Conductive film forming composition and use thereof

Abstract

To provide a technique capable of forming a Pt conductive film excellent in conductivity.SOLUTION: The electrically conductive film forming composition disclosed herein is an electrically conductive film forming composition for forming the Pt electrically conductive film 14 on the substrate 12. The conductive film forming composition contains Pt and a sintering control element which is at least one element selected from the group consisting of Rh, Pd, Ru, and Ir. A content ratio of the sintering control element is 2 mol% or more and less than 50 mol% when a substance amount of the Pt is 100 mol%.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a composition for forming a conductive film and use thereof. [Background technology]

[0002] Conductive film-forming compositions are widely used to form electrodes and wiring patterns in electronic components. The use of platinum (Pt) as a conductive component in such conductive film-forming compositions has been investigated. For example, Patent Documents 1 to 3 listed below disclose conductive film-forming compositions containing Pt. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-214202 [Patent Document 2] Japanese Patent Application Publication No. 8-176177 [Patent Document 3] Japanese Patent Application Publication No. 10-212442 Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, there has been an increasing demand for higher performance electronic components, and Pt conductive films are also required to have excellent conductivity.

[0005] The present disclosure has been made in view of the above circumstances, and its main purpose is to provide a technique capable of forming a Pt conductive film with excellent conductivity. [Means for solving the problem]

[0006] To achieve this object, the present disclosure provides a conductive film-forming composition for forming a Pt conductive film on a substrate. The conductive film-forming composition includes Pt and a sintering control element, which is at least one element selected from the group consisting of Rh, Pd, Ru, and Ir. The content of the sintering control element is 2 mol % or more and less than 50 mol %, where the amount of Pt is taken as 100 mol %. This conductive film-forming composition allows the formation of a Pt conductive film with excellent conductivity.

[0007] In a preferred embodiment of the conductive film-forming composition disclosed herein, the Pt content is 50 mol % or more and 90 mol % or less, when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %. This is preferable because it ensures better conductivity in the Pt conductive film that is formed.

[0008] In a preferred embodiment of the conductive film-forming composition disclosed herein, the content of the Pt is 70 mol % or more and 90 mol % or less, when the total amount of substance of the metal components contained in the conductive film-forming composition is 100 mol %, and the content of the sintering control element is 5 mol % or more and 35 mol % or less, when the amount of substance of the Pt is 100 mol %. This configuration is preferable because it can ensure better conductivity in the Pt conductive film that is formed.

[0009] In a preferred embodiment of the conductive film-forming composition disclosed herein, the sintering control element includes Rh, and the content of Rh is 2 mol % or more and 10 mol % or less when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %. With this configuration, the effects of the technology disclosed herein can be realized at a higher level.

[0010] In a preferred embodiment of the conductive film-forming composition disclosed herein, the sintering control element includes Pd, and the Pd content is 8 mol % or more and 20 mol % or less when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %. With this configuration, the effects of the technology disclosed herein can be achieved at a higher level.

[0011] In a preferred embodiment, the conductive film-forming composition disclosed herein further contains at least one matrix-forming element selected from the group consisting of Si, Bi, Ti, Al, and Zn. This configuration is preferred because it provides excellent adhesion between the Pt conductive film formed and the substrate.

[0012] In another aspect, the present disclosure provides a substrate with a Pt conductive film, the substrate including a substrate and a Pt conductive film disposed on the substrate and formed of a fired body of any of the compositions for forming a conductive film disclosed herein. Such a substrate with a Pt conductive film is preferred because it has excellent conductivity.

[0013] In a preferred embodiment of the substrate with a Pt conductive film disclosed herein, the average thickness of the Pt conductive film is 1 μm or less, and the volume resistivity of the Pt conductive film is 1×10 1 This is preferable because the Pt conductive film can be thin and have excellent conductivity. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a cross-sectional view schematically illustrating a wiring substrate according to an embodiment. [Figure 2] 1 is an FE-SEM observation image (10,000 magnifications) of the Pt conductive film according to Example 1. [Figure 3] 1 is an FE-SEM observation image (100,000 magnifications) of the Pt conductive film according to Example 1. [Figure 4] 10 is an FE-SEM observation image (10,000 magnifications) of the Pt conductive film according to Example 12. [Figure 5] 10 is an FE-SEM observation image (100,000 magnifications) of the Pt conductive film according to Example 12. [Figure 6] 10 is an FE-SEM observation image (100,000 magnifications) of a cross section of a Pt conductive film according to Example 12. DETAILED DESCRIPTION OF THE INVENTION

[0015] Preferred embodiments of the technology disclosed herein are described below. Matters other than those specifically mentioned in this specification that are necessary for implementation (e.g., a method for manufacturing a substrate onto which a conductive film-forming composition is applied) can be understood based on the technical content taught by this specification and the general technical common sense of a person skilled in the art. The technology disclosed herein can be implemented based on the content disclosed in this specification and the general technical common sense of a person skilled in the art. In this specification, the expression "A to B" indicating a range means "A or more and B or less." It also encompasses the meanings of "greater than A" and "less than B."

[0016] In this disclosure, the term "particles (fine particles)" refers to a group of many particles (fine particles) (i.e., particles), except when specifically referring to a single particle. In Japanese, it is unclear whether the term is singular or plural, so the term "particles (fine particles)" is defined as above to clarify its meaning. Furthermore, in this disclosure, the term "conductive film-forming composition" can be a concept that encompasses slurry compositions and ink compositions.

[0017] <Composition for forming conductive film> The conductive film-forming composition disclosed herein is a conductive film-forming composition for forming a Pt conductive film on a substrate. This conductive film-forming composition contains Pt and a sintering control element, which is at least one element selected from Rh, Pd, Ru, and Ir. The content of the sintering control element is characterized by being 2 mol % or more and less than 50 mol % when the amount of Pt is taken as 100 mol %. This conductive film-forming composition can form a Pt conductive film with excellent conductivity.

[0018] The inventors' investigations have revealed that, during the formation of a Pt conductive film, so-called island formation occurs, in which Pt particles are spaced apart. Such island formation is undesirable because it may prevent the formation of a Pt conductive film. Therefore, the inventors' extensive investigations have revealed that the island formation is caused by excessive Pt particle growth during firing. In contrast, the conductive film-forming composition having the above-described configuration effectively suppresses island formation, resulting in a Pt conductive film with excellent conductivity. While not intended to be limiting, the following may be the possible reasons for this effect. First, Rh, Pd, Ru, and Ir are elements that readily form oxides during firing. Furthermore, oxides of these elements exist around Pt during firing, suppressing the growth of Pt particles. This suppresses island formation due to excessive Pt particle growth. However, adding excessive amounts of these elements (hereinafter also referred to as "sintering control elements") may substantially prevent Pt particle growth, potentially resulting in reduced conductivity. For this reason, in the present disclosure, the content ratio of the sintering control element to Pt is set to 2 mol % or more and less than 50 mol %, which ensures the Pt grain growth necessary for electrical conductivity while suppressing Pt island formation due to excessive Pt grain growth, thereby obtaining a Pt conductive film with excellent electrical conductivity.

[0019] (1)Pt component Platinum (Pt) is a component for forming a Pt conductive film with high electrical conductivity (hereinafter simply referred to as "conductivity"). Pt is a major component among the elements contained in the conductive film-forming composition. The Pt content is not particularly limited as long as the effects of the technology disclosed herein are achieved. The Pt content is preferably 50 mol % or more, more preferably 60 mol % or more, even more preferably 70 mol % or more, and even more preferably 80 mol % or more, when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %. This ensures that the conductive components in the conductive film-forming composition are sufficiently contained. Furthermore, the upper limit of the Pt content is preferably 90 mol % or less, more preferably 87 mol % or less, when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %. This ensures that the proportions of sintering control elements and the like in the conductive film-forming composition are sufficiently contained. For example, when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %, a Pt content of 50 mol % to 90 mol % is preferable because it ensures excellent conductivity in the resulting Pt conductive film. The Pt content can be measured, for example, using a commercially available ICP emission spectrometer (the same applies to the content of sintering control elements and other components, as described below). Note that, in this disclosure, the term "metal component contained in the conductive film-forming composition" may refer to components contained in the conductive film-forming composition, excluding organic components containing carbon (C) (e.g., organic solvents and organic binders, as described below) and nonmetallic elements (e.g., chlorine (Cl), oxygen (O), and sulfur (S)). In other words, the term "metal component" in this disclosure may include metalloid components (metalloid elements) such as boron (B), silicon (Si), germanium (Ge), antimony (Sb), tellurium (Te), selenium (Se), and astatine (At).

[0020] (2) Sintering control elements As described above, the conductive film-forming composition disclosed herein contains a sintering control element. The sintering control element can appropriately control excessive grain growth of Pt during firing. Examples of sintering control elements include Rh, Pd, Ru, and Ir, and these may be contained alone or in combination of two or more. As described above, the conductive film-forming composition disclosed herein is characterized in that the content of the sintering control element is 2 mol% or more and less than 50 mol%, when the amount of Pt is taken as 100 mol%. By setting the total content of the sintering control elements relative to Pt within the above range, Pt island formation is suppressed, resulting in a Pt conductive film with excellent conductivity. Here, from the perspective of more suitably achieving the effects described above, the content of the sintering control element is preferably 5 mol% or more, and more preferably 6 mol% or more, when the amount of Pt is taken as 100 mol%. Furthermore, the content of the sintering control element is preferably 45 mol% or less, when the amount of Pt is taken as 100 mol%. Each sintering control element is described below.

[0021] Rhodium (Rh) is a sintering control element that can appropriately control excessive grain growth of Pt during firing. The content of Rh is not particularly limited as long as the total content of the sintering control elements satisfies the above range. The content of Rh is, for example, 1 mol % or more, preferably 2 mol % or more, more preferably 3 mol % or more, and even more preferably 4 mol % or more, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. This allows for more appropriately controlling excessive grain growth of Pt during firing. Furthermore, the upper limit of the content of Rh may be, for example, less than 50 mol % or 45 mol % or less, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. The upper limit is preferably 10 mol % or less, more preferably 9 mol % or less, or 5 mol % or less. This not only achieves the above-mentioned effects, but also ensures sufficient conductive components in the conductive film-forming composition.

[0022] Palladium (Pd) is one of the sintering control elements that can appropriately control excessive grain growth of Pt during firing. The content of Pd is not particularly limited as long as the total content of the sintering control elements satisfies the above range. The content of Pd may be, for example, 1 mol % or more, or 2 mol % or more, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. It is preferably 8 mol % or more, more preferably 9 mol % or more, and even more preferably 13 mol % or more, or 15 mol % or more. This allows for more appropriately controlling excessive grain growth of Pt during firing. Furthermore, the upper limit of the content of Pd may be, for example, less than 50 mol % or 45 mol % or less, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. It is preferably 20 mol % or less, more preferably 19 mol % or less, or 16 mol % or less. This not only achieves the above-mentioned effects, but also ensures sufficient conductive components in the conductive film-forming composition.

[0023] Ruthenium (Ru) is one of the sintering control elements that can appropriately control excessive grain growth of Pt during firing. The content of Ru is not particularly limited as long as the total content of the sintering control elements satisfies the above range. The content of Ru is preferably 1 mol % or more, more preferably 2 mol % or more, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. This allows for more appropriately controlling excessive grain growth of Pt during firing. Furthermore, the upper limit of the content of Ru may be, for example, less than 50 mol % or 45 mol % or less, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. The upper limit is preferably 10 mol % or less, more preferably 5 mol % or less. This allows for the aforementioned effects as well as sufficient conductive components to be secured in the conductive film-forming composition.

[0024] Iridium (Ir) is one of the sintering control elements that can appropriately control excessive grain growth of Pt during firing. The content of Ir is not particularly limited as long as the total content of the sintering control elements satisfies the above range. The content of Ir is preferably 1 mol % or more, more preferably 2 mol % or more, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. This allows for more appropriately controlling excessive grain growth of Pt during firing. Furthermore, the upper limit of the content of Ir may be, for example, less than 50 mol % or 45 mol % or less, when the total amount of the metal components contained in the conductive film-forming composition is taken as 100 mol %. The upper limit is preferably 10 mol % or less, more preferably 5 mol % or less. This allows for the aforementioned effects as well as sufficient conductive components to be secured in the conductive film-forming composition.

[0025] In a preferred embodiment, the content of Pt is 70 mol % or more and 90 mol % or less when the total amount of substance of the metal components contained in the conductive film-forming composition is 100 mol %, and the content of the sintering control element is 5 mol % or more and 35 mol % or less (more preferably 5 mol % or more and 10 mol % or less) when the amount of substance of Pt is 100 mol %. This configuration is preferable because it can ensure better conductivity in the Pt conductive film that is formed.

[0026] (3) Other ingredients The conductive film-forming composition disclosed herein may further contain components (other components) other than the above-mentioned components, as long as the effects of the technology disclosed herein are exhibited. Examples of other components include yttrium (Y), zirconium (Zr), samarium (Sm), calcium (Ca), barium (Ba), chromium (Cr), and tin (Sn). The content of the other components can be, for example, within a range of 1 mol % to 5 mol %, assuming that the total amount of metal components contained in the conductive film-forming composition is 100 mol %.

[0027] The conductive film-forming composition disclosed herein may further contain a conductive component other than Pt, as long as the content ratio of the sintering control element relative to Pt satisfies the above range. Examples of such conductive components include silver (Ag), gold (Au), and copper (Cu). The content ratio of such conductive component can be, for example, 1 mol % to 30 mol % (preferably 2 mol % to 20 mol %), when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %.

[0028] The conductive film-forming composition disclosed herein preferably further contains a matrix-forming element, which is at least one element selected from the group consisting of silicon (Si), bismuth (Bi), titanium (Ti), aluminum (Al), and zinc (Zn). This matrix-forming element advantageously improves the fixability (adhesion) of the Pt conductive film to the substrate, depending on the substrate to be coated (e.g., particularly glass and ceramic substrates, as described below). Examples of such matrix-forming elements include Si, Bi, Ti, Al, and Zn, and these elements may be present alone or in combination of two or more. The Si content can be, for example, 1 mol % to 10 mol % (preferably 1 mol % to 5 mol %), based on the total amount of metal components contained in the conductive film-forming composition as 100 mol %. The Bi content can be, for example, 3 mol % to 20 mol % (preferably 3 mol % to 18 mol %), based on the total amount of metal components contained in the conductive film-forming composition as 100 mol %. The Ti content can be, for example, 1 mol % to 10 mol % (preferably 1 mol % to 5 mol %) when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %. The Al content can be, for example, 1 mol % to 10 mol % (preferably 1 mol % to 5 mol %) when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %. The Zn content can be, for example, 1 mol % to 10 mol % (preferably 1 mol % to 5 mol %) when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %.

[0029] The form in which each component (specifically, Pt, a sintering control element, other components, etc.) in the conductive film-forming composition is contained is not particularly limited, as long as the effects of the technology disclosed herein are exhibited. Each component may be contained in the conductive film-forming composition in the form of, for example, a metal resinate, a metal alkoxide, a complex, a polymer, or particles (typically, fine particles). Each component may be contained in one form or in two or more forms. In a preferred embodiment, each component is contained primarily in the form of a metal resinate. For example, when each component is contained in the form of a metal resinate, it is believed that Pt island formation is likely to occur during firing. Therefore, such an embodiment can be said to be suitable for the technology disclosed herein.

[0030] Here, the metal resinate is an organic compound of metal. Any conventionally known resin material that can be used for metal resinates can be used as this organic compound, without any particular limitations. Examples of such resin materials include carboxylic acids with a high carbon number (e.g., 8 or more carbon atoms), such as octylic acid (2-ethylhexanoic acid), abietic acid, naphthenic acid, stearic acid, oleic acid, linolenic acid, and neodecanoic acid; sulfonic acids; resin acids contained in rosin; resin sulfide balsams containing essential oil components such as turpentine oil and lavender oil; alkyl mercaptides (alkylthiolates); aryl mercaptides (arylthiolates); and mercaptocarboxylic acid esters.

[0031] Although not particularly limited, it is preferable that the conductive film-forming composition be substantially free of Pt particles (Pt fine particles). This prevents the Pt conductive film from becoming thick due to aggregation of Pt particles, thereby enabling the Pt conductive film to be thinned. Pt particles refer to an aggregate of spherical, scale-like, or plate-like particles composed primarily of Pt. Although not limited thereto, the average particle diameter of such Pt particles is, for example, 0.1 μm to 1 μm. The "average particle diameter of Pt particles" refers to the particle diameter corresponding to the 50% cumulative value from the smallest particle diameter in the volume-based particle size distribution based on the laser diffraction / scattering method (D50 particle diameter). This measurement can be performed, for example, using a commercially available device, the Microtrac MT3000II manufactured by Microtrac-Bell Corporation. Furthermore, "substantially free" refers to the absence of intentionally added Pt particles. Therefore, when a component that can be interpreted as Pt particles is contained in a small amount due to raw materials, a manufacturing process, etc., this is included in the concept of "substantially free" in this specification. For example, when the entire conductive film-forming composition is taken as 100 wt%, the content of Pt particles can be said to be "substantially free" when it is 0.01 wt% or less (preferably 0.005 wt% or less, more preferably 0.001 wt% or less, even more preferably 0.0005 wt% or less, and particularly preferably 0.0001 wt% or less).

[0032] The components (elements) that may be contained in the conductive film-forming composition disclosed herein have been described above. In addition to the above-described components, the conductive film-forming composition disclosed herein preferably contains various other components in consideration of the adhesion to the substrate surface, the formability of the conductive film, and the like. Below, other components that may be contained in the conductive film-forming composition disclosed herein are described. However, the other components described below can be any conventionally known components that may be used in conductive film-forming compositions, without any particular restrictions, as long as they do not significantly impede the effects of the technology disclosed herein. In other words, the components of the conductive film-forming composition disclosed herein other than the above-described essential elements can be appropriately changed depending on the application.

[0033] The conductive film-forming composition disclosed herein preferably uses a solvent (typically, an organic solvent) that disperses or dissolves the above-mentioned components. As such an organic solvent, those that have been conventionally used in conductive film-forming compositions or those used in aqueous gold solutions can be used without any particular limitation. Examples of such organic solvents include 1,4-dioxane, 1,8-cineole, 2-pyrrolidone, 2-phenylethanol, N-methyl-2-pyrrolidone, p-tolualdehyde, benzyl benzoate, butyl benzoate, eugenol, caprolactone, geraniol, methyl salicylate, cyclohexanone, cyclohexanol, cyclopentyl methyl ether, citronellal, di(2-chloroethyl)ether, diethylene glycol monomethyl ether, diethylene glycol monobutyl ether, dihydrocarvone, dibromomethane, dimethyl sulfoxide, dimethylformamide, nitrobenzene, pyrrolidone, propylene glycol monophenyl ether, pulegone, benzyl acetate, benzyl alcohol, benzaldehyde, turpentine oil, lavender oil, etc. These organic solvents may be used alone or in combination of two or more. When using a metal resinate, for example, it is commercially available as a resinate paste, and such a resinate paste may be used as is.

[0034] The weight ratio of the organic solvent that can be contained in the conductive film-forming composition is not particularly limited, as the preferred range varies depending on the application method of the conductive film-forming composition, and can be adjusted as appropriate. For example, when the entire conductive film-forming composition is taken as 100 wt%, the content of the organic solvent may be approximately 10 wt% to 50 wt%. As an example, when applying by inkjet, the content of the organic solvent in the conductive film-forming composition is preferably, for example, 10 wt% to 50 wt%. As another example, when applying by brush, the content of the organic solvent in the conductive film-forming composition is preferably, for example, 10 wt% to 30 wt%.

[0035] The viscosity of the composition for forming a conductive film may be appropriately adjusted according to the coating method of the composition for forming a conductive film, and is not particularly limited. The viscosity of the composition for forming a conductive film can be, for example, about 10 mPa·s to 500 mPa·s. As such viscosity, for example, the value measured at 25°C using a commercially available rotational viscometer can be adopted. Note that the viscosity of the composition for forming a conductive film can be appropriately adjusted by the amount of the organic solvent, addition of an organic binder, etc.

[0036] In addition, the composition for forming a conductive film disclosed herein may optionally contain other components as long as the effects of the technology disclosed herein are not significantly impaired. Examples of the additional components include, for example, an organic binder, a protective material, a surfactant, a dispersant, a thickener, a pH adjuster, a preservative, an antifoaming agent, a plasticizer, a stabilizer, an antioxidant, etc.

[0037] <Substrate 10 with Pt conductive film> Hereinafter, an embodiment of the substrate with a Pt conductive film disclosed herein will be described. Here, FIG. 1 is a cross-sectional view schematically showing a wiring substrate according to an embodiment. As shown in FIG. 1, the substrate 10 with a Pt conductive film according to the present embodiment includes a substrate 12 and a Pt conductive film 14 disposed on the substrate 12. The Pt conductive film 14 is made of a fired body of any of the compositions for forming a conductive film disclosed herein.

[0038] As described above, according to the composition for forming a conductive film disclosed herein, a Pt conductive film 14 having excellent conductivity can be formed. Therefore, the Pt conductive film 14 made of a fired body of such a composition for forming a conductive film is preferable because it has excellent conductivity. Further, according to the composition for forming a conductive film disclosed herein, even when fired at a high temperature (for example, 500°C or higher, preferably 800°C or higher), platinum does not islandize and a Pt conductive film 14 having excellent conductivity can be formed. Hereinafter, each component will be described.

[0039] <Substrate 12> As described above, the substrate 12 is a substrate on which the Pt conductive film 14 is formed. The type of substrate 12 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. The substrate 12 is preferably made of a material that is not damaged or excessively deformed when fired at high temperatures, for example. Examples of the substrate 12 include a ceramic substrate, a glass substrate, and a semi-metallic substrate.

[0040] A ceramic substrate is a substrate primarily composed of ceramics. Here, "primarily composed of ceramics" can mean that the largest component of the ceramic substrate is ceramic. Furthermore, it can mean that, when the total mass of the ceramic substrate is taken as 100%, the ceramic substrate contains, for example, 50% or more, preferably 60% or more, and more preferably 70% or more, 80% or more, or 90% or more. Examples of such ceramics include silica (SiO), alumina (AlO), zirconia (ZrO), magnesia (MgO), titania (TiO), ceria (CeO), and yttria (YO). These may be used alone or in combination.

[0041] A glass substrate is a substrate mainly composed of a glass component. Here, "mainly composed of a glass component" can mean that the largest component of the components constituting the glass substrate is a glass component. It can also mean that when the total mass of the glass substrate is taken as 100%, the glass component is contained in an amount of, for example, 50% or more, preferably 60% or more, more preferably 70% or more, 80% or more, or 90% or more. Examples of such glass include quartz glass, soda-lime glass, and borosilicate glass. These may be contained alone or in combination of two or more.

[0042] A semimetallic substrate is a substrate mainly composed of a semimetal. Here, "composed of a semimetal" can mean that the largest component of the components constituting the semimetallic substrate is a semimetal. It can also mean that when the total mass of the semimetallic substrate is taken as 100%, it contains, for example, 50% or more, preferably 60% or more, more preferably 70% or more, 80% or more, or 90% or more of a semimetal. Examples of such semimetals include silicon (Si), boron (B), and antimony (Sb). These may be contained alone or in combination of two or more.

[0043] The thickness, shape, hardness, color, etc. of the substrate 12 can be changed as appropriate depending on the application of the Pt conductive film-coated substrate 10, and detailed description thereof will be omitted as they do not limit the technology disclosed herein. Furthermore, the substrate 12 may further include other layers (e.g., a coating layer, a conductive layer, an insulating protective layer, an anti-reflection layer, an optical adjustment layer, a moisture-proof layer, etc.) as necessary.

[0044] In a preferred embodiment, the Pt conductive film-coated substrate 10 further includes a coating layer (underlayer) on the substrate 12 for the purpose of protecting the substrate 12 and improving adhesion to the Pt conductive film 14. The coating layer may contain various additives, such as glazes, antioxidants, antistatic agents, lubricants, plasticizers, and colorants. Furthermore, for example, if the coating layer contains a matrix-forming element, the adhesion between the substrate 12 and the Pt conductive film 14 is favorably improved. Examples of such matrix-forming elements include silicon (Si), bismuth (Bi), titanium (Ti), aluminum (Al), and zinc (Zn). These elements may be contained alone or in combination. For example, if a coating layer containing a matrix-forming element is present on the substrate 12, the adhesion between the Pt conductive film 14 and the substrate 12 is favorably ensured, and therefore the conductive film-forming composition does not necessarily contain the matrix-forming element. On the other hand, if a coating layer containing a matrix-forming element is present on the substrate 12 and the conductive film-forming composition also contains a matrix-forming element, this is preferable because the adhesion between the Pt conductive film 14 and the substrate 12 is particularly well ensured.

[0045] <Pt conductive film 14> As described above, the Pt conductive film 14 is composed of a fired body of the composition for forming a conductive film disclosed herein. Therefore, the Pt conductive film 14 has excellent conductivity. Note that, as shown in FIG. 1, in the present embodiment, the Pt conductive film 14 is disposed only on one side of the substrate 12, but is not limited thereto. For example, in other embodiments, the Pt conductive film 14 may be disposed on both sides of the substrate 12. Further, as shown in FIG. 1, in the present embodiment, the Pt conductive film 14 is disposed over the entire surface of the substrate 12, but is not limited thereto. For example, in other embodiments, the Pt conductive film 14 may be disposed only on a part of the substrate 12. And the shape of the Pt conductive film 14 can be appropriately changed according to the use of the substrate 10 with the Pt conductive film.

[0046] The average film thickness of the Pt conductive film 14 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. The average film thickness of the Pt conductive film 14 is, for example, 10 μm or less, may be 5 μm or less, and from the viewpoint of being suitably used for miniaturized electronic components and the like, is preferably 1 μm or less, more preferably 500 nm or less, and particularly preferably 200 nm or less. Further, the lower limit of the average film thickness of the Pt conductive film 14 is, for example, 10 nm or more, and from the viewpoint of the ease of formation of the Pt conductive film 14, is preferably 20 nm or more, more preferably 30 nm or more. In the present disclosure, the "average film thickness of the Pt conductive film" may mean, for example, the average value when the shortest distance from the surface of the substrate on which the Pt conductive film is formed to the surface of the Pt conductive film is measured at three points. Measurement of such an average film thickness can be carried out using, for example, a commercially available electron microscope or the like.

[0047] The volume resistivity of the Pt conductive film 14 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. The volume resistivity of the Pt conductive film 14 is preferably 1×10 1 Ω·cm or less, and more preferably 1×10 -1is less than Ω·cm, more preferably 1×10 -2 is less than Ω·cm, particularly preferably 1×10 -3 is less than Ω·cm, 1×10 -4 is less than Ω·cm. The measurement of such volume resistivity can be carried out using, for example, a commercially available resistivity meter or the like.

[0048] From the above, in a preferred embodiment, in the substrate 10 with a Pt conductive film, the average thickness of the Pt conductive film 14 is 1 μm or less, and the volume resistivity of the Pt conductive film 14 is 1×10 1 is less than Ω·cm. According to such a configuration, in the Pt conductive film 14, thinning and excellent conductivity are compatible, which is preferable. Such a substrate 10 with a Pt conductive film can be suitably used for electronic components and the like. According to the composition for forming a conductive film disclosed herein, such an embodiment can be preferably realized.

[0049] The sheet resistance of the Pt conductive film 14 is not particularly limited as long as the effects of the technology disclosed herein are exhibited. From the viewpoint that the Pt conductive film 14 can be suitably used for electronic components and the like, the sheet resistance is preferably 1×10 4 is less than Ω / □, more preferably 1×10 3 is less than Ω / □, still more preferably 1×10 2 is less than Ω / □, particularly preferably 1×10 1 is less than Ω / □. The measurement of such sheet resistance can be carried out using, for example, a commercially available high resistivity meter or the like.

[0050] <Method for manufacturing a substrate with a Pt conductive film> Subsequently, an example of the method for manufacturing a substrate with a Pt conductive film disclosed herein will be described. The following description is not intended to limit the method for manufacturing a substrate with a Pt conductive film disclosed herein to this.

[0051] The method for producing a substrate with a Pt conductive film disclosed herein (i.e., a method for producing a substrate with a Pt conductive film) includes: preparing a substrate; preparing any of the compositions for forming a conductive film disclosed herein; supplying the composition for forming a conductive film onto the substrate; and firing the substrate to which the composition for forming a conductive film has been supplied. More specifically, first, a desired substrate is prepared. For example, any of the above-mentioned ceramic substrates, glass substrates, and semi-metallic substrates is prepared. Next, a composition for forming a conductive film is prepared. The composition for forming a conductive film can be prepared, for example, by combining various raw materials and, if necessary, a solvent and other components in a container, and mixing them using a stirrer or the like. At this time, it is preferable that the viscosity of the composition for forming a conductive film be adjusted within an appropriate range.

[0052] Next, a conductive film-forming composition is applied onto the prepared substrate. The method for applying the conductive film-forming composition is not particularly limited. For example, various printing methods such as spin coating, inkjet printing, brush coating, gravure printing, and screen printing can be used. The substrate onto which the conductive film-forming composition has been applied is then fired. This allows a Pt conductive film to be formed on the substrate. The firing is preferably carried out in a firing furnace at a temperature ranging from 500°C to 1200°C, more preferably from 800°C to 1000°C. The firing time is, but is not limited to, for example, from 1 minute to 60 minutes, and more preferably from 10 minutes to 30 minutes.

[0053] In this manner, a Pt conductive film-coated substrate having a conductive film with good conductivity can be manufactured. Furthermore, the Pt conductive film of such a Pt conductive film-coated substrate can be made thinner. Such a Pt conductive film-coated substrate can be used, for example, in electronic components, semiconductor devices, and as a replacement for plating.

[0054] [Test example] Test examples are described below, but it is not intended that the present disclosure be limited to such test examples.

[0055] 1. Preparation of conductive film-forming composition In this test, a conductive film-forming composition containing Pt as the conductive component was prepared. In Examples 2 to 16, compositions containing a sintering control element in addition to Pt were prepared. Each value in Table 1 represents the content (mol%) of each element when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol%. Specifically, various raw materials were mixed in an ointment pot and mixed for 2 minutes at 1800 rpm using a mixer manufactured by Thinky Corporation (product name: Awatori Rentaro). In this way, the conductive film-forming compositions of Examples 1 to 16 were prepared. The viscosity of the conductive film-forming compositions was 10 mPa·s to 15 mPa·s. The viscosity was measured at 25°C using a B-type viscometer. The raw materials for each element used here are shown below. Pt: Pt resinate (platinum resin sulfide balsam) Rh: Rh resinate (rhodium resin sulfide balsam) Pd: Pd resinate (palladium resin sulfide balsam) Ru:Ru resinate (ruthenium resin sulfide balsam) Ir:Ir resinate (iridium resin sulfide balsam) Ag:Ag resinate (silver resin sulfate) Si:Si resinate (silicon resin acid salt) Bi: Bi resinate (bismuth resinate)

[0056] (Examples 1 to 13) A white porcelain plate (length: 15 mm, width: 15 mm) with a coating layer (glaze) applied to its surface was prepared as a substrate. The conductive film-forming composition prepared above (any of Examples 1 to 16) was applied (sprayed) onto the entire surface of one side of the white porcelain plate. The thickness of the Pt conductive film after firing was adjusted to 1 μm or less (30 nm to 200 nm). A spin coater (Opticoat MS-A-150) manufactured by Mikasa Co., Ltd. was used to apply the conductive film-forming composition. The spin coater was set to spin conditions of 3000 rpm to 5000 rpm for 10 seconds so that the Pt conductive film had the above-mentioned thickness. The white porcelain plate with the conductive film-forming composition applied was dried on a hot plate at 60°C for 1 hour and then fired at 800°C for 10 minutes. This resulted in the white porcelain plates of Examples 1 to 13 with a Pt conductive film formed on the surface of the substrate.

[0057] (Example 14) An alumina substrate of Example 14 having a Pt conductive film formed on the surface of the substrate was obtained in the same manner as in Examples 1 to 13, except that an alumina substrate (length: 15 mm, width: 15 mm) was used as the substrate.

[0058] (Example 15) A quartz substrate of Example 15 having a Pt conductive film formed on the surface of the substrate was obtained in the same manner as in Examples 1 to 13, except that a quartz substrate (length: 15 mm, width: 15 mm) was used as the substrate.

[0059] (Example 16) A silicon substrate of Example 16 having a Pt conductive film formed on the surface of the substrate was obtained in the same manner as in Examples 1 to 13, except that a silicon (Si) substrate (length: 15 mm, width: 15 mm) was used as the substrate.

[0060] 2. Conductive film evaluation (1) Evaluation of sheet resistance The sheet resistance (Ω / □) of the white porcelain flat plates (Examples 1 to 16) on which the Pt conductive film was formed, obtained as described above, was measured. The sheet resistance was measured using a high resistivity meter (High Resistivity Meter Hiresta-UP MCP-HT450) manufactured by Mitsubishi Chemical Corporation. The measurement was also performed using a ring probe (URS probe MCP-HTP14) manufactured by Mitsubishi Chemical Corporation, with the applied voltage being 1000 V. 1×10 4 A film with a resistance of Ω / □ or less was evaluated as having sufficient conductivity. On the other hand, "O / L" in the table indicates a resistance of 1×10 4 This means that the value exceeded Ω / □, and the conductive film was evaluated as not having sufficient conductivity. The results are shown in the "sheet resistance" column of Table 1.

[0061] (2) Evaluation of volume resistivity The volume resistivity (Ω·cm) of the white porcelain plates (Examples 1 to 16) on which the Pt conductive film was formed, obtained as described above, was measured. The volume resistivity was measured using a resistivity meter (Loresta GP MCP-T610) manufactured by Mitsubishi Chemical Analytech Co., Ltd. The volume resistivity was calculated for an area of ​​15 mm × 15 mm and a film thickness of 100 nm. 1 A film with a resistivity of Ω·cm or less was evaluated as having sufficient conductivity. On the other hand, "O / L" in the table indicates a value of 1×10 1 This means that the value exceeded Ω·cm, and the film was evaluated as not having sufficient conductivity. The results are shown in the "Volume Resistivity" column in Table 1.

[0062] 2 and 3 are FE-SEM observation images of the Pt conductive film according to Example 1. Also, FIGS. 4 and 5 are FE-SEM observation images of the Pt conductive film according to Example 12. And FIG. 6 is an FE-SEM observation image of a cross section of the Pt conductive film according to Example 12.

[0063] [Table 1]

[0064] As shown in Table 1, the conductive film-forming compositions of Examples 3 to 16, which contain Pt as a conductive component and a sintering control element that is at least one element selected from the group consisting of Rh, Pd, Ru, and Ir, and in which the content of the sintering control element is 2 mol % or more and less than 50 mol % when the substance amount of Pt is 100 mol %, were able to form Pt conductive films with low sheet resistance and volume resistivity and excellent conductivity.On the other hand, the conductive film-forming compositions of Example 1, which contains Pt but does not contain a sintering control element, and Example 2, in which the content ratio of the sintering control element to Pt is outside the above range, both had over-range (0 / L) sheet resistance and volume resistivity, and were unable to form Pt conductive films with excellent conductivity.

[0065] Furthermore, in a conductive film-forming composition in which the Pt content is 70 mol% or more and 90 mol% or less when the total amount of metal components contained in the conductive film-forming composition is taken as 100 mol%, and the sintering control element content is 5 mol% or more and 35 mol% or less (particularly 5 mol% or more and 10 mol% or less) when the amount of Pt is taken as 100 mol%, a Pt conductive film with lower sheet resistance and volume resistivity and better conductivity could be formed.

[0066] Furthermore, it was confirmed from Examples 13 to 16 that the conductive film-forming composition disclosed herein can form a Pt conductive film regardless of the type of substrate. Furthermore, as shown in Figures 2 and 3, it was confirmed that island formation occurred in the Pt conductive film after firing with the conductive film-forming composition of Example 1. On the other hand, as shown in Figures 4 to 6, it was confirmed that island formation was suitably suppressed in the Pt conductive film after firing with the conductive film-forming composition of Example 12.

[0067] As described above, it is clear that the conductive film-forming composition disclosed herein can form a Pt conductive film with excellent conductivity.

[0068] Although specific examples of the present disclosure have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and alterations of the specific examples exemplified above.

[0069] As described above, specific aspects of the technology disclosed herein include those described in the following items.

[0070] Section 1: A conductive film-forming composition for forming a Pt conductive film on a substrate, Pt and a sintering control element which is at least one element selected from the group consisting of Rh, Pd, Ru, and Ir; Including, The conductive film-forming composition, wherein the content of the sintering control element is 2 mol % or more and less than 50 mol % when the substance amount of the Pt is taken as 100 mol %.

[0071] Section 2: Item 2. The conductive film-forming composition according to Item 1, wherein the content of Pt is 50 mol % or more and 90 mol % or less when the total amount of metal components contained in the conductive film-forming composition is 100 mol %.

[0072] Section 3: The content of the Pt is 70 mol % or more and 90 mol % or less when the total amount of metal components contained in the conductive film-forming composition is 100 mol %, and Item 3. The conductive film-forming composition according to item 1 or 2, wherein the content of the sintering control element is 5 mol % or more and 35 mol % or less when the substance amount of the Pt is taken as 100 mol %.

[0073] Section 4: the sintering control element includes Rh, Item 4. The composition for forming a conductive film according to any one of Items 1 to 3, wherein the content of Rh is 2 mol % or more and 10 mol % or less when the total amount of metal components contained in the composition for forming a conductive film is taken as 100 mol %.

[0074] Section 5: The sintering control element includes Pd, Item 5. The composition for forming a conductive film according to any one of items 1 to 4, wherein the content of Pd is 8 mol % or more and 20 mol % or less when the total amount of metal components contained in the composition for forming a conductive film is taken as 100 mol %.

[0075] Item 6: Item 6. The conductive film-forming composition according to any one of items 1 to 5, further comprising a matrix-forming element that is at least one element selected from the group consisting of Si, Bi, Ti, Al, and Zn.

[0076] Section 7: A substrate; A Pt conductive film disposed on the substrate and made of a fired body of the conductive film-forming composition according to any one of items 1 to 6; A substrate with a Pt conductive film.

[0077] Section 8: The average thickness of the Pt conductive film is 1 μm or less, The volume resistivity of the Pt conductive film is 1×10 1 Item 8. The substrate with a Pt conductive film according to Item 7, wherein the electrical resistance is Ω·cm or less. [Explanation of symbols]

[0078] 10 Pt conductive film substrate 12 PCB 14 Pt conductive film

Claims

1. A conductive film-forming composition for forming a Pt conductive film on a substrate, comprising: Pt and a sintering control element which is at least one element selected from the group consisting of Rh, Pd, Ru, and Ir; Including, The conductive film-forming composition, wherein the content of the sintering control element is 2 mol % or more and less than 50 mol % when the substance amount of the Pt is taken as 100 mol %.

2. 2. The conductive film-forming composition according to claim 1, wherein the content of the Pt is 50 mol % or more and 90 mol % or less when the total amount of metal components contained in the conductive film-forming composition is 100 mol %.

3. the content of the Pt is 70 mol % or more and 90 mol % or less when the total amount of metal components contained in the conductive film-forming composition is 100 mol %, and 3. The conductive film-forming composition according to claim 1, wherein the content of the sintering control element is 5 mol % or more and 35 mol % or less when the amount of substance of the Pt is taken as 100 mol %.

4. the sintering control element includes Rh, 3. The conductive film-forming composition according to claim 1, wherein a content of the Rh is 2 mol % or more and 10 mol % or less when a total amount of metal components contained in the conductive film-forming composition is taken as 100 mol %.

5. The sintering control element includes Pd, 3. The conductive film-forming composition according to claim 1, wherein the content of Pd is 8 mol % or more and 20 mol % or less when the total amount of metal components contained in the conductive film-forming composition is 100 mol %.

6. 3. The conductive film-forming composition according to claim 1, further comprising a matrix-forming element which is at least one element selected from the group consisting of Si, Bi, Ti, Al and Zn.

7. A substrate; a Pt conductive film disposed on the substrate and comprising a fired body of the conductive film-forming composition according to claim 1; A substrate with a Pt conductive film.

8. The average thickness of the Pt conductive film is 1 μm or less, The volume resistivity of the Pt conductive film is 1×10 １ The substrate with a Pt conductive film according to claim 7 , wherein the resistivity is Ω·cm or less.

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