide film of Example 15.

Example 16
The zirconium carbide powder (ZrC _x ) was changed to one with x = 1.3, particle size 4.4 μm, and specific surface area 5.1 m ² /g (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), and the same treatment as in Example 1 was carried out. During the formation of the laminated film, the laminated film was irradiated with a flash lamp (manufactured by NovaCentrix) at a pulse width of 1000 μsec and irradiation energy of 7.11 J/cm ² to obtain the zirconium carbide film of Example 16.

(Example 17)
The zirconium carbide powder (ZrC _x ) was changed to one with x = 1.0, particle size 4.4 μm, and specific surface area 5.1 m ² /g (manufactured by Daiichi Kigenso Kagaku Kogyo Co., Ltd.), and the same treatment as in Example 1 was carried out. During the formation of the laminated film, the laminated film was irradiated with a flash lamp (manufactured by NovaCentrix) at a pulse width of 2000 μsec and irradiation energy of 12.7 J/cm ² to obtain the zirconium carbide film of Example 17.

(Measurement of average particle size of zirconium carbide powder)
The particle size of the zirconium carbide powders described in Examples 1, 3, 4, 10, 11, and 13 was measured using a laser diffraction/scattering particle size distribution analyzer "LA-950" (manufactured by Horiba, Ltd.) More specifically, 0.15 g of the sample and 40 ml of a 0.2% aqueous sodium hexametaphosphate solution were placed in a 50 ml beaker, which was then placed in the apparatus (laser diffraction/scattering particle size distribution analyzer "LA-950") for measurement.
The measurement conditions were as follows:
Dispersion conditions: ultrasonic dispersion for 2 minutes at 100 W Refractive index: 1.70-0.0i

(Measurement of specific surface area of zirconium carbide powder)
The specific surface area of the zirconium carbide powders described in Examples 1, 3, 4, 10, 11 and 13 was measured by the BET method using a specific surface area meter ("Macsorb" manufactured by Mountec).

(X-ray diffraction)
The phase of the zirconium carbide film was identified using an X-ray diffraction (XRD) (Rigaku Corporation, SmartLab). The measurement conditions were a voltage of 40 kV, a current of 30 mA, a scan rate of 4°/min, and a diffraction angle of ₁₀ to 70°. Figure 1 shows the XRD measurement results for Example 1. As shown in Figure 1, peaks attributable to ZrC were observed at 33, 38, 55, 66, and 69°. A RuO2 peak was also observed around 27°. Furthermore, a peak attributable to _ZrO2 was observed at 30° in the raw zirconium carbide powder (Figure 1). However, the XRD diffraction pattern of the zirconium carbide film of Example ₁ formed on the polyimide substrate did not contain any ZrO2 phase. This is due to the formation of the ZrC phase through a photochemical reaction between _ZrO2 and the carbon in the metal organic compound in the atmosphere. Similarly, the zirconium carbide films of Examples 2, 5, 6, 7, 15, 16, and 17 did not contain _a ZrO2 phase. On the other hand, as shown in FIG. 2, a _ZrO2 phase was confirmed in the zirconium carbide film of Example 3. Similarly, _{a ZrO2} phase was confirmed in the zirconium carbide films of Examples 4, 8, and 9. Note that a _RuO2 peak was confirmed in Examples 2 to 10, 13, 14, 15, 16, and 17. A carbon black peak was confirmed in Examples 11, 12, 16, and 17.

(Scanning electron microscope observation)
Next, the zirconium carbide film was observed using a scanning electron microscope (SEM observation). A JEOL JCM-6000 scanning electron microscope was used. An SEM image of the zirconium carbide film of Example 1 is shown in Figure 3. As shown in Figure 3, it was confirmed that a dense film was formed in the zirconium carbide film of Example 1. On the other hand, pores were confirmed in the zirconium carbide film of Example 3, which was exposed to a lower irradiation energy (Figure 4).

(Resistance measurement)
Four-terminal electrodes were prepared using silver paste on the zirconium carbide films of Examples 1 to 17 (100°C, 20 minutes), and the sheet resistance and temperature dependence of resistance were measured by the DC four-terminal method (DC current 3 mA). The measurement temperature range was 25°C to 250°C. The sheet resistance at room temperature (20°C to 30°C) is shown in Table 1. The average temperature coefficient of resistance (TCR) in the range of 25°C to 250°C for Examples 1, 2, 10, 11, 12, and 14 is shown in Table 2. The measurement results for the zirconium carbide film of Example 1 are shown in Figure 5.

As shown in Table 2, the zirconium carbide films of Examples 1, 2, 10, 11, 12, and 14, which satisfy the requirements of the present invention, tended to have low average temperature coefficients of resistance (TCR). In particular, the zirconium carbide films of Examples 1, 2, 10, 11, and 12 tended to have low average temperature coefficients of resistance (TCR). Furthermore, as shown in Figure 5, the zirconium carbide film of Example 1 showed almost no fluctuation in resistance value in the high temperature range.

(Photothermal conversion performance)
Using a solar simulator (Minakata Electric Manufacturing Co., Ltd.: XES-40S3), the film was irradiated with simulated sunlight at 1000 W/m ² or 1800 W/m ² , and the temperature of the film was measured with a thermocouple.

In the case of the zirconium carbide film of Example 13, the temperature rose from 25°C to 62°C at 1000 W/ ^m2 , and rose by 75°C at 1800 W/ ^m2 .

For the polyimide substrate, the temperature rose from 25°C to 53°C at 1000 W/ ^m2 , and 55°C at 1800 W/ ^m2 .

The zirconium carbide film of Example 13 exhibited higher photothermal conversion performance than the invention of Patent Document 4. Furthermore, the zirconium carbide film of Example 13 increased in temperature (generated heat) by 20°C or more more than the polyimide substrate when irradiated with light of 1800 W/ ^m2 .

As explained above, the zirconium carbide film according to this embodiment exhibits a sufficiently small average temperature coefficient of resistance at 250°C, a temperature at which high heat resistance materials are expected to be used, and similarly exhibits high photothermal conversion performance. Furthermore, a sintered body made of zirconium carbide alone exhibits metallic conductivity and does not have a small temperature coefficient of resistance like the zirconium carbide film according to this embodiment.

The zirconium carbide film disclosed herein makes it possible to produce low-cost resistor elements that meet the tolerance for resistivity change over the operating temperature range of semiconductors, and that are lead-free, glass-free, or contain reduced amounts of these components. In addition, because zirconium carbide films can be fabricated on resin, they are expected to be widely adopted as resistor materials for semiconductors. Furthermore, the zirconium carbide film disclosed herein can effectively convert sunlight into heat, enabling industrial applications in a variety of fields, including agriculture, plant factories, aquaculture, hot water thermal storage, and snow melting on infrastructure equipment (solar power, utility poles, roads, etc.), structures, and electric wires. Therefore, the zirconium carbide film disclosed herein has high industrial applicability.

Claims (21)

The main component is zirconium carbide,
Contains at least one of metal oxide, metal, and carbon;
A zirconium carbide film having an average temperature coefficient of resistance of 500 ppm/K or less in the temperature range of 25°C to 250°C . The zirconium carbide film of claim 1 comprising said metal. The zirconium carbide film according to claim 1, wherein zirconium oxide is present on the surface or inside of the zirconium carbide film. The zirconium carbide film according to claim 1 , wherein the metal oxide is present on the surface and in the interior of the zirconium carbide film. The zirconium carbide film according to any one of claims 1 to 4 , wherein the metal oxide is at least one selected from the group consisting of tin oxide, indium oxide, ruthenium oxide, zinc oxide, titanium oxide, and perovskite oxide. 6. The zirconium carbide film according to claim 5, wherein the perovskite oxide is represented by A _1-x D _x EO _y , wherein A is any one of Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, D is any one of Sr, Ca, and Ba, and E is any one of Mn, Fe, and Ni, and wherein x satisfies the following formula (1), and y satisfies the following formula ( 2 ):
0≦x≦1 (1)
2.65<y<3.05...(2) 7. The zirconium carbide film according to claim 1, wherein the metal is at least one selected from the group consisting of Ni, Ag, Cu, Pd, Sn, In, Ru, Ti , and Cr. 8. The zirconium carbide film according to claim 1, wherein the sheet resistance at room temperature is 1000 Ω/□ or less. The zirconium carbide film according to any one of claims 1 to 7 , having a sheet resistance of more than 1000 Ω/□ at room temperature. A substrate;
The zirconium carbide film according to any one of claims 1 to 9 formed on the substrate;
A zirconium carbide substrate comprising: 11. The zirconium carbide substrate according to claim 10 , wherein the substrate is one of alumina, zirconia, a low-temperature fired multilayer ceramic substrate, a liquid crystal polymer, and polyethylene naphthalate. 12. The zirconium carbide substrate according to claim 10 , wherein the heat-resistant temperature of the substrate is 150°C or less. A resistor comprising the zirconium carbide substrate according to any one of claims 10 to 12 . A heat generating member comprising the zirconium carbide substrate according to any one of claims 10 to 12 . The heat-generating member according to claim 14 , wherein the temperature of the zirconium carbide film is increased by 20°C or more relative to the temperature of the substrate when irradiated with light of 1800 W/ ^m2 or more. Zirconium carbide,
At least one carbon material and one or more metal organic compounds;
a slurry preparation step of mixing at least the aqueous solution and a solvent to prepare a slurry;
a coating film forming step of applying the slurry obtained in the slurry preparation step onto a substrate and drying the applied slurry to form a coating film;
a zirconium carbide film forming step of forming a zirconium carbide film by subjecting the coating film obtained in the coating film forming step to a photoreaction . The method for producing a zirconium carbide film according to claim 16 , wherein a flash lamp or an ultraviolet laser is used for the photoreaction. 18. The method for producing a zirconium carbide film according to claim 16 or 17, wherein the zirconium carbide is a zirconium carbide powder made of zirconium carbide represented by the general formula ZrC _x1 (wherein x1 is 0.5 or more and 2.0 or less), the zirconium carbide powder has an average particle size of 0.2 μm to 15 μm, and the zirconium carbide powder has a specific surface area of 0.5 m ² / g to 20 m ² /g. The x1 is 0.6 or more and 1.8 or less,
The average particle size is 1 μm to 10 μm,
19. The method for producing a zirconium carbide film according to claim 18 , wherein the specific surface area is 2 m ² /g to 15 m ² /g. A zirconium carbide powder made of zirconium carbide represented by the general formula ZrC _x1 (where x1 is 0.5 or more and 2.0 or less),
The zirconium carbide powder has an average particle size of 0.2 μm to 15 μm,
The zirconium carbide powder has a specific surface area of 0.5 m ² /g to 20 m ² /g. The x1 is 0.6 or more and 1.8 or less,
The average particle size is 1 μm to 10 μm,
21. The zirconium carbide powder according to claim 20 , wherein the specific surface area is from 2 m ² /g to 15 m ² /g.